Abstract:
A method of treating respiratory disorders by delivering antibiotic to the lung alveoli using an aerosol drug delivery system.

Description:
[0001]     This application claims priority from co-pending U.S. provisional application No. 60/811672 filed on Jun. 7, 2006. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention is directed to a method of treating respiratory disorders by delivering antibiotic to the lung alveoli.  
         [0003]     Known aerosol drug delivery systems include, for example, a unit dose dry-powder inhaler, a dry powder pulmonary device, a pressurized metered dose inhaler, a metered-dose inhaler, a nebulizer, and the like. However, these systems have not been applied to delivery of antibiotics to the lungs to treat cystic fibrosis.  
         [0004]     Some aerosol devices are capable of delivering the smaller droplet sizes needed for deep lung penetration. One commercially available example is the SWIRLER® aerosol drug delivery system which is described at amici-inc.com, and in U.S. Pat. Nos. 5,603,314, 5,630,409, 5,611,332 and 6,230,703, which patents are incorporated by reference herein.  
         [0005]     As described in greater detail in the aforementioned patents, the SWIRLER® aerosol drug delivery system is an aerosol inhalation device that provides an aerosol mist to a patient. This device includes a nebulizer having a liquid reservoir containing the liquid to be inhaled, a gas inlet for receiving pressurized gas, and an aerosol outlet. An important feature of the device is a gas swirling or flow control means which creates a swirling action to the gas forming the aerosol; this produces a greater shear force and smaller particle sizes. The swirling gas creates a vacuum as it exits the outlet and this vacuum draws liquid form the reservoir, producing an aerosol. The device is capable of producing aerosol particles less than one micrometer in size.  
         [0006]     ZOSYN® is an injectable antibacterial combination product consisting of the semi-synthetic antibiotic piperacillin sodium and the (beta)-lactamase inhibitor tazobactam sodium for intravenous administration. The product is disclosed in U.S. Pat. Nos. 4,562,073, 4,477,452, 4,534,977, and 6,207,661.  
         [0007]     Piperacillin sodium is derived from D(−)-(alpha)-aminobenzyl-penicillin. The chemical name of piperacillin sodium is sodium (2S ,5R ,6R)-6-[(R)-2-(4-ethyl-2,3-dioxo-1-piperazine-carboxamido)-2-phenylacetamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate. The chemical formula is C 23  H 26  N 5  NaO 7 S and the molecular weight is 539.5. The product is disclosed in U.S. Pat. No. 4,562,073.  
         [0008]     The chemical structure of piperacillin sodium is:  
                         
 
         [0009]     Tazobactam sodium, a derivative of the penicillin nucleus, is a penicillanic acid sulfone. Its chemical name is sodium (2S ,3S ,5R)-3-methyl-7-oxo-3-(1H -1,2,3-triazol-1-ylmethyl)-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate-4,4-dioxide. The chemical formula is C 10 H 11  N 4  NaO 5  S and the molecular weight is 322.3. The product is disclosed in U.S. Pat. No. 4,958,020.  
         [0010]     The chemical structure of tazobactam sodium is:  
                         
 
         [0011]     TYGACIL® (tigecycline) is a first in class glycylcycline antibacterial disclosed in U.S. Pat. No. 5,494,903. The chemical name of tigecycline is (4S,4aS,5aR, 12aS)-9-[2-(tert-butylamino)acetamido]-4,7-bis(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2-naphthacenecarboxamide. The empirical formula is C 29 H 39 N 5 O 8  and the molecular weight is 585.65. It is a 9-tert-butyl-glycylamido derivative of monocycline which exhibits antibiotic activity typical of tetracyclines, but has more potent activity against tetracycline-resistant organisms having efflux and ribosomal protection mechanisms of resistance. Tigecycline has an expanded spectrum of activity against gram positives, gram negatives, anaerobes, and atypicals including resistant pathogens, and allows for flat dosing. The product is disclosed in U.S. Pat. Nos. 5,494,903, 5,299,900, and 5,284,963.  
         [0012]     The following represents the chemical structure of tigecycline:  
                         
 
         [0013]     There exists a need for a method of delivering antibiotics to the lungs to treat cystic fibrosis and other respiratory disorders.  
       SUMMARY OF THE INVENTION  
       [0014]     These and other embodiments are provided for by the invention disclosed and claimed herein.  
         [0015]     The present invention relates to a method of treating respiratory disorders comprising administering an antibiotic aerosol to a mammal via an aerosol drug delivery system wherein the aerosol drug delivery system produces an antibiotic particle size of at least about 90%, preferably at least about 95%, of the particles in the aerosol of about 1-3 microns or less, thereby allowing the antibiotic aerosol to reach the alveoli of the lung. In another embodiment the antibiotic is delivered at a particle size of less than 1.1 microns.  
         [0016]     The method above is used for treating a respiratory disorder such as, but not limited to, cystic fibrosis.  
         [0017]     The aerosol drug delivery system can be for example a unit dose dry-powder inhaler, a dry powder pulmonary device, a pressurized metered dose inhaler, a metered-dose inhaler, a nebulizer, or any suitable aerosol drug delivery system as described in Guidelines for the Diagnosis and Management of Asthma, National Asthma Education and Presentation Program, Clinical Practice Guidelines, Table 6-3 Aerosol Delivery Devices, www.ncbi.nlm.nih.gov/books, hereby incorporated by reference; and Adkinson: Middleton&#39;s Allergy: Principles and Practice, 6th ed., chapter 46-Aerosols, pages 759-772, hereby incorporated by reference.  
         [0018]     For delivery the antibiotic aerosol may comprise an antibiotic and a diluent. The diluent can be for example sterile water for Injection, 0.9% sodium chloride for injection, 5% dextrose for injection, 5% dextrose and 0.9% sodium chloride for injection, 5% dextrose in lactated Ringers for injection, 5% dextrose-0.45% sodium chloride-0.15% potassium chloride for injection and lactated Ringers for injection. The antibiotic aerosol comprises a particle size range of 600 particles of ≧25 microns and not more than 6000 particles ≧10 microns.  
         [0019]     Antibiotics of the present invention include anti-infective agents known in the art, such as those found in the current Physician&#39;s Desk Reference published by Medical Economics Company (www.pdr.net) and hereby incorporated by reference, and include but are not limited to ZOSYN®, Piperacillin, Tazobactam, and TYGACIL®. The antibiotic can be administered alone or in combination with other antibiotics. At least one of the antibiotics is administered in an aerosol medium composition. Additional antibiotics may be administered orally, or by intralesional, intraperitoneal, intramuscular or intravenous injection; infusion; liposome-mediated delivery; topical, nasal, anal, vaginal, sublingual, uretheral, transdermal, intrathecal, ocular or otic delivery. In order to obtain consistency in providing the compound of this invention it is preferred that a compound of the invention is in the form of a unit dose. Suitable unit dose forms include tablets, capsules and powders in sachets or vials. Such unit dose forms may contain from 0.1 to 300 mg of a compound of the invention, and preferably from 2 to 100 mg. Still further preferred unit dosage forms contain 5 to 50 mg of a compound of the present invention. The effective amount will be known to one of skill in the art; it will also be dependent upon the form of the compound. One of skill in the art could routinely perform empirical activity tests to determine the bioactivity of the compound in bioassays and thus determine what dosage to administer.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     The present invention relates to an aerosol medium composition containing an antibiotic. The aerosol medium composition may comprise diluents such as sterile water for Injection, 0.9% sodium chloride for injection, 5% dextrose for injection, 5% dextrose and 0.9% sodium chloride for injection, 5% dextrose in lactated Ringers for injection, 5% dextrose-0.45% sodium chloride-0.15% potassium chloride for injection or lactated Ringers injection.  
         [0021]     The antibiotic is suspended in the aerosol medium at a particle size range that will meet the subvisible particulate testing acceptance criteria as per USP 788 viz. not more than 600 particles≧25 microns and not more than 6000 particles≧10 microns.  
         [0022]     The aerosol drug delivery system described herein can be but is not limited to delivery in small, disposable, unit dose dry-powder inhalers (DPI&#39;s), dry powder pulmonary devices, pressurized metered dose inhalers (pMDI&#39;s), metered-dose inhaler (MDI) or a nebulizer.  
         [0023]     When used herein, the term “about” shall generally mean within 20 percent.  
         [0024]     It will be understood by those with skill in the art that the invention may be performed within a wide and equivalent range of conditions, parameters and the like, without affecting the spirit or scope of the invention or any embodiment thereof. The following non-limiting examples illustrate certain aspects of the present invention.  
         [0000]     Experimentals  
         [0025]     Piperacillin (2 g-4 g lyophilized powder per vial) and at least one intravenous diluent, for example but not limited to sterile water for injection, 0.9% sodium chloride injection, 5% dextrose injection, 5% dextrose and 0.9% sodium chloride injection, 5% dextrose in Lactated Ringers injection, 5% dextrose-0.45% sodium chloride-0.15% potassium chloride injection or lactated Ringers injection will be administered using an aerosol drug delivery system at a particle size of 95% particles ranging from 1-3 microns, and preferably less than 1.1 microns, to ensure deep lung delivery to the alveolar region of the lungs.  
         [0026]     Tazobactam (0.25 g-0.50 g lyophilized powder per vial) and at least one intravenous diluent, for example but not limited to sterile water for injection, 0.9% sodium chloride injection, 5% dextrose injection, 5% dextrose and 0.9% sodium chloride injection, 5% dextrose in Lactated Ringers injection, 5% dextrose-0.45% sodium chloride-0.15% potassium chloride injection or lactated Ringers injection will be administered using an aerosol drug delivery system at a particle size of 95% particles ranging from 1-3 microns, and preferably less than 1.1 microns, to ensure deep lung delivery to the alveolar region of the lungs.  
         [0027]     ZOSYN® (2-4 g piperacillin plus 250-500 mg tazobactam) and at least one intravenous diluent, for example but not limited to sterile water for injection, 0.9% sodium chloride injection, 5% dextrose injection, 5% dextrose and 0.9% sodium chloride injection, 5% dextrose in Lactated Ringers injection, 5% dextrose-0.45% sodium chloride-0.15% potassium chloride injection or lactated Ringers injection will be administered using an aerosol drug delivery system at a particle size of 95% particles ranging from 1-3 microns, and preferably less than 1.1 microns, to ensure deep lung delivery to the alveolar region of the lungs.  
         [0028]     Tygacil (50 mg lyophilized powder per 5 mL vial) and at least one intravenous diluent, for example but not limited to sterile water for injection, 0.9% sodium chloride injection, 5% dextrose injection, 5% dextrose and 0.9% sodium chloride injection, 5% dextrose in Lactated Ringers injection, 5% dextrose-0.45% sodium chloride-0.15% potassium chloride injection or lactated Ringers injection will be administered using an aerosol drug delivery system at a particle size of 95% particles ranging from 1-3 microns, and preferably less than 1.1 microns, to ensure deep lung delivery to the alveolar region of the lungs.  
       EXAMPLE  
     Tygacil®(Tigecycline) for Deep Lung Delivery  
       [0029]     The commercial Tygacil®2 nd  Generation product was used to conduct the study. Sterile Water for injection and 0.9% Normal Saline were used at diluents. Tygacil® is a sterile, lyophilized powder for intravenous infusion, containing 53 mg of the Tigecycline active ingredient. Tygacil® additionally contains lactose monohydrate as a diluent/stabilizer and hydrochloric acid and/or sodium hydroxide (as needed) for pH adjustment. The product is supplied in a single dose; Type I, clear, glass vial, sealed under a blanket of nitrogen with a gray butyl rubber stopper and a snap-off aluminum crimp seal.  
       The Quantitative Composition of Tygacil® is Depicted in Table 1 Below.  
       [0030]    
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                   
               
               
                 Quantitative Composition for Tygacil ® 
               
             
          
           
               
                   
                 Reference to 
                   
                   
               
               
                 Ingredient 
                 Standards 
                 Function 
                 Quantity per Vial 
               
               
                   
               
               
                 Tigecycline a   
                 In-House 
                 Active 
                  53 mg 
               
               
                   
                 Monograph 
               
               
                 Lactose 
                 NF/Ph. Eur. b   
                 Diluent/ 
                 106 mg 
               
               
                 Monohydrate 
                   
                 Stabilizer 
               
               
                 Hydrochloric Acid 
                 NF/Ph. Eur. 
                 pH Adjustment 
                 Q.S. to adjust pH 
               
               
                 Sodium Hydroxide 
                 NF/Ph. Eur. 
                 pH Adjustment 
                 Q.S. to adjust pH 
               
               
                 Water for 
                 USP/Ph. Eur. 
                 Vehicle 
                 — c   
               
               
                 Injection c   
               
               
                 Nitrogen d   
                 NF/Ph. Eur. 
                 Blanket 
                 Q.S. to 
               
               
                   
                   
                   
                 Headspace 
               
               
                   
               
               
                     a A 6% overage is included to compensate for the non-withdrawable amount of solution after constitution, i.e. solution adhering to the inside wall of the vial.    
               
               
                     b An in-house specification for bacterial endotoxins test is also applied.    
               
               
                     c Removed during lyophilization.    
               
               
                     d Used for sparging and blanketing the bulk solution and as inert cover in the filled vials.    
               
             
          
         
       
     
         [0031]     Prior to reconstitution, Tigecycline for Injection is an orange powder or cake. One (1) vial of Tygacil® was reconstituted using 100 ml of 0.9% Sodium Chloride (Normal Saline) or Sterile Water for Injection USP. The Tigecycline powder was allowed to dissolve in the diluents. A clear yellow to orange solution was obtained. The solution was then transferred into the SWIRLER® device. Oxygen was supplied to the SWIRLER® via an NG tube to aerosolize the solution. An oxygen air pressure regulator was used to set the air pressure to 15 CFM. A Malvern MXS, S/N 6196 was used to measure the particle size of the droplets. Results show a high percentage (90%) of the particles are less than 1.1 micron which is the desired size for deep lung delivery. Data are reported in Table 2 below:  
                                                           TABLE 2                           PARTICLE SIZE DISTRIBUTION OF TYGACIL ®       RECONSTITUTED WITH NORMAL SALINE OR STERILE       WATER FOR INJECTION AND ADMINISTERED       THROUGH A SWIRLER ® FOR DEEP LUNG DELIVERY                Obscuration   D 10   D 50   D 90           (%)   (um)   (um)   (um)                        Water                       Trial 1   32.7   0.38   0.58   0.93       Trial 2   32.7   0.41   0.61   0.99       Trial 3   36.7   0.37   0.56   0.88       0.9% NaCl       Trial 1   28.1   0.42   0.62   1.02       Trial 2   31   0.4   0.6   0.98       Trial 3   33.9   0.4   0.6   0.98       0.9% NaCl + TYG*       Trial 1   27.8   0.41   0.61   1       Trial 2   16.6   0.39   0.59   0.96       Trial 3   14.9   0.38   0.58   0.94       0.9% NaCl + TYG**       Trial 1   28   0.45   0.65   1.11       Trial 2   25.2   0.44   0.64   1.1       Trial 3   30.4   0.44   0.65   1.08       Water + TYG***       Trial 1   32.9   0.42   0.62   1.01       Trial 2   30.6   0.41   0.61   0.99       Trial 3   33.5   0.41   0.61   1                 *100 ml of 0.9% Sodium Chloride (Normal Saline) was used to dissolve 50 mg (1 vial) of Tygacil ®           **100 ml of 0.9% Sodium Chloride (Normal Saline) was used to dissolve 100 mg (2 vials) of Tygacil ®           ***100 ml of Sterile Water for Injection (USP) was used to dissolve 50 mg (1 vial) of Tygacil ®            
 
         [0032]     Many variations of the present invention not illustrated herein will occur to those skilled in the art. The present invention is not limited to the embodiments illustrated and described herein, but encompasses all the subject matter within the scope of the appended claims.