Investigation Of Bilayer Matrix Tablet For Biphasic Delivery Of Loratadine And Pseudoephedrine
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Date
2011-06
Authors
Murthy, Bhavanasi Krishna
Journal Title
Journal ISSN
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Publisher
Universiti Sains Malaysia
Abstract
The oral route of administration is often preferred due to its convenience, high patient compliance, less stringent production conditions, and lower costs. It has become common to incorporate two or more drugs in a single dosage form, for different indications. In the present study, different designs of matrix tablet systems were examined for their ability in modifying the drug release especially for the delivery of more than one drug at different release rates. The study commenced with the preparation of press coated matrix tablets and a conventional monolithic system with floating features, using paracetamol as a model drug. Subsequently, to achieve biphasic drug delivery profiles, the press coated and bilayered matrix tablet systems were examined, again using paracetamol as a model drug. An increase in hydroxypropyl methylcellulose and xanthan gum at 40% level was able to sustain the drug release for 12 hr. At similar polymer concentration, the drug release profiles of bilayer and press coated tablets were comparable. More than 50% of drug was released within 1 hour followed by a slow drug release over an extended period of time dependent on the content and types of polymer used. The two systems were further evaluated for biphasic delivery of loratadine and pseudoephedrine, in comparison with Clarinase® tablets. The release profiles of loratadine and pseudoephedrine from the press coated and bilayer matrix tablet were compared with those of Clarinase® tablets to establish similarity. The bilayer matrix tablet was preferred and selected for in vivo study using rabbits. Prior to the in vivo study, HPLC method was developed and validated for the determination of pseudoephedrine and loratadine in rabbit plasma. Formulation containing hypromellose and sodium carboxymethyl cellulose (F19) was used for in vivo study. The results obtained show that the rate and extent of absorption of loratadine and pseudoephedrine of studied bilayer matrix tablets were comparable with those of Clarinase® tablets. In short, the bilayer matrix tablet system could be used as an alternative drug delivery system for biphasic delivery of two drugs with different solubility.
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Keywords
Bilayer matrix tablet for biphasic delivery , of loratadine and pseudoephedrine