ACTA Pharmaceutica Sciencia									
									
										2011 , Vol 53 , Num 3										
									
								
								
								 
											        			
											        			EFFECT OF HYDROPHILIC POLYMERS PROPERTIES IN CONTROLLING THE DRUG RELEASE 
											        			
											        			
											        			 
											        					
											        					Department of Pharmaceutical Sciences, JNTUH Campus, Hyderabad 
											        			
											        		
		
											        														        			
																											        					
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											        				Extended release matrix formulations are the most promising among the controlled release category. Various types of polymers available for formulation of extended release formulations, among them hydrophilic polymers are the most promising polymers. The release control mechanism of hydrophilic polymers following ingestion is complex, but is known to be based on diffusion of the drug through the hydrated portion of the matrix and erosion of the outer hydrated polymer on the surface of the matrix. For the selection of controlled release polymer in formulating the extended release formulations, one should expertise with the release behaviour of the selected polymer. In this study metoprolol succinate extended release matrix tablets were manufactured with various concentrations of controlled release hydrophilic polymers namely hypromellose (HPMC) K200M and polyethylene oxide (Polyox) WSR-303. The rate of swelling and erosion was different with two studied polymers. The effect of this swelling and erosion properties of the polymers on the drug release profile was studied. Dissolution studies were conducted using USP official methods. From the studies conducted, it was observed that a rate of swelling in initial time points and erosion in later time points were higher with Polyox WSR-303 than HPMC K200M. Comparatively, Polyox WSR-303 was able to greatly control the drug release in initial time points, and HPMC K200M was greatly control the drug release in later time points. 
											        			
											        			
																											        			
											        			Keywords : 
											        				EXTENDED RELEASE, GELATION INDEX, HYPROMELLOSE K200M, METOPROLOL SUCCINATE, POLYOX WSR-303, SWELLING INDEX 
											        				
											        														        	 
			 
	 
	

