Nanosuspension formulation & evaluation of ritonavir & valsartan by using poloxamer as a stabilizing agent to enhance the oral bio availability

Abstract

The Nano ionization technology is particularly promising for improving  the oral  absorption and bioavailability of BCS class II drugs. One such approach is Nano ionization  thereby increasing  surface  area  and hence dissolution and ultimately the bioavailability. Ritonavir is a BCS class II and IV drug. Valsartan is a commonly used antihypertensive agent belonging to the family of angiotensin II receptor antagonists. Valsartan is a BCS class II drug being slightly soluble in water. It has a very low oral bioavailability of 25-35% due to its limited solubility in biological fluids.  Poor water solubility of drugs shows insufficient bioavailability and fluctuating plasmalevels. Based on their physicochemical and biopharmaceutical properties, Ritonavir and Valsartan were  selected   as   a   drug   candidates   for    developing    Nanosuspension  based    formulations for improving the solubility and bioavailability    by    enhancing the rate and extent ofdissolution.The scope of the present work is to enhance the solubility, dissolution rate and oral bio availability of poorly soluble drugs Ritonavir and Valsartan by formulating them into Nanosuspension with Poloxamer as a stabilizing agent and  subsequently  converting  the optimized Nanosuspension of Ritonavir/Valsartan drug molecule into tablets and capsuleswith the help of various extragranular agents.