Metabolism of para-aminobenzoate over time.

Potassium para-aminobenzoate incorporated into rat chow was fed ad libitum for 14 days to adult female Buffalo rats. Determination of the principal urinary metabolites, namely, p-aminobenzolyacetylester and p-aminobenzoylglucuronide, namely, p-aminobenzoylacetylester and p-aminobenzoylglucuronide, as well as p-aminobenzoylglycine and p-hydroxybenzoylglycine (hippurates), showed significantly greater amounts of the metabolites at the 14th day compared to day 1. There was no significant change in free p-aminobenzoate excretion during this interval. The results suggest that para-aminobenzoate stimulates its own metabolism during chronic administration.