[The physiologic disposition and pharmacokinetics of guaiacol acetylsalicylate in rats].

Guaiacol acetylsalicylate (GASL) has been shown to possess significant anti-inflammatory, antipyretic and expectorant activities and has been used clinically in chronic bronchitis with fairly good results. In the present work, the absorption, distribution and excretion of metabolites of the drug were studied in rats using quantitative TLC scanning technique. GASL was shown to be unstable in rat gastrointestinal tract and guaiacol salicylate (GSLT) and salicylic acid (SLA) were found in plasma. The plasma SLA concentration-time curve obtained after oral administration of GASL to rats was shown to fit a one compartment open model with the following pharmacokinetic parameters: T1/2ka = 1.25 h, T1/2ke = 3.28 h, ka = 0.5554/h, ke = 0.2111/h, Tmax = 3.02 h, Cmax = 331.46 micrograms/ml, AUC = 2832.93 micrograms/ml.h The SLA concentration was found to be high in muscle, moderate in spleen, testicle, kidney, lung, plasma, heart and liver and low in brain. The GSLT concentration was found to be low in plasma and organs. Within 24 h following ig administration of GASL the total SLA excreted in urine and feces was 10.9 and 0.41 of the GASL dose, respectively.