The use of the Brouers-Sotolongo fractal kinetic equation for the study of drug release

We have applied the Brouers-Sotolongo fractal kinetic equation (BSf(n,alpha)), improving notably the precision, to nine cases reported recently in the literature on drug release. The reason for using this equation is that it contains as approximations some of the mostly used empirical formula used in that field. Moreover, this equation is now successfully employed for the investigation of sorption of contaminants in aqueous media. An important extension of the BSf(n,alpha) has been the introduction of variation of the fractal time coefficient (alpha(t(v))). This improvement can lead to greater precision of the fits and deduce some information on the nature of the drug release process. We, therefore, suggest the use of the BSf(n,alpha(t(v))) formula, as a first step, in any detailed investigation and practical application of drug release data both in vitro and in vivo studies starting with the Weibull and Hill approximations to follow properly the physical solution.