The effect of antacid and food on the absorption of proquazone (Biarison) in man.

The study was carried out on a group of twelve healthy volunteers in order to determine the effect of food and antacid on the absorption of proquazone when administered orally as a single dose. Each subject received, in a randomised cross-over sequence, 600 mg of proquazone after a 10 h overnight fast, 15 min. after 20 ml of an antacid (Maaloxan) and 15 min. after a standard breakfast. The interval between each administration was at least 7 days. Blood plasma samples were obtained up to 24 hours after administration. The samples were analysed using a modified fluorimetric method which determined the amount of unchanged drug. The only effect of antacid, compared to fasting, was to slow the rate of absorption without appreciably altering the extent of absorption. Food, on the other hand, markedly increased the maximal plasma concentration and also the area under the plasma concentration/time curve in a statistically significant and, most probably, clinically relevant manner. Possible explanations for this effect are discussed and it is concluded that the administration of proquazone with or after food should be doubly advantageous for the patient as it ought to offer protection from local gastrointestinal irritation and at the same time lead to an enhanced bioavailability.