Polymer and drug containing compositions and method of preparing suchcompositions are disclosed. The dispersed phase formulation has a polymer, apharmaceutically or biologically active agent and a small fraction of low pKaacid additive. Stable, filter sterilizable, non-gelling solutions containingGnRH analogues at least at levels typically used in sustained releaseformulations and a method of increasing solubility of a high level of a GnRHanalogue or a freeze-dried antagonist of GnRH in a polymer containing solutionare also disclosed. The amount of the acid additive in the polymer solution issuch that it is sufficient to increase the solubility of the high level of theGnRH analogue in the polymer solution without affecting the releasecharacteristics of the microspheres prepared therefrom.
