The influence of formulation variables on stability and microbicidal activity of monoglyceride monocaprin

Several fatty acids and monoglycerides have been found to possess potent in vitro microbicidal activity against enveloped viruses and bacteria. It has been suggested that pharmaceutical formulations containing microbicidal lipids could be used to prevent transmission of pathogens to mucosal membranes or for the treatment of established mucosal or skin infections caused by a virus, a bacterium or a fungus. The aim of this work was to evaluate the effect of formulation variables on the stability and microbicidal activity of the lipid monocaprin, the 1-monoglyceride of capric acid, in solutions and hydrogels. Activity against herpes simplex virus type 1 (HSV-1) was used as a model for the microbicidal activity of the formulations. The results indicate that the presence of carbomer 974P (0.65%) in the formulations improves the stability of the monoglyceride. Increased amounts of the surfactant polysorbate 20 in the solutions reduces the microbicidal activity of monocaprin.