Determination of misoprostol in workplace air by high performance liquid chromatography / 中华劳动卫生职业病杂志

Objective: To establish a high performance liquid chromatography method for the determination of misoprostol in workplace air. Methods: From February to August 2021, the misoprostol in the workplace air was collected by glass fiber filter membrane, and theeluent was separated by C18 liquid chromatography column, determined by UV detector, and quantified by external standard method. Results: The quantitative lower limit of misoprostol determination method was 0.05 μg/ml, and the lowest quantitative concentration was 1.4 μg/m(3) (calculated by collecting 75 L air sample). The concentration of misoprostol has a good linear relationship between 0.05 to 10.00 μg/ml. The relative coefficient was 0.9998. The regression equation of the standard working curve was y=495759x-45257. The range of average recovery rates were from 95.5% to 102.8%. The intra-assay precision of the method was 1.2%-4.6%, and the inter-assay precision was 2.0%-5.9%. The samples could be stored stably for 7 days at 4 ℃. Conclusion: The high performance liquid chromatography method for the determination of misoprostol has high sensitivity, good specificity and simple procedure of sample pretreatment. It is suitable for the detection of misoprostol in the workplace air.

Optimization and verification of size exclusion chromatography-high performance liquid chromatography for determination of recombinant human growth hormone-Fc immunofusion protein polymer / 中国生物制品学杂志

@#Objective To optimize and verify the size exclusion chromatography-high performance liquid chromatography(SEC-HPLC) method for the determination of recombinant human growth hormone(rhGH)-Fc immunofusion protein polymer.Methods The multimer content of rhGH-Fc immunofusion protein was detected by SEC-HPLC.The detection conditions(salt concentration,mobile phase pH,flow rate,column temperature and column model) were optimized to observe the separation effect of the target proteins and polymers.The system suitability,specificity,linearity and range,precision,accuracy and limit of quantification of the method were verified.Results The optimized method was to use TSK-gel G2000SW_(x1)column(5 μm,7.8 mm × 300 mm),mobile phase of 50 mmol/L phosphate buffer(pH 6.80),detection wavelength of280 nm,injection volume of 100 μL,flow rate of 0.6 mL/min and column temperature of 45 ℃.The resolution of rhGHFc immunofusion protein and polymer,the theoretical plate number and the tailing factor all met the requirements;the peak time of rhGH-Fc immunofusion protein was the same as that of the control,while the peak time of GH national standard was different from that of the control,and the protein buffer showed no peak;the concentration of rhGH-Fc immunofusion protein was in the range of 0.307～1.842 mg/mL with good linear correlation between the peak area integral value and the injection volume(R~2=0.999 4);the RSD of peak area and purity in repeatability verification were 0.7% and 0.1%,respectively;the RSD of intermediate precision verification was 0.8%;the average recovery rate of accuracy verification was 99.1% with the RSD of 1.9%;the limit of quantification was 6 μg/mL.Conclusion The optimized SEC-HPLC method was used to detect the content of polymer in rhGH-Fc immunofusion protein with improved accuracy,and the column efficiency and separation were in accordance with the relevant requirements of Chinese Pharmacopoeia(Volume Ⅳ,2020edition),which could be used for the detection of polymer content in samples.

Study on determination of 2-thioxothiazolidine-4-carboxylic Acid in urine by high performance liquid chromatography / 中华劳动卫生职业病杂志

Objective: To establish a high performance liquid chromatography method for the determination of 2-thioxothiazolidine-4-carboxylic acid (TTCA) in urine. Methods: After acidification with hydrochloric acid, TTCA in urine was first extracted by ethyl acetate with excessive sodium chloride, then gradient separated by a symmetry C18 column and then detected by a diode array detector. The quantification was based on a working curve of external standard method. Results: The linear relationship of TTCA in urine was good in the range of 0.03-10.00 mg/L, and the correlation coefficient was 0.9999. The detection limit and minimum quantitative concentration of TTCA in urine were 0.008 mg/L and 0.027 mg/L. The intra-assay precision of the method was 0.9%-1.4%, the inter-assay precision was 1.3%-3.5%, and the average recovery was 85.0%-92.7% while the concentrations of TTCA in urine was 0.8, 2.0 and 8.0 mg/L, respectively (n=6) . Conclusion: The gradient elution high performance liquid chromatography method has simple operation and high sensitivity, and it is suitable for the determination of TTCA on a low level in urine for occupational workers exposure to carbon disulfide.

Pharmacokinetic Study of Letrozole Polymorphs in Rats / 医药导报

Objective To study the gastrointestinal absorption process of three letrozole polymorphs in rats, and evaluate the different pharmacokinetics parameters of different polymorphs. Methods A total of 18 SD rats were given the different letrozole polymorphs. Then the high-performance liquid chromatographic method was used for the determination of plasma concentration of letrozole in these SD rats.Finally the pharmacokinetic parameters among the different polymorphs were calculated. Results Cmax of letrozole crystal form I, crystal form II and crystal form III were (9.247± 4.612) ,(23.387± 9.049) and (15.682±1.589) mg·L-1, respectively, and AUC0→t were(198.115±47.014) ,(476.641±125.467) and (271.817±41.068) mg·L-1·h,respectively. Conclusion The different crystal forms of letrozole result in different plasma concentration in SD rats. Crystal form II may be its preponderant polymorphs which deserves further research and development.

Simultaneous Determination of Five Components in Fufang Heishen Oral Liquid by Dual-wavelength HPLC / 医药导报

Objective To establish a method that could detect 5 components of Fufang Heishen oral liquid simultaneously. Methods The component was performed by high performance liquid chromatography ( HPLC) equipped with Agilent Hypersil ODS (4.6 mm×250 mm,5 μm).The mobile phase consisted of acetonitrile-0.1% Phosphoric acid with gradient elution.The flow rate was 1.0 mL·min-1with the 210 nm and 270 nm detection wavelength,20 μL injection volume and 30 ℃column temperature. Results A good linear relationship was observed with the range of 7.12-85.44 mg·L-1for Harpagide (r＝0.999 9),2.50-30.00 mg·L-1for Harpagoside(r＝0.999 8),25.35-304.20 mg·L-1for Cinnamic acid(r＝0.999 7),0.73-8.70 mg·L-1for Tectoridin(r＝0.999 7)and 1.20-14.40 mg·L-1for Irisflorentin(r＝0.999 8).The average recovery of each detected component of Fufang Heishen Oral Liquid was 98.8%,102.7%,98.8%,99.3%,99.9% the RSD were 1.23%,2.89%, 2.60%,1.44%,2.84%(n＝6). Conclusion The method is simple,rapid and accurate and can be used to detect the content of Harpagide,Harpagoside,Cinnamic acid,Tectoridin and Irisflorentin of Fufang Heishen Oral Liquid.

Determination of Nigeglanoside in Seeds of Nigella glandulifera by HPLC / 医药导报

Objective To establish a method for the determination of nigeglanoside in seeds of Nigella glandulifera. Methods The content of nigeglanoside was determined by HPLC.The separation was performed on a C18column ( YMC-Pack ODS-A,250 mm×4.6 mm,5 μm) with a gradient elution system of acetonitrile and 0.017 5 mol·L-1acetic acid solution at the flow rate of 1.0 mL·min-1.The detection wavelength was set at 290 nm,and column temperature was 30 ℃. Results The linear range of nigeglanoside was 0.01-0.30 mg·mL-1(R2＝0.9991).The RSDs of precision,stability and repeatability were all less than 2%.The average recovery was 96.66% (RSD＝1.25%,n＝6). Conclusion The method is accurate and reproducible. It is effective in controlling the quality of seeds of Nigella glandulifera .

Quality Standard of Yinqiao Xiaozhen Mixture / 医药导报

Objective To establish a quality standard of yinqiao xiaozhen mixture. Methods Preparation of Forsyth-ia,Arctium lappa L.,and Honeysuckle were identified by TLC method.The concentration of baicalin in yinqiao xiaozhen mixture was determined by HPLC method. Results The qualitative identification method can detect Forsythia,Arctium lappa L.,and Honeysuckle.TLC spots were clear.TLC method has strong specificity.The linear range of baicalin was 0.122 5-1.531 2 μg,r=0.999 9,the average sample recovery rate was 99.42%,RSD was 2.19%,respectively. Conclusion The method is simple,ac-curate and repeatable,which can be used for quality control of Qinqiao xiaozhen mixture.

Simultaneous Determination of Benzoic Acid and Salicylic Acid in Compound Benzoic Acid Embrocation by High Performance Liquid Chromatography / 医药导报

Objective To develope a high performance liquid chromatography ( HPLC) method for simultaneous determination of benzoic acid and salicylic acid in compound benzoic acid embrocation. Methods An Alltima C18 column (150 mm×4.6 mm,5 μm) was used for the separation, with methanol-0.1％ phosphoric acid (50:50) as the mobile phase at the flow rate of 1.0 mL?min-1 .The detection wavelength was set at 236 nm.The column temperature was 35 ℃ . Results The good linearity was obtained with the correlation coefficient (r) of 1.0000 for benzoic acid and salicylic acid;the precisions and stability were satisfactory, and the relative standard deviations (RSDs) were less than 0.3％.The average recoveries (n= 9) were 100.15％ and 99.85％ for benzoic acid and salicylic acid, respectively. Conclusion The established method is accurate, simple and rapid, and can be utilized for the simultaneous determination of benzoic acid and salicylic acid in compound benzoic acid embrocation.

Percutaneous Absorption of Mupirocin Ointment in Vitro / 医药导报

Objective To compare the percutaneous absorption of experimentally prepared mupirocin ointment and commercially sold mupirocin ointment, and to study the dynamics mode of transdermal absorption of mupirocin ointment. Methods Inerstil ODS-SP column (4.6 mm× 150 mm,5 μm) was used with a mixture of 0.1 mol·L-1 sodium dihydrogen phosphate buffer solution (pH value was adjusted to 6.3 by 0.1 mol·L-1 sodium hydroxide solution) and acetonitrile (75:25) as a mobile phase by HPLC.The detection wavelength was set at 230 nm.The flow rate was 1.0 mL·min-1 .Improved Franz type diffusion cells were used for in vitro permeation studies and excised Obama Suckling pig skins in vitro were used as the transdermal barrier.The concentration of the receptor solution was determined by HPLC to investigate its cumulative permeation quantities at different time and the two sets of ointment were compared. Results The average recovery rate of hydrophilic medium was 99.4％,and RSD was 1.2％(n= 9).The average recovery rate of lipophilic medium was 99.0％,and RSD was 1.3％(n= 9).There was no significant difference of the concentration between two ointment within 12 h.The osmotic release of the drug of the sample and the reference preparation, which were in hydrophilic medium, was similar to that of the Zero equation, and roughly Higuchi equation in the lipophilic medium. Conclusion The results showed that the release behavior of mupirocin ointment followed Zero equation in the hydrophilic medium,and Higchi equation in the lipophilic medium.

Quality Standards of Salt Eucommia Dispensing Granules / 医药导报

Objective To establish the quality standards for salt eucommia dispensing granules. Methods The extractives were obtained by alcohol extraction method. HPLC was applied for the determination of pinoresinol diglucoside in dispensing granules. HPLC fingerprints were established by the contrast of Agilent 1260 HPLC, Waters HPLC and various chromatogram column. Results Pinoresinol diglucoside showed a good linear relationship ( Y = 2. 9594X + 3. 2825,R2 =0.9999) at 102.8-2056.0 mg?L-1 with average recovery of 99.85％ (RSD = 0.31％,n = 9). Conclusion The method is easy-operated and accurate,which has a good specificity for the quality control of common salt eucommia dispensing granules.

Determination of 10-Hydroxyl Carbamazepine in Human Serum by High Performance Liquid Chromatography / 医药导报

Objective To establish a method for the determination of 10-hydroxyl carbamazepine (MHD),which is an activity metabolite of oxcarbazepine in human serum. Methods Serum samples were detected by high performance liquid chromatography (HPLC) after being processed by methanol protein deposition.The chromatographic column was Agilent TC-C18 (4.6 mm × 250 mm, 5 μm), with the mobile phase of acetonitrile-10 mmol ? L-1 KH2 PO4 ( 33 : 67) at a flow rate of 1.0 mL?min-1 .The detection wavelength was 230 nm,and phenacetin was used as an internal standard. Results The average recovery range of low,middle and high (1.0,10.0,60.0 μg?mL-1 ) concentrations for MHD was from 100.3％ to 106.0％.The RSD of intra-day and inter-day was ≤5.8％ (n= 5) and ≤7.4％ (n= 5),respectively.The limit detection of analysis method was 0.1 μg?mL-1 .Regression equation was Y = 0.1308X+ 0.0679 ( r = 0.9966,n = 5). Serum samples remained stable at room temperature,freezing and freeze thawing condition. Conclusion This method is sensitive,accurate,simple and quick,and can be used for monitoring the oxcarbazepine metabolites MHD in serum for clinical and pharmacokinetic study.

Determination of Entrapment Efficiency of Levodopa-loaded PEGylated-Solid Lipid Nanoparticles by Mini-Column Centrifugation-HPLC / 医药导报

Objective To establish a mini-column centrifugation-HPLC method to determine the entrapment efficiency of levodopa-loaded PEGylated-solid lipid nanoparticles.Methods A dextran gel(Sephadex G-50) mini-column centrifugation was employed to separate the free drug from solid lipid nanoparticles.The content of levodopa was qualified by HPLC.Results Under the applied chromatographic condition,the excipients had no influence on the determination of levodopa.A calibrated linear of levodopa concentration was within 10.54-527.00 μg·mL-1.The recoveries of high,medium and low concentrations of levodopa were 99.13%,99.51% and 99.04%(RSD were 1.25%,1.91% and 1.71%), respectively.The free levodopa was well separated from solid lipid nanoparticles by using mini-column centrifugation.The addition of blank solid lipid nanoparticles recovery was 98.84% with RSD of 0.80%(n=3).The average adsorption rates of the three concentrations of free levodopa were 100.00%,98.75% and 98.56%(RSD were 0.00%,0.19% and 0.18%,n=3),respectively.The adsorption rate of the physical mixtures of three different concentrations of drugs and empty PEGylated solid lipid nanoparticles were 99.68%,98.46% and 99.21%(RSD were 1.52%,0.23% and 0.21%),respectively.Conclusion The method was simple,accurate and reproducible,which can be used for determination of the entrapment efficiency of levodopa-loaded PEGylated-solid lipid nanoparticles.

Stability of Alkaline in Process of Preparation for Jianghuang Qingzhi Tablets / 广州中医药大学学报

Objective To study the stability of alkaline and degraded products of curcumin by high performance liquid chromatography(HPLC) and HPLC-mass spectrometry (MS) for the optimization of alkaline-dissolved process parameters of the Jianghuang Qingzhi Tablets and for the quality control of the tablets.Methods HPLC was performed for the determination of the alkaline-dissolved stability of curcumin with acetonitrile-acetic acid at volume coefficient of 4％ (48 ∶ 52) as mobile phase,the detection wavelength being 430 nm.The alkalinedegraded products were tested by HPLC-MS assembling with electron spray ionization (ESI) and quadrupole timeof-flight (Q-TOF) in the scan range of 100-2 000 m/z.Results The degradation of curcumin in the alkaline solution was increased with the temperature.When the temperature was below 20 ℃,the degradation slowed down,while when the temperature reached to 80 ℃,curcumin was degraded completely within 2 h.The probable degradation products in the alkaline solution were p-hydroxy benzaldehyde,vanillin,p-coumaric acid,ferulic acid,et al.Conclusion Curcmin compounds are instable in aqueous alkali.To obtain the high-quality of Jianghuang Qingzhi Tablets with high content of curcumin and less degraded products,the alkaline-solution temperature should be controlled below 20 ℃.

Determination of Solubility and Apparent Oil/Water Partition Cofficient of Salicylic Acid by RP-HPLC / 医药导报

Objective To determine equilibrium solubility and apparent partition coefficient of salicylic acid at 25 ℃,and to provide a theoretical basis for design and preparation of its formulation.Methods Equilibrium solubility and apparent partition coefficient (Papp) of salicylic acid were respectively investigated in water,hydrochloric acid solution (pH 1.0) and phosphate buffer solution system (pH 2.0,3.0,4.0,5.0,6.0,7.0,7.8) at 25 ℃.The shake flask method and HPLC were used.The column was Waters C18 (4.6 mm ×250 mm,5 μn) with the mobile phase as methanol-0.1％ phosphoric acid water (47:53).The column temperature was room temperature.The flow rate was 1.0 mL·min-1.The detection wavelength was 270 nm and injection volume was 20 μL.Results Equilibrium solubility of salicylic acid was (2.205 ±0.020) mg·mL-1 at 25 ℃ in Water and its Papp was (6.18 ±0.08).The solubility were (1.169 × 10-3 ±7.40 × 10-6),(2.250 ±0.010),(2.410±0.010),(2.694 ±0.003),(5.208 ±0.010),(5.826 ±0.006),(6.255 ±0.030),(3.353 ±0.070) mg·mL-1,respectively,at hydrochloric acid solution (pH 1.0) and phosphate buffer solution system (pH 2.0,3.0,4.0,5.0,6.0,7.0,7.8),and the corresponding Papp were (16.39 ±0.19),(4.23 ±0.07),(6.03 ±0.11),(5.56 ±0.10),(1.25 ±0.01),(0.27 ± 0.001),(0.08 ± 0.001) and (0.07 ± 0.002),respectively.Conclusion The solubility of salicylic acid increases and its oil-water partition coefficient declines with pH value increasing.Salicylic acid is slightly soluble in water and oil.It belongs to Class Ⅳ drug in Biopharmaceutics Classification System (BCS).

Determination of Three Active Components in Shuanghua Caoshanhu Hanpian by HPLC / 医药导报

Objective To establish a HPLC method for determination of three active components in Shuanghua Caoshanhu Hanpian.Methods Agilent TC-C18 (4.6 mm × 250 mm,5 μm) column was used.The mobile phase was acetonitrile-water containing 0.2％ phosphoric acid with gradient elution mode at a flow rate of 1.0 mL· min-1,the column temperature was 30 ℃,the detection wavelength was 327 mn (0-10 min) for chlorogenic acid,342 nm (10-35 min) for isofraxidin and msmarinic acid.Results Chlorogenic acid had a good linearity in the range of 0.052-0.939 μg (r =0.999 8,n =6),the average recovery was 99.23％ with RSD of 1.4％ (n =9).Isofraxidin had a good linearity in the range of 0.004-0.077 μg (r =0.999 8,n =6),the average recovery was 100.33 ％ with RSD of 1.8 ％ (n =9).Rosmarinic acid had a good linearity in the range of 0.012-0.213 μg (r =0.999 9,n =6),the average recovery was 99.42％ with RSD of 1.4％ (n =9).Conclusion The method is simple,accurate and reliable.It can be used to determine chlorogenic acid,isofraxidin and rosmarinic acid in Shuanghua Caoshanhu hanpian at the same chromatogram condition.

Comparison of HPLC and CMIA Method in Monitoring Concentration of Phenytoin in Epileptic Patients' Plasma / 医药导报

Objective To establish a high performance liquid chromatography (HPLC) method for determining phenytoin concentration in epilepsy patients' plasma,and compare this method with chemiluminescence microparticle immunoassay (CMIA),and to evaluate the consistency of the two methods.Methods HPLC and CMIA methods were applied to determine the plasma concentration of phenytoin in 60 epileptic patients,respectively.The difference of results was analyzed by two-side paired t-test,and then the correlation and consistency of the two methods were investigated with Passing-Bablok regression and Bland-Altman method.Results There was no significant difference between the results of the two methods (P ＞0.05).The regression equation of the determination results by HPLC (Y) and CMIA (X) was Y=0.992 9X +0.143 7 (R2 =0.992 6,n =60),which indicated the correlation of the two methods was good.Bland-Altman analysis showed that the consistency of the two methods for determining was good.Conclusion HPLC and CMIA method in monitoring plasma concentration of phenytoin have good correlation and consistency.Both methods can be used for therapeutic drug monitoring of phenytoin.

Determination of Contents of Five Indole Alkaloids in Rauvolfia by High Performance Liquid Chromatography / 医药导报

Objective To establish an high perfermance liquid chromatography method for determination of five indole alkaloids in Rauvolfia.Methods The Diamonsil C18 column was used at 25 ℃ with methanol-water (gradient elution) as the mobile phase,the flow rate was 1.0 mL·min-1,the detective wavelength was 280 nm,and the injection volume was 5 μL.Results In the range of 1.56-200 μg· mL-1,the correlation coefficients of regression equations of sarpagine,yohimbine,ajmaline,ajmalicine,reserpine were higher than 0.999 0.The average recovery (n =9) of five indole alkaloids was between 95.0％-105.0％.Conclusion This method is simple with good accuracy and repeatability.It can be used for quality control of Rauvolfia.

Comparison of Reversed Phase High Performance Liquid Chromatography and Fluorescence Polarization Immunoassay for the Determination of Plasma Concentration of Carbamazepine / 医药导报

Objective To evaluate the correlation and difference of reversed phase high performance liquid chromatography (RP-HPLC) and fluorescence polarization immunoassay (FPIA) on determining serum concentration of carbamazepine.Methods Fifty serum samples were collected,both RP-HPLC and FPIA methods were employed to determine the concentration of carbamazepine.The results were analyzed by paired t test,Bland-Altman and Deming regression methods,respectively.Results The results of measuring 50 samples by the two methods showed that FPIA datas were significantly higher than RP-HPLC datas,and there was statistically significant difference(P<0.05) and poorer consistency between two methods;There was good correlation between carbamazepine concentrations determined by the two methods.Deming regression equation was CFPIA=1.195 3 CRP-HPLC-0.144 0,and Pearson correlation coefficient was 0.968 5.Conclusion Clinicians should pay more attention to the difference of carbamazepine concentration determination by different methods when carbamazepine individualized dosage regimen was adjusted according to therapeutic drug monitoring.

Determination of 18β-isomer in Magnesium Isoglycyrrhizinate by HPLC / 医药导报

Objective To establish a HPLC method for determination of 18β-isomer in magnesium isoglycyrrhizinate. Methods The determination was performed by Agilent Extend-C18 column ( 4. 6 mm × 250 mm, 5 μm ) . Mobile phase consisted of 0. 1 mol·L-1 potassium dihydrogen phosphate buffer solution ( adjusted to pH 7. 0 with potassium hydroxide )-acetonitrile (80︰20) at the flow rate of 1.0 mL·min-1. The column temperature was 30 ℃, and the detection wavelength was set at 250 nm. Results The resolution of magnesium isoglycyrrhizinate and 18β-isomer was greater than 2.0. The linear range of them was 0.41-2.46μg·mL-1( r=0.9998) , the detection limit was 0.21 ng, and the average recovery were 100.2%,99.1%, 110.2%,RSD were 0.9%,0.1%,0.2%(n=3). Conclusion The method is simple and accurate, and can be used for determination of 18β-isomer in magnesium isoglycyrrhizinate.

Determination of 18β-isomer in Magnesium Isoglycyrrhizinate by HPLC / 医药导报

Objective To establish a HPLC method for determination of 18β-isomer in magnesium isoglycyrrhizinate. Methods The determination was performed by Agilent Extend-C18 column ( 4. 6 mm × 250 mm, 5 μm ) . Mobile phase consisted of 0. 1 mol·L-1 potassium dihydrogen phosphate buffer solution ( adjusted to pH 7. 0 with potassium hydroxide )-acetonitrile (80︰20) at the flow rate of 1.0 mL·min-1. The column temperature was 30 ℃, and the detection wavelength was set at 250 nm. Results The resolution of magnesium isoglycyrrhizinate and 18β-isomer was greater than 2.0. The linear range of them was 0.41-2.46μg·mL-1( r=0.9998) , the detection limit was 0.21 ng, and the average recovery were 100.2%,99.1%, 110.2%,RSD were 0.9%,0.1%,0.2%(n=3). Conclusion The method is simple and accurate, and can be used for determination of 18β-isomer in magnesium isoglycyrrhizinate.