Development and Evaluation of Press Coated Tablets of Fexofenadine Hydrochloride as Pulsatile Delivery System

摘要

Pulsatile drug delivery systems are developed to deliver drug according to circadian behavior of diseases. The product is characterized by a time period of no release (lag time) followed by a rapid and complete drug release as a pulse after the lag time. Thus drug can be delivered at right time, in right amount and at right site of action by use of such approach. These systems are beneficial for drugs with chronopharmacological behavior, where nocturnal dosing is required. Common symptoms of allergic rhinitis ;sneezing, nasal rhinorrhea, red itchy eyes, nasal pruritus and nasal congestion were found to occur most frequently before breakfast and in the morning and least frequently in the middle of the day. An oral press-coated tablet of Fexofenadine HCl was developed by means of wet granulation and direct compression to achieve time-controlled tablet with a predetermined lag time. The preparation of press coated tablet involved preparation of fast dissolving core tablets by wet granulation method, where 60 mg of Fexofenadine HCl was formulated with different types and concentrations of superdisintegrants, and an outer coat which is formulated with different weight ratios of hydrophobic polymer; Ethyl cellulose (EC) and hydrophilic polymer; Hydroxy propyl methylcellulose (HPMC) using direct compression. The Formulation was evaluated on basis of acceptable physical properties and in vitro drug release. The results indicated that press-coated tablet composed of B3 (as core tablet formula) and C2 (as coat formula) gave complete and rapid release of Fexofenadine HCl after 6 hours lag time which is suitable to achieve time-controlled release of Fexofenadine hydrochloride, based on chronopharmaceutical approach for the treatment of morning allergic rhinitis through providing maximum concentration of the drug at time of its maximum need.