Matrix tablet

Methimazole is active pharmaceutical ingredient effectively utilized in hyperthyroidism. Methimazole inhibits peroxidase as well as iodine interactions with thyroglobulin to produce triiodothyronine with thyroxine. Methimazole shows very low protein binding (1-10%) bounds to plasma proteins and easily metabolized by liver. In this investigation, efforts given to develop a sustained release matrix tablet of Methimazole. Sustained release drug delivery systems are for a maximum of 24 hours clinical effectiveness. Such systems are primarily for the drugs of short elimination half-life. However, drugs with long half-life also qualify if a reduction in steady state fluctuation is desired. Matrix tablets of methimazole were prepared by utilizing direct compression method. HPMC along with Sodium carboxy methyl cellulose used to retard drug release from the dosage form. Matrix tablets of methimazole were evaluated for different quality control test to improve quality of the product. In vitro release study of methimazole matrix tablets shows that polymer percentage used in the formula is enough to extend the release of the drug for at least 12 hr. In dissolution study of matrix of methimazole formulation F2 shows maximum drug release 97.93 % at the end of 6 hours while F1 shows least 83.64 %.

Oral drug delivery systems most preferred option of administration for various drugs. Sustained release drug delivery system is the novel drug delivery system. The terms Sustained release, prolonged release, modified release, extended release or depot formulation are used to identified drug delivery systems that are designed to achieve or extend therapeutic effect by continuously releasing medication over an extended period of time after administration of a single dose. Sustained release dosage forms are designed to release a drug at a predetermined rate by maintaining a constant drug level for a specific period of time with minimum side effects. The basic rationale of sustained release drug delivery system optimizes the biopharmaceutical, pharmacokinetics, and pharmacodynamic properties of a drug in such a way that it’s utility is maximized, side effects are reduced and cure of the disease condition is achieved. Sustained release drug delivery is improved patient compliance due to less frequent drug administration, reduction of fluctuation in steady-state drug levels, maximum utilization of the of the drug, improved therapy and shorter treatment period.

In the present study, an attempt was made to prepare and evaluate matrix tablets of Ondansetron HCl using HPMC, EC and Eudragit for Sustained release of Ondansetron HCl. The matrix tablets were prepared by wet granulation method. All the formulations are evaluated for the Hardness, Friability, Weight variation, Drug Content, In-Vitro Drug Release. The weight variation and drug contents of all the tablets were found to be uniform with the low SD values. The FTIR study indicated that the drug is stable in the formulations. The prepared matrix tablets were capable of releasing the drug for 12 hours depending upon the formulation variables. The tablets prepared with HPMC and Eudragit combination have shown higher drug release Drug release mechanism followed non-Fickian transport from both the polymers matrices. The drug released from the formulation is depends on the concentration of the polymers.

The aim of this investigation was to develop and optimize Metformin HCl matrix tablets for sustained release application by response surface methodology based on two factor-three response factorial design. The effects of the amounts of polysaccharide from tamarind and polysaccharide from jackfruit in Metformin HCl matrix tablets on the properties of Metformin HCl sustained release matrix tablets drug release was analyzed and optimized. The observed responses were coincided well with the predicted values by the experimental design. The optimized Metformin HCl matrix tablets showed prolonged sustained release of Metformin HCl over 6 hours. These matrix tablets followed the first-order model with anomalous (non-Fickian) diffusion mechanism.

  The present study was undertaken to investigate the release retardant potential of Borassus flabellifer mucilage in tablet formulations. In the present study six batches of diclofenac sodium matrix tablets were prepared by wet granulation method with different concentrations of BFM (2.5, 5, 7.5,10 and 12.5%w/w) and compared with guar gum as standard release retardant polymer. The tablets had uniform physical appearance, average weight, drug content, and adequate hardness. The results of in vitro release revealed that as the proportion of mucilage in the matrix was increased there was a corresponding decrease in the release of drug. Among the formulations studied formulation F5 containing BFM in the concentration of 12.5% showed sustained and required dissolution profile of drug for 12hrs with cumulative percent release of 98%. Further, the matrix tablets were found to release the drug by diffusion coupled with erosion mechanism. The swelling studies revealed that, as the proportion of mucilage in tablets was increased, there was a corresponding increase in percent swelling of tablets. The SEM photomicrographs showed both pores and gelling structures were present on the surface of tablets indicates the combination of diffusion and erosion mechanism in the release of diclofenac. No chemical interaction between drug, mucilage and mixture of mucilage/drug was seen as confirmed by DSC and IR studies. Optimized formulation (F5) showed no change in physical appearance, drug content, or in dissolution pattern after storage at 40±2°C and 75±5% RH for 3 months.

Presently pharmaceutical industries are focusing on development of sustained release formulations due to its inherent boons. Sustained release dosage forms are designed to release a drug at a predetermined rate by maintaining a constant drug level for a specific period of time with minimum side effects. The basic rationale of sustained release drug delivery system optimises the biopharmaceutical, pharmacokinetic and pharmacodynamic properties of a drug in such a way that its utility is maximized, side-effects are reduced and cure of the disease is achieved. There are several advantages of sustained release drug delivery over conventional dosage forms like improved patient compliance due to less frequent drug administration, reduction of fluctuation in steady-state drug levels, maximum utilisation of the drug, increased safety margin of potent drug, reduction in healthcare costs through improved therapy and shorter treatment period. Sustained release products are designed to bring the blood level of a drug immediately to therapeutic concentrations by means of an initial dose portion called loading dose and then sustain this level for a certain predetermined time with the maintenance portion. The basic goal of sustained release is provide promising way to decrease the side effect of drug by preventing the fluctuation of the therapeutic concentration of the drug in the body and increase patient compliance by reducing frequency of dose. Key Words: Oral sustained release system, Matrix tablet, Patient compliance, Half-life