Formulation and evaluation of a tablet containing pioglitazone HCl microspheres

Solubility is an important physicochemical factor for any drug molecule that affects its absorption along with its therapeutic effectiveness. Drug absorption is predominantly dependent upon its prompt dissolution. In the case of poorly water-soluble drugs, dissolution is the rate-limiting step in the process of drug absorption. Microspheres were prepared by solvent evaporation method using polymers namely Eudragit L100 and Eudragit RL100. Direct compression technique was used for the preparation of tablets. Tablets were prepared with MCC and PVP K-30 as polymers using an 8mm punch on a rotary press machine with a constant force. Microspheres and the prepared tablets were evaluated using various evaluation tests. The prepared microspheres showed >80% entrapment efficiency and percent yield. Batch F3 exhibited the highest drug release up to 98.30%. Fourier transform infrared (FT-IR) studies revealed no drug-polymer interaction. The results of SEM exhibited that the microspheres are spherical in shape with an average size 5 mu m. The result of all batches was within an acceptable limit. F2 batch tablet showed a higher drug release of 98.30% as compared with other batches. It was concluded that microcrystalline cellulose or PVP K-30, when used separately, caused retardation in drug release, whereas when used in combination (1:1) it achieved drug release in a controlled manner.