The Time Required for Absorption and Urinary Excretion of Acetylsalicylic Acid and Methyl Salicylate

Abstract

The two salicylates (acetylsalicylic acid and methyl salicylate) are well absorbed.The time required to be eliminated into urine after oral administration and dermalapplication of these two drugs was compared in female and male. The renal eliminationtime after skin application of methyl salicylate was shown to be longer than that afteroral administration of acetylsalicylic acid (P<0.025) in an empty stomach (without food). When administer with meal, it took longer time to eliminate the oral salicylateinto urine than that of the empty stomach (P<0.001). No difference in absorption andexcretion time of the two salicylates was observed between female and male (P>0.05).

It is suggested, therefore, that the gastrointestinal absorbable form of salicylates(acetylsalicylic acid) enters and leaves the body faster than topically applied as methylsalicylate. No sex difference was observed on the three phenomena. Presence of foodin the stomach delays the body entry and leaving time of oral acetylsalicylic acid in both sexes.