Controlled release tablet formulations of isoxsuprine hydrochloride using direct compression technique

Isoxsuprine hydrochloride is a peripheral vasodilator. It is advisable to prepare the drug in sustained release dosage forms to improve patient compliance and to achieve a steady state blood level with minimum side effects. Different hydrophilic and hydrophobia polymers in addition to their combinations were used in different ratios to select the best level of the matrix forming material that provides the most sustaining effect. The effect of different types and concentrations of polymers on the release rate of the drug was investigated. The drug release decreased by increasing the concentration of the polymer in all the studied formulations. Tablet formula containing either 30% [w/w] HPMC 15000 or 30% [w/w] Eudragit RSPM gave the most sustaining effect among the single polymers. The drug release rate from tablets prepared using polymer blends is slower compared to that from those containing single polymers. The slowest drug release was obtained from tablet formulae containing: drug, 10% [w/w] HPMC 15000 and 40% [w/w] Eudragit RSPM and drug, 10% [w/w] Eudragit RSPM and 40% [w/w] Eudragit RLPO. The release of isoxsuprine HCl from matrices prepared using single polymer followed Higuchi 's diffusion model However, zero-order release kinetics was elucidated for the release of isoxsuprine HCl from the investigated polymer blends in phosphate buffer [pH 6.8]

Preparation and comparative evaluation of sustained release metoclopramide hydrochloride matrix tablets

Metoclopramide hydrochloride [MCP] is commonly used for the management of gastrointestinal disorders. Frequent administration and the undesired side effects [extra pyramidal symptoms] of the drug on the central nervous system due to the fluctuations of its plasma concentrations may lead to patient incompliance, and hence, improper therapy. Therefore, the present work will be devoted to formulate the drug in sustained release formulations. MCP was incorporated in 12 formulae containing different polymers and/or different polymer ratios. These polymers were hydroxypropylmethyl cellulose [HPMC], carboxymethylcellulose [CMC] and ethyl cellulose [EC]. Sodium starch glycolate [SSG] was added to some formulae in different amounts in order to soften and/or disintegrate the tablets. The physical properties were found to be satisfactory for all the formulae. The dissolution profiles of the tablets were constructed using the change-over method. The drug release involved a combination of both diffusion and polymer-chain relaxation mechanisms. The time required to release 50% of MCP ranged from 1.2 to more than 8 hours. Direct compression and dry granulation techniques produced sufficient sustaining of the drug release. However, the pellets made by wet granulation released MCP in about 2 hrs, i.e., Pelletization spheronization technique was not effective in sustaining the drug