Claims for Patent: 9,012,469

Summary for Patent: 9,012,469

Title:	Crystalline naloxol-peg conjugate
Abstract:	Naloxol-polyethlyene glycol conjugates of the formula: are provided in oxalate or phosphate salt forms including crystalline forms. Methods of preparing the salt forms and pharmaceutical compositions comprising the salt forms are also provided.
Inventor(s):	.ANG.slund; Bengt Leonard (Alderley Park, GB), Aurell; Carl-Johan (Alderley Park, GB), Bohlin; Martin Hans (Alderley Park, GB), Healy; Eric Thomas (Waltham, MA), Jensen; David Richard (Waltham, MA), Jonaitis; David Thomas (Waltham, MA), Parent; Stephan (Waltham, MA), Sebhatu; Tesfai (Alderley Park, GB), Ymen; Bo Ingvar (Alderley Park, GB)
Assignee:	AstraZeneca AB (Sodertalje, SE) Nektar Therapeutics (San Francisco, CA)
Application Number:	13/823,953
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 9,012,469
Patent Claims:	1. A crystalline oxalate salt of mPEG.sub.7-O-naloxol. 2. A method of producing a naloxol-polyethylene glycol conjugate oxalate salt, wherein the salt comprises an ionic species of mPEG.sub.7-O-naloxol and oxalic acid having the formula: ##STR00008## the method comprising: dissolving mPEG.sub.7-O-naloxol free base in 2 relative volumes of acetonitrile; adding 3 equivalents of water to the dissolved mPEG.sub.7-O-naloxol solution; adding oxalic acid in ethyl acetate to the dissolved mPEG.sub.7-O-naloxol over a period of at least 2 hours to produce a slurry; and filtering the slurry to yield the naloxol-polyethylene glycol conjugate oxalate salt in solid form. 3. A method of producing a naloxol-polyethylene glycol conjugate oxalate salt, wherein the salt comprises an ionic species of mPEG.sub.7-O-naloxol and oxalic acid having the formula: ##STR00009## the method comprising: dissolving mPEG.sub.7-O-naloxol free base in 2 relative volumes of ethanol; adding 8 relative volumes of methyl t-butyl ether to the dissolved mPEG.sub.7-O-naloxol solution; adding oxalic acid in methyl t-butyl ether to the dissolved mPEG.sub.7-O-naloxol over a period of at least 2 hours to produce a slurry; and filtering the slurry to yield the naloxol-polyethylene glycol conjugate oxalate salt in solid form. 4. A naloxol-polyethylene glycol conjugate oxalate salt prepared according to the method of claim 2. 5. A naloxol-polyethylene glycol conjugate oxalate salt, wherein the naloxol-polyethylene glycol conjugate has the formula: ##STR00010## 6. The naloxol-polyethylene glycol conjugate oxalate salt of claim 5, wherein the salt is in a substantially pure crystalline form. 7. The naloxol-polyethylene glycol conjugate oxalate salt of claim 6 wherein the crystalline form exhibits Form A X-ray powder diffraction pattern substantially as that shown in FIG. 2. 8. The naloxol-polyethylene glycol conjugate oxalate salt of claim 6 wherein the crystalline form exhibits Form B X-ray powder diffraction peak d values (.ANG.) comprising 13.2; 7.9; 7.0; 6.6; 6.0; 5.7; 5.2; 5.1; 4.44; 4.39; 3.95; 3.88; 3.63; and 3.43. 9. The naloxol-polyethylene glycol conjugate oxalate salt of claim 8, wherein X-ray powder diffraction peak d values (.ANG.) comprise 13.2; 12.0; 9.7; 9.4; 8.3; 8.2; 7.9; 7.4; 7.0; 6.6; 6.0; 5.7; 5.6; 5.4; 5.2; 5.1; 4.91; 4.86; 4.78; 4.71; 4.48; 4.44; 4.39; 4.17; 4.09; 3.95; 3.91; 3.88; 3.69; 3.63; 3.43; 3.29; 3.14; and 3.01. 10. The naloxol-polyethylene glycol conjugate oxalate salt of claim 6 wherein the crystalline form exhibits Form B X-ray powder diffraction 2.theta. angle peaks at (degrees): 6.72; 11.24; 12.65; 13.44; 14.72; 15.61; 17.01; 17.34; 19.98; 20.21; 22.50; 22.93; 24.53; and 25.99. 11. The naloxol-polyethylene glycol conjugate oxalate salt of claim 6 having a purity of at least about 90%. 12. The naloxol-polyethylene glycol conjugate oxalate salt of claim 6, wherein the salt exhibits a single endothermal peak on differential scanning calorimetry between room temperature and about 150.degree. C., wherein the single endothermal peak maximum occurs between about 91.degree. C. to about 94.degree. C. 13. A pharmaceutical composition comprising the naloxol-polyethylene glycol conjugate oxalate salt of claim 6 and a pharmaceutically acceptable excipient. 14. The pharmaceutical composition of claim 13 formulated for oral administration to a subject.