Combination of surfactants with other excipients: Effects on drug release and dimensional changes in matrices

Purpose: To investigate the effect of polymers and surfactants on drug release, gelling, and dimensional changes of matrices. Methods: Flurbiprofen and propranolol were formulated using different types and ratios of polymers including hydrophilic polymers (sodium carboxymethyl cellulose, CMC), and a hydrophobic polymer (Eudragit RS 100). Both cationic (cetrimide, CET)) and anionic (sodium lauryl sulfate (SLS) surfactants were also used. Dissolution rate, swelling rate, and dimensional changes were investigated in dissolution media mimicking gastrointestinal fluids (pH 1.2 and 7.4). Results: The highest drug release rate was 45 and 78 % for flurbiprofen/RS 100 and propranolol/CMC, respectively. Surfactants have also exerted an additional effect on drug release in that SLS enhanced the release of flurbiprofen (blended with RS 100) by 5 % while CET improved propranolol (CMC by 7 %. Clear wetting, swelling, and gelling were observed in the tablets prepared with CMC. Surfactant has no effect on dimensional changes in the tablets. Conclusions: The release rate of propranolol and flurbiprofen is generally governed by polymer type and drug solubility. Dimensional changes in the tablet matrices are mainly constrained by the type of polymers used