Patent Publication Number: US-2006002862-A1

Title: High pressure spray-dry of bioactive materials

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims priority to and benefit of a prior U.S. Provisional Application No. 60/579,850, High Pressure Spray-Dry of Antibodies, by Vu Truong-Le, et al., filed Jun. 14, 2004. This application is a Continuation in Part of prior U.S. Utility patent application Ser. No. 10/738,971, “High Pressure Spray-Dry of Bioactive Materials”, by Vu Truong-Le, et al., filed Dec. 16, 2003, and a prior U.S. Provisional Application No. 60/434,377, “High Pressure Spray-Dry of Bioactive Materials”, by Vu Truong-Le, et al., filed Dec. 17, 2002. The full disclosure of the prior applications is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION  
      The invention is in the field of spray-dry particle formation and preservation of bioactive materials. The present invention provides, e.g., formulations for high pressure spray drying of bioactive materials, such as peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes, vaccines and/or the like. High pressure spraying allows fine spray droplets to be dried, e.g., in a shorter time, at a lower temperature, with less concomitant degradation of sensitive molecules. Formulations of bioactive material for high pressure spraying include, for example, the bioactive material, amino acids and sugars. High pressure spraying produces powder particles wherein the incorporated bioactive material can be more readily reconstituted at higher concentrations. The present invention provides methods and systems to precisely control spray droplet size and powder particle size by adjustment of process variables.  
     BACKGROUND OF THE INVENTION  
      Methods to preserve biologic materials in storage have a long history, from the preservation of food to the preservation of modern pharmaceutical compositions. Biological materials have been dried, salted, frozen, cryoprotected, spray dried, and freeze-dried. Optimal methods of preservation can depend on the acceptable degree of degradation, the desired storage time, and the nature of the biological material.  
      For centuries, food has been preserved for later consumption by drying. Food harvested in times of plenty was laid out in the sun to remove excess water. Drying can make the food unsuitable for growth of spoilage bacteria and fungi. Autolytic processes, in which plant and animal tissues self destruct, can also be prevented by drying. Salting food can provide a similar preservative effect. Dried and salted food usually experiences a loss of fresh appearance and nutritional value. Drying and salting bioactive materials, such as enzymes and pharmaceuticals, can destroy activity by heat, oxidation, water removal, production of radicals and peroxides, photobleaching, and the like, that denature the material.  
      Spray drying has been used in food processing and pharmaceutical production with some advantages over salting or slow drying. Water can be quickly removed by spraying a fine mist of the dissolved biological molecules into a stream of hot gasses. The dried particles can have a large surface to volume ratio for speedy reconstitution with aqueous buffers. In Platz et al., U.S. Pat. No. 6,165,463, “Dispersible Antibody Compositions and Methods for Their Preparation and Use”, for example, dry powder particles are prepared by spray drying for inhaled administration of pharmaceuticals to patients. The biological molecules, in a dilute solution, are sprayed at moderate pressures (e.g., 80 psi) into a stream of hot gasses (e.g., 98-105° C.) for primary drying, then the particles are further dehydrated by prolonged exposure to high temperatures (e.g., 67° C.). Although such processes are suitable for food and rugged biomolecules, sensitive molecules can be denatured, or otherwise inactivated, by the stress, long drying periods, and high temperatures of these methods.  
      Freezing can be an effective way to preserve biological molecules. Cold temperatures can slow degradation reaction kinetics. Freezing can reduce the availability of water to degradation reactions and contaminant microbes. Ice can reduce oxidation of the molecules by blocking contact with air. However, freezing can have negative effects such as concentration of salts that can denature proteins in the unfrozen zones of solution, or the formation of sharp ice crystals that can pierce cell structures. Some of the damage caused by freezing can be mitigated by the addition of cryoprotectants which prevent denaturation by lowering the freezing temperature and inhibiting formation of ice crystals. Even in cases where freezing and thawing degradation can be avoided, continuous operation of refrigeration equipment can make preservation by storage in a freezer inconvenient and expensive.  
      Freeze-drying processes have many of the benefits of freezing and drying. Degradation is suspended by freezing then water removal makes the product more stable for storage. Drying by sublimation of the frozen water into a vacuum can avoid the high heat of some spray drying processes. The lyophilized product can be quite stable in storage even at room temperatures. However, the molecules can still experience denaturing salt concentrations during the freezing step. In addition, many freeze-drying protocols call for prolonged secondary drying steps at high temperatures to reduce moisture content. Bulky cakes of lyophilized material can be slow to reconstitute and must be finely ground for delivery by inhalation.  
      A need remains for compositions and methods to prepare stable particles containing bioactive materials without loss of purity due to excessive heat, chemical, or shear stress. It would be desirable to have formulations for high pressure spray drying of bioactive materials that would enhance the stability and reduce reconstitution time for resultant powder particles. The present invention provides these and other features that will become apparent upon review of the following.  
     SUMMARY OF THE INVENTION  
      The present invention provides, e.g., methods to prepare stable compositions of bioactive materials including, but not limited to, peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes, vaccines and/or the like with low process denaturation. Methods of preparing powder particles, e.g., by spray drying viscous solutions at high pressures reduce shear stress and heat stress degradation. The invention provides adjustments in process parameters to precisely tune the size of sprayed droplets and dried powder particles. Stability and shelf life are increased for the powder particles high pressure spray dried from formulations having suitable concentrations of sugars and amino acids. Powder particles sprayed from such formulations can be reconstituted without undue aggregation and quickly reconstituted to high concentrations.  
      Preferred formulations for spray drying of bioactive materials by methods of the invention include, for example, amino acids and sugars. The amino acids can act, e.g., as zwitterions, antioxidants, buffers, stabilizers, bulking agents, solubilizers, and/or the like, to improve qualities of the powder particle product. The sugars can act, e.g., as viscosity enhancing agents, stabilizers, bulking agents, solubilizing agents, and/or the like. In one aspect of the invention, the formulation for spray drying therapeutic bioactive material includes from about 4% to about 10% by weight of the therapeutic bioactive material, from about 0.1 mM to about 50 mM total of one or more amino acids, from about 0.5% to about 4% by weight of a sugar, and water. Optionally, the bioactive material is a virus present in the liquid formulation at from about 10 3  TCID 50 /mL to about 10 12  TCID 50 /mL. The formulation can optionally include, e.g., surfactants and polymers. A preferred formulation comprises about 8% by weight of the bioactive material, about 10 mM histidine (pH 6.0), about 0.5% arginine, and about 2% sucrose.  
      Antibody bioactive materials in certain formulations are typically monoclonal antibodies that can act as therapeutic agents on administration to a patient. The antibody is often an IgG. Specifically, antibodies to be used in the invention include, but are not limited to, synthetic antibodies, polyclonal antibodies, monoclonal antibodies, recombinantly produced antibodies, multispecific antibodies (including bi-specific antibodies), human antibodies, humanized antibodies, chimeric antibodies, intrabodies, single-chain Fvs (scFv) (e.g., including monospecific and bi-specific, etc.), Fab fragments, F(ab′) fragments, disulfide-linked Fvs (sdFv), anti-idiotypic (anti-Id) antibodies, and epitope-binding fragments, and antibodies conjugated to toxins. In many embodiments, the formulation comprises about 8% of the antibody by weight.  
      Preferred amino acids for bioactive material formulations of the invention include, e.g., glycine, histidine and arginine. In a preferred embodiment, the amino acids include from about 1 mM to about 20 mM histidine or from about 0.1% to about 2% of arginine by weight. In a more preferred embodiment, the one or more amino acids comprise about 10 mM histidine and about 30 mM arginine.  
      Preferred sugars for bioactive material formulations include, e.g., sucrose, trehalose, and mannitol. Many of the formulations include about 2% of the sugar by weight.  
      Other excipients in bioactive material formulations include polymers and surfactants. For example the formulation can include from about 0.01% to about 0.2% polyoxyethylenesorbitan monooleates or polyethylene glycol sorbitan monolaurates. The formulations can include, e.g., from about 0.5% to about 0.05% polyvinyl pyrrolidone (PVP).  
      In methods of spraying bioactive materials, the formulations are spray dried using high pressures to form fine dry powder particles. Such powder particles can typically be quickly reconstituted to a concentration of about 200 mg bioactive material per ml or more while retaining a purity and activity substantially unchanged from the pre-dried formulation.  
      Methods of the invention for high pressure spray drying bioactive materials include preparing an aqueous formulation containing the bioactive material, a sugar and an amino acid; spraying the formulation at high pressure; and drying the spray droplets. For example, the methods can include preparing powder particles of an bioactive material by preparing an aqueous suspension or solution comprising: from about 4% to about 10% by weight of the bioactive material, and preferably having about 8% of the bioactive material by weight, from about 0.1 mM to about 50 mM total of one or more amino acids, and from about 0.5% to about 4% by weight of a sugar; spraying the suspension or solution through a nozzle at a high pressure to form a mist of fine droplets; drying the droplets to form powder particles; and, recovering the particles. Optionally, the bioactive material is a virus present in the liquid formulation at from about 10 3  TCID 50 /mL to about 10 12  TCID 50 /mL. In preferred embodiments, the bioactive material comprises a peptide sequence of any of SEQ ID NOs. 1 to 20, or a conservative variation thereof, the sugar is sucrose, and the drying chamber drying gas outlet temperature ranges from about 40° C. to about 60° C. during drying of the particles.  
      In certain embodiments of the methods, antibody formulations are sprayed. The antibody can be any type of antibody, such as defined above, and the like. Preferred antibodies for high pressure spray drying methods of the invention include, but are not limited to, e.g.,: anti-RSV, anti-hMPV, anti-avb3 integrin, anti-avb5 integrin, anti-alpha IIb/beta 3 integrin, anti-alpha 4 integrin, anti-EphA2, and anti-EphA4, anti-EphB4, anti-IL9, anti-IL4, anti-IL5, anti-IL13, anti-IL15, anti-CTLA4, anti-PSA, anti-PSMA, anti-CEA, anti-cMET, anti-C5a, anti-TGF-beta, anti-HMGB-1, anti-interferons alpha and anti-interferon alpha receptor, anti-IFN beta and gamma, anti-chitinase, anti-TIRC7, anti-T-cell, MT-103 BiTE®, anti-EpCam, anti-Her2/neu, anti-IgE, anti-TNF-alpha, anti-VEGF, anti-EGF and anti-EGF receptor, anti-CD22, anti-CD19, anti-Fc, anti-LTA, anti-Flk-1, and anti-Tie-1. In particular, antibodies for production of powder particles by the methods include antibodies having the any of the peptide sequences of SEQ ID NOs. 1 to 20.  
      Process parameters of the methods can be adjusted to obtain powder particles with desired characteristics. Favored spray pressures for the formulation and/or pressurized atomization gas ranging from about 800 psi to about 1800 psi, or about 1300 psi. Favored formulation spray droplets range in diameter from about 3 μm to about 30 μm. It is preferred to spray the formulation into a particle formation vessel that acts as, or is in fluid connection with, a drying chamber. The drying chamber can have a drying gas inlet and an outlet. Preferred drying conditions include a drying gas outlet temperature during particle formation comprises a temperature ranging from about 40° C. to about 60° C. Preferred powder particle average diameters range from about 2 μm to about 10 μm, e.g., for rapid reconstitution or pulmonary administration.  
      The dried powder particles containing bioactive materials can be reconstituted from the powder particles, e.g., by addition of water to provide a solution or suspension containing about 200 mg of the antibodies per milliliter. The reconstituted solution or suspension can be administered, e.g., to a human patient by subcutaneous injection to treat a disease state.  
      The methods of preparing stable particles can also include, e.g., preparing an aqueous suspension or solution (formulation) with a bioactive material and a viscosity enhancing agent, spraying the formulation through a nozzle at high pressure to form a mist of fine droplets, drying the droplets to form powder particles, and recovering the particles. The viscosity enhancing agent can be present in a concentration, e.g., sufficient to provide a 5% or more viscosity increase, or a 0.05 centipoise or more viscosity increase, over the formulation without viscosity enhancing agent.  
      The bioactive materials of the method can include peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes, and/or the like. For example, the bioactive material can be present in the process formulation at a concentration ranging from about 1 mg/ml to about 200 mg/ml, from about 5 mg/ml to about 80 mg/ml, or about 50 mg/ml. Optionally, the bioactive material can be, e.g., a virus present in the formulation in a titer ranging from about 2 log FFU (focus forming units)/ml to 12 log FFU/ml, or about 8 log FFU/ml.  
      The viscosity enhancing agents can be, e.g., a polyol and/or a polymer. For example, the polyol can be trehalose, sucrose, sorbose, melezitose, glycerol, fructose, mannose, maltose, lactose, arabinose, xylose, ribose, rhamnose, palactose, glucose, mannitol, xylitol, erythritol, threitol, sorbitol, raffinose, and/or the like. Exemplary polymer viscosity enhancing agents can include starch, starch derivatives, carboxymethyl starch, hydroxyethyl starch (HES), dextran, dextrin, polyvinyl pyrrolidone (PVP), human serum albumin (HSA), inulin, gelatin, and/or the like. The viscosity enhancing agents of the invention can be present in the formulation, e.g., an amount ranging from about 0.1 weight percent to about 20 weight percent, 2 weight percent to 8 weight percent, or 6 weight percent. Optionally, the viscosity enhancing agent can be present in a concentration, e.g., sufficient to provide a 50%, a 0.05 centipoise, or a 100 centipoise increase in viscosity, or more.  
      The solution or suspension of the method can include a surfactant and/or a zwitterion. Surfactants in the method can include, e.g., polyethylene glycol sorbitan monolaurates (e.g., Tween 80), polyoxyethylenesorbitan monooleates (e.g., Tween 20), or block polymers of polyethylene and polypropylene glycol (e.g., Pluronic F68), and/or the like. Zwitterions of the method can include, e.g., arginine, histidine, glycine, and/or the like. The average size of sprayed droplets can be adjusted by varying the concentration of surface active agents in the formulation, e.g., preferably in the presence of sucrose.  
      High pressure spraying through nozzles in the method can include, e.g., high pressure spraying of liquid, atomization with a high pressure gas, and/or spraying into a cold fluid. Spraying can be by high pressure nitrogen gas atomization. The nozzle can have an internal diameter ranging, e.g., from about 50 μm to about 500 μm, from about 75 μm to about 150 μm, or the nozzle orifice can have an internal diameter of about 100 μm. The high pressure spraying nozzle can be an atomizing nozzle with channels for a high pressure atomizing gas, e.g., to enhance dispersal of the sprayed droplets. The high pressure atomizing gas, such as nitrogen, can have a pressure and/or temperature at least 10% or 15% away from a critical point for the gas.  
      The method of the invention can include, e.g., spray freeze-drying the suspension and/or solution droplets. The fine droplets can be, e.g., immersed in a cold fluid to freeze the droplets. The cold fluid can be, e.g., gaseous or liquid argon, helium, carbon dioxide, and/or nitrogen. The cold fluid can range in temperature, e.g., from about −80° C. to about −200° C. The droplets can be dried, e.g., by applying a vacuum and raising the temperature of the environment around the droplets to form powder particles (e.g., freeze dried). The vacuum can be a gas pressure less than about 200 Torr or less than about 10 Torr.  
      Solutions or suspensions can be sprayed at high pressure to create a fine mist of droplets. The high pressure can be, e.g., between about 200 psi and about 2500 psi, between about 1000 psi and 1500 psi, or about 1300 psi. The fine mist can include droplets with an average diameter between about 2 μm and about 200 μm, between about 3 μm and about 70 μm, between about 5 μm and about 30 μm, or about 10 μm.  
      Droplets can be dried to form powder particles, e.g., by displacement of the gas from the fine mist with a drying gas to remove water vapor and spray gasses. The drying gas can be, e.g., a substantially inert gas, such as nitrogen at a temperature between about 25° C. and about 99° C., about 35° C. and about 65° C., or about 55° C. The powder particles of the invention can have an average size ranging from about 0.1 μm to about 100 μm, or from about 2 μm to about 10 μm.  
      The method of the invention can provide a high process yield without significant reduction in product purity. For example, the method can have a process yield (e.g., specific activity retention) ranging from about 40 percent to about 98 percent, or about 90 percent. The product purity of a protein bioactive material can remain high through spraying, e.g., with less than about 5 percent, 4 percent 3 percent, 2 percent, or less total aggregates and fragments on reconstitution of the powder particles. The product purity or specific activity of a protein bioactive material or viability of a virus bioactive material can be substantially the same before and after the drying of droplets.  
      Powder particles can be used, e.g., to administer the bioactive material according to the methods of the invention. The powder particles can be delivered to a mammal by inhalation through the nasal and/or pulmonary route. Alternately, the powder particles can be reconstituted with an aqueous buffer for delivery of the bioactive material by injection. Powder particles of the method can be reconstituted into a formulation of bioactive material at a concentration ranging, e.g., from about 1 mg/ml to about 400 mg/ml, or 5 mg/ml to about. 200 mg/ml. Substantially isotonic (an osmolality within about 10% of physiological values) reconstituted material can comprise antibodies at a concentration of about 200 mg/ml.  
      Compositions of the invention can be, e.g., stable powder particles readily reconstituted to solutions of highly pure bioactive materials at high concentrations. Compositions of the invention can be, e.g., particles containing a bioactive material made by the process of preparing an aqueous formulation with the bioactive material and a viscosity enhancing agent, spraying the formulation through a nozzle at high pressure to form a mist of fine droplets, drying the droplets to form powder particles, and recovering the particles. The viscosity enhancing agent can be present, e.g., at a concentration adequate to provide a 5% or more increase in viscosity, or a 0.5 centipoise increase in viscosity, over the suspension of solution without the viscosity enhancing agents.  
      The bioactive materials can be peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes and/or the like. Bioactive materials can be present in the process formulation at a concentration ranging, e.g., from about 1 mg/ml to about 200 mg/ml, about 5 mg/ml to about 80 mg/ml, or about 50 mg/ml. Viral bioactive materials, such as influenza virus, can be present in formulations at a titer ranging from about 2 log FFU/ml to about 12 log FFU/ml, or about 8 log FFU/ml. In the powder particle product, the bioactive material can be present, e.g., in the powder particles in an amount ranging from about 0.1 weight percent or less to about 80 weight percent.  
      In one exemplary embodiment, the bioactive material of the composition can be present in the process formulation in an amount ranging from about 0.5 weight percent to about 20 weight percent, or about 8 weight percent. The viscosity enhancing agent of the composition can include, e.g., a polyol, such as sucrose or trehalose, or a polymer, such as hydroxyethyl starch (HES), dextran, dextrin, inulin, or polyvinyl pyrrolidone (PVP). The sucrose can be present in the formulation in an amount ranging from about 1 weight percent to about 10 weight percent, or about 6 weight percent. The aqueous formulation can contain antibodies in combination with arginine and sucrose. Optionally, the viscosity enhancing agents can include PVP.  
      A composition containing a bioactive material can be, e.g., powder particles with a ratio of excipients (other total solids on drying) to the bioactive material ranging from about 1/100 to about 100/1, about 2/3 to about 3/2, or about 1/1. The bioactive material composition of powder particles can incorporate, e.g., sucrose in an amount ranging from about 30 weight percent to about 60 weight percent. The powder particles can contain less than about 5 percent moisture.  
      The bioactive material in powder particles can be quite stable, e.g., with less than about 3% aggregates on reconstitution of the powder particles after storage at about 4° C. for 1 year, 5 years, or about 7 years. Bioactive materials dried to powder particles using formulations and methods of the invention can have, e.g., less than about 3% aggregates on reconstitution of the powder particles after storage at about 25° C. for 0.1 years, 0.5 years, 1 year, or about 1.5 years, or more.  
      The bioactive material compositions of the invention can be reconstituted powder particles. For example, an aqueous buffer can be added to the powder particles to form a reconstituted formulation of bioactive material. Such a solution can be, e.g., substantially similar to the formulation sprayed in the process. Optionally, the powder particles can be reconstituted with appropriate buffers to provide desired characteristics such as isotonicity and/or high bioactive material concentrations. The reconstituted solution or suspension of the bioactive material can have, e.g., a concentration ranging from less than about 0.1 mg/ml to about 500 mg/ml. In a preferred embodiment, the powder particles can be reconstituted in 10 minutes or less, e.g., to a concentration of bioactive material of about 200 mg/ml. In another preferred embodiment, the powder particles can be reconstituted to a substantially isotonic formulation containing a bioactive material concentration of up to about 200 mg/ml.  
      A composition of reconstituted bioactive material can comprise a 50 mg/ml to 500 mg/ml solution, or more, with less than about 3 percent aggregates or fragments. In a preferred embodiment, the bioactive materials are reconstituted at a concentration of 200 mg/ml or more. Such compositions can be manufactured by the process of preparing an aqueous formulation of the bioactive material with a viscosity enhancing agent, spraying the formulation through a nozzle at high pressure to form a mist of fine droplets, drying the droplets to form powder particles, recovering the particles, and reconstituting the particles in an aqueous solution. The composition can be prepared from a formulation increased in viscosity with the viscosity enhancing agent by 50%, 0.05 centipoise, or more. The formulations for spraying drying particles of bioactive material will typically include, e.g., significant amounts of amino acids and sugars.  
      The compositions of the invention can include, e.g., a polyol and/or polymer viscosity enhancing agents. The polyols of the compositions can be, e.g., trehalose, sucrose, sorbose, melezitose, glycerol, fructose, mannose, maltose, lactose, arabinose, xylose, ribose, rhamnose, palactose, glucose, mannitol, xylitol, erythritol, threitol, sorbitol, raffinose, and/or the like. The polymers of the compositions can be, e.g., starch, starch derivatives, carboxymethyl starch, inulin, hydroxyethyl starch (HES), dextran, dextrin, polyvinyl pyrrolidone (PVP), human serum albumin (HSA), gelatin, and/or the like. The formulation in the process of making the compositions can have viscosity enhancing agents, e.g., in an amount between about 0.1 weight percent and about 20 weight percent, or about 5 weight percent.  
      The aqueous solution or suspension sprayed in the process of the composition can include, e.g., zwitterions, such as arginine, histidine, glycine, and/or the like. Arginine can be present in the process formulation in an amount, e.g., between about 0.1 weight percent to about 5 weight percent, or about 0.5 weight percent. In a preferred embodiment, the compositions of the invention are prepared from formulations containing sucrose at concentrations ranging from about 0.4% to about 4% and arginine at concentrations ranging from about 0.1% to about 0.5%.  
      The aqueous solution or suspension sprayed in the process of the composition can include, e.g., a surfactant. The surfactant can be, e.g., polyethylene glycol sorbitan monolaurates, polyoxyethylenesorbitan monooleates, block polymers of polyethylene and polypropylene glycol, e.g., Tween 80, Tween 20, Pluronic F68, and/or the like.  
      The present invention provides processes of making compositions by high pressure spraying, e.g., with atomizing high pressure nitrogen gas, and/or into a cold fluid. The process for preparing the composition can provide, e.g., immersion of the fine droplets in a cold fluid, thereby freezing the droplets, followed by drying the frozen droplets by applying a vacuum and raising the temperature of the droplets.  
      Powder particles of the composition can vary, e.g., in average particle diameter (size), formula, and component proportions. For example, the average size of the powder particles can range from about 0.1 μm to about 100 μm, or from about 2 μm to about 10 μm. The powder particles can contain sucrose in an amount ranging, e.g., from about 20 weight percent to about 60 weight percent, or about 40 weight percent. The powder particle composition can contain arginine ranging in concentration from about 1% to about 20% by weight, or about 5% by weight. The composition of powder particles can contain PVP ranging in concentration from about 0% to about 5%, or about 0.05% to about 0.5% by weight.  
      The size of spray droplets can be controlled in systems and methods of the invention by adjusting one or more parameters. For example, the size of droplets or particles can be controlled by adjusting the percent surface active agent in the formulation, adjusting a spraying pressure, adjusting an atomizing gas pressure, adjusting a viscosity, adjusting the total solids in the formulation, adjusting a flow rate of the formulation, adjusting a mass flow ratio (formulation flow to atomizing gas flow), adjusting a temperature of the formulation, and/or the like.  
      Compositions of the invention include, e.g., dry powder particles with an average particle size ranging from about 2 μm to about 200 μm, a particle density of about 1, and 40 weight percent to about 60 weight percent bioactive materials with more than about 90 percent purity (non-aggregated and non-fragmented). In preferred embodiments the particle size is less than 10 μm and the bioactive material purity is 97% or more. The composition of dry particles can be stable with, e.g., bioactive materials less than about 3% aggregated on reconstitution of the powder particles after storage at about 4° C. for about 1 year to about 7 years. The composition of powder particles on reconstitution after storage at about 25° C. for about 0.1 years to about 1.5 years can have, e.g., less than about 3% aggregates. Such powder particle compositions can include, e.g., about 40 weight percent to about 60 weight percent sucrose or trehalose, and/or arginine.  
      In a preferred composition of the invention, particles containing a virus are prepared by: preparing an aqueous formulation suspension or solution containing the virus and sucrose, spraying the suspension or solution through a nozzle at high pressure to form a mist of fine droplets, drying the droplets to form powder particles, and recovering the particles. The presence of the viscosity enhancing agent in the suspension can increase viscosity by 50%, 0.05 centipoise, or more. High pressure spraying can be by atomization with a gas at temperatures and pressures at least 10% away from a critical point for the gas. The virus can include influenza virus. Using the methods and formulations of the invention, viability of the virus is not reduced significantly in the recovered particles.  
     DEFINITIONS  
      Before describing the present invention in detail, it is to be understood that this invention is not limited to particular described methods or biological materials, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used in this specification and the appended claims, the singular forms “a”, “an” and “the” can include plural referents unless the context indicates otherwise. Thus, for example, reference to “a polyol” can include a combination of two or more polyols; reference to “sugars” can include mixtures of one or more sugars, and the like.  
      Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although any methods and materials similar or equivalent to those described herein can be used in the practice for testing of the present invention, the preferred materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.  
      The term “particle size”, as used herein, generally refers to the average physical diameter of particles.  
      The term “specific activity”, in the context of bioactive materials of the invention refers to the bioactivity (determinable, e.g., by an appropriate bioassay) relative to the amount of agent. A highly pure, undenatured bioactive material can have, e.g., a high specific activity. A denatured bioactive material can have a low specific activity. A highly pure bioactive material can be low in fragments, dimers, trimers, and aggregates, as measured, e.g., by a size exclusion chromatography.  
      The term “high pressure spraying”, as used herein, refers to spraying a formulation fed through an orifice at a pressure greater than used for standard spray dryers. High pressures can be, e.g., greater than about 200 psi. Preferred high pressure spraying pressures range from about 1000 psi to about 2000 psi. High pressure spraying can include, e.g., pressurization and/or atomization of the formulation with a gas at a pressure more than 10% away, or more than 15% away, from a critical pressure (at a given temperature) and/or from a critical temperature (at a given pressure) for the gas.  
      The term “viscosity enhancing agent”, as used herein, refers to molecular species in the formulations of the invention that significantly increase the viscosity of the formulation. For example, a molecular species can be a viscosity enhancing agent in a formulation in an amount that substantially increases the viscosity of the formulation and significantly reduces shear stress denaturation of proteins sprayed in the formulation. Preferred viscosity enhancing agents include, e.g., polyols, polymers, sugars, and polysaccharides.  
      The term “bioactive materials”, as used herein, refers to peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes, vaccines and/or the like, or as commonly referred to by those of skill in the art.  
      The term “therapeutic bioactive material” is a bioactive material, as defined above, which is suitably formulated to be administered to a human or animal subject in need of a therapy provided by the bioactivity.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  shows a chart comparing droplet size versus mass flow ratio (MFR) for solutions sprayed at high pressure versus solutions sprayed at lower pressures.  
       FIG. 2  shows a chart presenting critical temperature and pressure points of phase transition for a gas.  
       FIG. 3  shows chart of droplet size versus atomization pressure for a solution containing viscosity enhancing agents and/or surface active agents.  
       FIGS. 4A and 4B  show charts of dry powder particle size versus mass flow ratio and atomization pressure, respectively.  
       FIG. 5  is a schematic diagram of an exemplary high pressure spray nozzles.  
       FIG. 6  shows a chart of droplet size versus liquid feed rate for combinations of pressures and atomizing nozzle orifice internal diameters.  
       FIG. 7  shows chromatographic charts indicating the viscosity enhancing agent prevention of denaturation in the high pressure spray-drying process.  
       FIG. 8  shows chromatographic charts indicating the high purity, high concentration, and high stability of reconstituted compositions of the invention.  
       FIG. 9  is a schematic diagram of an exemplary high pressure spray dry system.  
      FIGS.  10 A-D are schematic diagrams of exemplary triple-inlet high pressure spray nozzles. 
    
    
     DETAILED DESCRIPTION  
      The present invention provides compositions and methods for preparing stable particles containing bioactive materials, such as, e.g., peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes, vaccines and/or the like. The method includes, e.g., quick drying of spray droplets into particles without high drying gas heat by using high spray pressures to inject a fine mist into a warm stream of drying gas. Favored formulations for spray drying of therapeutic bioactive materials include amino acids and sugars to form stable easily reconstituted powder particles.  
      The methods of the invention provide preferred formulations for high pressure spray drying of therapeutic bioactive material. The formulations can provide stable powder particles that are readily reconstituted to high concentrations. The formulations can include, e.g., from less than about 4% to about 10% by weight of the therapeutic bioactive material, from about 0.1 mM to about 50 mM total of one or more amino acids, and from about 0.5% to about 4% by weight of a sugar in an aqueous solution or suspension. Where the bioactive material is a virus, e.g., in an attenuated live virus vaccine, the virus can be present in the liquid formulation in an amount ranging from about 10 3  TCID 50 /mL to about 10 12  TCID 50 /mL, or from about 10 5  TCID 50 /mL to about 10 9  TCID 50 /mL. Other constituents can be added to the formulation, e.g., to provide desirable benefits in stability, reconstitution time, and physical characteristics.  
      The method of the invention generally provides, e.g., spray drying of bioactive materials in a composition with viscosity enhancing agents at a high pressure to produce fine droplets that dry quickly to powder particles with little initial loss of in purity or viability. The high initial purity and protective effects of excipients provide, e.g., a long shelf life and excellent stability for powder particles storage. The fine powder particles and highly soluble excipients allow ready reconstitution of bioactive materials to a high concentration with high specific activity.  
      The methods of the invention to prepare powder particles include high pressure spraying of formulations with, e.g., about 8% bioactive material, about 0.5% arginine, and about 2% of sucrose, into a dry powder. Alternately, where the bioactive material is a live virus, the bioactive material can be present at much lower mass ratio, e.g., with attenuated virus present at from about 10 3  TCID 50  (50% Tissue Culture Infecting Dose)/mL to about 10 12  TCID 50 /mL. In one aspect or the invention, dried powder particles can be administered to human patients by reconstitution to a concentration of about 200 mg/ml bioactive material for subcutaneous injection.  
      Methods of High Pressure Spray Drying  
      Methods of the invention combine high pressure spraying with protective formulations for fast drying of pure and stable bioactive materials. The methods of the invention include production of powder particles containing bioactive materials, such as peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes, vaccines and/or the like, e.g., by preparing an aqueous formulation of the bioactive material with a sugar and amino acid, spraying the suspension or solution through a nozzle at high pressure to form a mist of fine droplets, drying the droplets to form powder particles, and recovering the particles for storage or immediate use.  
      The methods can be modified to provide suitable products depending on, e.g., the sensitivity of the bioactive material, the expected storage conditions, and the proposed route of administration. A variety of viscosity enhancing agents, such as, e.g., polyols and polymers, are available which can provide desirable characteristics, in addition to shear stress protection, including antioxidation, hydrogen bonding with the bioactive material to replace water of molecular hydration, high solubility to aid in reconstitution, and safety for injection in humans. High pressure to spray formulations of the bioactive material can be provided, e.g., by hydraulic pressure, pressurized gases, or high pressure pumps, such as HPLC pumps. Drying of droplets can be achieved, e.g., by freezing and sublimation, warm streams of humidity and/or temperature controlled drying gasses, and/or suspension in a fluidized bed. Recovering the particles can include separation of particles by size, filtering, settling, filling into sealed containers, and the like. Particles of the invention can be used, e.g., to administer the bioactive material by inhalation, to reconstitute for administration by injection, to store analytical reference samples for long term references, and/or the like.  
      Preparing a Formulation of a Bioactive Material for Spraying  
      A bioactive material of interest can be added to a solution comprising a sugar and amino acid to prepare the spray drying formulation of the invention. Additional excipients can be added to enhance solubility of components, reduce oxidation, increase viscosity, add bulk, reduce surface tension, reduce the porosity of the particles, control pH, and/or the like.  
      Individual constituents can play multiple roles as components in a formulation. For example, an amino acid can be a stabilizer, buffer, antioxidant, bulking agent, etc. A sugar can be a stabilizer, reconstitution accelerator, cryoprotectant, bulking agent, viscosity enhancing agent, etc. A formulation component, such as viscosity enhancing agent, excipient, buffer, sugar, amino acid, surfactant, stabilizer, and/or the like, can be represented by the cumulative different individual constituents that contribute to the role of the component in the formulation.  
      Although the preferred bioactive materials of the invention are antibodies and vaccines, methods and formulations can be applied to, e.g., industrial reagents, analytical reagents, pharmaceuticals, therapeutics, and the like. Bioactive materials of the invention include, e.g., peptides, polypeptides, proteins, viruses, bacteria, antibodies, monoclonal antibodies, cells, liposomes, and/or the like. Preparation steps for liquid formulations of these materials can vary depending on the unique sensitivities of each material.  
      Liquid formulations for spraying can be prepared by mixing the bioactive material, sugar, amino acids, and additional excipients, in an aqueous solution. Many bioactive materials, such as antibodies, can dissolve readily into an aqueous solution. Other bioactive materials, such as, e.g., some peptides, viruses, bacteria, and liposomes can be particles that exist as a suspension in the formulation. Whether the bioactive material can exist in a solution or suspension, it is often necessary, e.g., to avoid severe conditions of shear stress or high temperatures when mixing them into a formulation. Where other formulation constituents require heat or strong stirring to bring into solution, they can, e.g., be dissolved separately then gently blended with the bioactive material after cooling.  
      The total solids in the final formulation are generally, e.g., high, to help provide the high viscosity and/or quick low temperature drying aspects of the invention. For example, process formulations for spraying in the invention can include from about 5 percent to about 50 percent total solids (residual on drying), from about 10 percent to 20 percent total solids, or about 15 percent total solids. The formulations for high pressure spraying can have a viscosity significantly greater than that of water at room temperature (0.01 poise), and greater than the viscosity of the bioactive material formulation without addition of supplementary viscosity enhancing agents. For example, addition of the viscosity enhancing agent can increase the viscosity of the formulation for spraying by 0.02 centipoise, 0.05 centipoise, 0.1 centipoise, 0.5 centipoise, 1 centipoise, 5 centipoise, 10 centipoise, 0.5 poise, 1 poise, 5 poise, 10 poise, or more. In another aspect, addition of the viscosity enhancing agent can increase the viscosity of the formulation for spraying by 1%, 5%, 25%, 50%, 100%, 500%, or more. In a preferred embodiment, viscosity enhancing agents are present at a concentration sufficient to increase the viscosity by 0.05 centipoise or more, or sufficient to increase the viscosity of the formulation by 5% or more. In a preferred embodiment, the addition of a viscosity enhancing agent provides a significant (e.g., measurable) reduction in bioactive material deactivation, fragmentation or aggregation compared to the same formulation without the additional viscosity enhancing agent.  
      The concentration of bioactive material in the formulation can vary widely, depending on, e.g., the specific activity, concentration of excipients, route of administration, and/or intended use of the material. Where the bioactive material is, e.g., an antibody for therapeutic administration by inhalation or injection, or a liposome for topical administration, the required concentration can be higher. Where the bioactive material is a peptide vaccine, live attenuated virus, killed virus for vaccination, or bacteria, for example, the required concentration of material can be quite low. In general, bioactive materials can be present in the solutions or suspensions of the invention at a concentration, e.g., between less than about 1 mg/ml to about 200 mg/ml, from about S mg/ml to about 80 mg/ml, or about 50 mg/ml. Viral particles can be present in the formulations in amounts, e.g., ranging from about 10 pg/ml to about 50 mg/ml or about 10 ug/ml; or, e.g., present in the liquid formulation in an amount ranging from about 10 3  TCID 50 /mL to about 10 12  TCID 50 /mL.  
      Viscosity enhancing agents of the invention are generally, e.g., sugars or water soluble polymers which can be dissolved or effectively suspended into the solution or suspension at concentrations high enough to provide significant protection against shear disruption or denaturation of the bioactive material. In general, effective amounts of viscosity enhancing polymers are lower than effective amounts required for sugars due to the higher viscosity produced by longer molecules in solution. Viscosity enhancing agents can be present in the formulations of the invention in amounts, e.g., between about 0.05 weight percent to about 30 weight percent, from about 0.1 weight percent to about 20 weight percent, or about 2 weight percent to about 6 weight percent. Many viscosity enhancing agents are carbohydrates that can provide, e.g., protective effects to bioactive materials under other process stresses, such as, e.g., freezing and drying.  
      The formulation of the invention can include, e.g., a surfactant compatible with the particular bioactive material involved. A surfactant can enhance solubility of other formulation components to avoid aggregation or precipitation at higher concentrations. Surface active agents can, e.g., lower the surface tension of the formulation so that bioactive materials are not denatured at gas-liquid interfaces, and/or so that spraying forms finer droplets. Surfactants can be present in the solutions or suspensions of the invention in an amount ranging from about 0.005 percent to about 1 percent, from about 0.01 percent to about 0.5 percent, or about 0.02 percent.  
      Formulations for Spray Drying Bioactive Materials  
      Formulations of the invention can be particularly useful for spraying stable powder particles with good reconstitution characteristics. Formulations particularly useful for spray drying of bioactive material can include, e.g., 4% to 10% of the bioactive material by weight, 0.5% to 4% of a sugar and from about 0.1 mM to about 50 mM of amino acids. The formulations can beneficially also include, e.g., surfactants, polymers, and/or buffers providing a pH at or below about pH 6. In a preferred embodiment, a formulation for high pressure spray drying of bioactive materials includes, e.g., about 8% of the bioactive material by weight, about 10 mM histidine, about 0.5% arginine and about 2% sucrose at about pH 6. In other preferred embodiments, formulations for high pressure spray drying of vaccines includes, e.g., from about 10 3  TCID 50 /mL to about 10 12  TCID 50 /mL attenuated virus, about 10 mM histidine, about 0.5% arginine and about 2% sucrose at about pH 6.  
      Therapeutic bioactive materials benefiting from the particular formulations can include, e.g., peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes, vaccines and/or the like.  
      Antibodies of the formulations include, but are not limited to, an antibody having the sequence, or containing a sequences of a complementarity determining region (CDR), or containing sequences that are merely conservative variations of novel sequences in: 1) an anti-RSV antibody disclosed in U.S. Pat. No. 5,824,307; Johnson S, et al., “Development of a Humanized Monoclonal Antibody (MEDI-493) with Potent In Vitro and In Vivo Activity Against Respiratory Syncytial Virus.” J. Infect Dis., 176(5): 1215-24, (November 1997); U.S. Pat. No. 6,656,467, or U.S. Published application 20030091584; or 2) an α v β 3  disclosed in U.S. Pat. No. 6,531,580, U.S. application No. 20030166872, or Wu, H. et al., “Stepwise In Vitro Affinity Maturation of Vitaxin, an α v β 3 -Specific Humanized mAb”, Proc Natl Acad Sci USA, 26; 95(11): 6037-42, (May 1998); or 3) an anti-EphA2 antibody disclosed in U.S. patent application Publication No. 20040091486. In a preferred embodiment, a bioactive material is an antibody as defined above. Specifically contemplated antibodies include, but are not limited to: anti-RSV, anti-hMPV, anti-avb3 integrin, anti-avb5 integrin, anti-alpha IIb/beta 3 integrin, anti-alpha 4 integrin, anti-EphA2, and anti-EphA4, anti-EphB4, anti-IL9, anti-IL4, anti-IL5, anti-IL13, anti-IL15, anti-CTLA4, anti-PSA, anti-PSMA, anti-CEA, anti-cMET, anti-C5a, anti-TGF-beta, anti-HMGB-1, anti-interferons alpha and anti-interferon alpha receptor, anti-IFN beta and gamma, anti-chitinase, anti-TIRC7, anti-T-cell, MT-103 BiTE®, anti-EpCam, anti-Her2/neu, anti-IgE, anti-TNF-alpha, anti-VEGF, anti-EGF and anti-EGF receptor, anti-CD22, anti-CD19, anti-Fc, anti-LTA, anti-Flk-1, and anti-Tie-1.  
      Vaccine antigens to be used in the invention include, but are not limited to, viral vaccines which can be live whole virus vaccines, killed whole virus vaccines, subunit vaccines, purified or recombinant viral antigens, recombinant virus vaccines, anti-idiotype antibodies, cancer vaccines, and DNA vaccines. In certain preferred embodiments, a bioactive material is a vaccine antigen. Specifically contemplated vaccines comprise one or more antigens from the following: Epstein Barr virus, Streptoccocus, pneumococcal, RSV (respiratory syncytial virus), PIV (para-influenza virus), hMPV (human metapneumovirus), EphA2 cancer vaccine, HPV (human papilloma virus) HPV-16, HPV-18, CMV (cytomegalo virus), Pneumocystis carinii, Influenza virus, rubella, measles, mumps, anthrax, botulism, ebola, chicken pox, shingles, small pox, polio, yellow fever, hepatitis B, Rift Valley fever, tuberculosis, viral meningitis, pandemic flu, avian flu, and adenovirus.  
      Sugars can provide many useful characteristics to formulations of bioactive materials for spray drying. Sugars in the formulations can enhance stability, accelerate reconstitution, reduce shear denaturation during spraying and administration, etc. In the present invention, it is preferred that sugars be present in the formulation for high pressure spray drying in an amount ranging from about 0.1% to about 8% by weight or more, from about 0.5% to about 4%, from about 1% to about 3%, or about 2%. Preferred sugars are generally not reducing sugars. Exemplary sugars for spray drying biomaterial formulations include sucrose, mannitol and/or trehalose.  
      Amino acids can be included in formulations for high pressure spray drying of bioactive materials, e.g., to enhance stability, buffer the pH, provide readily soluble bulk, and/or the like. Formulations for spraying bioactive materials, in the invention can include, e.g., amino acids in amounts ranging from about 0.05 mM to about 100 mM, from about 0.1 mM to about 50 mM, from about 1 mM to about 30 mM, or about 20 mM total amino acids. Preferred amino acids include, e.g., glycine, leucine, histidine and arginine. Preferred histidine concentrations in the formulations range from about 2 mM to about 20 mM, or about 10 mM. Preferred arginine concentrations in the formulations range from about 5 mM to about 50 mM, from about 10 mM to about 40 mM or about 30 mM (about 0.5% by weight). Of course, formulations free of histidine or arginine are envisioned, but generally less preferred.  
      In a preferred embodiment, at least one amino acid in the formulation is a small hydrophobic amino acid, as such Leucine. Use of small hydrophobic amino acids in the formulations can particularly benefit the properties of powders sprayed in the presence of organic solvents. For example, leucine in combination with an ethanol-mediated spray drying process can improve the dispersibility and flowability of resultant powders. Inter-particle cohesion and reconstitution time can also be reduced for powders sprayed using a combination of solvent and small hydrophobic amino acid. Preferred solvent spraying techniques can include spraying with formulations having 0-2% w/v leucine and/or mannitol.  
      Surface active agents can be included in formulations for high pressure spray drying of bioactive materials, e.g., to enhance stability and reduce reconstitution times for the bioactive material. Surfactants can be present in the formulations in amounts ranging from 0% to about 2%, from about 0.001% to about 1%, from about 0.01% to about 0.5%, from about 0.05% to about 0.2%, or about 0.1%. Preferred surfactants for the high pressure spraying formulations include 0.01% to about 0.2% of nonionic detergents, such as polyoxyethylenesorbitan monooleates (Tween-20) or polyethylene glycol sorbitan monolaurates (Tween-80).  
      In addition to amino acids and sugars, polymers can be added to the formulations for high pressure spray drying of bioactive materials. A preferred polymer is polyvinyl pyrrolidone (PVP). Polymers, when present in the formulation, are preferred in amounts ranging from about 0.01% to about 2%, from about 0.05% to about 0.5%, or about 0.1% to about 0.2%.  
      In particular embodiments of high pressure spray drying, the bioactive materials are antibodies described as having a sequence of any of SEQ ID NOs. 1 to 20, or a conservative variation thereof. Conservative amino acid substitutions, in one or a few amino acids in an amino acid sequence are substituted with different amino acids with highly similar properties, are also readily identified as being highly similar to a disclosed construct. Such conservative variations of each disclosed sequence are a feature of the present invention. One of skill will recognize that individual substitutions, deletions or additions which alter, add or delete a single amino acid or a small percentage of amino acids (typically less than 5%, more typically less than 4%, 2% or 1%) in an encoded sequence are “conservatively modified variations” where the alterations result in the deletion of an amino acid, addition of an amino acid, or substitution of an amino acid with a chemically similar amino acid. Thus, “conservative variations” of a listed polypeptide sequence of the present invention include substitutions of a small percentage, typically less than 5%, more typically less than 2% or 1%, of the amino acids of the polypeptide sequence, with a conservatively selected amino acid in the same conservative substitution group. The conservative variations particularly include those which do not substantially change the specificity or affinity of the identified antibodies.  
               TABLE 1                       Conservative Substitution Groups                                                    1   Alanine (A)   Serine (S)   Threonine (T)           2   Aspartic acid (D)   Glutamic acid (E)       3   Asparagine (N)   Glutamine (Q)       4   Arginine (R)   Lysine (K)       5   Isoleucine (I)   Leucine (L)   Methionine (M)   Valine (V)       6   Phenylalanine (F)   Tyrosine (Y)   Trytophan (W)                  
 
 In Table 1, substitution of an amino acid with another amino acid of the same group can be considered a conservative variation substitution. 
 
 Spraying the Formulation 
 
      Formulations of the invention are sprayed, e.g., from a spray nozzle at high pressure to produce a fine mist of droplets. Spray parameters can vary, e.g., according to the viscosity of the solution, the desired particle size, the intended method of drying, the design of atomization nozzles, and/or sensitivities of the bioactive material.  
      High pressure spraying has significant advantages over lower pressure spraying methods, e.g., because of the fine droplets, and ultimately, fine dry powder particles thus obtained. As shown in  FIG. 1 , high pressure spraying (plot  10 ) can provide droplet sizes less than 10 μm with mass flow ratios (MFR—the ratio of atomizing gas mass flow per liquid mass flow) less than 1, whereas standard (lower pressure atomizing nozzles, plot  11 ) can require MFRs in the range of about 15 to obtain droplet sizes less than 10 μm. High pressure spraying can provide a significant reduction in the use of atomizing gasses while spraying finer average droplet sizes than obtainable with lower pressure spray methods. Optionally, high pressure spraying can be practiced without simultaneous discharge of atomizing gas, i.e., spraying of high pressure liquid from a nozzle without a jet of gas.  
      The formulation can be sprayed from a nozzle at a pressure effective in providing the desired droplet size. Higher pressures generally provide, e.g., smaller droplet sizes. When the solution is more viscous, e.g., a higher pressure can be required to provide the desired droplet size. The presence of a surfactant, e.g., often lowers the pressure required to provide the desired droplet size in high pressure spraying processes. Where formulations are atomized by spraying in the presence of a pressurized gas flow, the mass flow ratio can affect droplet sizes. The spray pressures of the invention can be, e.g., between about 200 psi (pounds per square inch) and about 5000 psi, between about 500 psi and 2500 psi, 1000 psi and 1500 psi, or can be about 1300 psi. The size of spray droplets and/or dried particles can be controlled by, e.g., adjusting the percent surface active agent in the formulation, adjusting a spraying pressure, adjusting an atomizing gas pressure, adjusting a viscosity, adjusting the total solids in the formulation, adjusting a flow rate of the formulation, adjusting a mass flow ratio, adjusting a temperature of the formulation, and/or the like.  
      Where the spray of droplets is atomized with a high pressure atomizing gas, the atomizing gas can have, e.g., a pressure or temperature at least 10%, or at least 15%, or at least 20%, away from a critical point for the gas. As shown in  FIG. 2 , pressurization and/or cooling of many gasses can lead to a phase transition from the gas state to a liquid or solid state. These transitions from the gas state can take place at critical pressures and/or critical temperatures. It is an aspect of the invention that in some embodiments, atomizing gasses are more than 10%, more than 15%, or more than 20% below the critical pressure for the gas at a given temperature. It is an aspect of the invention that in some embodiments, atomizing gasses are more than 10%, more than 15%, or more than 20% above the critical temperature (as measured in degrees Kelvin) for the gas at a given pressure.  
      In one embodiment, the formulation includes both a viscosity enhancing agent and a surface active agent, e.g., to provide improved control of sprayed droplet size at a given spray pressure. In the presence of viscosity enhancing agents, sprayed droplet sizes are generally greater than for solutions without viscosity enhancing agents. In the presence of surface active agents, sprayed droplet sizes are generally smaller than for solutions without surface active agents. However, when formulations include both a viscosity enhancing agent and a surface active agent, some useful and unexpected results can be obtained. A chart of droplet size versus atomization pressure can be prepared to show relationships between pressures, surface active agents, viscosity enhancing agents and droplet sizes, as shown for example in  FIG. 3 . At some pressures, e.g., 900 to 1100 psi, pure water  30  can spray into smaller droplet sizes than for water with surface active agent (Tween 80) and/or viscosity enhancing agent (Sucrose). At other pressures, e.g., from about 1300 psi to about 2200 psi, solutions or suspensions containing surface active agent can spray into droplet sizes smaller than for pure water. At a certain enhanced surfactant control ranges of spray pressures, surface active agents can exert a particularly significant influence on the droplet size of solutions or suspensions containing viscosity enhancing agents. For example, at 1500 psi the average droplet size of 20% sucrose solution  31  can be more than for water at about 14 μm, but the average droplet size can be less than for water at about 8 μm for 20% sucrose solution with 0.1% Tween 80  32 . In one embodiment of the invention, the droplet size of sprayed formulations is controlled at a particular atomization pressure by adjustment of the surface active agent concentration. For example, incremental adjustments of surface active agent concentrations can provide tuned droplet sizes even if other parameters, such as orifice internal diameter, viscosity enhancing agent concentration, pressure, and MFR are held constant. Enhanced surfactant control ranges can be determined empirically for bioactive agent, surface active agent, viscosity enhancing agent combinations of interest.  
      Methods of the invention particularly suitable for high pressure spray drying of bioactive materials can include, e.g., spraying preferred formulations of the bioactive material with sugars and amino acids to form a mist of droplets, and drying the droplets to form powder particles. The formulation can be constituted as described above in the Formulations for Spray Drying Bioactive Materials section, e.g., with from about 4% to about 10% bioactive material by weight (or optional described virus concentrations), from about 0.1 mM to about 50 mM amino acid, and from about 0.5% to about 4% of a sugar. Spraying can be at a high pressure, e.g., from about 200 psi to about 5000 psi, from about 800 psi to about 1800 psi, from about 1000 psi to about 1500 psi, or about 1300 psi. High pressure spraying of the bioactive material can produce any suitable size of droplets, but preferred droplets will produce dry powder particles ranging in size from about 0.5 μm to about 100 μm, from about 1 μm to about 50 μm, from about 2 μm to about 20 μm, from about 7 μm to about 18 μm or from about 10 μm to about 15 μm. For example, the droplets, before drying, can range in size from about 1 μm to about 200 μm, from about 2 μm to about 100 μm, from about 3 μm to about 30 μm, from about 10 μm to about 20 μm or about 15 μm.  
      Droplet sizes can be affected by the mass flow ratio (MFR) of atomizing gas and the formulation. Under conditions of low MFR for a given atomizing pressure, as shown on the left side of the chart in  FIG. 4A , larger particles are formed. Under conditions of higher MFR for a given atomizing pressure, as shown on the right side of the chart, smaller powder particles are formed on drying of the sprayed droplets. One explanation for this observation can be that higher relative flows of atomizing gas are able to disrupt a given fluid flow into smaller droplets. In many cases, average droplet size (and final dried particle sizes) can be tuned by adjusting the flow rate of a formulation to be high pressure sprayed while any atomizing gas pressure remains constant. Optionally, the MFR can be varied to adjust droplet size by varying the pressurized atomizing gas flow while the flow of formulation is held constant, as shown in  FIG. 4B .  
      In a preferred embodiment, formulations are high pressure spray-dried with an atomizing stream of pressurized nitrogen gas. Atomization with the nitrogen gas stream can contribute to reduced droplet sizes as a given pressure as compared to direct high pressure spraying without a atomizing gas. Nitrogen has an advantage over atomization with pressurized air in that it is relatively inert and can protect bioactive materials, e.g., from oxidation. Nitrogen has advantages over carbon dioxide in that it does not form acids in aqueous solutions and has a greater capacity to hold water vapor. Nitrogen is less expensive than other substantially inert gasses, such as helium and argon, which can also be used in high pressure spray dry processes. Appropriate nozzles for high pressure spraying with atomizing nitrogen include, e.g., dual channel atomizing nozzles and nozzles with T intersections of liquid with the atomizing gas. As shown in  FIG. 4B , particle sizes of dried droplets generally decrease with higher atomization pressures at a given MFR.  
      In another preferred embodiment, the bioactive material, can be spray dried as a formulation in the presence of an organic solvent. Typically the formulation and solvent are sprayed from a nozzle along with a high pressure atomization gas, such as, e.g., nitrogen and/or carbon dioxide. For example, the formulation can be introduced into a triple-inlet effervescent atomization nozzle along with separate inputs of solvent and gas. One nozzle inlet can be dedicated to a high pressure atomization gas (e.g., nitrogen or CO2), one inlet dedicated to the (liquid) formulation and active ingredients, and one inlet dedicated to organic solvents that modify evaporation behavior of the droplets. Methanol and/or ethanol (1-50% v/v concentration range relative to the total formulation plus solvent sprayed) have been found to improve evaporative efficiency and, e.g., affecting particle surface morphology, powder particle size, and/or particle density. These changes can help improve powder dispersibility and flowability aimed at enhancing deep lung delivery.  
      High pressure spray drying processes can be scaled up, e.g., by spraying larger volumes of formulations. Larger volumes can be sprayed, e.g., by using multiple spray nozzles, by spraying at higher pressures, by spraying at a higher formulation flow rate, and/or by spraying through a larger internal diameter spray orifice.  FIG. 5  shows some examples of high pressure spray nozzle configurations.  FIG. 5B  shows a high pressure liquid spray nozzle with a constrictor at the orifice. When spraying from an atomizing nozzle, e.g., as shown in  FIGS. 5A and 5C , the MFR can change with the flow rate of the formulation resulting with changed droplet sizes at a given atomizing gas pressure. This is because as the flow rate of the liquid increases, the flow of atomizing gas can become restricted. For example, as shown in  FIG. 6 , as the liquid feed rate increases for a formulation being atomized with a 2500 psi gas through a 250 μm orifice, the droplet size begins to increase in a nonlinear fashion at a liquid flow rate of about 30 ml/min (plot  60 ). This is due to restriction of the atomizing gas flow by the flow of liquid and resultant drop in the MFR. Such a rapid increase in droplet size can be delayed by employing an atomizing nozzle with a larger orifice internal diameter, as shown in plot  61  for a formulation being atomized with a 1170 psi gas through a 500 μm orifice.  
      Triple-inlet spray nozzles can have any functional configuration. For example, the nozzles can have inlets to “T” intersections, radially arrayed inlets, or staged combination of input fluids.  FIG. 10A  shows how gas, formulation and solvent can be combined and sprayed from a nozzle having a T intersection of fluid inlets.  FIG. 10B  shows radial introduction and combination of fluids ( FIG. 10C  is a cross-section through  10 B, as indicated).  FIG. 10D  shows preliminary combination of formulation and solvent before aspiration with a gas flow at the nozzle outlet.  
      Molecular, particulate, and cellular bioactive materials sensitive to shear stress can experience denaturation or deactivation when sprayed at high pressure. This problem can be reduced, e.g., by spraying with a viscosity enhancing agent.  FIG. 7 , for example, shows size exclusion analyses of a solution of antibodies before and after spray drying.  FIG. 7A  shows a size exclusion chromatograph of the antibody before spraying.  FIG. 7B  shows a size exclusion chromatograph of the antibody after spraying without effective amounts of a viscosity enhancing agent, wherein the amount of aggregate  70  has increased about 6-fold and fragments  71  have increased slightly. Aggregates of the antibody can have a lowered specific activity due to shear stress denaturation of the antibody protein and associated abnormal hydrophobic interactions between the antibody molecules.  FIG. 7C  shows a size exclusion chromatograph of the same antibody which has been protected from aggregation and fragmentation by including a viscosity enhancing agent in the solution before spraying.  
      The spray nozzle of the invention can be adapted to provide the desired fine mist of droplets. The nozzle can have, e.g., a conduit feeding the formulation at high pressure to a spray orifice that has an internal diameter of between about 50 μm and about 500 μm, between about 75 μm and about 250 μm, or about 100 μm. Wider diameter orifices can provide, e.g., higher production rates but can result in larger droplet sizes. The nozzle can be configured as an atomizer, i.e., with a second channel routing a pressurized gas into the stream of formulation, to aid in the dispersal of the droplets. The nozzles can include additional channels, e.g., for blending of additional fluids (e.g., solvents) into the stream.  
      The process formulation can be sprayed from the nozzle at high pressure to form fine droplets that are readily dried into desired powder particles of the invention. The droplets can be sprayed, e.g., into a stream of inert warm drying gas, into a vacuum of 200 Torr or less, or into a freezing stream or pool of a cold fluid. The droplets can have an average diameter of about 2 μm to about 200 μm, about 3 μm to about 70 μm, about 5 μm to about 30 μm, or about 10 μm. If the droplets are frozen, e.g., in a cold stream of gaseous or liquid, argon, helium, carbon dioxide, or nitrogen, at between about −80° C. to about −200° C., they can be dried by sublimation to form particles about the same size as the droplets but having a low density (and a lower aerodynamic diameter). If the formulation is high in total solids, the dried particles can be, e.g., larger and/or more dense.  
      Drying the Droplets  
      Sprayed droplets can be dried to form powder particles. Droplets sprayed using methods of the invention can be dried, e.g., without excessively hot temperatures to provide high recovery of particles with high purity, high specific activity, and high stability. Drying can be, e.g., by exposure to a temperature, humidity, and/or pressure controlled environment. Drying can be by sublimation of ice, vacuum drying, contact with drying gasses, suspension in a fluidized bed, retention in a drying chamber, and/or the like. Primary drying generally includes, e.g., removal of liquid or ice water bulk from the droplets of the formulation. Secondary drying generally includes, e.g., removal of trapped moisture and/or water of hydration from particles to a level of 15 percent residual moisture, 10 percent residual moisture, 5 percent residual moisture, 3 percent residual moisture, 1 percent residual moisture, or less.  
      Drying can be by, e.g., spraying the droplets into a stream of drying gas controlled for humidity and/or temperature. Drying parameters can be controlled, e.g., to provide conditions necessary to obtain particles with the desired activity, density, residual moisture, and/or stability. Drying parameters can be controlled to provide the desired particle characteristics within a time frame compatible with process requirements, such as drying time, drying chamber retention time, agglomeration prevention, etc. The gas can be, e.g., an inert gas, such as nitrogen, that displaces the water vapor, and other gases emanating from the sprayed mist of formulation. The drying gas can be the same gas as the high pressure spray gas, e.g., to facilitate drying gas recycling. The gas can be dry, e.g., with a low relative humidity, to absorb moisture and speed evaporation of the droplets. The gas can be, e.g., controlled to a temperature between about 10° C. to about 90° C., about 15° C. and about 70° C., between 25° C. and about 60° C., or about 35° C. to about 55° C. The temperature of drying gas at a drying chamber inlet can be controlled to provide a drying gas temperature at the drying chamber outlet ranging from about 30° C. to about 80° C., from about 40° C. to about 60° C., or about 50° C. Drying temperatures can remain, e.g., below the glass transition temperature (T g ) of the particle constituents to avoid changing the porosity, density, stability, and/or reconstitution time of the particles. The small particle sizes, spray plume size, spray plume turbulence, and high total solids of the invention can, e.g., allow for short drying times and cooler drying temperatures that will not substantially degrade many sensitive bioactive materials.  
      The droplets can be dried, e.g., by application of a vacuum (gas pressures less than atmospheric pressure, such as 200 Torr, about 100 Torr, about 50 Torr, about 10 Torr, or less) to the sprayed mist or partially dried particles. Vacuum drying has the benefit, e.g., of quickly “boiling” or sublimating away water from the droplets while reducing the temperature of the droplets. The temperature of the droplets falls as latent heat is lost during the phase transition of liquid water to gas. Thus, vacuum drying can significantly reduce heat stress on the bioactive material. In the case of droplets frozen in a stream of cold fluid, or frozen by the loss of latent heat during drying processes, vacuum pressures can sublimate water directly from the solid ice phase to the gas phase providing freeze-dried (lyophilized) particles.  
      Secondary drying conditions can be used, e.g., to further lower the moisture content of particles. Particles can be collected in a chamber and held at a temperature between about 20° C. and about 99° C., about 25° C. and about 65° C., or about 35° C. and 55° C., e.g., in a vacuum (pressure below atmospheric), for from about 2 hours to about 5 days, or about 4 hours to about 48 hours, to reduce residual moisture. Secondary drying can be accelerated by providing an updraft of drying gasses in the chamber to create a fluidized bed suspension of powder particles. Particles with lower residual moisture generally show better stability in storage with time. Secondary drying can continue until the residual moisture of the powder particles is between about 0.5 percent and about 10 percent, or less than about 5 percent. At very low residual moisture values, some bioactive material molecules can be denatured by loss of water molecules of hydration. This denaturation can often be mitigated by providing hydrogen binding molecules, such as sugars, polyols, and/or polymers, in the process formulation.  
      Powder particles of the invention can have a size, e.g., suitable to the handling, reconstitution, and/or administration requirements of the product. For example, powder particles of bioactive materials for administration by intranasal delivery by inhalation can be larger, at between about 20 μm to about 150 μm or more, than for deep pulmonary delivery by inhalation, at between about 2 μm to about 10 μm (average physical diameter). The average particle size for products that reconstitute slowly can be smaller to speed dissolution of the particles. Spray freeze-dried particles can have, e.g., a lower density, because the ice can be removed from droplets without collapse of a cake structure of the remaining solids. Such particles can have, e.g., a physically larger acceptable size for inhaled administration due to their lower aerodynamic radius. Freeze-dried particles can, e.g., be larger than particles dried from liquid droplets and still retain quick reconstitution properties due to the porous nature of freeze-dried particles. Freeze dried powder particles of the invention can have average physical diameters, e.g., between about 0.1 μm and about 200 μm, or between about 2 μm and about 100 μm, or about 10 μm.  
      Drying spray mist droplets of formulations that include bioactive materials other than viruses or antibodies can generally proceed as described above. In preferred embodiments, high pressure sprayed droplets of bioactive material formulations come into contact with a drying gas having a temperature, e.g., from about 30° C. to about 80° C. It can be preferred to dry the droplets in a drying chamber having a drying gas inlet and a drying gas outlet. Preferred outlet gas temperatures for drying of high pressure sprayed droplets of the invention containing antibodies range from about 30° C. to bout 80° C., from about 40° C. to about 60° C., or about 50° C. Preferred drying gasses include air or inert gasses, such as, e.g., nitrogen. It is further preferred to recycle gas from the drying chamber outlet, e.g., by removing water and by adjusting the temperature before returning the drying gas to dry additional droplets in the drying chamber. Dried powder particles of bioactive material formulations can be recovered from the drying chamber or other collection vessel. The powder particles can be administered as powder particles, e.g., by inhalation, dry injection, or by injection on reconstitution.  
      The average size and size uniformity of particles can be controlled, e.g., by adjusting spraying parameters and/or by adjusting drying parameters. For example, average droplet size can be affected by nozzle size, solution pressures, solution viscosity, and solution constituents, etc., as described above in the Spraying the Formulation section above. Average particle size, and size distribution, can be affected by drying conditions that affect shrinkage or agglomeration of particles, such as, e.g., the use of freeze-drying, the completeness of drying, the neutralization of static charges, particle density during drying, the rate of drying, the temperature of drying, and/or the like. The average size and size uniformity of particles can be selected as described in the Recovery of Particles section, below.  
      Recovery of Particles  
      Powder particles of the invention can be physically recovered from the process stream, e.g., by settling or filtration. The recovery of bioactive material activity (e.g., antibody titer or plaque forming units) in the spray drying process is the product of the physical recovery times the specific activity (measured activity per material mass) of recovered agent.  
      Physical recovery of powder particles can depend, e.g., on the amount of material retained or expelled by the spray-drying equipment and losses incurred due to particle size selection methods. For example, material containing the bioactive material can be lost in the plumbing, and on surfaces of the spray-drying equipment. Solutions or particles can be lost in the process, e.g., when an undesired agglomeration of spray droplets grows and falls out of the process stream or when under sized droplets dry to minute particles that are carried past a collection chamber in a process waste gas stream. Process yields (the percent recovery of input bioactive material through the process) of the invention can range, e.g., from about 40 percent to about 98 percent, about 90 percent, or more.  
      Particles of a desired average size and size range, can be selected, e.g., by filtration, settling, impact adsorption, and/or other means known in the art. Particles can be sized by screening them through one or more filters with uniform pore sizes. Large particles can by separated by allowing them to fall from a suspension of particles in a moving stream of liquid or gas. Smaller particles can be separated by allowing them to be swept away in a stream of liquid or gas moving at a rate at which larger particles settle. Large particles can be separated by surface impact from a turning gas flow that carries away particles with less momentum.  
      Recovery of active bioactive material can be affected, e.g., by physical losses, agent disruption, denaturation, aggregation, fragmentation, oxidation, and/or the like, experienced during the spray-dry process. The methods of the invention offer improved recovery of bioactivity over the prior art, e.g., by providing spray dry techniques that reduce shear stress, reduce drying time, reduce drying temperatures, and/or enhance stability. For example, monoclonal antibodies spray dried by the methods of the invention can experience less than 4 percent aggregation and fragmentation on initial production and after in storage for up to about 7 years at 4° C. Methods of the invention can provide dried powder having bioactive material substantially unchanged activity or viability compared to the same bioactive material in the formulation before high pressure spraying.  
      Administration of the Bioactive Material  
      Where it is appropriate, the bioactive material of the invention can be administered, e.g., to a mammal. Bioactive materials of the invention can include, e.g., peptides, polypeptides, proteins, viruses, bacteria, antibodies, cells, liposomes, and/or the like, and as defined herein. Such agents can act as therapeutics, nutrients, vaccines, pharmaceuticals, prophylactics, and/or the like, that can provide benefits on administration to a patient, e.g., by gastrointestinal absorption, topical application, inhalation, and/or injection. Optionally, cells or tissues can come in contact with the bioactive materials of the invention to provide a biological effect or response.  
      The bioactive material can be administered to a patient by topical application. For example, the powder particles can be mixed directly with a salve, carrier ointment, and/or penetrant, for application to the skin of a patient. Alternately, the powder particles can, e.g., be reconstituted in an aqueous solvent before admixture with other ingredients before application.  
      Bioactive materials of the invention can be administered by inhalation. Dry powder particles about 10 μm in aerodynamic diameter, or less, can be inhaled into the lungs for pulmonary administration. Optionally, powder particles about 20 μm, and greater, in aerodynamic diameter can be administered intranasally, or to the upper respiratory tract, where they are removed from the air stream by impact to the mucus membranes of the patient. The powder particles can alternately be reconstituted to a suspension or solution for inhalation administration as an aqueous mist.  
      Bioactive materials of the invention can be administered by injection. The powder particles can be administered directly under the skin of a patient using, e.g., a jet of high pressure air. More commonly, the powder particles can be, e.g., reconstituted with a sterile aqueous buffer for injection through a hollow syringe needle. Such injections can be, e.g., intramuscular, intra venous, subcutaneous, intrathecal, intraperitoneal, and the like, as appropriate. Powder particles of the invention can be reconstituted to a solution or suspension with a bioactive material concentration of from less than about 1 mg/ml to about 500 mg/ml, or from about 5 mg/ml to about 400 mg/ml, or about 200 mg/ml, as appropriate to the dosage and handling considerations. Reconstituted powder particles can be further diluted, e.g., for multiple vaccinations, administration through IV infusion, and the like.  
     COMPOSITIONS OF THE INVENTION  
      Compositions of the invention are generally bioactive materials, such as antibodies, in dry powders prepared using the methods of the invention. Numerous combinations of bioactive materials, processing steps, process parameters, and composition constituents, as described herein, are available to suit the intended use of the composition.  
      The compositions of the invention provide, e.g., powder particles containing a bioactive material which are made by preparing an aqueous formulation of the bioactive material (e.g., a therapeutic antibody or vaccine) and a viscosity enhancing agent, spraying the formulation through a nozzle at high pressure to form a mist of fine droplets, drying the droplets to form powder particles, and recovering the particles, as is described in the Methods sections, above. In a particular embodiment of the composition, the powder particles contain antibodies as the bioactive material that can be reconstituted into a 200 mg/ml solution, 400 mg/ml solution, or more concentrated solution, with the antibodies having less than about 3 percent aggregates or fragments. The compositions of the invention include, e.g., stable powder particles and highly concentrated solutions of bioactive materials with high purity and high specific activity. Powder particles containing viral bioactive materials can be prepared by high pressure spraying a suspension of the virus, sucrose, and a surface active agent. Particle compositions of viruses are often processed from liquid formulations with the virus present in an amount ranging from about 10 1  TCID 50 /mL to about 10 12  TCID 50 /mL, or from about 10 6  TCID 50 /mL to about 10 9  TCID 50 /mL. Dried powder particle compositions of the invention can provide virus present in an amount, e.g., from about 10 1  TCID 50 /g to not more than 10 12  TCID 50 /g. Dried powder particle compositions can provide virus present in an amount, e.g., of about 10 1  TCID 50 /g, about 10 2  TCID 50 /g, about 10 3  TCID 50 /g, about 10 4  TCID 50 /g, about 10 5  TCID 50 /g, about 10 6  TCID 50 /g, about 10 7  TCID 50 /g, about 10 8  TCID 50 /g, about 10 9  TCID 50 /g, about 10 10  TCID 50 /g, or about 10 11  TCID 50 /g.  
      Powder Particles  
      Powder particles of the invention are dried droplets of the process formulations of the invention. The particles include, e.g., stable bioactive materials in a dried matrix of excipients, such as the sugar, amino acid, surfactants, polyol and/or polymer viscosity enhancing agents. The particles range in average physical diameter (size), e.g., from about 0.1 μm to about 200 μm, about 1 μm to about 100 μm, about 2 μm to about 30 μm, about 4 μm to about 20 μm or 15 μm, or about 7 μm to about 10 μm. The bioactive material can be present in the powder particles in a ratio ranging, e.g., from less than about 1/100 to about 100/1, about 1/5 to about 5/1, or about 2/3 to about 3/2, or about 1/1, with respect to excipients, by weight. In one embodiment, powder particles of the invention average about 5 μm in diameter with about 55 weight percent of an antibody, about 15 weight percent arginine, about 2 weight percent polyvinyl pyrrolidone, about 33 weight percent sucrose, and about 5% moisture. In another embodiment, a composition of the invention comprises dry powder particles with about 55 weight percent of an antibody, about 21 weight percent arginine, about 1 weight percent polyvinyl pyrrolidone, about 14 weight percent sucrose, and about 5% moisture. In another embodiment, the composition of dry powder particles includes, e.g., a live attenuated virus at about 0.01% by weight, about 15 percent arginine, 70 percent polyol, and less than 5 percent moisture.  
      Bioactive Materials  
      Bioactive materials of the composition (powder particles) include, for example, antibodies, peptides, polypeptides, proteins, viruses, bacteria, cells, liposomes, and/or the like and as defined herein. Bioactive materials in the powder particles of the invention can be, e.g., highly pure and active at the time of drying the powder particles, due to the reduced shear stress, the low drying temperatures, protective excipients, and the short drying times used in their preparation. Bioactive materials are, e.g., stable in the powder particles due to the low initial process degradation and protective aspects of the composition excipients. Bioactive materials of the composition can be, e.g., reconstituted at high concentrations without degradation due to the high surface to volume ratio of the particles and the solubility enhancements provided by the excipients of the composition.  
      Formulations, for high pressure spray-drying according the invention contain, e.g., the bioactive materials of the invention in amounts ranging from less than about 1 mg/ml to about 400 mg/ml, from about 5 mg/ml to about 200 mg/ml, or about 50 mg/ml. Bioactive materials in the dry powder particles of the invention can be present in amounts ranging, e.g., from less than about 0.1 weight percent to about 80 weight percent, from about 40 weight percent to about 60 weight percent, or about 50 weight percent. Bioactive materials of the reconstituted composition can be present in concentrations ranging, e.g., from less than about 0.1 mg/ml to about 500 mg/ml, from about 5 mg/ml to about 400 mg/ml, about 100 mg/ml to about 300 mg/ml, or about 200 mg/ml. In one aspect of the invention, the bioactive material is a virus present in the suspension to be sprayed at a titer ranging from about 2 log FFU/ml to about 12 log FFU/ml, or about 3 log FFU (focus forming units) to 13 log FFU per gram of dry powder particles.  
      Viscosity Enhancing Agents  
      Viscosity enhancing agents of the composition include, e.g., polyols and/or polymers that can provide protection to bioactive materials against shear stress when the solutions or suspensions of the invention are sprayed at high pressure. The viscosity enhancing agents can ultimately become a significant part of the powder particle bulk and provide additional benefits. For example, the viscosity enhancing agents in the particles can, e.g., help stabilize the bioactive material by providing hydrogen bonding replacement for water molecules of hydration lost in drying, increase the solubility of the particles for quicker reconstitution at high concentrations, provide a glassy matrix to retard reaction kinetics, and physically block destabilizing molecules (such as oxygen) from gaining access to the bioactive material.  
      Polyols useful as viscosity enhancing agents should be, e.g., compatible with the intended use of the composition. For example, viscosity enhancing agents in particles intended for injection into humans should be generally recognized as safe. Viscosity enhancing polyols can include, e.g., trehalose, sucrose, sorbose, melezitose, glycerol, fructose, mannose, maltose, lactose, arabinose, xylose, ribose, rhamnose, palactose, glucose, mannitol, xylitol, erythritol, threitol, sorbitol, raffinose, and/or the like. Non-reducing sugars are generally recommended, e.g., where the bioactive material is a peptide, in order to avoid chemical modification of the side chains.  
      Polymers useful as viscosity enhancing agents can include, e.g., starch, starch derivatives, carboxymethyl starch, inulin, hydroxyethyl starch (HES), dextran, dextrin, polyvinyl pyrrolidone (PVP), human serum albumin (HSA), gelatin, and/or the like. Many polymers are, e.g., more viscous in solution by weight than polyols so can often provide adequate shear stress protection at lower concentrations.  
      Viscosity enhancing agents can be present in the formulations of the invention before spray-drying in amounts between about 0.1 weight percent to about 20 weight percent, between about 2 weight percent and 8 weight percent, or about 6 weight percent. In many embodiments, polyol viscosity enhancing agents are present at about 2 to 6 weight percent in the formulation, while polymer viscosity enhancing agents are present at about 0.5 to 2 weight percent. Viscosity enhancing agents are preferably present in the formulations of the inventions at concentrations sufficient to increase the viscosity of the formulation by about 5% or more, or by 0.05 centipoise or more.  
      Other Excipients  
      The compositions of the invention can include additional excipients (e.g., not solvent or the bioactive material) to provide appropriate characteristics and benefits. For example, the compositions can include surfactants, zwitterions, buffers, and the like.  
      Surfactants can be included in the formulations of the invention, e.g., to increase the solubility of composition constituents, and/or to reduce surface tension. Surfactants can, e.g., increase the suspension or solubility of certain bioactive materials by surrounding them with charged or hydrogen bonding groups. Surfactants can help in reconstitution of powder particles by, e.g., accelerating the dissolution of the excipient matrix on exposure to water. By reducing surface tension, surfactants can reduce aggregation and conformational changes that can occur with some bioactive materials at the air/liquid interface of droplets during spraying. Surfactants of the formulations can include, e.g., any appropriate surfactant, such as polyethylene glycol sorbitan monolaurates, polyoxyethylenesorbitan monooleates, or block polymers of polyethylene and polypropylene glycol, e.g., Tween 80, Tween 20, or Pluronic F68. Surfactants can be present in the formulations in amounts between about 0.01 weight percent to about 2 weight percent, between about 0.02 weight percent and 0.5 weight percent, between about 0.1 weight percent and 0.3 weight percent, or about 0.2 weight percent. Surface active agents can provide benefits in the control of droplet and particle sizes, as described above.  
      Zwitterions, such as amino acids, can be included in the compositions, e.g., as counter ions to charged groups of the bioactive materials or surfactants. The presence of these counter ions can, e.g., help the bioactive materials retain non-denatured conformations, prevent aggregation, and inhibit adsorption of charged bioactive materials onto surfaces of processing equipment. The zwitterions can, e.g., help protect the bioactive materials against deamidation reactions, act as antioxidants, and provide pH buffering capacity. Zwitterions of the invention can include, e.g., arginine, leucine, histidine, glycine, and/or the like. Zwitterions can be present in the powder particles of the invention in amounts ranging between about 0.1 percent and about 20 percent, between about 0.5 percent and about 15 percent, between about 1 percent and about 10 percent, or about 7 percent of the total solids.  
      Buffers can be included in the compositions of the invention, e.g., to control pH, increase product stability, and/or to increase the comfort of administration. Buffers of the composition can include, e.g., phosphate, carbonate, citrate, glycine, amino acids, acetate, and the like.  
     EXAMPLES  
      The following examples are offered to illustrate, but not to limit the claimed invention.  
     Example 1  
     High Pressure Spray Drying of Antibodies  
      Antibodies are generally high pressure spray dried under the following conditions to provide desired powder particles. Formulations of about 8% monoclonal antibody flowing at about 1-2 mL/min through a 150 μm nozzle at 1300 psi with 15-25 mL/min nitrogen flow are sprayed into a drying chamber. The drying chamber (Buchi 191 model) has a 30 m 3 /hr flow of nitrogen drying gas (3-7% RH at 24° C.) from a chamber inlet at 60° C. to 80° C. to an outlet at 40° C. to 60° C.  
      An aqueous solution formulation is prepared to contain 8 weight percent of monoclonal antibody against RSV, 2 weight percent sucrose, 0.2 weight percent PVP, 10 mM histidine, 0.5 weight percent arginine, and 0.2 weight percent Tween-20, pH 6.0. The formulation is sprayed from a nozzle at about 1300 psi to provide droplets with an average diameter of about 10 μm. The droplets are dried in a stream of dry nitrogen gas ranging in temperature from about 60° C. inlet to about 45° C. outlet to produce powder particles with an average diameter of about 4 μm and a moisture less than 5 percent. The powder particles are initially reconstituted into solutions with antibody concentrations of up to 200 mg/ml and with less than 3 percent total aggregates and fragments.  
      An aqueous solution formulation is prepared to contain 8 weight percent of monoclonal antibody against α v β 3  integrin, 2 weight percent sucrose, 10 mM histidine pH 6.0, 0.5 weight percent arginine, and 0.2 weight percent Tween-80. The formulation is sprayed from a nozzle at about 1300 psi to provide droplets with an average diameter of about 10 μm. The droplets are dried in a stream of dry nitrogen gas ranging in temperature from about 60° C. inlet to about 45° C. outlet to produce powder particles with an average diameter of about 4 μm and a moisture less than 5 percent.  
      An aqueous solution was prepared to contain 8 weight percent of a monoclonal antibody, 6 weight percent sucrose, 0.2 weight percent PVP, and 2 weight percent arginine. The solution was sprayed from a nozzle at about 1150 psi to provide droplets with an average diameter of about 10 μm. The droplets were dried in a stream of dry nitrogen gas ranging in temperature from about 60° C. to about 45° C. to produce powder particles with an average diameter of about 4 μm and a residual moisture less than 5 percent. The powder particles were initially reconstituted into solutions with antibody concentrations of up to 500 mg/ml and with less than 3 percent total aggregates and fragments.  FIG. 8  shows the antibody after reconstitution at high concentrations and storage for nine days, or more, at 50° C. The powder particles remained stable with trend analysis predicting stability, with less than 3 percent aggregates, over about 7 years in storage at 4° C., or for about 1.5 years in storage at 25° C.  
      In another example of stability for high pressure spray dried formulations, an aqueous solution was prepared to contain 8 weight percent of a monoclonal antibody, 6 weight percent sucrose, 0.002% Tween 20, and 2 weight percent arginine. The solution was sprayed from a nozzle at about 1300 psi into an inlet nitrogen drying gas temperature of about 60° C., with a drying chamber outlet temperature of about 45° C. Stability data indicate the dried powder particles should form only about 1.5% additional aggregates after more than 6 years in storage at 4° C. or after about 2 years in storage at 25° C.  
      In another example, a low tonicity, fast dissolving formulation was high pressure spray-dried to prepare stable powder particles. An aqueous solution was prepared to contain 8 weight percent of a monoclonal antibody, 2 weight percent sucrose, 0.008% Tween 20, and 0.5 weight percent arginine for high pressure spraying with atomizing nitrogen at 1300 psi into an inlet nitrogen drying gas temperature of about 60° C., with a drying chamber outlet temperature of about 45° C. The dried powder was reconstituted to an antibody concentration of 180 mg/ml with a dissolution time of only 10 minutes using orbital shaking at room temperature. Such a formulation can have practical benefits of quick preparation for injection and reduced pain and irritation at the site of injection. Stability data indicate more than 2 years in storage at 4° C. before the formation of 2% additional aggregates in the dried powder.  
     Example 2  
     High Pressure Spray Drying of Live Virus  
      An aqueous solution was prepared of live influenza virus at about 7.5 log FFU/mi in formula AVO47r (5% sucrose, 2% trehalose, 10 mM methionine, 1% arginine, 0.2% Pluronic F68, 50 mM KPO4, pH 7.2) was high pressure sprayed at 1300 psi into a drying chamber with a 55° C. inlet temperature. Reconstitution of the dry powder showed no significant viability loss with a titer of about 7.5 log FFU/ml. The formulation required 23 days at a 37° C. accelerated storage temperature to experience a 1 log loss of viability.  
     Example 3  
     A High Pressure Spray Dry System  
      A high pressure spray drying system can include, e.g., a high pressure pumping system to deliver formulation to a high pressure spray nozzle, and a spray drying system to carry droplets and particles in a stream of conditioned gasses. As shown in  FIG. 9 , formulation  90 , with a bioactive material, is transferred from a holding container to high pressure spray nozzle  91  using high pressure pump  92 . High pressure gas from gas source  93  is pumped through high pressure gas pump  94  to atomize the formulation into a fine mist spray of droplets  95  into particle formation vessel  96 . Temperature controlled gas  97  is drawn by fan  98  in a stream that displaced water vapor from the spray to dry droplets  95  into powder particles  99 . Powder particles  99  were transferred to secondary drying chamber  100  where residual moisture is removed to an acceptable level. The powder particle product settled into collection vessel  101  at the bottom of drying chamber  100  for recovery.  
      High pressure spraying can be accomplished in a variety of ways known in the art, such as by high pressure spraying directly from a high pressure nozzle, atomizing the spray with a jet of gasses, and/or high pressure spraying into a cold fluid. For high pressure spraying, the formulation can be fed to the nozzle by a high pressure pump, such as a HPLC pump, or by application of a high pressure gas on the holding container. For atomized spraying, a pressurized gas can be released from outlets near the spray outlet orifice to further disrupt and disperse the sprayed droplets. For spray freeze drying, the droplets can be sprayed in to a cold (e.g., about −80° C., or less) gas or liquid in the particle formation vessel.  
      Drying the droplets with a temperature controlled gas can include displacement of spray gasses and evaporation of water into a temperature, humidity, and/or pressure controlled gas. Fan  98  can draw a stream of gas  97  into the spray of droplets  95  to displace spray gasses, such as water vapor, and/or volatile solution components. Temperature controller  102  can be a heater or refrigeration system to adjust the gas temperature before it enters particle formation vessel  96 . The gas can flow through humidity controller  103  (a condenser coil or desiccant) to remove moisture. A vacuum pump in fluid contact with the collection vessel can remove gasses from the drying chamber to speed evaporation from liquid droplets or to lyophilize frozen droplets. Drying gasses can be routed through filters, dryers, heat exchangers, activated charcoal beds, or other devices to recondition the gas for recycling through the particle formation and drying chambers. The process gasses can recirculate in a closed system of conduit or the system can be enclosed in an environmental control chamber. For example, the recycling loop can include an environmental control chamber, e.g., into which the entire spray dry system has been placed. Temperature and humidity sensors in the recirculating gasses can be adapted to regulate heating, cooling, and/or humidity control devices.  
     Example 4  
     Antibody Amino Acid Sequences  
      The present invention includes spray drying of antibodies disclosed in: U.S. Pat. No. 5,824,307, “Human-Murine Chimeric Antibodies Against Respiratory Syncytial Virus, to Johnson, et al., flied Aug. 15, 1994; Johnson S, et al. “Development of a Humanized Monoclonal Antibody (MEDI-493) with Potent In Vitro and In Vivo Activity Against Respiratory Syncytial Virus.” J. Infect Dis. November 1997;176(5):1215-24; U.S. Pat. No. 6,656,467, “Ultra High Affinity Neutralizing Antibodies”, to Young et al., filed Jan. 26, 2001; U.S. Published application 20030091584, Methods of Administering/Dosing Anti-RSV Antibodies for Prophylaxis and Treatment”, by Young, filed Nov. 28, 2001; U.S. Pat. No. 6,531,580 “Anti-αvβ3 Recombinant Human Antibodies and Nucleic Acids Encoding Same”, to Huse et al., filed Jun. 24, 1999; U.S. application No. 20030166872, ” Anti-αvβ3 Recombinant Human Antibodies, Nucleic Acids Encoding Same and Methods of Use”, by Huse et al., filed Nov. 25, 2002; Wu, H. et al. “Stepwise In Vitro Affinity Maturation of Vitaxin, an αvβ3-Specific Humanized mAb”, Proc Natl Acad Sci USA. May 26, 1998;95(11):6037-42; and, U.S. patent application Publication No. 20040091486, “EphA2 Agonistic Monoclonal Antibodies and Methods of Use Thereof”, by Kinch et al., filed May 12, 2003. Each of these references is hereby incorporated by reference in their entirety.  
      The following table includes preferred amino acid sequences for antibodies useful in formulations and methods of the invention.  
      Table 2—Amino Acid Sequences of Antibodies  
      A) Sequences of Anti-RSV antibodies comprise one or more of the following sequences, as published in application No. 20030091584, and B) Sequences of Anti-αvβ3 antibodies comprise one or more of the following sequences, as published in U.S. Pat. No. 6,531,580.  
                   TABLE 2                       Cross Reference of Sequence Identification Numbers in This Specification           to Those Found in the Published in Application Number 20030091584 and       U.S. Pat. No. 6,531,580                                                A. SEQ ID Numbers       SEQ ID Numbers From Application           This Specification   Sequence Source   Number 20030091584               SEQ ID NO 1   Heavy chain CDR1   SEQ ID NO 1: TSGMSVG                   SEQ ID NO 2   Heavy chain CDR2   SEQ ID NO 2: IWWDDKKDYNPSLKS               SEQ ID NO 3   Heavy chain CDR3   SEQ ID NO 3: SMITNWYFDV               SEQ ID NO 4   Light chain CDR1   SEQ ID NO 4: KCQLSVGYMH               SEQ ID NO 5   Light chain CDR2   SEQ ID NO 5: DTSKLAS               SEQ ID NO 6   Light chain CDR3   SEQ ID NO 6: FQGSGYPFT               SEQ ID NO 7   Heavy Chain Variable   SEQ ID NO 7           Region               SEQ ID NO 8   Light Chain Variable   SEQ ID NO 8           Region               SEQ ID NO 9   Heavy chain CDR1   SEQ ID NO 10: TAGMSVG               SEQ ID NO 10   Light Chain Variable   SEQ ID NO 11           Region               SEQ ID NO 11   Heavy chain CDR2   SEQ ID NO 19: IWWDDKKHYNPSLKD               SEQ ID NO 12   Heavy chain CDR3   SEQ ID NO 20: DMIFNFYFDV               SEQ ID NO 13   Light chain CDR1   SEQ ID NO 39: SASSRVGYMH               SEQ ID NO 14   Heavy Chain Variable   SEQ ID NO 48           Region                                 B. SEQ IDs       SEQ ID From Patent       This Specification   Sequence Source   Number 6,531,580               SEQ ID NO 15   Heavy chain CDR1   SEQ ID NO 34: Gly-Phe-Thr-Phe-Ser-Ser-               Tyr-Asp-Met-Ser.               SEQ ID NO 16   Light chain CDR3   SEQ ID NO 90: Gln-Gln-Ser-Gly-Ser-Trp-               Pro-Leu-Thr.               SEQ ID NO 17   Heavy chain CDR2   SEQ ID NO 102: Lys-Val-Ser-Ser-Gly-               Gly-Gly-Ser-Thr-Tyr-Tyr-Leu-Asp-Thr-               Val-Gln-Gly.               SEQ ID NO 18   Heavy chain CDR3   SEQ ID NO 106: His-Leu-His-Gly-Ser-               Phe-Ala-Ser               SEQ ID NO 19   Light chain CDR1   SEQ ID NO 110: Gln-Ala-Ser-Gln-Ser-               Ile-Ser-Asn-Phe-Leu-His               SEQ ID NO 20   Light chain CDR2   SEQ ID NO 112: Tyr-Arg-Ser-Gln-Ser-               Ile-Ser.                  
 
      Preferred antibodies against RSV for use in the formulations and methods of the invention include those with heavy chain peptide sequences including CDR1 SEQ ID NOs 1 or 9, CDR2 SEQ ID NOs 2 or 11, and/or CDR3 SEQ ID NOs 3 or 12; or conservative variations thereof. More preferred antibodies against RSV include heavy chain variable regions with peptide sequence SEQ ID NOs 7 or 14, or conservative variations thereof.  
      Preferred antibodies against RSV for use in the formulations and methods of the invention include those with light chain peptide sequences including CDR1 SEQ ID NOs 4 or 13, CDR2 SEQ ID NO 5, and/or CDR3 SEQ ID NO 6; or conservative variations thereof. More preferred antibodies against RSV include light chain variable regions with a peptide sequence of SEQ ID NOs 8 or 10, or conservative variations thereof.  
      Most preferred antibodies against RSV for use in the formulations and methods of the invention include those with heavy chain peptide sequences including CDR1 SEQ ID NOs 1 or 9, CDR2 SEQ ID NOs 2 or 11, and/or CDR3 SEQ ID NOs 3 or 12; and, with light chain peptide sequences including CDR1 SEQ IDs 4 or 13, CDR2 SEQ ID 5, and/or CDR3 SEQ ID 6; or conservative variations thereof.  
      With regard to antibodies against integrin αvβ3, preferred antibodies for use in the formulations and methods of the invention include those with heavy chain peptide sequences including CDR1 SEQ ID NO 15, CDR2 SEQ ID NO 17, and/or CDR3 SEQ ID NO 18; or conservative variations thereof. Preferred antibodies against αvβ3 include those with light chain peptide sequences including CDR1 SEQ ID NO 19, CDR2 SEQ ID NO 20, and/or CDR3 SEQ ID NO 16; or conservative variations thereof. Most preferred antibodies include heavy chain peptide sequences including CDR1 SEQ ID NO 15, CDR2 SEQ ID NO 17, and CDR3 SEQ ID NO 18; and light chain peptide sequences including CDR1 SEQ ID NO 19, CDR2 SEQ ID NO 20, and CDR3 SEQ ID NO 16; or conservative variations thereof.  
     Example 5  
     Formulations for Spraying with Solvents  
      The data table below describes the formulation combination that was used with the EtOH spray drying process.  
                                                                   Mab:Excips   Process   Powder       Powder   Particle Size   Particle Size           Formulation #   Initial Soln Concs.   Loss   Yield       Density   Dv50   Dv90   Other Exptl.       M493SD-   (% w/v)   (% A)   (% Theor)   MC (%)   (g/mL)   (um)   (um)   Parameters                                                                     1e   8*:2 Sucr:0.5 Arg   0.31   60.7   2.13   —   5.07   11.30   60C Inlet        2   8:1 Sucr:2 Mann   0.22   74.6   2.18   0.32   3.51   6.19   60C Inlet        3   8:2 Mann:0.5 Arg   −0.34   73.9   2.38   0.30   3.51   5.91   60C Inlet        4   8:1 Sucr:2 Mann:0.5 Leu   0.06   65.7   1.42   0.36   3.11   5.66   60C Inlet        5   8:2 Sucr:0.5 Leu   0.09   62.5   2.66   0.31   3.68   6.05   60C Inlet        6   8:2 Sucr:0.5 Arg, 20% EtOH   0.78   54.7   2.32   0.14   4.04   7.31   60C Inlet        7   8:1 Sucr:2 Mann:0.5 Leu + 20% EtOH   0.07   40.0   1.75   0.13   4.30   7.18   60C Inlet        8   8:2 Sucr:0.5 Arg + 30% Water   0.45   49.2       0.38           60C Inlet        9   8:1 Sucr:2 Mann:1 Leu + 20% EtOH   0.14   26.9       0.07           60C Inlet        9b   8:1 Sucr:2 Mann:1 Leu       68.6       0.32           60C Inlet       10   8:1 Sucr:2 Mann:1.5 Leu + 20% EtOH   0.14   23.8       0.04           60C Inlet       11   8:1 Sucr:2 Mann:2 Leu + 20% EtOH   0.13   19.2       0.06           60C Inlet       12a   8:1 Sucr:2 Mann:1 Leu       57.7       0.29           4% Solids, 60C Inlet       12b   8:1 Sucr:2 Mann:1 Leu       46.4       0.28           4% Solids, 90C Inlet       13   8:1 Sucr:2 Mann:1 Leu, 50% EtOH       5.2       0.02           2% Solids, 50% EtOH                 *‘8’ = 8% mAb concentration in formulation             
 
      It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims.  
      While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be clear to one skilled in the art from a reading of this disclosure that various changes in form and detail can be made without departing from the true scope of the invention. For example, all the techniques and apparatus described above can be used in various combinations without undue experimentation.  
      All publications, patents, patent applications, and/or other documents cited in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, patent application, and/or other document were individually indicated to be incorporated by reference for all purposes.