Issues in Biological Sciences and Pharmaceutical Research Vol.3(2),pp. 14-20, February 2015 Available online at http://www.journalissues.org/IBSPR/ http://dx.doi.org/10.15739/ibspr.008 Copyright © 2015 Author(s) retain the copyright of this article ISSN 2350-1588 Original Research Article Eudragit L-100 for enteric coating of hard gelatine capsules: Formulation and evaluation Accepted 27 February, 2015 Harith Jameel Mahdi Department of Applied Chemistry, Faculty of Applied Chemistry, University of Samarra, Iraq. Author’s E-mail: ph_harith75@yahoo.com Tel:+964-7702660991 In an attempt to combine the favourite properties of hard gelatine capsules with the protective and controlled release properties of enteric coating to get an appropriately and acceptably formulated enteric coated hard gelatine capsules with pH dependent drug release characteristic. Two hard gelatine capsule sizes were selected i.e. size #0 and size #1 in order to test the effect of capsule size on coating process. Eudragit L-100, a pH dependent solubility polymer, was tested for suitability for coating of hard gelatine capsules. A number of formulations with various Eudragit L-100 concentrations were investigated in order to select the best formula that provides the most ap- propriate coating properties. A formulations with 3, 5, 6.5 and 10 % (w/w) Eudragit L-100 were tested. Formula with 6.5 % (w/w) Eudragit L-100 was selected as it provides a good adhered and continuous coating film with ac- ceptable disintegration time, dissolution test and excellent stability on storage for both capsule sizes. Key words: Hard gelatine capsule, eudragit L-100, enteric coating, direct coating, and sub-coating. INTRODUCTION Since the first development and production of hard gelatine capsule as pharmaceutical dosage form by Mr. Mothes, France, in 1834 (Fridrun and Brian, 2004; Katerina et al., 2010) an annual increases in use and continuous in devel- opment of new pharmaceutical dosage form using hard gelatine capsules were recorded (De Carvalho and Grosso, 2006; Sven, 2002). Hard gelatine capsules provides a unique properties such as fewer manufacturing steps, suit- ability for poor compaction powder and mostly lower in manufacturing cost and steps than tablet, (Bussemer and Bodmeier, 2003; Ashlesha et. al., 2011). In addition to that, during initial stages of new drug development one of the most important and sensitive situation is the very limited quantity of the under investigated active pharmaceutical ingredient, lack of adequate information about physical and chemical properties, tight schedule time and with too many variables that may affects on pharmacokinetic and/or pharmacodynamic behaviour associated with tablet's manufacturing (Katerina et al., 2010). All that makes the hard gelatine capsules to be more favoured dosage form, suitable and actually preferred in manufacturing of solid dosage form over tablets. On the other hand, in some cases like acid sensitive drugs, drugs that irritant to stomach or in case of drug designed to target a specific site of gastro- intestinal tract (Ashlesha et al., 2011), hard gelatine capsules appears to be inappropriate. The enteric preparations so far frequently used generally occur as granules, tablets, and capsules filled with enteric granules (Singh et al., 2012). However, some drugs are not amenable for production of compressed table but must be made up into enteric granules or capsules filled therewith (Jaleh et al., 2012). In such case, it is required that the gran- ules should be uniform in shape and size (Pallavi et al., 2010) and so forth so that they can have satisfactory