Stability of Fagron's Phytobase Cream Compounded with Various Hormones

The objective of this study was to evaluate the stability of 5 common hormones used as active pharmaceutical ingredients in Fagron Phytobase cream. The active pharmaceutical ingredients were tested using a bracketed format, as well as individually, and in one combination: estrone 0.1%, estrone 1%, estradiol 0.05%, estradiol 2%, estriol 0.05%, estriol 2%, progesterone 0.1%, progesterone 20%, testosterone 0.1%, testosterone 20%; combination (estradiol 0.05%, estriol 0.05%, progesterone 0.5%), and combination (estradiol 2%, estriol 1%, progesterone 20%). All creams were stored at controlled room temperature (20ÆC to 25ÆC) in a Topi-CLICK container-closure. Stability was assessed by measuring the percent recovery at varying time points throughout a 180-day period. Active pharmaceutical ingredients' quantifications were performed by highperformance liquid chromatography via a stabilityindicating method. Antimicrobial effectiveness testing per United States Pharmacopeia Chapter <51> guidelines was carried out for each compounded formulation. Given the percent recovery of the active pharmaceutical ingredients within the cream base, the beyond-use date was determined to be 180 days in all samples except estrone, which was determined to be 150 days. This suggests that Phytobase cream is able to maintain the stability of various compounded hormones in the base over an extended time of storage.