Comparative studies on effect of some hydrophilic polymers onthe dissolution rate of a poorlywater soluble drug, meloxicam

In the present investigation, effect of hydrophilic polymers like gum karaya (GK), modified gum karaya (MGK), guar gum (GG), xanthan gum (XG), hydroxypropyl methylcellulose (HPMC) and sodium carboxy methylcellulose (NaCMC) on the in vitro dissolution rate of a poorly water soluble drug, meloxicam (MX) was investigated. Solid mixtures of drug with each polymer were prepared by using three different methods (physical mixing, co-grinding and kneading) in four different ratios (1:1, 1:4, 1:9 and 1:19 w/w; drug:polymer). Viscosity and swelling studies were performed for all the polymers to explain the results. Low polymer-drug ratio was found to be suitable for improving dissolution rate of MX from solid mixtures particularly containing high viscosity carriers. The method of preparation of the solid mixtures was found to have marked influence on the improvement of dissolution rate of MX. It is suggested that co-grinding method is suitable for the preparation of solid mixtures using carriers of high viscosity. The order of polymers according to their effect on improvement of dissolution rate is GGdissolution rate of MX.