Formulation optimization study for an immediate-release tablet

A simple method based on statistical analysis was used to optimize an immediate-release tablet formulation that includes a water soluble drug. The objective of this study was to optimize different factors to develop a tablet formulation that has good tablet characteristics (hardness of 85 to 90 Newtons), disintegration time between 3 to 6 minutes, and friability of less than 1%. The critical formulation/process factors were the type and concentration of microcrystalline cellulose, the ratio of lactose to microcrystalline cellulose, the concentration of croscarmellose, and the the compression force. A two-step approach was implemented. First an optimization study was performed to determine the type of microcrystalline cellulose and its ratio to lactose. Subsequently, a final optimization formulation study was performed based on the results obtained in the preliminary study. Data were analyzed using the SPSS 15 (Statistical Software for Social Sciences). The differences in means between the formulation and the targeted product were tested using the independent t-test. The optimization study gave the following results: croscarmellose 1%, anhydrous lactose: Avicel PH-302 at a ratio of 3 to 1, magnesium stearate 0.25% compressed into tablets at a pressure of 2.5 tons. A high P value reflected no statistical difference with the reference product. A final formulation was scaled up to 52 tablets and product quality was confirmed. The new formulation was successfully developed using a simple two-step approach. The results of the study in terms of disintegration, hardness, and friability showed no statistically significant defference between the new and the targeted formulation. Statistical analysis provides a systemic approach and allows a rapid and effective way to compound an immediate-release tablet for a water-soluble drug.