Microbiological Stability of Allopurinol, Clindamycin Hydrochloride, Naltrexone Hydrochloride, Spironolactone and Ursodiol Oral Liquids Compounded in PCCA Base, SuspendIt®.

Abstract

The individual physicochemical stabilities of Allopurinol, Clindamycin Hydrochloride, Naltrexone Hydrochloride, Spironolactone and Ursodiol in the proprietary suspending vehicle PCCA SuspendIt® have been previously studied and published by the author. Accordingly, Beyond-Use-Dates (BUDs) of 180 days were assigned to the five drugs based on the results of the respective studies. The data were donated to the United States Pharmacopeia (USP) for possible adoption as Official Compounded Drug Monographs. Following an extensive review process, all five studies were approved and published by the USP. However, due to a lack of microbiological stability information, the BUDs were limited to 90 days. The current study was undertaken as a follow-up project to determine the microbiological stability of these five drugs in PCCA SuspendIt® utilizing the same compounding procedures from the original studies. A stable extemporaneous product is defined as one that retains at least 90% of the initial drug concentration throughout the sampling period and is protected against microbial growth. The goal was to provide a viable, compounded alternative for Allopurinol, Clindamycin Hydrochloride, Naltrexone Hydrochloride, Spironolactone and Ursodiol in a thixotropic liquid dosage form, with an extended BUD of 6 months to meet patient needs. Given that the physical and chemical stabilities of all five drugs have been previously established and adopted by the USP as official compounded monographs, additional microbiological stability data would allow the official BUDs in the USP to be extended to 180 days to conform to the physicochemical stabilities. The current study showed that the preservative system in PCCA SuspendIt® successfully protected all the suspensions from growth of challenge microorganisms per the USP Chapter <51> AME Test. The results of the current study combined with the previous physicochemical studies demonstrate the following: Allopurinol is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature over a bracketed allopurinol concentration range of 10 - 20 mg/mL. Clindamycin Hydrochloride is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature at a concentration of 10-mg/mL of clindamycin. Naltrexone Hydrochloride is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature, over a bracketed naltrexone hydrochloride concentration range of 0.5 - 5.0 mg/mL. Spironolactone is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature at a concentration of 5 mg/mL of spironolactone. Ursodiol is physically, chemically and microbiologically stable in PCCA SuspendIt for 180 days in the refrigerator and at room temperature, over a bracketed ursodiol concentration range of 50 - 100 mg/mL. Taken collectively, the current study in conjunction with the earlier studies provide viable, compounded alternatives for Allopurinol, Clindamycin Hydrochloride, Naltrexone Hydrochloride, Spironolactone and Ursodiol in the suspending vehicle PCCA SuspendIt in liquid dosage forms, with an extended beyond-use-date to meet patient needs.