Hydroxypropylmethylcellulose

The study aimed to formulate and evaluate sustained release ondansetron tablet. Conventional ondansetron tablets not only produce rapid and relatively high peak blood levels resulting in adverse effects but also should be administered three to four times daily. These drawn backs can be overcome by designing a suitable sustained release formulation. Sustained release tablets of ondansetron to be taken once daily were formulated with ondansetron hydrochloride equivalent to 8 mg of ondansetron base. Matrix system based on swellable as well as non-swellable polymers was selected for sustaining the drug release. Different polymers such as hydroxypropylmethylcellulose (HPMC), Carbopol were studied. Combinations of non-swellable polymers with HPMC were also tried in order to get the desired sustained release profile over a period of 24 h. The effect of drug to polymer ratio on in vitro release was studied. The marketed formulation was evaluated for different parameters such as appearance, weight variation, drug content and in vitro drug release. The optimized formulation was subjected to stability studies at different temperature and humidity conditions as per ICH guidelines. In vivo studies were carried out for the optimized formulation in six healthy human volunteers and the pharmacokinetic parameters.

  The aim of the present study was to prepare and characterize twice-daily sustained-release matrix tablets of Timolol maleate (TM) using different concentrations of hydrophilic Hydroxypropylmethylcellulose (HPMC K100M CR) alone and its combination with hydrophobic ethyl cellulose (EC). Formulations prepared by the wet granulation technique and were evaluated for the release of TM over a period of 12 hours using United States Pharmacopoeia (USP) type-II dissolution apparatus. Along with physical properties, the dynamics of water uptake and erosion degree of tablets were also studied. The in-vitro drug release study revealed that formulation F3 (40% wt/wt HPMC K100M) could extend the drug release up to 8 hours. The most successful formulation of the study, F5 (HPMC to EC, 1:1), extended the drug release up to 12 hours, exhibited satisfactory drug release in the initial hours, and the total release pattern was close to the theoretical release profile. The drug release from optimized formulation (F5) followed first-order kinetics via Non-Fickian (anomalous) diffusion. FTIR studies revealed that there was no interaction between the drug and excipients. In conclusion, the results indicated that the prepared sustained-release tablets of TM could perform therapeutically better than conventional tablets with improved efficacy and better patient compliance.   Key words: Timolol maleate; Matrix tablets; Sustained-release; Ethyl cellulose; Hydroxypropylmethylcellulose; In-vitro drug release.