Dissolution evaluation of marketed tetracyclines solid oral dosage forms.

Tetracyclines are produced by several pharmaceutical industries, mainly as capsule dosage form. This paper aimed to evaluate quality performance of commercially available tetracycline and oxytetracycline hydrochloride capsules and doxycycline hydrochloride enteric-coated tablets by means of in vitro dissolution test. 36 samples from 12 different producers containing 500 mg of tetracycline and oxytetracycline and 100 mg of doxycycline were analyzed using the USP XXIII procedures. Thirty four samples (94.4%) were approved and the remaining two samples (5.6%) were rejected. Although only one of the producers had some samples rejected, this fact must be seriously taken into account, considering the need of a highly qualified industrial production of medicines.