Preparation and In Vitro, In Vivo Characterization of Thermosensitive Transdermal Hydrogel for Arthritis

In rheumatoid arthritis (RA) various opioid analgesics and nonsteroidal anti inflammatory drugs are used for the management of the chronic pain and inflammation. But often the drugs show gastric irritation and require high dosage frequency. Therefore, a thermosensitive transdermal hydrogel was formulated as a safer and more effective alternative for the topical use for prolonged relief from pain and inflammation in arthritis. The thermosensitive transdermal hydrogel was prepared from the ethanolic extract of roots of Aconitum vilmorinianum Kom. (AV) and Urtica dioica (UD) with poly lactic acid-polylactide glycolic acid (PLA-PLGA) copolymer. The prepared hydrogel was evaluated for various physicochemical parameters, in vivo primary skin irritation test, in vivo analgesic and in vivo anti-inflammatory activities against complete freund's adjuvant induced arthritis in rats. The prepared hydrogel was pale yellow, translucent and clear with pH 6.7. The hydrogel was non-irritant to the skin in primary skin irritation test on Wistar rats. The hydrogel showed 67.70% inhibition of rat paw edema while the standard (indomethacin gel) showed 69.27 % in arthritic rats at the end of 2 days. The hydrogel showed 55.13% analgesia as compared to standard (60.25%). It was concluded that the thermosensitive transdermal hydrogel prepared from the root extract of Aconitum vilmorinianum Kom. (AV) and Urtica dioica (UD) was very effective in the management of pain and inflammation in the rheumatoid arthritis.