Influence of Ultrasound Mediated Transdermal Delivery of Losartan Potassium

The effect of ultrasound energy on transdermal permeation of Losartan Potassium (LP) across albino rat skin was studied in vitro. Experiments were performed using therapeutic ultrasound (1MHz) at different intensities (0.5 and 2.5 W/cm2) for 10 and 30 minutes in continuous and pulsed (1:1) modes. Ultrasound variables used in present investigation were selected on the basis of 23 full factorial design. The flux observed from passive transdermal permeation was found to be 12.52 ± 3.32 μg/cm2/h. Significant enhancement in LP flux was observed when higher intensity (2.5 W/cm2) was applied for 30 min in pulsed and continuous mode. Sonophoresis (2.5 W/cm2) for 30 min in continuous mode resulted in greater LP transport (142.00 ± 13.93 μg/cm2/h). However, sonophoresis applied for 0.5 W/cm2 (30 min.) and 2.5 W/cm2 (30 min.) in pulsed mode resulted in net LP transport of 60.55 ± 9.04 and 104.60 ± 15.29 μg/cm2/h, respectively. There was ∼8.3-fold (2.5 W/cm2, 30 min) enhancement in transcutaneous steady-state flux values in pulsed mode and ∼11.3-fold (2.5 W/cm2, 30 min) enhancement in continuous mode as compared to control. The results were substantiated by histopathological studies and factorial design results. Given the promising results, it was concluded that the sonophoresis is a promising technique for transdermal delivery of LP and has the potential to be predictable.