Simultaneous analysis of allopurinol and oxypurinol using a validated liquid chromatography-tandem mass spectrometry method in human plasma
	    		
		   		
	    	
    	
    	
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Rathod M. Dhiraj
			        		
			        		;
		        		
		        		
		        		
			        		Patel R. Keyur
			        		
			        		;
		        		
		        		
		        		
			        		Mistri N. Hiren
			        		
			        		;
		        		
		        		
		        		
			        		Jangid G. Arvind
			        		
			        		;
		        		
		        		
		        		
			        		Shrivastav S. Pranav
			        		
			        		;
		        		
		        		
		        		
			        		Sanyal Mallika
			        		
			        		
		        		
		        		
		        		
		        		
		        		
			        		
			        		
		        		
	        		
        		 
        	
        	
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Allopurinol;
			        		
			        		
			        		
				        		Oxypurinol;
			        		
			        		
			        		
				        		Liquid chromatography-tandem mass spectrometry;
			        		
			        		
			        		
				        		Bioequivalence study
			        		
			        		
	        			
        			
        		
 
        	
            
            
            	- From:
	            		
	            			Journal of Pharmaceutical Analysis
	            		
	            		 2017;7(1):56-62
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	The present study describes a simple, reliable and reproducible liquid chromatography–tandem mass spectro-metry method (LC–MS/MS) for the simultaneous determination of allopurinol and its active metabolite, oxypurinol in human plasma for a pharmacokinetic/bioequivalence study. After protein precipitation (PPT) of 100 μL plasma sample with 1.0%formic acid in acetonitrile, the recovery of the analytes and allopurinol-d2 as an internal standard ranged from 85.36% to 91.20%. The analytes were separated on Hypersil Gold (150 mm×4.6 mm, 5 μm) column using 0.1% formic acid-acetonitrile (98:2, v/v) as the mobile phase. Quantification was done using electrospray ionization in the positive mode. The calibration concentration range was established from 60.0 to 6000 ng/mL for allopurinol and 80.0–8000 ng/mL for oxypurinol. Matrix effect in human plasma, expressed as IS-normalized matrix factors ranged from 1.003 to 1.030 for both the analytes. The developed method was found suitable for a clinical study with 300 mg allopurinol tablet formulation in healthy subjects.