Non-aqueous injectable formulation preparation with pH adjusted for extended release of somatotropin

A method of making a composition of matter comprising somatotropin (ST), a pH-adjusting constituent (PAC), and a substantially non-aqueous hydrophobic carrier;

• the method comprising:
• a) mixing an aqueous ST solution or slurry with a PAC to produce a pH-adjusted ST, lyophilizing the pH-adjusted ST, and suspending the lyophilized pH-adjusted ST in a substantially non-aqueous hydrophobic carrier;
• wherein the pH of the ST solution or slurry is greater than or equal to about 10, and wherein the PAC comprises an acid, an acid salt, or a mixture of an acid and an acid salt;
• or,
• b) providing the ST as a dry solid and the PAC as a dry solid, and suspending the dry solid ST and dry solid PAC in a substantially non-aqueous hydrophobic carrier, wherein the dry solid ST is obtained, by lyophilization, from an alkaline, aqueous ST solution or slurry;
• wherein the PAC is present in the composition in an amount effective to maintain the pH of the composition ST at or near to the isoelectric point (pI) of the ST, at such time as the composition becomes aqueous;
• and
• wherein the composition is suitable for parenteral administration to a mammal.