In this article, morphology of proges-terone polymorphs prepared by polymer-inducedheteronucleation (PIHn) technique was studied. Hy-droxypropyl methylcellulose(HPMC), such as dex-tran T-500 and gelatin G-9382, polyisoprene (PI), andacrylonitrile/butadiene copolymer (NBR) were usedas substrates. The crystallizations were performedby solvent evaporation at room temperature from0.5, 10, and 40 mg/ml solutions in chloroform andacetone. Progesterone polymorphs were identified byX-ray diffraction. Differential scanning calorimetryand total attenuated reflectance infrared spectroscopywere used as complementary techniques in the iden-tification. Depending on the polymeric matrix andthe concentration used, form 1, form 2, or mixtureof both polymorphs were obtained. Scanning elec-tron microscopy pictures evidenced difference in mor-phology and in homogeneity of the two progesteronepolymorphs. These polymorphs prepared by PIHn,did not present a distinctive morphology that allowsidentifying polymorph by its crystal habit. Hence,polymeric matrix induced the crystallization, affect-ing polymorphism and morphology.
