Calculation of predominant drug release mechanism using Peppas-Sahlin model (substitution method): A linear regression approach

B. Ravindra Babu* and K. Naveen Babu

The objective of this study was to develop NCRD controlled release floating tablets using combination of hydrophilic and hydrophobic polymers by melt granulation technique. The in vitro drug release characteristics were determined using USP XXII type 2 (paddle type) apparatus, in a medium of 0.1N HCl. The dissolution profile of all the batches were extended up to 24 hrs. To study and model the drug delivery from polymeric floating tablets, the dissolution data was fitted to a pioneered method Korsmeyer-Peppas equation. The results indicate that, all the formulations followed super Case-II release mechanism, except MCS4 which followed non-Fickian or anomalous release mechanism. In order to determine the predominant mechanism (diffusion/ relaxation model), drug release data was incorporated into Peppas-Sahlin model. The results revealed that, Fickian release contribution was preponderance than corresponding Case-II relaxational contribution in all the formulations. In addition to this, the relaxational contribution was observed with negative sign in all the formulations but, only at specific time intervals. Relaxational contribution with negative values indicates the Fickian release mechanism was more pronounced than relaxation i.e. almost the relaxational mechanism was absent.