Formulation Optimization of Vitamin C Vaginal Bioadhesive Sustained-release Tablets by Central Composite Design

Objective:To prepare vitamin C vaginal bioadhesive sustained-release tablets,to investigate the influencing factors on their release and bioadhesive profiles and to apply central composite design to optimize their formulation.Methods:The sustained-release tablets were prepared by using hydroxypropyl methyl cellulose(HPMC) as the matrix material and carbopol as the bioadhesive material.The biohensive force of the tablets was measured by self-made device,and the release profiles of the tablets prepared based on different formulations were evaluated by similarity factor method.The optimal formulation was predicted by using the bioadhesive force and total release score as indicators,and the amounts of HPMC and carbopol as factors via multiple linear regression and binomial fitting.Results:The optimal formulation was obtained by the predictive analysis.The observed and predicted values of the indicators for the tablets prepared with the optimal formulation were closely fitted.Conclusion:The application of central composite design in optimization of the formulation of vitamin C vaginal bioadhesive sustained-release tablets is practicable.