Potential of Sonophoresis as a Skin Penetration Technique in the Treatment of Rheumatoid Arthritis with Transdermal Patch.

Rheumatoid arthritis, a chronic disorder, limits the use of chemical penetration enhancers for a prolonged period of time. Moreover, systemic routes of administration of the first-line drug, methotrexate, have shown undesirable systemic as well as local side effects. The objective of this research was to overcome the limitations associated with treatment of rheumatoid arthritis by utilizing three physical transdermal penetration enhancement techniques namely cold-laser, electroporation, and sonophoresis to deliver methotrexate. Methotrexate patch was prepared using solvent casting method and the ex-vivo release of methotrexate in combination with three physical penetration enhancers (sonophoresis, electroporation, and cold laser) were studied. The best technique was employed in pre-clinical testing in arthritic and control groups of male Wistar rats excluding remaining two techniques. The comparative ex-vivo studies showed that the penetration enhancement of methotrexate is maximum by sonophoresis followed by electroporation and cold laser (sonophoresis > electroporation > cold laser). In pharmacodynamic studies, the reduction in diameter of injected and non-injected paw on day 5 and day 21 for group 4 (ultrasound pre-treated group) was higher as compared to group 3 (group receiving only methotrexate patch). The motility score and the reduction in pain were significantly improved for group 4 than group 3 on both day 5 and day 21 (P ˂ 0.05) which confirmed the faster recovery of animals of group 4 due to penetration enhancement of methotrexate patch by ultrasound treatment. From the results, it can be concluded that sonophoresis along with methotrexate patch has shown a significant effect in the treatment of rheumatoid arthritis.