In previous work we proposed an HPLC method for modernization
of tetracycline-related USP monographs. The method
was validated for the tetracycline hydrochloride drug substance
and oral suspension. The present work proves that the
method is accurate, precise, specific, linear, and sensitive for
the assay of tetracycline hydrochloride and the limit of 4-
epianhydrotetracycline hydrochloride in capsule. So far, we
have presented the validation results related to the modernization
of three tetracycline-related USP monographs. The feasibility
of using this procedure for modernization other
tetracycline-related USP monographs is still underway.