Novel Gastroretentive Controlled Release Formulations for Once-Daily Administration: Assessment of Clinical Feasibility and Formulation Concept for Raltegravir.

Background: Raltegravir is an integrase strand transfer inhibitor indicated in combination with other anti-retroviral medicinal products for the treatment of HIV-1 infection, given twice daily. Although a BCS class II compound, raltegravir exhibits low colonic absorption, thus making development of modified release formulations challenging. It was hypothesized that a gastroretentive (GR) formulation would increase trough (C) concentrations of raltegravir, hence being amenable to a once-daily (QD) regimen.