Analysis of the results of an international proficiency testing program for veterinary drug residue determination in food / 上海预防医学

ObjectiveTo evaluate the proficiency and consistency of domestic and foreign testing institutions in the field of veterinary drug residue detection in food， and to promote international cooperation and mutual recognition of testing results among these institutions. MethodsA robust statistical analysis was conducted on the testing results of 20 laboratories in eight countries and regions across North America， Europe， and Asia. The laboratories’ testing capabilities were evaluated using Z-score comparison. ResultsAmong the 20 participating laboratories， 18 achieved satisfactory results， resulting in a satisfaction rate of 90%， while 2 laboratories （10%） failed to meet the requirements. The satisfaction rate of domestic laboratories （100%） was higher than that of foreign laboratories （81.8%）. ConclusionDomestic laboratories perform better than overseas laboratories in determining veterinary drug residues in food. To enhance testing capabilities， these overseas laboratories with unsatisfactory evaluation results should strengthen their daily quality control and ensure traceability of original records.

Analysis of contaminated microorganisms in commercial honey / 上海预防医学

Objective To investigate the microbial contamination in 54 batches of commercial honey. Methods Aerobic plate colony counts for bacteria and colonies of mould and osmophilic yeasts in honey were determined according to the National Food Safety Standard. The bacteria and fungi in unqualified samples were further identified and analyzed by morphology， MALDI-TOF-MS and large subunit （LSU） rRNA gene sequence. Results Three unqualified batches were found. One batch had aerobic plate colony counts exceeding the standard， with a variety of bacteria including Bacillus sp.， Paenibacillus sp. and Brevibacillus sp. Two batches had mould counts exceeding the standard. Aspergillus sp was detected in both samples （from the same manufacturer）， and the DNA sequence homology was very high， suggesting the mould might come from the same pollution source. Conclusion There are many kinds of microbial contamination in honey. Manufacturers should strengthen the microbe control in monitoring process to avoid the repeated microbial contamination.

Establishment and analysis of microbial limit test methods for commonly used pediatric drugs / 上海预防医学

ObjectiveTo establish microbial limit test methods for 44 pediatric drugs. MethodsAccording to the general guidelines in Chinese Pharmacopoeia （2015 and 2020 edition， volume Ⅳ），a suitability test of the methods for 44 drugs was carried out by pour-plate method， neutralization method or dilution method. ResultsTotal aerobic microbial count： chemical oral liquid samples can be tested by 1∶10 plate method；traditional Chinese medicine need to be neutralized firstly. Then oral liquids could be tested by 1∶10 plate method and 1∶100 plate method was used for granules. Total count of molds and yeasts： all the samples can be tested by the 1∶10 plate method. The recoveries of five test strains were between 0.5 and 2.0. The specified microorganisms were all detected in the test group， while not found in the negative control group. ConclusionThe microbial limit test methods for the 44 pediatric drugs are established and the results are reliable and can be used in the quality control．

Multi-enzyme isothermal rapid amplification assay for the detection of Escherichia coli O157∶H7 / 上海预防医学

ObjectiveA rapid enrichment and detection method for Escherichia coli O157∶H7 was developed by using multienzyme isothermal rapid amplification （MIRA） fluorescence method combined with metal organic frameworks immunomagnetic beads. MethodsUsing rfbE gene as the target， the primers， probes and reaction system were screened， and the specificity， sensitivity and practical application of this method were investigated. ResultsThe detection limit of Escherichia coli O157∶H7 was 1.18×105 CFU‧mL-1， and the detection limit of DNA concentration was 9 pg‧μL-1. The detection process was completed in 20 minutes. The test results of 47 strains （24 target strains and 23 non-target strains） were consistent with real-time PCR （RT-PCR）. ConclusionA method based on metal-organic framework immunomagnetic beads enrichment combined with MIRA assay is developed in this study. The method is simple， rapid and suitable for rapid enrichment and detection of Escherichia coli O157∶H7 in food.

Sample preparation and analysis of proficiency test containing Staphylococcus aureus with drug matrix / 上海预防医学

Objective To prepare samples of proficiency testing （PT） containing live Staphylococcus aureus with drug matrix in microbial PT program of drug testing， and to evaluate the laboratory capability of microbiology tests in China. Methods Two kinds of PT samples containing living bacteria with drug matrix were prepared and evaluated. The results of laboratories participated in PT program and their response to the survey questionnaire were collected and analyzed. Results The homogeneity and stability of the PT samples complied with the requirements of CNAS-CL03： 2010. Samples could be stored stably for at least 6 months at -20 ℃. Among 63 laboratories participating in PT program， 53 laboratories （84.1%） achieved satisfactory results. The satisfaction rate was 94.1% （16/17） in 17 government laboratories （27.0% of total 63 laboratories）， 81.4% （35/43） in 43 pharmaceutical quality control laboratories （68.3% of total 63 laboratories）， and 66.7% （2/3） in 3 non-government laboratories （4.8% of total 63 laboratories）， respectively. Conclusion The government laboratories performed better than pharmaceutical quality control laboratories in microbiology tests of drug， and the testing abilities of some pharmaceutical laboratories needs to be improved. The preparation and application of microbial samples in drug matrix could provide evaluation tools for drug testing laboratories in microbiology.

Sample preparation and analysis of proficiency test containing Staphylococcus aureus with drug matrix / 上海预防医学

Objective To prepare samples of proficiency testing （PT） containing live Staphylococcus aureus with drug matrix in microbial PT program of drug testing， and to evaluate the laboratory capability of microbiology tests in China. Methods Two kinds of PT samples containing living bacteria with drug matrix were prepared and evaluated. The results of laboratories participated in PT program and their response to the survey questionnaire were collected and analyzed. Results The homogeneity and stability of the PT samples complied with the requirements of CNAS-CL03： 2010. Samples could be stored stably for at least 6 months at -20 ℃. Among 63 laboratories participating in PT program， 53 laboratories （84.1%） achieved satisfactory results. The satisfaction rate was 94.1% （16/17） in 17 government laboratories （27.0% of total 63 laboratories）， 81.4% （35/43） in 43 pharmaceutical quality control laboratories （68.3% of total 63 laboratories）， and 66.7% （2/3） in 3 non-government laboratories （4.8% of total 63 laboratories）， respectively. Conclusion The government laboratories performed better than pharmaceutical quality control laboratories in microbiology tests of drug， and the testing abilities of some pharmaceutical laboratories needs to be improved. The preparation and application of microbial samples in drug matrix could provide evaluation tools for drug testing laboratories in microbiology.

Comparative Study of Microbial Limit Test and Criteria of TCM Decoction Pieces among United States Pharma- copeia，European Pharmacopeia ，Japanese Pharmacopeia and Chinese Pharmacopeia / 中国药房

OBJECTIVE：To compare the difference of microbiological limit test and criteria of TCM decoction pieces among 43 edition of United States Pharmacopeia （USP43），10.0 edition of European Pharmacopeia （EP10.0），17 edition of Japanese Pharmacopeia （JP17）and 2020 edition of Chinese Pharmacopeia （ChP2020），and to provide refernce for the revision and improvement of microbiological standards for TCM decoction pieces in China. METHODS ：The differences in the microbial enumeration tests method （including sampling and sample preparation ，selection of bacteria and culture medium ，count of microorganisms and heat-resistant bacteria ，etc.），tests for specified microorganisms （including sample pretreatment ，enrichment， separation and identification ，etc.）and microbial related limit criteria were compared among USP 43，EP10.0，JP17 and ChP 2020. RESULTS & CONCLUSIONS ：In terms of microbiological examination of TCM decoction pieces ，USP43，EP10.0，JP17 had their own independent provisions. Chp 2020 added“general rule 1108”. In terms of inspection items ，in addition to the total aerobic bacteria count and total combined yeasts and molds count ，ChP2020 and EP 10.0 provided three methods for the inspection of control bacteria （bile-resistant Gram-negative bacteria ， Escherichia coli ， Salmonella）. On the basis ， JP17 supplemented Staphylococcus aureus test；However，USP43 added Clostridium test method and put forward the concept of objectionable microorganisms risk assessment ；ChP2020 also added a new method for counting heat-resistant bacteria. In terms of microbial limit criteria，USP43 was the most detailed in the classification of TCM decoction pieces ，which was more strict than EP 10.0 and JP 17； ChP2020 had not set up a unified limit for the inspection of control bacteria of TCM decoction pieces. ChP 2020 revised the “microbial limit standard for TCM extracts and TCM decoction pieces ”，but it was not perfect compared with the Pharmacopoeia of the United States ，Europe and Japan. It is suggested that according to the current situation of microbial contamination and control of TCM decoction pieces ，the microbial limit test and criteria of TCM related products in Pharmacopoeia should be gradually improved ，and the microbial limit level of corresponding products should be reasonably refined.

Determination of Sodion and Salt-forming Rate in Cefalotin Sodium by Ion Chromatography / 中国药师

Objective:To establish a method for the determination of sodion in cefalotin sodium by ion chromatography and investi-gate the salt-forming rate of the products. Methods: A TSKgelSuper IC-CR cation exchange column (150 mm × 4. 6 mm, 3. 0 μm) was used. The mobile phase was the mixture of 2. 2 mmol·L-1 methanesulfonic acid and 1 mmol·L-1 18-crown-6-ether with the flow rate of 0. 8 ml·min-1 . The column temperature was 40℃ and the injection volume was 20μl. The detector was an electric conductiv-ity detector. Results:The linear correlation of sodion was good within the range of 3. 0-60. 0μg·ml-1(r=0. 999 9). The average re-covery was 99. 8%(RSD=0. 8%, n=9). The mole number ratio of sodion to cefalotin was within the range of 0. 97-1. 03. Conclu-sion:The method is specific, precise and accurate, and can be used in the determination of sodion in cefalotin sodium. The salt-form-ing rate of the 8 batches of samples is promising.

Determination of Gentamicin C Components and Related Substances Respectively by HPLC with Post Col-umn-derivatization and Electrochemical Detection / 中国药师

Objective:To establish an HPLC coupled with post column derivatization method for the determination of gentamicin C components and the related substances based on the latest European Pharmacopeia and compare with the electrochemical method. Methods:A Hydrophilic C18(250 mm ×4.6 mm, 5 μm)column was used with acetonitrile-50 mmol·L-1 sodium hydroxide solution ( pH 2. 6) containing 0. 7% trifluoroacetic acid and 0. 025% pentafluoropropanoic acid (1. 5∶98. 5) as the mobile phase. The temper-ature of post-column reaction was set at 30℃, and the samples were detected by a fluorescence detector withλex of 340nm andλem of 430nm. A pulsed amperometric detector (PAD) was applied in the electrochemical method with golden working electrode in a four-po-tential working mode. Results: According to the results of the two detection methods, the linear range of C1a , C2 , C2a and C1 was 5.82-233.00,6.92-277.00,4.00-160.00and6.23-249.00 μg·ml-1(r >0.9993) , respectively. The limit of detection and quantization were 0. 92-3. 28ng and 1. 37-5. 19ng, respectively. Conclusion:There is no significant difference between the determina-tion results of the two methods.

Study on the proficiency testing program of pharmaceutical preparation analysis / 药学学报

This proficiency testing program is established to evaluate the pharmaceutical preparation analysis capacity of laboratories recommended by 18 countries and economies. It was authorized by Asia Pacific Laboratory Accreditation Cooperation (APLAC), and organized by Shanghai Institute for Food and Drug Control (SIFDC) and China National Accreditation Service for Conformity Assessment (CNAS). The 0.3sigma test is used to evaluate the homogeneity and stability of the proficiency testing sample. The results of the laboratories were assessed by Z-score. The robust average and the robust standard deviation of the participants' results were calculated as assigned value and standard deviation for performance assessment of hydrochlorothiazide and captopril using robust statistics. Thirty-three of 38 laboratories recommended by 18 countries and economies sent their results back. Twenty-four laboratories' results were observed as satisfactory. Five laboratories were identified as having reported at least one questionable result. Four laboratories were identified as having reported at least one unsatisfactory result.