ABSTRACT
OBJECTIVE:To provide ideas for revise and improve the standard and related method of the quality control of ben-zalkonium chloride in Chinese Pharmacopoeia (2015 edition,Ⅱ). METHODS:The standards and related methods of the quality control of benzalkonium chloride in Chinese Pharmacopoeia(2015 edition,Ⅱ),British Pharmacopoeia(2013 edition),European Pharmacopoeia (7.0 edition) and United States Pharmacopoeia (36 edition) were comprehensively compared. RESULTS:Com-pared with Chinese Pharmacopoeia(2015 edition,Ⅱ),the standards abroad provided the component and the ratio of the benzalko-nium chloride substituted homolog,the method for ammonia compound test had higher sensibility,it also added the test for benzyl alcohol,benzaldehyde and benzyl chloride impurity,as well as the component ratio test and average relative molecular mass calcu-lation. CONCLUSIONS:The standard and related method of the quality control of benzalkonium chloride in Chinese Pharmacopoe-ia(2015 edition,Ⅱ)still need to be further improved.
ABSTRACT
OBJECTIVE:To establish a method for the determination of related substances in bifonazole raw material. METH-ODS:HPLC method was performed on the column of Kromasil C18 with mobile phase of methanol-0.02 mol/L phosphoric acid(ad-justed pH to 7.5 with triethylamine)(70:30,V/V)at a flow rate of 1.0 ml/min,detection wavelength was 258 nm,volume injection was 20 μl,and the column temperature was 40 ℃. RESULTS:The linear range was 0.05-0.25 μg/ml for bifonazole(r=0.9996), 0.05-0.25 μg/ml for impurity A(bifonol)(r=0.9997)and 0.05-0.25 μg/ml for impurity B(4-C isomer)(r=0.9995);the detec-tion limits were 8.2 ng/ml,7.5 ng/ml and 8.4 ng/ml,and the quantification limits were 27.1 ng/ml,24.7 ng/ml and 27.8 ng/ml,re-spectively;RSDs of precision and reproducibility tests were lower than 1%;recovery of impurity B was 95.13%-101.29%(RSD=1.89%,n=9);both impurity A and impurity B were were detected in the 3 batches of samples. CONCLUSIONS:The method is accurate,sensitive and reproducible,and can be used for the determination of the related substances in bifonazole raw material.
ABSTRACT
OBJECTIVE:To establish a method for the content determination of Aciclovir cream. METHODS:Centrifugal parti-tion chromatography(CPC)was conducted. The solvent system was hexane-acetonitrile-water(2∶1∶1,V/V/V),the injection vehicle was an aqueous solution of 5%Tween 80 and the volume was 1.0 ml;the flow rate was 5 ml/min;the wavelength was 254 nm. RE-SULTS:There was a good linear relationship between quality concentration and peak area in the range of 0.012 7-0.126 7 mg/ml (r=0.998 7). The RSD of precision,stability and reproducibility tests was all no more than 2.0% and the average recovery was 97.34%(RSD=0.90%,n=9). CONCLUSIONS:The method is with high precision and accuracy,and can be used for the content determination of principal components of Aciclovir cream.
ABSTRACT
Objective:To establish an HPLC method for the determination of gabapentin and the related substances in gabapentin capsules. Methods:A Kromasil C8 column (250 mm × 4. 6 mm,5μm)was used. The mobile phase was methanol-0. 01 mol·L-1 po-tassium dihydrogen phosphate solution (adjusting pH to 6. 9 with 2 mol·L-1 potassium hydroxide) (40∶60). The detection wave-length was 210 nm. The column temperature was 40℃ and the injection volume was 20μl. The main component and the known impuri-ty were determined by an external standard method. The unknown impurities were determined by a self-control method. Results: The calibration curve of gabapentin was linear within the range of 2.5-20.0 mg·ml-1(r=0.999 9). The average sample recovery was 100. 74% with RSD of 0. 24%(n=5). Conclusion:The method is simple, accurate,specific and applicable in the determination of gabapentin and the related substances in gabapentin capsules.