Improvement of Losartan Transdermal Permeation using Oleic Acid Pretreatment: in Vitro Observation and in Vivo Prediction

ABSTRACTThe effect of oleic acid on losartan transdermal permeation has been observed to explore its ability as chemical enhancer.� Potassium losartan solutions in citric buffer pH 5.0 were made in two levels of concentration i.e. 2 mg/mL and 10 mg/mL using propylene glycol 15% as solubilizing agent. Losartan transport from such solutions with and without oleic acid one hour pretreatment were tested using male Wistar rat skin as a membrane for 30 hours in vertical diffusion sel.� The transport profiles were analyzed based on the lag time diffusion method.� It is showed that oleic acid pretreatment did not effect on losartan permeation rate and efficiency of 2 mg/mL potassium losartan concentration. However, such pretreatment enhanced losartan permeation rate and efficiency 21 and 23-fold higher respectively for 10 mg/mL the potassium losartan concentration.� It is predicted that losartan minimum effective plasma concentration can be achieved in transdermal administration through this transport improvement in normal application area