LAUSR

The role of co-processing in improving tablet mechanical properties was investigated in this work. Gabapentin was used as the model compound owing to its poor tableting properties such as low tensile strength, strain rate sensitivity, high ejection force and tablet capping. Gabapentin was blended with HPMC (Methocel®) in a high shear mixer to obtain an interactive mixture consisting of finer HPMC particles adsorbed onto the surface of larger gabapentin particles. Interactive mixture containing <1% by weight Methocel® was compressed on a material testing system (Instron®) to evaluate tablet mechanical properties. This co-processed gabapentin demonstrated improvement in tablet tensile strength and strain rate sensitivity which was attributed to improved particle bonding. In comparison, Methocel® 10% (w/w) low-shear mixture demonstrated strain rate sensitivity and lower tensile strength. Furthermore, Methocel® coating on gabapentin particles provided lubricity and decreased die-wall friction resulting in reduced tablet capping. This methodology has applications in improving mechanical properties of poorly compressible high dose drugs without the use of high level of excipients. Furthermore, reduction in die-wall friction through particle surface coating could prove beneficial for formulations prone to over-lubrication and slow dissolution due to magnesium stearate.