Chiang Mai Journal of Science

Production of composites of mefenamic acid (MEF) and polyethylene glycol (PEG 4000) by the Gas Anti-Solvent (GAS) technique can be used to modify the dissolution rate of this poorly water-soluble drug. It was found that when using a dichloromethane and ethanol ratio of 80:20 %v/v and a mass ratio of drug and polymer of 1.5:3.5 at 45 ฐC, the highest % drug loading (22.83%) was achieved. A reduction in temperature or an increase in drug and polymer concentration yielded slightly smaller size of composite particles. In addition, it was found that the composites exhibited a higher dissolution rate than the MEF precipitated by the GAS process and could dissolve completely within 3 hours. However, the dissolution rate of the composites was lower than that of the physical mixture of MEF and PEG 4000. This could be attributed to the larger particle sizes of the composites compared to those of the physical mixture, less efficient wetting and lower degree of powder dispersion by PEG in the composites.