Abstract

Pain is a subjective experience; it is a direct response to an untoward event associated with injury and inflammation. Sydnone derivatives have been synthesized with biological interest and reported to possess a wide spectrum of biological and pharmacological activities like antimicrobial, anti-inflammatory, anti-pyretic, antitumor, antiarthritic and antioxidant properties. Rat tail flick method was adopted to study the analgesic activity of various test compounds. Aspirin as standard drug was used for comparison of analgesic activity. The animals were tested for the tail flick response at 30, 60 and 90 minutes after drug administration. A cut off time of 8 seconds was fixed to avoid injury to the animal. Mesoionic compound no’s 3, 6, 8 and 9 were evaluated for analgesic activity. The percentage protection for mesoionic test compound no’s 3, 6, 8 and 9 were 50, 0, 0 & 33.33 % in comparison to 83.33 % in aspirin group. In addition these mesoionic test compounds were also evaluated for ulcerogenic potential. Mesoionic test compound no’s 8 and 9 showed far lesser gastric damage compared to standard drug phenylbutazone.