[Experimental study of the pharmacokinetics of acetylsalicylic acid upon transdermal administration].

A comparative analysis of the concentrations of acetylsalicylic acid (ASA) and its metabolite, salicylic acid (SA), in the blood was performed and the other pharmacokinetic parameters were studied after conventional intragastric and transdermal administration in rabbits. It is established that the ASA concentration in the blood upon transdermal administration in a dose of 100 mg/kg is above the minimum therapeutic level during 24 h. Prolonged action of a transdermal therapeutic system (TTS) in comparison to intragastric administration was proved. After the transdermal administration via TTS, the ASA half-elimination time and the mean retention time increased in comparison to the values upon intragastric administration. The ASA bioavailability upon the transdermal administration increased by a factor of 4.5 in comparison to the case of peroral administration.