Antimicrobial preservatives are substances that are added into formulation or product to prevent microbial spoilage and thus,
prolong the product shelf-life. Our preliminary study indicated ethanolic extract of Syzygium malaccense leaf (SmL) exhibited
antimicrobial activity via the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) test.
SmL was then incorporated into a formulated topical application product before being subjected to a preservative efficacy test.
Microbial preservative efficacy of SmL at 0.25% (w/v) and 0.5% (w/v) were evaluated against Staphylococcus aureus,
Pseudomonas aeruginosa, Escherichia coli, and Candida albicans for the duration of 28 days. Euxyl-K300 (0.5%, w/v)), a
synthetic chemical preservative was used as positive control in the study. The preservative efficacy study showed that both the
0.25% (w/v) and 0.5 % (w/v) of SmL exhibited inhibitory activity against S. aureus on the 7 day and against C. albicans on the
21 day. The SmL has the potential to be developed as antimicrobial preservative agent in the topical application products.