Bioavailability of doxycycline monohydrate. A comparison with equivalent doses of doxycycline hydrochloride

Two derivatives of doxycycline, the monohydrate-free base and the hydrochloride salt were given orally to 12 volunteers in a crossover study. There was no difference in absorption and bioavailability between the two preparations. Secondary plasma peaks indicating reabsorption were noticed for both derivatives. Doxycycline monohydrate, proven to have a lower risk of inducing esophageal lesions, is a good alternative to the hydrochloride salt in oral treatment.