OBJECTIVE To establish the method on determination of
metronidazole and
chlorhexidine acetate in Taizou lotion by HPLC.METHOD
An HPLC method was established by using a C 18 column ( 250 mm ×4.6 mm , 10μm) as analytical column , methanol acetonitrile triethylamine buffer solution ( 0.05 mol·mL -1 ,adjusted pH to 2.5 with H 3PO 4 ) ( 30 ∶ 30 ∶ 40 ,v/v) as mobile phase , prednisone acetate as an internal standard . The flow rate was 1.0 mL·min -1 , and detection wavelength was at 254 nm.RESULTS The linearity was obtained over the range of 32～128μg·mL -1 for
metronidazole ( r = 0.99996 ) and 20～80μg·mL -1 for chlorhexidine acetate ( r = 0.99997 ) ,
respectively . The average recovery of method was 100.4% with RSD 0.19 % for metronidazole and 99.94% with RSD 0.20 % for chlorhexidine acetate , respectively. The intra day and inter day RSD for metronidazole were 0.12 % ( n = 6 ) and 0.32 % ( n = 5 ) , that for chlorhexidine acetate were 0.18 % ( n = 6 ) and 0.35 % ( n = 5 ) , respectively.CONCLUSIONS The method is simple , rapid , accurate and can be used for the quality control of the preparation.