Comparative Study of Three Different Brands of Doxycycline Capsules Available in Karachi

Doxycycline (DOX) is lipophilic and synthetic derivative of tetracycline. DOX is a bacteriostatic agent that is active against gram-positive and gram-negative aerobic and anaerobic bacteria, My- coplasmas, Chlamydiae, Rickettsiae, and some Protozoa. It inhibits the protein synthesis by re- stricting the binding of RNA to 30S ribosomal subunit. It is used for inflammatory conditions; pe- riodontitis and acute coronary syndromes, variety of cancers, pulmonary fibrosis, emphysema, asthma, acute lung injury and for prophylaxis of malaria. The aim of this study is to evaluate the pharmaceutical equivalence of the three different brands of doxycycline capsules available in Ka- rachi, Pakistan. For this purpose three different brands of doxycycline capsules (100 mg) were randomly selected from the local market using probability tools and evaluated for quality control parameters which are weight variation, disintegration and dissolution tests specified by BP/USP (British and United state Pharmacopoeia). Weight variation values of all brands comply with USP limits. Disintegration time for all brands was within 15 minutes also complying with the USP spe- cification. All brands exhibited more than 80% drug release within 20 minutes. The present out- comes suggest that all the three brands of doxycycline capsule available in Karachi meet the USP specification for quality control analysis.