In the present study, a simple and reliable HPLC-UV method was developed for the determination of mefunidone. The bioanalytical specific procedure involved extraction of mefunidone from a 500-μL hepatic microsomal sy...In the present study, a simple and reliable HPLC-UV method was developed for the determination of mefunidone. The bioanalytical specific procedure involved extraction of mefunidone from a 500-μL hepatic microsomal system through protein precipitation by methanol. Chromatographic separation was achieved using an Agilent TC-C（18） column（4.6 mm×250 mm, 5 μm） with an isocratic mobile phase consisting of 10 mM ammonium formate（pH 2.9, later adjusted by using 10% formic acid）–acetonitrile（70：30, v/v） at a flow rate of 1.0 mL/min. The UV detection wavelength was set at 245 nm. Mefunidone and pirfenidone（PFD, internal standard, IS） were eluted at 6.0 and 9.7 min, separately, with the total running time of 12 min. According to US Food and Drug Administration bioanalytical guidelines, method validation was performed, and the results met the acceptance criteria in details. The calibration curve of mefunidone in liver microsomes was linear over the concentration range of 0.5–16 μg.mL^（–1）. Intra-and inter-run precisions of mefunidone were less than 9.0%, and the biases were within ±10.0%. After incubation of mefunidone in liver microsomes, this method was successfully applied to the pharmacokinetic study.展开更多
Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms.Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use ...Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms.Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics.In order to overcome the resistance problem and to safely use antibiotics,the correct measurement of potency and bioactivity of antibiotics is essential.Microbiological assay and high performance liquid chromatography（HPLC） method are used to quantify the potency of antibiotics.HPLC method is commonly used for the quantification of potency of antibiotics,but unable to determine the bioactivity;whereas microbiological assay estimates both potency and bioactivity of antibiotics.Additionally,bioassay is used to estimate the effective dose against antibiotic resistant microbes.Simultaneously,microbiological assay addresses the several parameters such as minimal inhibitory concentration（MIC）,minimum bactericidal concentration（MBC）,mutation prevention concentration（MPC） and critical concentration（Ccr） which are used to describe the potency in a more informative way.Microbiological assay is a simple,sensitive,precise and cost effective method which gives reproducible results similar to HPLC.However,the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results.展开更多
基金The National Natural Science Foundation of China(Grant No.81302819),the National Natural Science Foundation of China(Grant No.C0709-31201056)the Fundamental Research Funds for the Central Universities of China(Grant No.7601110179)the Fundamental Research Funds for the Central south Universities of China(Grant No.2016zzts494)
文摘In the present study, a simple and reliable HPLC-UV method was developed for the determination of mefunidone. The bioanalytical specific procedure involved extraction of mefunidone from a 500-μL hepatic microsomal system through protein precipitation by methanol. Chromatographic separation was achieved using an Agilent TC-C（18） column（4.6 mm×250 mm, 5 μm） with an isocratic mobile phase consisting of 10 mM ammonium formate（pH 2.9, later adjusted by using 10% formic acid）–acetonitrile（70：30, v/v） at a flow rate of 1.0 mL/min. The UV detection wavelength was set at 245 nm. Mefunidone and pirfenidone（PFD, internal standard, IS） were eluted at 6.0 and 9.7 min, separately, with the total running time of 12 min. According to US Food and Drug Administration bioanalytical guidelines, method validation was performed, and the results met the acceptance criteria in details. The calibration curve of mefunidone in liver microsomes was linear over the concentration range of 0.5–16 μg.mL^（–1）. Intra-and inter-run precisions of mefunidone were less than 9.0%, and the biases were within ±10.0%. After incubation of mefunidone in liver microsomes, this method was successfully applied to the pharmacokinetic study.
文摘Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms.Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics.In order to overcome the resistance problem and to safely use antibiotics,the correct measurement of potency and bioactivity of antibiotics is essential.Microbiological assay and high performance liquid chromatography（HPLC） method are used to quantify the potency of antibiotics.HPLC method is commonly used for the quantification of potency of antibiotics,but unable to determine the bioactivity;whereas microbiological assay estimates both potency and bioactivity of antibiotics.Additionally,bioassay is used to estimate the effective dose against antibiotic resistant microbes.Simultaneously,microbiological assay addresses the several parameters such as minimal inhibitory concentration（MIC）,minimum bactericidal concentration（MBC）,mutation prevention concentration（MPC） and critical concentration（Ccr） which are used to describe the potency in a more informative way.Microbiological assay is a simple,sensitive,precise and cost effective method which gives reproducible results similar to HPLC.However,the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results.
