Development and evaluation of a suppository formulation containing Lactobacillus and its application in vaginal...

Lactobacillus has long been considered the protective flora in the vagina that displaces and kills vaginal pathogens. Lactic acid, H2O2, and antibacterial agents such as lactocin and bacitracin produced by Lactobacillus act against the vaginal pathogens. The first objective of this research was to develop a local application pharmaceutical formulation of a vaginal suppository containing lyophilized culture of Lactobacillus. The second objective was to establish its in vivo performance by developing in vitro methods of evaluation. Lyophilized culture of Lactobacillus sporogenes was selected for this study. Three formulations of the suppositories were prepared by the molding method. Formulations I, II, and III contained cocoa butter, glycerinated gelatin, and PEG 1000 base, respectively. The prepared suppositories were characterized for physical properties. Assembly to simulate the application site was designed. Methods to evaluate the viability, production of lactic acid, and H2O2 produced by the released Lactobacillus at the application site were developed and the antagonistic activity was demonstrated. From the physical characteristics of the suppository formulations, the glycerinated gelatin suppository (formulation II) containing lyophilized Lactobacillus was found to be satisfactory. The developed assembly was satisfactory in simulating the application site. The Lactobacillus released was viable and exhibited the production of lactic acid, hydrogen peroxide, and antagonistic activity against the uropathogen. The suppository formulation containing Lactobacillus and the methods of its evaluation were successfully developed in this research work and have several applications in the vaginal diseases of women.