Pioglitazone, a widely prescribed anti diabetic drug belongs to class IΙ under BCS and exhibit low and variable oral bioavailability due to its poor aqueous solubility. Its oral absorption is dissolution rate limited and it requires enhancement in the solubility and dissolution rate for increasing its oral bioavailability. The objective of the study is to evaluate the feasibility of formulating pioglitazone –βCD– Poloxamer 407 /PVP K30 inclusion complexes into tablets and to evaluate the effects of βCD, Poloxamer 407 and PVP K30 on the dissolution rate and dissolution efficiency of pioglitazone tablets in 23 factorial study. A comparative evaluation of wet granulation and direct compression methods was made for the preparation of tablets employing drug – βCD – Poloxamer 407 / PVP K30 inclusion complexes. Drug – βCD- Poloxamer 407 / PVP K30 inclusion complexes were prepared by kneading method. Tablets each containing 30 mg of pioglitazone were prepared by wet granulation and direct compression methods employing various βCD complexes as per 23 factorial design and the tablets were evaluated for dissolution rate and other physical properties. Pioglitazone tablets formulated employing dug – βCD – Poloxamer 407 / PVP K30 inclusion complexes and prepared by direct compression method disintegrated rapidly when compared to those made by wet granulation method. Pioglitazone dissolution was rapid and higher from the tablets formulated employing drug- βCD- Poloxamer 407/ PVP K30 inclusion complexes when compared to the tablets containing pioglitazone alone in both wet granulation and direct compression methods. The individual as well as combined effects of the three factors involved i.e., βCD ( factor A), Poloxamer 407 ( factor B) and PVP K30 ( factor C) were highly significant (P< 0.01) in enhancing the dissolution rate (K1) and dissolution efficiency (DE 30) of pioglitazone in both wet granulation and direct compression methods. Among the three factors Poloxamer 407 (factor B) gave highest enhancement in the dissolution rate (K1) and dissolution efficiency (DE 30) of pioglitazone tablets in both wet granulation and direct compression methods. βCD alone gave low dissolution rates in both wet granulation and direct compression methods. Combination of βCD with Poloxamer 407 or PVP K30 gave a significantly higher dissolution rate (K1) of pioglitazone in both wet granulation and direct compression methods. Overall direct compression method gave higher dissolution rates (K1) and dissolution efficiency (DE 30) values than the wet granulation method in all the cases. Hence Poloxamer 407 alone or a combination of βCD with either Poloxamer 407 or PVP K30 is recommended to enhance the dissolution rate and efficiency of pioglitazone tablets. Direct compression method was more suitable to prepare pioglitazone tablets with rapid disintegration and dissolution characteristics employing drug- βCD - Poloxamer 407 / PVP K30 inclusion complexes.
