Objective: The study was conducted to determine the preservative activity of ethanolic extract of mangosteen (Garcinia mangostana L.) pericarp and its compatibility in an antacid suspension. Methods: The extract was subjected to phytochemical screening and was used as preservative in a formulated antacid suspension. Compatibility with the active pharmaceutical ingredient (API) and excipients were analyzed using fourier transform-infrared spectroscopy. Preservative activity of the formulation against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa was assessed using the United States Pharmacopoeia (USP) antimicrobial effectiveness test, with methylparaben as positive control and suspension without preservative as negative control. Results: The extract exhibited pharmaceutical compatibility with API and excipients. The formulation revealed comparable reduction in microbial count of E. coli, S. aureus, and P. aeruginosa with positive control at Day 14 (p=0.916, 0.624, 0.335). At Day 28, comparable activity with positive control was only observed against E. coli and S. aureus (p=0.999, 0.854). However, it displayed significant increase in activity against P. aeruginosa (p=0.010) at Day 28. These activities may be attributed to glycosides and reducing substances present in the extract. Conclusion The ethanolic extract from Garcinia mangostana L. pericarp acted as a preservative in the formulation of an antacid suspension. It conformed to the USP criteria for antimicrobial effectiveness test on bacteria.
Garcinia mangostana ; Suspensions