A new formulation of aspirin: bioavailability and analgesic efficacy in migraine attacks

Plasma aspirin and salicylate concentrations were followed after 600 mg of a new palatable glycinated preparation of aspirin was given to six healthy male volunteers in an attempt to investigate whether pre-gastric absorption of aspirin could occur. In each subject the drug was administered by three different routes, viz. (i) swallowed with water, (ii) dissolved sublingually and retained in the mouth, and (iii) allowed to disperse on the tongue, and then swallowed without water intake. Using the latter route of administration and the same aspirin formulation, plasma aspirin and salicylate concentrations were also followed in 10 patients during acute migraine attacks. These results were compared with those from another 10 migraineurs given 600 mg of soluble aspirin swallowed with water during attacks. Aspirin and salicylate pharmacokinetic parameters (Cmax, tmax, t1/2, Kabs and AUC) in the normal volunteers were not significantly different (p greater than 0.05) whether glycinated aspirin was swallowed with water or swallowed without water after dispersion in the mouth. However, negligible aspirin was absorbed when the glycinated preparation was retained in the mouth. In migraine patients, there was no significant difference (p greater than 0.05) between the bioavailabilities of soluble aspirin swallowed with water (AUC = 5.7 +/- 2.3 mg h/l) and glycinated aspirin swallowed without water (AUC = 4.4 +/- 1.6 mg h/l). There also was no significant difference (p greater than 0.05) when the time courses of pain relief were compared, both treatments being associated with a significant (p less than 0.01) analgesic effect. The glycinated aspirin was thus bioequivalent to swallowed aspirin but has no advantages for migraineurs over soluble aspirin if water is readily available for self-administration.