DETERMINATION OF IRON(II) IN POLYVITAMIN COMPOUNDS BY USING 6-[2’-(5-BROMOTHIAZOLYLAZO)]-3,5- DIHYDROXY-1,2-BENZENEDISOLFONIC ACID AS COMPLEXANT (BR-TDB)

Naseera P., Rashidah K. Ansari*, Dr. Nishad K. M., Dr. Shijikumar P. S. and Dr. Sirajudheen M. K.

ABSTRACT

The aim of this review work was to study the effect of the combination of HPC and HPMC on modified release tablets. Modified release dosage and its variants are mechanisms used in tablets and capsules to dissolve a drug over time in order to be released slower and steadier into the bloodstream while having the advantage of being taken at less frequent intervals than immediate release formulation of the same drug. The polymers have significant role in modified release formulations. The main role of polymer is to protect the drug from physiological environment and prolong release of drug to improve its stability. The drug release from polymer is takes place by diffusion, degradation and swelling. Hydroxypropyl cellulose and Hydroxypropyl methyl cellulose are the examples for such type of polymers. HPMC, also known an hydromellose, is one of the best known cellulose polymer. It is available in various grades. It act as an excellent hydrophilic gel forming polymer. HPMC is used as a matrix that swells and expands after absorbing water. Hydroxypropyl cellulose[HPC] is a cellulosic derivative which has characters such as non-polar, water solubility and highly pH sensitive. It acts as a thickening agent by altering the viscosity. It can be used for the binding of tablet dosage forms. It serves as a film coating agent. In this work, the properties of polymers are considered at various level.

Keywords: Hydroxypropyl methyl cellulose, Hydroxypropyl cellulose, Carbopol, Cellulose etc.