TY - JOUR TI - Antimicrobial and rheological properties of benzoyl peroxide formulated polycarbophil/carbomer 934P hydrogel DO - https://doi.org/doi:10.7282/T3K935MR PY - 2014 AB - BACKGROUND: The human vagina is colonized by a variety of indigenous microflora; in healthy individuals Lactobacillus is a predominant bacterial genus while those with bacterial vaginosis (BV) carry a variety of anaerobic bacteria. The disruption of healthy microflora and shift to primarily facultative anaerobic bacteria leads to microbial disease. Benzoyl peroxide (BPO) is chosen as a new antimicrobial agent since it is listed as safe for use in bleaching in food product and as an active ingredient of acne topical treatments. Polycarbophil/Carbomer 934P are chosen to be the network polymers of the hydrogel to encapsulate BPO, due to their good muco-adhesion. EXPERIMENTS: In this study, the antimicrobial activity of BPO against Gardnerella vaginalis, one of the primary causative agent of BV, and their safety for vaginal lactobacilli such as L. acidophilus, L. gasseri, L. plantarum, and L. vaginalis is evaluated using a well diffusion assay, direct contact assay and diffusible agent assay. The rheological properties of the formulations are measured using an oscillation frequency sweep, an oscillation shear stress sweep and a flow shear rate experimental design. RESULTS: It is shown that in the well diffusion assay G. vaginalis is inhibited at 0.01% (w/w) hydrogel-encapuslated BPO and that the tested Lactobacillus spp. are inhibited at 2.5%. In direct contact assays (cells grown in a liquid culture containing hydrogel, hydrogel containing 1.0% BPO or BPO particles), hydrogels loaded with 1.0% BPO caused 6-log reduction of G. vaginalis. Conversely, three of the lactobacilli spp. are not inhibited while L. acidophilus growth is delayed. Encapsulation of BPO into polycarbophil/Carbomer 934P hydrogel improves its antimicrobial activity against G. vaginalis. The rheological properties of the hydrogel formulation are not greatly compromised by encapsulation of 1.0% BPO. The new formulation still possesses a solid-like behavior, with a low yield stress and a high viscosity after diluted. CONCLUSION: Hydrogel containing BPO can be a new drug in BV treatment based on its antimicrobial activity on BV-associated pathogen/not on healthy vaginal lactobacilli when it is encapsulated into polycarbophil/Carbomer 934P hydrogel, and its good rheological properties. KW - Food Science KW - Vagina--Diseases--Treatment KW - Shear flow KW - Benzene in the body KW - Colloids LA - eng ER -