Ibuprofen release kinetics from controlled-release tablets granulated with aqueous polymeric dispersion of ethylcellulose II: influence of several parameters and coexcipients.

The objective of this study was to investigate the mechanism of ibuprofen (IBF) release from tablets prepared by wet granulation method, using Surelease as a granulating agent. The influence of certain parameters such as the levels of Surelease solids content (SSC), pH of dissolution media, selected dissolution method, and agitation speed on the release profiles of IBF was investigated. The effect of partial replacement of lactose (primary excipient) by various coexcipients such as microcrystalline cellulose, starch, polyvinylpyrrolidone (PVP), sodium alginate, hydroxypropylmethylcellulose (HPMC), and sodium carboxymethyl cellulose (CMC-Na) was also studied. Tablets prepared with surelease as a granulating agent were non-disintegrating and exhibited prolonged release rates as compared to control tablets. The release of IBF from the tablets appears to occur either via water-filled pores or by diffusion through membrane, depending on the levels of SSC. At higher SSC levels pH independent release profiles for IBF were achieved. Dissolution method and agitation speed exhibited no significant effect on the release profiles. All the coexcipients studied enhanced the release rates, irrespective of whether the coexcipients were water-soluble or water-insoluble.