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Development and Method Validation for the Determination of Norfloxacin Raw Material by UPLC)
Development and Method Validation for the Determination of Norfloxacin Raw Material by UPLC)
The Ultra Performance Liquid Chromatography (UPLC) was developed and validated for determination of Norfloxacin raw material. The chromatographic conditions using Acquity UPLC BEH C18 column, 2.1 × 100 mm, 1.7 μm, column maintained at 30 °C, using 0.1% trifluoroacetic acid solution and acetonitrile mixed by gradient system as a mobile phase, flow rate 0.4 mL/min, runtime 14 minutes per injection and PDA detector at 265 nm. The chromatographic system suitability meets the suitability requirements of the United States Pharmacopoeia 41th revision (USP41). The specificity and selectivity were proved by good separation of Norfloxacin from other related compounds including Norfloxacin related compound A, Norfloxacin related compound E, Norfloxacin related compound H, Norfloxacin related compound K and degradation products. The relationship between concentration and area under curve was linear over the range of 5 to 25 μg of Norfloxacin per mL with the correlation coefficient of 0.99998. The accuracy of the results assessed by percentage recoveries of three concentration levels i.e. 5, 15 and 25 μg/mL were 100.05, 100.83 and 101.12, respectively. The system precision, performed by 3 standard solutions gave % RSD of 0.10, 0.16 and 0.15. The intermediate precision was no statistical difference of the results when the analysts, instruments and days were changed. The variations of different batches of column, column temperature, injection volume, concentration of acid in mobile phase, and flow rate did not affect the chromatographic system suitability. Limit of detection and limit of quantitation were 0.06 and 0.18 μg/mL, respectively. The UPLC method for determination of Norfloxacin raw material is simple, specific, accurate, precise, and robust. It reduces working time and reagent expense. In addition, the advantage of using not extremely high column temperature is to prolong the column life time. Therefore, the proposed method is suitable for use as a standard method for the determination of Norfloxacin raw material. Key words: Norfloxacin, UPLC
Development and Method Validation for the Determination of Norfloxacin Raw Material by UPLC)
Development and Method Validation for the Determination of Norfloxacin Raw Material by UPLC)
Quality of Medicines in Thailand: 15 Years of Data from the Quality Assurance of Medicines Program, Department of Medical Sciences, Ministry of Public Health
Quality of Medicines in Thailand: 15 Years of Data from the Quality Assurance of Medicines Program, Department of Medical Sciences, Ministry of Public Health
Substandard medicines have a great impact on health systems. For example, they can engender drug resistance, adverse effects, drug toxicity, increase mortality and morbidity, etc. As a result, a larger budget is needed for longer healthcare treatment, while health personnel lose confidence in drug quality monitoring and generic drugs. This study employs a descriptive retrospective design. It aims to analyze the database of test results from the Quality Assurance of Medicines Program, which was operated by the Department of Medical Sciences between the fiscal years of 2002 to 2016. The international pharmacopoeia, for example, the United States Pharmacopeia (USP) or British Pharmacopoeia (BP), were used as reference standards. The findings revealed that 428 government hospitals voluntarily sent medicine samples to the Quality Assurance of Medicines Program. The total number of modern medicine samples was 572 items or 16,212 samples. The number of substandard samples decreased from 19.0% in 2002 to 0.8% in 2016. Based on the latest 3-year data, 2.9% of domestic generic drugs failed the standard specifications, whilst 0.9% of imported drugs failed. Dissolution and content of active ingredients were the most common issues found. The corresponding organizations in pharmacovigilance and pharmaceutical manufacturing, for example, the Thai Food and Drug Administration (Thai FDA), the Department of Medical Sciences (DMSc), the Government Pharmaceutical Organization (GPO), and the Thai Pharmaceutical Manufacturers Association (TPMA) should cooperate to monitor and improve the quality of domestic generic drugs in order to achieve greater confidence in using domestic generic drugs while also making budget savings. This could also strengthen the domestic pharmaceutical industry and enhance national drug security. http://kb.hsri.or.th/dspace/handle/11228/4861
Quality of Medicines in Thailand: 15 Years of Data from the Quality Assurance of Medicines Program, Department of Medical Sciences, Ministry of Public Health
Quality of Medicines in Thailand: 15 Years of Data from the Quality Assurance of Medicines Program, Department of Medical Sciences, Ministry of Public Health
Cytotoxicity Testing of Plastic Parenteral Container by Agar Diff usion Technique
Cytotoxicity Testing of Plastic Parenteral Container by Agar Diff usion Technique
Even though direct contact technique was used to screen the cytotoxicity of plastic parenteral containers according to TIS 531, some difficulties were encountered when samples having bag and bottle forms were found moving in the wells during testing. In order to be able to test all types of containers, agar diffusion technique was applied to evaluate 34 plastic parenteral containers parallel with direct contact technique. The L-929 cultures were grown to monolayer in Eagle’s Minimum Essential Medium (MEM) supplemented with 5% fetal bovine serum (FBS). After incubation, the agar layer (1.5%) supplemented with MEM in 5% FBS and neutral-red stain was added to replace the medium. The samples were cut and placed on the agar layer. After 24–hour exposure, the cell monolayers were observed for cell deaths beneath and surrounding the samples as well as changes in morphology and cell densities. In this study, USP Positive Bioreaction RS were used as positive material control. There were no statistical differences between both techniques (P>0.05). However, the agar diffusion technique was a useful method for screening plastic parenteral containers made from polyethylene, polypropylene, polyvinyl chloride and laminar. Therefore, it could be another useful method to be implemented for the cytotoxicity testing scheme in order to replace the direct contact technique. http://budgetitc.dmsc.moph.go.th/research/pdf/20159.pdf
Cytotoxicity Testing of Plastic Parenteral Container by Agar Diff usion Technique
Cytotoxicity Testing of Plastic Parenteral Container by Agar Diff usion Technique
New Approach for Analysis of Amphetamines in Urine
New Approach for Analysis of Amphetamines in Urine
Analytical results of amphetamines in urine are significant evidence of the legal proceedings. The methods used in the analysis must be highly effective. Bureau of Drug and Narcotic developed two fast, accurate and precise gas chromatography–mass spectrophotometry (GC-MS) and liquid chromatography - mass spectrophotometry (LC-MS) methods for qualitative and quantitative determination of amphetamines in urine. Amphetamines were extracted from urine by solid phase extraction method. The proposed method proved to be specific and selective without interference from urine matrixes. For GC-MS method, the linearity and range were 100-4,000 nanograms per milliliter for amphetamine and methamphetamine with correlation coefficients greater than 0.99. Mean percentage recoveries for amphetamine and methamphetamine were 75.40 and 76.89, respectively. Inter-day accuracy for all drugs range from 0.34 to 17.23 % RD. Inter-day precision for all drugs range from 3.84 to 12.57 % CV. The uncertainties at a confidence level of 95 were 2.00 ± 0.39 micrograms per milliliter and 2.00 ± 0.35 micrograms per milliliter, respectively. For LC-MS techniques, the linearity and range were 300-2,000 nanograms per milliliter for amphetamine and methamphetamine with correlation coefficients greater than 0.99. Inter-day accuracy for all drugs range from 2.22 to 16.11 % RD. Inter-day precision for all drugs range from 2.36 to 10.43 % CV. The uncertainties at a confidence level of 95 were 2.00 ± 0.27 micrograms per milliliter and 2.00 ± 0.24 micrograms per milliliter, respectively. The unit cost of material cost for the analysis by GC-MS and LC-MS are 628 baht and 438 baht, respectively. Therefore, the developed methods are applicable for analysis of amphetamines in urine with in the assigned level of narcotic acts. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241912/164637
New Approach for Analysis of Amphetamines in Urine
New Approach for Analysis of Amphetamines in Urine
Method Development for Determination of Dexamethasone and Prednisolone in Traditional Drug by High-Performance Liquid Chromatography
Method Development for Determination of Dexamethasone and Prednisolone in Traditional Drug by High-Performance Liquid Chromatography
The quantitative determination of the adulterated dexamethasone and prednisolone in traditional drug was developed by using high performance liquid chromatography (HPLC) with reversed phase C8 column (Hypersil BDS) and a mixture of acetonitrile and purified water as a mobile phase. The sample solution was cleaned up by solid phase extraction (SPE). The method validation data showed good linearity at the concentration range of 250-12,500 μg/L with the correlation coefficient of 0.9987 and 0.9988 for dexamethasone and prednisolone, respectively. Accuracy and precision were performed by adding 500, 6,000 and 12,000 μg/L of each of dexamethasone and prednisolone to sample matrix. The percentages of recovery were 100.30-104.53 and 100.02-102.18 for dexamethasone and prednisolone, respectively. The relative standard deviations of dexamethasone and prednisolone were 0.04-2.01 and 0.15-2.47, respectively. The limit of quantitation of dexamethasone and prednisolone are 250.14 and 249.30 μg/L, respectively. Therefore, the developed HPLC method is suitable for surveillance of the dexamethasone and prednisolone adulterants in traditional herbal medicines. https://he02.tci-thaijo.org/index.php/dmsc/article/view/242649
Method Development for Determination of Dexamethasone and Prednisolone in Traditional Drug by High-Performance Liquid Chromatography
Method Development for Determination of Dexamethasone and Prednisolone in Traditional Drug by High-Performance Liquid Chromatography
Development and Validation Method for Determination of Azithromycin Capsules and Azithromycin for Oral Suspension
Development and Validation Method for Determination of Azithromycin Capsules and Azithromycin for Oral Suspension
The development and validation of reversed phase high performance liquid chromatography (RP-HPLC) method for the determination of azithromycin capsules and azithromycin for oral suspension was established. The separation was achieved on a XTerra C18, 5-μm, 4.6 × 150 mm column, at 50 degree Celsius. The mobile phase was the mixture of acetronitrile, methanol and dibasic potassium phosphate with sodium 1-octanesulfonate pH 8.20 (21:40:39, v/v) at the flow rate of 1.5 ml per minute, setting the detection at 210 nm. Specificity test indicated that azithromycin peak was not interfered by its degradation product peaks from any stress conditions : heat, light, acid/base hydrolysis and oxidation. The described method was linear over the range of 0.1-0.6 mg per ml for azithromycin with correlation coefficient, r, 0.9979. The percentage mean recovery of azithromycin capsules and azithromycin for oral suspension were 99.48 (%RSD = 0.28) and 99.20 (%RSD = 0.61), respectively. The repeatability of azithromycin capsules and azithromycin for oral suspension were performed with %RSD 1.3 and 1.1, respectively. The intermediate precision data (%RSD) obtained among different days, analysts and HPLC instruments of azithromycin capsules and azithromycin for oral suspension were 1.4 and 1.1 respectively. The results showed that this method was robust when HPLC conditions such as the HPLC column, the pH of buffer solution, the ratio of mobile phase, the column temperature and even the flow rate, were changed. The proposed analytical method presented here revealed that it was suitable for the determination of azithromycin capsules and azithromycin for oral suspension. This validated method was further used to analyze azithromycin capsules and azithromycin for oral suspension; it was found that all of the samples complied with the specifications. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241957
Development and Validation Method for Determination of Azithromycin Capsules and Azithromycin for Oral Suspension
Development and Validation Method for Determination of Azithromycin Capsules and Azithromycin for Oral Suspension
Method Development and Validation for Determination of Arsenic, Lead and Cadmium in Herbal Medicines by Graphite Furnace Atomic Absorption Spectrophotometry
Method Development and Validation for Determination of Arsenic, Lead and Cadmium in Herbal Medicines by Graphite Furnace Atomic Absorption Spectrophotometry
Graphite Furnace Atomic Absorption Spectrophotometry (GFAAS) method was developed and validated for the determination of arsenic (As), lead (Pb) and cadmium (Cd) in herbal medicines. Samples were prepared by wet digestion. Validation was performed according to the International Committee on Harmonization (ICH) Guidelines. The proposed method permitted the determination of As, Pb and Cd in the ranges of 5-80 ng/ml, 10-80 ng/ml and 0.25-4.0 ng/ml, respectively, with correlation coefficients greater than 0.999. Limit of detection (LOD) were found to be 2.5 ng/ml, 2.5 ng/ml and 0.16 ng/ml for As, Pb and Cd, respectively, while limit of quantitation (LOQ) were found to be 1 μg/g, 2 μg/g and 0.1 μg/g for As, Pb and Cd, respectively. Mean percentage recoveries were in the range of 98.8-105.6 while intra- and inter-day precisions were less than 4.7% for all three heavy metals. The method was successfully applied to the study of heavy metal contamination in herbal medicines available in Thailand. A total of 86 samples were investigated and the results showed that all test samples contained As, Pb and Cd lower than the limit specified in the Thai Herbal Pharmacopoeia. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241959
Method Development and Validation for Determination of Arsenic, Lead and Cadmium in Herbal Medicines by Graphite Furnace Atomic Absorption Spectrophotometry
Method Development and Validation for Determination of Arsenic, Lead and Cadmium in Herbal Medicines by Graphite Furnace Atomic Absorption Spectrophotometry
UPLC Transfer and Method Validation of the Determination of Prednisolone Tablets
UPLC Transfer and Method Validation of the Determination of Prednisolone Tablets
The method transfer and validation for the determination of Prednisolone in tablets was established using Ultra Performance Liquid Chromatography (UPLC). The separation was achieved on a ZORBAX Eclipse Plus C18 (1.8 μm, 2.1 × 100 mm) at 35 degree Celsius. The mobile phase was the mixture of methanol and water (55:45, v/v) at the flow rate of 0.3 ml per minute with UV detection at 254 nm. Specificity test showed that prednisolone peak was not interfered by its degradation product peaks under stress conditions: acid, base, heat, hydrolysis, oxidation and light. The linearity test showed linear relationship between the area under the peak and the concentration levels in the range of 0.15-0.25 mg per ml with correlation coefficient, r, 0.9999. The percentage mean recovery from three concentration levels was 100.5 (% RSD = 1.17%). The precision test was performed by the assay of six samples within the same day, and different days and analysts gave % RSD of 0.7, 0.6 and 0.7, respectively. The robustness test indicated that the described method was robust when the chromatographic conditions were changed such as column batch, column temperature, composition and flow rate of mobile phase with no effect on the system suitability and the test result. This method takes less analytical time than the method specified in the United States Pharmacopoeia and British Pharmacopoeia. Therefore, the proposed method was suitable for the quantification of prednisolone in tablets and could be used as an alternative method. https://he02.tci-thaijo.org/index.php/dmsc/article/view/242344
UPLC Transfer and Method Validation of the Determination of Prednisolone Tablets
UPLC Transfer and Method Validation of the Determination of Prednisolone Tablets
Alternative to the Thai Herbal Pharmacopoeia Method for Quality Control of Andrographis Capsules
Alternative to the Thai Herbal Pharmacopoeia Method for Quality Control of Andrographis Capsules
Rationale and Objective: Reflux extraction is the standard sample preparation method described in the Thai Herbal Pharmacopoeia (THP) for the assay of andrographolide content in both Andrographis herbal material and capsules, and has been used since 1995. The disadvantages of this method are the consumption of large amounts of volatile and hazardous organic solvents, low extraction efficiency and a time-consuming process. The objectives of this study were to compare the extraction efficiency of ultrasonication and reflux extraction methods and to propose an alternative to the current THP method for quality control of Andrographis capsules. Methodology: Optimization of extracting solvent and sonication time were investigated. The best condition was further used for comparison of the extraction efficiency with reflux extraction. A total of 30 different lots of Andrographis capsules were tested. The analytical method as described in the THP was revalidated to ensure method performance and data integrity after the sample preparation had been changed. Results: Ultrasonication with 50% methanol for 15 minutes gave the highest andrographolide content extracted. Changes in sample preparation did not affect the analytical method performance. The contents of andrographolide extracted using ultrasonication were comparable and in most cases they were even higher than those obtained from the reflux method. Discussion and Conclusion: Ultrasonication is a more efficient, rapid and convenient method and can be used as an alternative sample preparation method to the current monographs in THP for the quality control of both Andrographis herbal material as well as medicinal products. https://he01.tci-thaijo.org/index.php/JTTAM/article/view/115106
Alternative to the Thai Herbal Pharmacopoeia Method for Quality Control of Andrographis Capsules
Alternative to the Thai Herbal Pharmacopoeia Method for Quality Control of Andrographis Capsules
Quality of Amoxicillin and Clavulanic acid Tablets in Thailand
Quality of Amoxicillin and Clavulanic acid Tablets in Thailand
Amoxicillin and Clavulanic acid combination is the well-known dosage form of antibiotics. It was developed to improve the efficiency and optimize the effects. The crucial problem of this dosage form is its stability due to the tendency to degrade. To assure the quality of the products, the amoxicillin and clavulanic acid tablets have been chosen to study under the project “Quality Assurance of Medicines under the Universal Health Care Coverage” by Bureau of Drug and Narcotic, Department of Medical Sciences. The pharmaceutical testing was performed and evaluated using the verified method and in compliance with the USP 34 monograph. The total number of samples was 131. The samples came from 42 drug dossiers which were from four Thai local manufacturers and fifteen international ones. The samples were tested on the following topics: assay, weight variation, content uniformity, dissolution, and water determination. The results showed that 122 samples (93%) passed and 9 samples (7%) failed to meet the quality standards. The failed samples were one for the assay of clavulanic acid, two for the content uniformity of clavulanic acid, one for both the assay and content uniformity of clavulanic acid, and five for dissolution testing. The study revealed that the quality problems of Amoxicillin and Clavulanic acid Tablets still exist. Hence, the manufacturing process, the quality of ingredients, as well as the packaging and storage procedures play the important role in the quality of products. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241702
Quality of Amoxicillin and Clavulanic acid Tablets in Thailand
Quality of Amoxicillin and Clavulanic acid Tablets in Thailand
Analysis of the Composition of Amphetamine Tablets, Fiscal Years 2007-2013
Analysis of the Composition of Amphetamine Tablets, Fiscal Years 2007-2013
The wide spread of amphetamine abuse has caused serious problems to Thailand. The content analysis is one approach to control and suppressing the spread of amphetamine tablets. In order to determine the composition of amphetamine tablets, between October 2006 to September 2013, the situation on amphetamine tablet composition was evaluated. The authors collected database from Bureau of Drug and Narcotic, Department of Medical Sciences, for the qualitative and quantitative data of 44,140 samples of amphetamine tablets sent from the authority under the Royal Thai Police Headquarters. By using thin layer chromatography and gas chromatographic technique, the results showed that, for qualitative information, most amphetamine tablets consisted of methamphetamine hydrochloride and caffeine. The percentage by weight of methamphetamine hydrochloride quantitative detection was in the range of 0.00 to 40.00. From the seven years data, the highest range of percentage for methamphetamine hydrochloride detection was 15.01 to 20.00 from 32.98 to 83.86 percent of the total samples. There were also other ingradients in the drugs, such as N,N-dimethylamphetamine, ephedrine, paracetamol, chlorpheniramine maleate and diphenhydramine. Therefore, this study revealed the high incidence of amphetamine use, both the composition and the distribution. Therefore, information from this study is useful for the development of effective prevention programs to control illicit drugs in the country. http://thaidj.org/index.php/JHS/article/view/282
Analysis of the Composition of Amphetamine Tablets, Fiscal Years 2007-2013
Analysis of the Composition of Amphetamine Tablets, Fiscal Years 2007-2013
Establishment of Dissolution Specification for Fa-Tha-Lai Capsules
Establishment of Dissolution Specification for Fa-Tha-Lai Capsules
Recently, wide-spread usage of Fa-Tha-Lai capsules or Fa-Tha-Lai Chon capsules dramatically in-creased as an alternative medicine in Thailand. Apart from the safety and efficacy of the product, its quality control tests were considerably concerned. A dissolution method was one of the crucial tests of quality control because it was considered as a prerequisite to detect a defective product and to maintain content uniformity in batches including reproducibility among the production batches. Consequently, the establishment of dissolution specification for Fa-Tha-Lai capsules or Andrographis paniculata capsules in this study was carried out by developing a dissolution method in order to assess the quality of the product. The objective was to evaluate the dissolution behavior of Fa-Tha-Lai extract capsules, which were labeled the content of andrographolide, distributed in Thai markets. Various dissolution media were tested to optimize the dissolution method. The data of the dissolution media were evaluated by a one-way analysis of variance (ANOVA). As a result, the proposed dissolution method used a paddle type dissolution apparatus at the rotation speed 100 rpm, dissolution medium comprising 900 mL of 0.01 M hydrochloric acid containing 0.2% w/v sodium lauryl sulfate main-tained at 37.0±0.5 o C, and 45 minutes time-point. Therefore, this proposed method could be suitably used for establishing the dissolution specification of Fa-Tha-Lai extract capsules because it could discriminate the dissolution quality among the products available in Thai markets. http://thaidj.org/index.php/JHS/article/view/154
Establishment of Dissolution Specification for Fa-Tha-Lai Capsules
Establishment of Dissolution Specification for Fa-Tha-Lai Capsules
Development and Validation Method for Identification of PDE-5 inhibitors In Seized Materials
Development and Validation Method for Identification of PDE-5 inhibitors In Seized Materials
Identification of PDE-5 inhibitors in Seized Materials using TLC and HPLC methods was developed and validated. TLC method, the stationary phase was siliga gel 60 F 254, the mobile phase comprised two systems. System 1 was the mixture of ethyl acetate, acetonitrile and ammonia solution and system 2 was the mixture of ethyl acetate, ethanol and ammonia solution. TLC of isolated sample was firstly detected by UV radiation at 254 nm, spectrum scanning and then confirmed by color reaction with ethanolic-sulfuric acid and acidified iodoplatinate reagent. In system 1, Rf were found to be 0.49, 0.71, 0.50, 0.57, and 0.56 for sildenafil, tadalafil, vardenafil, aminotadalafil, methisosildenafil, respectively. In system 2, the Rf were found to be 0.31, 0.78, 0.45, 0.72, and 0.43 for sildenafil, tadalafil, vardenafil, aminotadalafil, methisosildenafil, respectively. A purple color after spraying with ethanolic-sulfuric acid reagent indicated the presence of tadalafil and aminotadalafil. When acidified iodoplatinate solution was used, a brown to purple color developed indicated the presence of sildenafil, tadalafil, vardenafil and aminotadalafil. With TLC techniques, limit of detections of sildenafil, tadalafil and vardenafil were 100, 1000 and 250 μg/ml respectively. HPLC method, the separation was performed on a C18 column by isocratic elution with a mobile phase of 0.01 M ammonium acetate buffer and methanol and PDA detection at 210-350 nm. All sildenafil, tadalafil, vardenafil, aminotadalafil and methisosildenafil peaks were completely resolved as shown by resolution values greater than 1.8, with no interference from matrix components. With HPLC techniques, limit of detections of sildenafil, tadalafil, vardenafil, aminotadalafil and methisosildenafil were 3.8, 1.0, 2.5, 0.8 and 2.3μg/ml respectively. The validated method was applied to the identification of illicit drugs containing PDE-5 inhibitors in seized materials in fiscal year 2015. It was found that among 230 samples tested, 213 samples contained sildenafil, 11 samples contained a mixture of sildenafil, vardenafil, aminotadalafil, tadalafil and one sample contained a mixture of sildenafil and vardenafil. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241326
Development and Validation Method for Identification of PDE-5 inhibitors In Seized Materials
Development and Validation Method for Identification of PDE-5 inhibitors In Seized Materials
Stability Study for Methamphetamine Standard Solutions
Stability Study for Methamphetamine Standard Solutions
Methamphetamine is a major drugs problem in the country. The spread of this drug and severity of the problem is continuing. One approach to control and reduce the spread of the drug is arrest and analysis of drug for further legal action. The analysis of drugs requires standard substance which is expensive and difficult supply. The aim of this study is to establish the shelf life of the methamphetamine standard solution prepared in BDN laboratory. The stability of methamphetamine standard solution was investigated by using a routine gas chromatographic technique, The quantitative detection of methamphetamine for illicit sample was performed in the duration of 128 days. Both methamphetamine standard solutions with the concentration about 0.4 milligrams per milliliter chloroform prepared and stored at 2-8 degree centigrade and the freshly prepared methamphetamine standard solution, were used for determination of methamphetamine content of illicit sample. At the end of the study periods, the percentage by weight different of two methamphetamine standard solution used was in the range of 0.11 – 1.96. This result showed that the expiry date of the methamphetamine standard solution was 128 days without any remarkable degradation. Therefore, all of illicit standard solutions should be studied for their expiry date to support the analysis of drug for the illicit drug control and legal action. https://he02.tci-thaijo.org/index.php/dmsc/article/view/241325
Stability Study for Methamphetamine Standard Solutions
Stability Study for Methamphetamine Standard Solutions
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