World Applied Sciences Journal 32 (10): 2063-2069, 2014 ISSN 1818-4952 © IDOSI Publications, 2014 DOI: 10.5829/idosi.wasj.2014.32.10.14165 Corresponding Author: Roohullah, Department of Pharmacy Abasyn University Peshawar, Pkistan. 2063 Preparation and In vitro Evaluation of Sustained Release Phenytoin Sodium Capsules Prepared by Co-Evaporation Method Using Different Polymers Roohullah, Zafar Iqbal, Ameer Zada, Fazli Nasir, Muhammad Akhlaq, 1 2 2 2 2 Sajid Khan Sadozai, Amjad Khan and Majid Khan Sadozai 3 2 3 Department of Pharmacy Abasyn University Peshawar, Pkistan 1 Department of pharmacy University of Peshawar, Peshawar Pakistan 2 Department of Pharmacy Sarhad University of Science and 3 Information Technology Peshawar, Peshawar, Pakistan Abstract: Sustained-release capsules of Phenytoin sodium were developed and evaluated. The Co-evaporation method was employed for the preparation of granules, hydroxy propyl methyl cellulose (HPMC), carboxymethyl cellulose (CMC) and polyvinylpyrrolidon-K90 (PVP-K90), were used as release sustaining materials. Formulations were designed using drug to polymers ratio 1:1, 1:1.5, 1:2 with the aim to develop twice daily sustained release capsules. Physical characterization of granules was evaluated. USP dissolution apparatus I was used for the In-vitro drug release study of the capsules. Drug release data was evaluated using various models like Zero-order, First-order, Higuchi model, Korsmeyer model and Hixson-Crowell model. The resulting capsules prepared with all the polymers were failed to fulfill the official criteria for dissolution required for a sustained dosage i.e. HPMC group of formulation with drug to polymer ratio 1:2 was able to controlled the release of the drug up to 8 hours, the CMC group with this ratio prolonged the release up to 6 hours and PVP group with the same ratio was able to sustained the release of the drug up to 4 hours. Key words: Hydrophilic Polymers (HPMC, CMC and PVP) Sustained Release Co-evaporation method Phenytoin sodium capsules INTRODUCTION overcome this problem. These polymers and gums on Phenytoin is commonly an antiepileptic drug which on the surface of the system from that they controlled the is used in the treatment of epilepsy. It exhibits non-linear release of the drug. As such, hydrophilic matrices pharmacokinetics characteristics and requires frequently dominate today’s market of oral controlled release plasma monitoring and dose adjustment. It possesses a products [2, 3, 4, 5, 6]. Hydroxypropyl methylcellulose relatively narrow therapeutic range (10–20 mcg/ml) with (HPMC) is the most commonly used hydrophilic polymer. signs and symptoms of central nervous system toxicity The hydrophilic polymers and gums like hydroxypropyl more likely at concentrations greater than 20 mcg/ml. Small methylcellulose (HPMC), carboxymethylcellulose (CMC), changes in the amount of Phenytoin administered or polyvinylpyrolidone (PVP), hydroxypropyl cellulose absorbed from the gastrointestinal tract may result in (HPC), hydroxyethyl cellulose (HEC), xanthan gum (XG) disproportionate changes in the plasma concentration [1]. and guar gum (GG), have been extensively used in the Due to its weakly acidic nature (pKa 8.31) and poor formulation of sustained release systems [2, 3, 4, 5, 7]. aqueous solubility (100 mcg/ml), phenytoin often shows The broad acceptance, cost effectiveness, nontoxic erratic absorption following oral administration, for this properties, ease of handling, ease of compression, ability reason certain hydrophilic polymers and gums are used to to accommodate a large percent of drug, negligible contact with aqueous medium swell and form a gel layer