~5~ The Pharma Innovation Journal 2016; 5(6): 05-13 ISSN: 2277- 7695 TPI 2016; 5(6): 05-13 © 2016 TPI www.thepharmajournal.com Received: 02-04-2016 Accepted: 03-05-2016 Pinki Rajbhar Shambhunath Institute of Pharmacy, Jhalwa, Allahabad, U. P, India. Atul K. Sahu Shambhunath Institute of Pharmacy, Jhalwa, Allahabad, U. P, India. S. S. Gautam Shambhunath Institute of Pharmacy, Jhalwa, Allahabad, U. P, India. Raj K. Prasad Shambhunath Institute of Pharmacy, Jhalwa, Allahabad, U. P, India. V. Singh Shambhunath Institute of Pharmacy, Jhalwa, Allahabad, U. P, India. S. K. Nair Shambhunath Institute of Pharmacy, Jhalwa, Allahabad, U. P, India. Correspondence Pinki Rajbhar Shambhunath Institute of Pharmacy, Jhalwa, Allahabad, U. P, India. Formulation and Evaluation of Clarithromycin Co- Crystals Tablets Dosage Forms to Enhance the Bioavailability Pinki Rajbhar, Atul K. Sahu, S. S. Gautam, Raj K. Prasad, V. Singh, S. K. Nair Abstract Clarithromycin is a semi-synthetic macrolide antibiotic which inhibits bacterial protein synthesis by binding to the bacterial 50S ribosomal subunit. In this work BCS Class II drug Clarithromycin is used as a model drug, which is having poor solubility but high permeability. A pharmaceutical co-crystal is a single crystalline solid that incorporates two neutral molecules, one being an active pharmaceutical ingredient (API) and the other a co-crystal former. Co-crystals of Clarithromycin were prepared using co- crystal former (urea), with method of preparation (solvent evaporation). In the present study, Clarithromycin co-crystals tablets were prepared and evaluated in order to improve the dissolution by enhancing the solubility of Clarithromycin using urea co crystals to improve the bioavailability. In this work, the wet granulation method was attempted for formulation of conventional tablets of Clarithromycin. The Clarithromycin tablets are available in 250mg- 500mg, doses in market. Dose of 250mg was selected for the present research work. Keywords: Clarithromycin, Poor solubility, co-crystal, Tablet, Bioavailability etc. Introduction The poor solubility of drug is a major problem which limits the development of highly potent pharmaceutics. The drugs with low solubility lead to low oral bioavailability and erratic absorption which is particularly pertinent to drugs within class II of the Biopharmaceutical Classification System (BCS). BCS Class II drug Clarithromycin is having poor solubility but high permeability 1-4 . Therefore, one of the most challenging tasks in drug development is to improve the drug solubility in order to enhance the bioavailability of these drugs. Several strategies have been employed to overcome these limitations. The approaches to increase the solubility and the available surface area for dissolution are classified as physical and chemical modifications. Clarithromycin, Fig. 1, is a semi-synthetic macrolide antibiotic which inhibits bacterial protein synthesis by binding to the bacterial 50s ribosomal subunit. In this work, the wet granulation method was attempted for formulation and evaluation of conventional tablets of Clarithromycin to improve the bioavailability 5-9 . O HO H 3 C CH 3 O H 3 C OH OCH 3 CH 3 O CH 3 CH 3 O H 3 C O O O CH 3 HO H 3 CO CH 3 H 3 C OH N(CH 3 ) 2 Clarithromycin Fig 1: Structure of Clarithromycin