Ion activated bioadhesive in situ gel of clindamycin for vaginal application

Vaginal preparations, although generally perceived as safer most , still they are associated with a number of problems, including multiple days of dosing, dripping, leakage and messiness, causing discomfort to users and expulsion due to the self-cleansing action of the vaginal tract. These limitations lead to poor patient compliance and failure of the desired therapeutic effects. For effective vaginal delivery of antimicrobial agents, the drug delivery system should reside at the site of infection for a prolonged period of time. In our present work, we have developed and optimized a chitosan (bioadhesive and permeation enhancer) and gellan gum (ion activated gelling polymer) based in situ gel system of clindamycin for vaginal application. The developed formulation was characterized for various in-vitro parameters e.g. clarity, refractive index, pH, isotonicity, sterility, viscosity, drug release profile, statistical release kinetics, bioadhesive force, retention time, microbial efficacy, irritation test and stability studies. To simulate vaginal conditions, a synthetic membrane (cellophane hydrated with modified simulated vaginal fluid) and sheep vaginal mucosa were used as model membranes. The developed formulation was found to be non irritant, bioadhesive with good retention properties. Developed formulation shows matrix model release kinetic by PCP disso software. The developed formulation is thus a viable alternative to conventional vaginal dosage forms. Keywords: sol-to-gel system; chitosan; gellan gum; vaginal; clindamycin