Influence of Wetting Factors on the Dissolution Behavior of Flufenamic Acid

The effects of surfactant, particle size, and additives on the dissolution rate of flufenamic acid (FFA) were evaluated in relation to the time course of the available surface area (S (t) ). The ratios of S (t) generated by time t to the total S (t) generated during the dissolution process (F (t)), obtained from the dissolution rate study, were well regressed to the Weibull probability distribution functions. By using the probability parameters obtained, it was possible to elucidate the influence of these factors on the surface characteristics of FFA quantitatively. When the concentration of the surfactant employed was below the critical micelle concentration (cmc), the initial S (t) generated was significantly increased as the surfactant concentration of the dissolution medium increased. Above the cmc, however, the increase was not so marked. The micronization of particles has a significant enhancing effect on the S (t) generated when the surfactant concentration in the dissolution medium was at cmc. The influence of numerous additives on the dissolution rate of FFA and the S (t) generated is also described.