ABSTRACT:
Solubility is an important physicochemical factor affecting absorption of drug and its therapeutic effectiveness. Diacerein (DIA) is a poorly water- soluble anti-inflammatory analgesic and antipyretic drug, developed specially for the treatment of osteoarthritis. Due to the poor solubility of diacerein in water and their low dissolution rate in aqueous G.I.T fluid often leads to insufficient bioavailability. In the present work, an attempt was made to improve the solubility and dissolution rate of a poorly water soluble drug, Diacerein by solid dispersion method using PEG-4000, PEG-6000 and PXM-407 as carriers. Solid dispersions of diacerein were prepared by solvent evaporation method and melt method separately with varying drug: carrier ratios viz.1:1, 1:2 and 1:3. The formulations were characterized for solubility parameters, percentage drug content, drug release studies and drug-polymer interactions by using saturation solubility studies, assay, invitro dissolution study, DSC, FTIR. All the formulations showed marked improvement in the solubility behavior and improved drug release. The drug content was found to be high and uniformly distributed in the all formulation. No chemical interaction was found between drug and carriers. Solid dispersions prepared by melt method shows faster dissolution of drug than solvent evaporation method. Formulation prepared by melt method containing drug: polymer ratio of 1:3 with PXM-407 showed the best release 97.44% in 70 min as compared to the pure drug i.e. 41.52 % in 120 min. It was concluded that PXM-407 as a carrier can be well utilized to improve the solubility and dissolution rate of poorly soluble drugs.