Pharmaceutical Compositions having a Selected Release Duration

A pharmaceutical composition comprising:

• a) a combination of leuprolide mesylate and leuprolide acetate, wherein the molar ratio of (mesylate+acetate) to leuprolide is ≤2:1 and the molar ratio of mesylate anion to leuprolide is from 1:1 to 2:1;
• b) a biodegradable polymer selected from the group of a homopolymer polylactide or polylatic acid, and a copolymer poly (lactic acid-co-glycolic acid) or poly (lactide-co-glycolide), wherein the ratio of lactide:glycolide (or lactic acid:glycolic acid) of the copolymer is from 50:50 to 100:0;
• and
• c)N-methyl-2-pyrrolidone (NMP);
• wherein the pharmaceutical composition having a selected release duration ranging from one month to 6 months can be prepared by varying the ratios of mesylate to leuprolide.

A pharmaceutical composition comprising:

• a) a combination of leuprolide mesylate and leuprolide formate, wherein the molar ratio of (mesylate+formate) to leuprolide is 2:1 and the molar ratio of mesylate anion to leuprolide is from 1:1 to 2:1;
• b) a biodegradable polymer selected from the group of a homopolymer polylactide or polylatic acid, and a copolymer poly (lactic acid-co-glycolic acid) or poly (lactide-co-glycolide), wherein the ratio of lactide:glycolide (or lactic acid:glycolic acid) of the copolymer is from 50:50 to 100:0;
• and
• c) N-methyl-2-pyrrolidone (NMP);
• wherein the pharmaceutical composition having a selected release duration ranging from one month to 6 months can be prepared by varying the ratios of mesylate to leuprolide.