Controlled Release Binary and Ternary HPMC-HPC-Gelucire® 50/13 Hybrids Based Solid Dispersions of Indomethacin: In vitro Evaluation and In vivo Anti-inflammatory Studies

Abstract

Aim: The aim of this study is to formulate and evaluate solid dispersions of indomethacin based on Gelucire 50/13, Hydroxylpropyl methylcellulose and/or Hydroxylpropyl cellulose hybrid binary or ternary system, with a view of enhancing oral bioavailability, sustaining drug release with optimum anti-inflammatory activity and minimal side effects. Methodology: Solid dispersions were prepared by solvent-evaporation method at varying polymer ratios (with HPMC and Gelucire 50/13 at 1:1, 2:1, 3:1, 4:1, 1:2, 1:3, 1:4 and HPMC, HPC and Gelucire 50/13 at 1:1:1) with a constant concentration of indomethacin (100 mg). The formulations were characterized in terms of morphology, stability and drug content. The release profiles of indomethacin from the solid dispersions were examined in vitro using two different media i.e. SGF and SIF, without enzymes. The anti-inflammatory properties were evaluated. Results: The formulated solid dispersions were stable and almost spherical to irregularly-shaped. The drug content of the formulations was accepted according to the Pharmacopoeial limit. In vitro dissolution studies showed an increased dissolution rate at pH 7.4 compared to pH 1.2 for the various batches with solid dispersions showing a faster and sustained dissolution rate than the pure crystalline drug. The percentage inhibitions of edema produced by the formulations in the in vivo studies were significantly higher and sustained than the pure drug. Conclusion: Solid dispersions prepared with these biodegradable polymer hybrids, HPMC/HPC/Gelucire® 50/13, showed promising potential in clinical practice for enhancing the delivery of indomethacin.