Formulation and Evaluation of Floating Pulsatile Drug Delivery System of Ibuprofen and Ranitidine Combination

Since rheumatoid arthritis patients experience severe pain, inflammation, and joint stiffness in the early morning hours a pulsatile drug delivery system of a suitable anti-inflammatory drug that is administered at bedtime but release the drug in the early morning would be a promising system. The objective of this work was to develop a pulsatile release tablet containing a combination of ibuprofen and ranitidine HCl from which ibuprofen gets released after a lag time of 6-7 hours. The methodology involves; analytical method development for simultaneous estimation of combination drugs, development of pulsatile release tablet and an in vivo study in rats. Lag time was controlled by coating the rapid release core tablet with different grades and concentrations of HPMC polymer. A floating gastroretentive layer was applied on top to prevent metabolism of ranitidine at the last part of the intestine. Six different formulations were prepared with three different concentrations of HPMCK4M and HPMCK100M. In vitro studies showed that the lag time increased with an increase in both concentration and viscosity of polymers. The formulation where the core tablet was coated with 100 mg of HPMCK100M had an optimum lag time of 6.3 hrs. In vivo study evaluated the ulcer protection of the formulation in four animal groups; first group remained as control, the second group received ibuprofen at a dose of 180 mg/kg, third and fourth groups received a combination of both the drugs but ranitidine in different doses. Based on this research, it can be concluded that pulsatile release of ibuprofen tablets can be successfully formulated by using HPMC polymers. The usage of ranitidine along with ibuprofen reduces the ulcerogenecity of the later.