Drug release from lipid liquid crystalline phases: relation with phase behavior

Introduction: We studied the release of propranolol hydrochloride (PHCl), a water-soluble amphiphilic drug, from monoolein (MO)/water and phytantriol/water systems. Methods: We related the dissolution profiles with phase behavior and viscosity of the different liquid crystalline phases. Diolein has been added aiming to stabilize the cubic phases and thus preventing formation of less viscous (lamellar) phases. Results: Formulations display first-order release rates and diffusion release mechanism. Some formulations (mostly MO) were close to zero-order release in the first 120 minutes. Discussion: Release mechanism can be influenced by phase changes during dissolution. Conclusions: Both MO and phytantriol show good potential to be used for propranolol hydrochloride sustained drug release.