Production and in vitro evaluation of a lamotrigine extended release tablet based on a controlled-porosity osmotic pump system.

Osmotic pump delivery systems have made significant advances in the past decades for controlled drug release over a long period of time. Usually, osmotic pump products require sophisticated and expensive laser drill technology resulting in increase in production cost and decrease in production efficiency. In this study, a lamotrigine extended release tablet based on a controlled-porosity osmotic pump (CPOP) system was developed to circumvent laser drill technology in reference, Lamictal XR®. The tablet core was coated by a polymer blend of Acryl-EZE® and HPMC E5. Lactose and HPMC were added in the CPOP core to adjust the release profile. An orthogonal design was employed to optimize the formulation from factors, i.e., core composition, coating materials ratio and coating levels. Comparisons of in vitro drug release profiles were also conducted. The optimized formulation showed a satisfactory zero-order release profile (R2 = 0.9912). Similarity factor, f2 of 77 was obtained in larger scale. The lamotrigine extended release tablets based on the CPOP system showed ideal reproducibility and stability. The developed system has the ability to be an alternative production method for Lamictal XR®, which could circumvent the laser drill technology and promote the osmotic pump generalization.