Studies On Salvianolic Acid Controlled Porosity Osmotic Pump Tablets

In this paper the salvianolic acid (SA) was selected as the model drug to prepare the controlled porosity osmotic pump tablets (CPOPT), Lactose and Sucrose were used to make the tablet core. Cellulose acetate (CA), polyethylene glycol 400 (PEG400) and diethylphthalate (DEP) were selected as the coating materials and acetone-isopropylalcohol (80:20) co-solvent was employed as the coating medium. The effects of the dissolution approach, basket rotation speed, the dissolution mediums and the osmotic pressure promoting agent, hardness of tablet core, hydrophobic plasticizer concentration, pore forming agent concentration, coating thickness on the drug release character were investigated.The Artificial Neural Network (ANN) was employed to optimize the SA CPOPT formulation in addition to the Uniform Design. According to the experimental design, drug : osmotic pressure promoting agent rate, the PEG 400 content in the coating solution and coating thickness were selected as the causal factors. The linear correlation coefficient of the accumulative drug release amount and the time in 12h, r (Y1) and the sum of the absolute value between determination value and predicted value (Y2) were used as the evaluation standard to optimize the formulation. The weight expression: Y=(1-Y1)^2+Y2^2. Furthermore the results of the ANN was compared with that of the Uniform Design and the results showed that their optimization ability was almost the same but ANN had the better estimate ability.Determining the content variation of salvianolic acid B in buffers with different pH, temperature and concentration, we investigated that the stability of salvianolic acid B in crude drug.