No abstract

The purpose of this review is to cover various aspects related with the use of ion exchange resins for taste masking of bitter drugs and for formulating sustained release dosage form. Ion exchange resins are water insoluble cross-linked polymers containing a salt-forming group at repeating positions on the polymer chain and have the ability to exchange counter-ions within aqueous solutions surrounding them. The bitterness of pharmaceutical medicines plays a critical role in patient compliance, as the oral administration of bitter drugs is often hampered by their unpleasant taste which leads to non-compliance and further worsening of diseased condition. One of the popular approaches in the taste masking of bitter drugs is based on IER. For taste masking purpose weak cation exchange or weak anion exchange resins are used, depending on the nature of drug. The drug resin complex is absolutely tasteless with no after taste, and at the same time, its bioavailability is not affected. Sustained release dosage forms are designed to release a drug at a pre determined rate in order to maintain a constant drug concentration for a specific period of time with minimum side effects. The usage of IER during the development of sustained release formulations plays a significant role because of their drug retarding properties. In this review also incorporates various patents related to taste masking and sustained release formulations using IER.

Objective: The objective of this study is to develop extended release matrix tablet by taking mixture of chitosan and anionic polymers and then to study the drug release pattern for a low solubility drug Tramadol Hydrochloride (TH). TH has mean elimination half-life is ~6 hrs and requires dosing every 6 hrs in order to maintain optimal relief of chronic pain. So once-daily extended-release tablets are formulated by taking Chitosan (CS) and anionic polymers Eudragit-L100-55. Methods: The tablets were prepared by direct compression method. In vitro drug release was carried out under simulated gastric and intestinal condition to achieve drug release more than 20 hrs. Fourier transform infrared spectroscopy (FTIR) study was conducted to study any interaction between dug and ingredients. Results: CS and Eudragit-L combination form a Poly Electrolyte Complex which is responsible for extending drug release for low solubility drug. This complex formation is also confirmed by FTIR study. Conclusion: Stability studies (40ºC and 75 ± 5%RH) for 3 months indicated that Tramadol hydrochloride was stable in the matrix tablets.