The purpose of this study was to elucidate the potential
clinical relevance and mechanism of action of antacids on fexofenadine
in simulated gastric juice at 37 C. 10 ml of 1 mmole
of fexofenadine is added and after 5 min 2 g sodium bicarbonate
is added at 15 min; the availability of fexofenadine is
shown in Tables 1–3. The % availability of fexofenadine in
simulated gastric juice with sodium bicarbonate, calcium carbonate
and magnesium carbonate was greater than fexofenadine
(0.406–0.494%) Figs. 1–5. While in presence of calcium
hydroxide, aluminum hydroxide, magnesium hydroxide, magnesiumtrisilicate,
simethicone and magaldrate the % availability
of fexofenadine decreased (Table 1).