Use of fluorocarbons for diagnosis and treatment of articular disorders

Methods for the diagnosis and treatment of articular disorders comprising the use of fluorocarbons are disclosed. The methods provide for the introduction of a fluorocarbon into an articular region to replace or augment natural synovial fluid. The introduced fluorocarbons, which may be in various forms including liquids, gels or emulsions, provide articular lubrication and cushioning which is effective for the treatment of disorders such as osteoarthritis and rheumatoid arthritis. Additionally, the methods of the present invention may be used to provide high resolution articular images, reduce articular inflammation and introduce bioactive agents to the articular region.

EXAMPLE 1 
 Preparation of a Suspension of Prednisone in a Fluorochemical Suitable for Administration to an Articular Region To further demonstrate the benefits of the present invention a bioactive preparation was provided in the form of a sol containing prednisone, a synthetic steroid commonly used for the treatment of rheumatoid arthritis. Three milliliters of the following fluorochemical continuous suspension was prepared: Composition 1: 0.38%, w/v, Prednisone (Sigma Chemical Co.) was dissolved into a solution composed of 1,4-dibromo-F-butane (50%,v/v; Exfluor, Austin, Tex.) and NF grade ethyl alcohol (50%,v/v; Spectrum Chemical Co). Fluorochemical Diluent: Perfluorooctylbromide (Atochem, France). An aliquot of composition 1 (60 &mgr;L) was injected with a syringe into a sample of perfluorooctylbromide (PFOB; 3 mL) contained in a 12×100 mm test tube. The tube was capped and the contents gently mixed by inverting the tube. An opalescent submicron sized drug in fluorocarbon suspension was obtained. The particle size distribution of the dispersions was measured using photon correlation spectroscopy (PCS) on a Nicomp 270 photon correlation spectrophotometer (Pacific Scientific). The resulting drug dispersion had an average particle diameter of 60±42 nm. 
 EXAMPLE 2 
 Administration of a Suspension of Prednisone to the Articular Region of a Patient A patient suffering from advanced osteoarthritis in a hip joint is treated using the methods of the present invention. The patient is positioned to facilitate gravitational dispersion of the free flowing bioactive preparation. A small amount (on the order of a few milliliters) of the bioactive preparation described in Example 1 is injected into the articular cavity using a standard syringe and needle. During administration the dispersion of the bioactive preparation in the cavity is monitored by imaging the articular region using conventional radiography. Upon observing complete dissemination of the bioactive preparation throughout the articular region the injection of material is halted and the needle withdrawn. The small particle size and even dispersion of the prednisone in the fluorocarbon serve to optimize the anti-inflammatory and immunosuppressive effects of the bioactive preparation. The process is repeated on the order of once a month for a period of six months in order to maintain an effective therapeutic amount of the bioactive preparation within the articular cavity. 
 EXAMPLE 3 
 Preparation of a Suspension of Paclitaxel in Fluorochemical Suitable for Administration to an Articular Region The versatility of the present invention with respect to the types of articular disorder that may be treated is shown by the formation of a bioactive preparation comprising paclitaxel, a potent anti-neoplastic agent. Three milliliters of the following fluorochemical continuous suspension was prepared: Composition 1: 0.40% w/v of paclitaxel (Sigma Chemical Co.) was dissolved into a solution composed of 1,4-dibromo-F-butane (50%,v/v; Exfluor, Austin, Tex.) and NF grade ethyl alcohol (50%,v/v; Spectrum Chemical Co.). Fluorochemical Diluent: Perfluorooctylbromide (Atochem, France). An aliquot of composition 1 (60 &mgr;L) was injected with a syringe into a sample of perfluorooctylbromide (PFOB; 3 mL) contained in a 12×100 mm test tube. The tube was capped and the contents gently mixed by inverting the tube. An opalescent submicron sized drug in fluorocarbon suspension was obtained. The particle size distribution of the dispersions was measured using photon correlation spectroscopy (PCS) on a Nicomp 270 photon correlation spectrophotometer (Pacific Scientific). The resulting drug dispersion had an average particle diameter of 50±32 nm. 
 EXAMPLE 4 
 Administration of a Suspension of Paclitaxel in Fluorochemical to an Articular Region of a Patient Suffering From Fibrosarcoma The paclitaxel sol formed in Example 3 is used to deliver the drug to bursa of a hip of a patient suffering from fibrosarcoma. Treatment is initiated by imaging the afflicted articular region using MRI to locate a bursa adjacent to and in contact with the tumor. Following preparation and positioning of the patient a needle is used to puncture the bursa. A small amount (on the order of 1 ml) of the bioactive preparation is injected into the bursa while the procedure is monitored. The needle is then withdrawn. This procedure is repeated once a week, alone or in combination with other therapy, until the tumor is eliminated. It will be appreciated that the bioactive preparation provides the high bioavailability and target specificity necessary to aggressively treat the tumor while reducing the inherent toxicity of the paclitaxel. This allows higher doses of the drug to be administered thereby shortening the duration of the treatment and reducing patient discomfort. 
 EXAMPLE 5 
 Preparation of a Submicron Sized Ciprofloxacin Suspension in Fluorochemicals Suitable for Administration to an Articular Region An antibacterial bioactive preparation comprising ciprofloxacin, suitable for use in the present invention, was formed. Specifically, three milliliters of the following submicron sized fluorochemical suspension was prepared: Composition 1: 0.35, w/v, Cyprofloxaxin•HCl (Miles, Inc.) was dissolved in the presence of 100mg Na 2 Co 3 (NF Grade, Spectrum Chemical) into a solution composed of 1,4-dibromo-F-butane (50%,v/v; Exfluor, Austin, Tex.) and NF grade ethyl alcohol (50%,v/v; Spectrum Chemical Co). Fluorochemical Diluent: Perfluorooctylbromide (Atochem, France). An aliquot of composition 1 (90 &mgr;L) was injected with a syringe into a sample of perfluorooctylbromide (PFOB; 3 mL) contained in a 12×100 mm test tube. The tube was capped and gently mixed by inverting the tube. An opalescent submicron sized drug in fluorocarbon suspension was obtained. The particle size distribution of the dispersions was measured using photon correlation spectroscopy (PCS) on a Nicomp 270 photon correlation spectrophotometer (Pacific Scientific). The resulting drug dispersion had an average particle diameter of 55±47 nm. 
 EXAMPLE 6 
 Administration of a Submicron Sized Ciprofloxacin Suspension in Fluorochemicals to a Patient Suffering from a Bacterial Infection of an Articular Region In accordance with the teachings herein, the suspension of Example 5 is adjusted to provide the proper dosing and administered by intra-articular injection to a patient with a bacterial infection of the synovial cavities in the ankle. Small volumes of approximately 0.5 ml or less are used with treatments repeated until the infection is eliminated. The even dispersion of the drug and localized bioavailability ensures the bactericidal efficacy of the preparation while the fluorocarbon reduces the bacterial induced inflammation of the synovium and provides lubrication and cushioning to reduce the discomfort of the patient. 
 EXAMPLE 7 
 Preparation of a Gentamicin Sulfate Reverse Emulsion Suitable for Administration to an Articular Region To demonstrate that a variety of fluorocarbon forms may be used in accordance with the present invention and that relatively hydrophilic drugs may be delivered effectively, three mL of the following reverse emulsion formulation containing Gentamicin was prepared. 0.051% w/v Gentamicin sulfate (Sigma) 1.0% w/v 1,2 Dioleoylphosphatidylethanolamine (DOPE; Avanti) 0.21% w/v Di-olein (Nu-Chek Prep, Elysian, MN) 90% v/v &agr;,&ohgr;-Dibromo-F-butane (Exfluor) 0.09% sodium chloride (Sigma) 0.09% calcium chloride (Sigma) 10% v/v water for injection Dioleoylphosphatidylethanolamine (100 mg) was dispersed in &agr;,&ohgr;-dibromo-F-butane (DBFB; 18 g) with a Vibracell™ sonicator (Sonics Materials, 30 mm o.d. titanium probe) at a power of 100 watts for approximately 1 minute (T&equals;5-10° C.). An electrolyte solution (1.0 mL, 10% v/v) was then added dropwise during sonication. After the addition was complete, the reverse emulsion was sonicated for a total of not less than 10 minutes. The electrolyte solution contained 0.9% w/v NaCl and 0.9% w/v CaCl 2 (2H 2 O). A milky water-in-fluorocarbon emulsion was obtained. Particle size of the emulsions was analyzed via laser light scattering on a Nicomp 270 photon correlation spectrometer (Pacific Scientific). Analysis was by the method of cumulants. Each emulsion sample was first diluted with n-octane since the refractive indices of the continuous and dispersed phases are nearly equal. The resulting reverse water-in-fluorocarbon emulsion had a mean droplet size of about 145±70 nm. The reverse character of the emulsion was established by conductivity and by stability after dilution with a hydrocarbon oil (i.e., n-octane). 
 EXAMPLE 8 
 Administration of a Gentamicin Sulfate Reverse Emulsion to an Articular Region of a Patient Suffering from a Bacterial Infection In keeping with the teachings herein the reverse emulsion of Example 7 is administered to the elbow of a patient suffering from an articular bacterial infection. The elbow is oriented to facilitate dispersion of the bioactive preparation and imaged using ultrasound. A small amount (on the order of 1 ml) of the bioactive emulsion is administered to the articular cavity using a conventional syringe. Alternatively, if the elbow was infected due to trauma or following surgery, administration may take place directly, i.e. by placing the reverse emulsion directly on the exposed articular tissue. In both cases ultrasound may be used to confirm the presence and dispersion of the bioactive emulsion. The method is repeated once after a period of three days to ensure the infection is eradicated. 
 EXAMPLE 9 
 Preparation of a Hydrocarbon-in-fluorocarbon Emulsion Suitable for Administration to an Articular Region To further demonstrate the diversity of the present invention, a hydrocarbon-in-fluorocarbon emulsion suitable for administration to provide articular cushioning and lubrication was prepared. An aliquot of F-Octanes (8.82 g) was titrated with n-hexane until phase separation occurred (1.70 mL). This was indicated by the formation of a cloudy white mixture which upon sitting quickly separated into two clear, colorless phases separated by a distinct interface. 1-(F-octyl)hexadecane (0.68 g) was then added to the mixture and the solution mixed to obtain a clear, colorless single liquid phase. The titration with hexane was continued until the solution took on a bluish tint characteristic of microemulsions containing very small droplets (diameter&lE;100 nm). The system was allowed to equilibrate at 20° C. No indication of phase separation was observed over a 10 day period and the formation of this phase was reversible. The particle size was measured by photon correlation spectroscopy (PCS; Nicomp Model 270 Submicron Particle Sizer) and the number weighted mean diameter determined to be 14.5 nm and relatively monodisperse (standard deviation&equals;±2.7 nm). The fluorocarbon continuous nature of this system was confirmed by the fact that the solution could be diluted with F-octanes without phase separation. When an excess of hydrocarbon (ca 50%, v/v) was added the solution separated into two roughly equivolume clear, colorless liquids with a distinct interface between them. These characteristics were consistent with the formation of 1-(F-octyl)hexadecane micelles into which the hydrocarbon oil had been solubilized. 
 EXAMPLE 10 
 Administration of a Hydrocarbon-in-fluorocarbon Emulsion to the Articular Region of a Patient Suffering from Rheumatoid Arthritis an Articular Region A patient suffering from rheumatoid arthritis in the hips is treated in accordance with the methods of the present invention. Initially, the patient is oriented in a position to facilitate dispersion of the fluorocarbon throughout the articular cavity. The articular region is imaged using conventional radiography. Ten milliliters of the emulsion of Example 9 is prepared in a conventional syringe arrangement. The tip of the needle is positioned within the articular cavity of the hip joint and injection of the emulsion is effected. Images of the area of interest are monitored to determine the spread of the bioactive preparation within the cavity. An effective therapeutic amount of emulsion, enough to augment the natural synovial fluid, is injected. The needle is then removed from the patient. The procedure may be repeated as needed (for example, once a month) for as long as necessary. It will be appreciated that hydrophobic drugs, such as steroids, could be solubilized into the hydrocarbon droplets prior to forming the emulsion. The administered emulsion will provide the desired mechanical support as previously described in addition to reducing the synovial inflammation. 
 EXAMPLE 11 
 Preparation of a Drug-containing Hydrocarbon-in-fluorocarbon Emulsion Suitable for Administration to an Articular Region To further demonstrate the ability of the present invention to effectively deliver a wide spectrum of bioactive agents to an articular region, the following bioactive preparation was formed: An aliquot of F-Octanes (8.82 g) was titrated with methyl salicylate (a bioactive agent) until phase separation occurred (10-20 &mgr;L). 1(F-hexyl)tetradecane (1.04 g) was then added to the mixture and the solution mixed to obtain a clear, colorless single liquid phase. The titration with methyl salicylate was continued until the solution took on a bluish tint characteristic of microemulsions containing very small droplets (diameter&lE;100 nm). The system was allowed to equilibrate at 20° C. and the particle size measured by photon correlation spectroscopy (PCS; Nicomp Model 270 Submicron Particle Sizer). The number weighted mean diameter was measured to be 9.0 nm (standard deviation&equals;±0.8 nm). These characteristics were consistent with the solubilization of methyl salicylate by 1(F-hexyl)tetradecane (F6H14) micelles. 
 EXAMPLE 12 
 Administration of a Drug-containing Hydrocarbon-in-fluorocarbon Emulsion to an Articular Region A patient is treated to reduce the pain and inflammation associated with a hyperextended knee. The articular region is imaged using conventional radiography to locate the synovial cavity nearest the site of inflammation. Approximately half a milliliter of the hydrocarbon-in-fluorocarbon bioactive emulsion described in Example 11 is administered to the suprapatellar synovial bursa of a patient. Insertion of the needle and introduction of the bioactive preparation is monitored through the real time radiographic images. The incorporated methyl salicylate acts to reduce the pain associated with a hyperextended knee while, at the same time, the fluorocarbon emulsion acts to reduce the inflammation in the area of the kneecap and lubricates the quadriceps femoris tendon. Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the spirit or central attributes thereof. In that the foregoing description of the present invention discloses only exemplary embodiments thereof, it is to be understood that other variations are contemplated as being within the scope of the present invention. Accordingly, the present invention is not limited to the particular embodiments which have been described in detail herein. Rather, reference should be made to the appended claims as indicative of the scope and content of the present invention.