Send Orders for Reprints to reprints@benthamscience.ae Current Drug Delivery, 2016, 13, 000-000 1 RESEARCH ARTICLE 1567-2018/16 $58.00+.00 © 2016 Bentham Science Publishers Chitosan-Hydroxypropyl Methylcellulose Matrices as Carriers for Hydro- dynamically Balanced Capsules of Moxifloxacin HCl Anurag Verma 1 , Juhi Dubey 1 , Navneet Verma 1 and Amit Kumar Nayak 2,* 1 Department of Pharmaceutics, College of Pharmacy, IFTM University, Lodhipur Rajput, Delhi Road, Moradabad-244 001, U.P., India; 2 Department of Pharmaceutics, Seemanta Institute of Pharmaceutical Sciences, Jharpokharia, Ma- yurbhanj-757086, Odisha, India A R T I C L E H I S T O R Y Received: March 31, 2016 Revised: May 13, 2016 Accepted: May 19, 2016 DOI: 10.2174/2213476X03666160525144 455? Abstract: Background: In recent years, gastroretentive, hydrodynamically balanced system (HBS) for stomach-specific floating sustained drug release has gained a lot of importance in improving absorption of drugs especially those absorbed from stom- ach and small intestine. Objective: The objective of the current investigation is to evaluate chitosan- hydroxypropyl methylcellulose (HPMC) based on polymeric matrices as a carrier for single-unit capsules based on HBS for stomach-specific floating sustained drug re- lease using moxifloxacin HCl (MX) as a model drug. Method: Various HBS capsules of MX were prepared by physical blending of MX with chitosan (low or medium molecular mass) or HPMC (K4M or K15M) or chitosan-HPMC combi- nations in varying proportions followed by encapsulation into size 0 capsules made of hard gelatin. The in vitro buoyancy and drug release in 0.1 N HCl (pH 1.2) were evaluated. Results: HBS capsules based on chitosan (low and medium molecular weight and their combination) as polymer matrix failed to float on 0.1 N HCl (pH 1.2). Whereas, formulations containing HPMC (K4M or K15M) or their mixture with chitosan, remained buoyant and released MX over 9 h in the acidic dis- solution medium following zero-order kinetics. Conclusion: HPMC (K4M, K15M, blend of K4M and K15M) or their mixture with low/medium mo- lecular mass chitosan may constitute excellent carrier systems for the stomach-specific sustained deliv- ery of MX over a longer period. Keywords: Chitosan, drug release, HPMC, hydrodynamically balanced system. 1. INTRODUCTION A considerable interest has recently been spotlighted on the potential applications of natural as well as synthetic bio- degradable and biocompatible polymeric materials as matri- ces for sustained oral drug delivery [1-3]. Among various biodegradable and biocompatible polymers, chitosan and hydroxypropyl methylcellulose (HPMC) have received spe- cial attention. Chitosan (deacetylated chitin) is one of the biologically derived cationic polysaccharides, which is re- garded as a ‘Generally Recognized as Safe’ (GRAS) material and has also been utilized in the development of several pharmaceutical dosage forms [4, 5]. During the last few dec- ades, chitosan has appeared as a suitable biopolymer for the delivery of drugs because of its excellent physicochemical, biological as well as pharmaceutical characteristics [6-10]. *Address correspondence to this author at the Department of Pharmaceutics, Seemanta Institute of Pharmaceutical Sciences, Mayurbhanj-757086, Od- isha, India; Te: +91-9583131603; E-mail: amitkrnayak@yahoo.co.in Currently, chitosan based dosage forms for oral administra- tion have widely been examined for their ability of these systems to localize at the desired-sites like stomach for the delivery of drugs to increase the contact time of the tissue surface of gastrointestinal tract (GIT) to get better permeabil- ity of drugs [11, 12]. In addition, chitosan has mucoadhesive ability on to the stomach mucosa resulting in stronger con- tact with the site of delivery [13, 14]. Also, HPMC has global regulatory acceptance for use in development of vari- ous pharmaceutical preparations [15, 16]. It is biocompatible and composed of alkylhydroxy, alkylcellulose ether with hydroxypropyl and methoxyl groups. As it is a nonionic wa- ter-soluble polymer, the probability of chemical interactions between ingredients is very much decreased. The polymeric- matrices made up of HPMC also exhibit pH-independent release of drugs [16, 17]. The aqueous solution of HPMC is stable enough over wider pH-range and is also resistant to enzymatic-degradation. These properties make HPMC as one of the most popular biopolymers for matrix application. A.K. Nayak