Stability of Compounded Ursodiol Suspensions in PCCA Base, SuspendIt

Ursodiol (ursodeoxycholic acid) is a nontoxic, naturally occurring bile acid that constitutes 1% to 2% of human bile. It suppresses hepatic synthesis of cholesterol, aids in the desaturation of biliary cholesterol, and aids in the dissolution of cholesterol gallstones. Ursodiol is commercially available as a 300-mg capsule and a 250-mg tablet. However, no commercial liquid dosage form of ursodiol exists. An extemporaneously compounded suspension from pure drug powder or commercial tablets/capsules would provide an alternative option to meet unique patient needs. The purpose of this study was to determine the physicochemical stability of extemporaneously compounded ursodiol suspensions in PCCA base SuspendIt. This base is a sugar-free, paraben-free, dye-free, and gluten-free thixotropic vehicle containing a natural sweetener obtained from the monk fruit. It thickens upon standing to minimize settling of any insoluble drug particles and becomes fluid upon shaking to allow convenient pouring during administration to the patient. The study design included two ursodiol concentrations to provide stability documentation over a bracketed concentration range for eventual use by compounding pharmacists. A robust, stability-indicating high-performance liquid chromatographic assay for the determination of the chemical stability of ursodiol in SuspendIt was developed and validated. Suspensions of ursodiol were prepared in SuspendIt at 50-mg/mL and 100-mg/mL concentrations, selected to represent a range within which the drug is commonly dosed. Samples were stored in plastic amber prescription bottles at two temperature conditions (5°C and 25°C). Samples were assayed initially and at the following time points: 7 days, 14 days, 30 days, 42 days, 59 days, 91 days, 120 days, and 181 days. Physical data such as pH, viscosity, and appearance were also noted. All measurements were obtained in triplicate. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period. The study showed that ursodiol concentration did not go below 97% of the label claim (initial drug concentration) at both temperatures studied. Viscosity and pH values also did not change significantly. This study demonstrates that ursodiol is physically and chemically stable in SuspendIt for 181 days in the refrigerator and at room temperature, thus providing a viable, compounded alternative for ursodiol in a liquid-dosage form, with an extended beyond-use-date to meet patient needs.