floating matrix tablet

The purpose of the study was to prolong the gastric residence time of  metformin hydrochloride  by designing its floating tablets and to study the influence of natural polymers like okra gum and fenugreek  gum on its release rate. Sodium bicarbonate was added as a gas generating agent that releases carbon dioxide in the gastric acidic environment which helped in maintain the buoyancy. Metformin hydrochloride  is a biguanide glucose-lowering agent that has been widely used in the management of NIDDM, whose hyperglycemia cannot be satisfactorily managed on diet alone. Metformin hydrochloride is incompletely absorbed from GI tract, with an absorption window confined to the upper part of GI tract. It also has a half life of about 2 hours and its absolute bioavailability is reported to be about 50-60% of the administered oral dose. An obstacle to the more successful use of metformin hydrochloride therapy is the high incidence of GI symptoms seen in about 30% patients, especially during initial weeks of treatment. Patient compliance decreases with frequent dosing regimen and side effects associated with the same. In order to optimize therapy research efforts have been focused on the development of oral sustained release (SR) preparations using natural polymers as well as controlled release gastroretentive dosage forms. The present study outlines a systematic approach for the development of hydrodynamically balanced tablet of metformin hydrochloride using natural polymers with a view to enhance its oral bioavailability and efficacy. Development of floating matrix tablets of metformin hydrochloride using natural polymers (okra and fenugreek).Comparative studies of both available marketed formulations and HPMC polymer.

  The objective of this study was to formulate and evaluate gastroretentive effervescent floating  matrix  tablet of two anti-asthmatic drugs, Salbutamol sulphate and Theophylline which are often indicated for the management of asthma, their frequent dosing may reduce compliance, thus making a prolonged release formulation necessary. Tablets were prepared by wet granulation method using Hydroxy propyl methylcellulose (HPMC) as a release retardant agent and sodium bicarbonate and Citric acid as a gas-generating agents. The prepared granules showed satisfactory flow properties and compressibility. Formulations were evaluated for in vitro drug release profile and swelling characteristics. The similarity factor and dissolution kinetics were used as parameters for selection of the best batch. The result of formulation C7 batch showed the best result and was found to extend the release of Salbutamol Sulphate and Theophylline upto 12 hr. and was found to be comparable with marketed sustained released tablet Theoasthalin SR (Cipla). The in- vitro drug release followed Korsemeyer-Peppas kinetics and the drug release mechanism was found to be of anomalous type i.e, swelling and diffusion.