Development and validation of LC-MS/MS method for determination of non-opioid analgesics in adulterated herbal medicines
| dc.contributor.author | Mpanyakavili, Anna Lucas | |
| dc.date.accessioned | 2023-04-06T09:36:32Z | |
| dc.date.available | 2023-04-06T09:36:32Z | |
| dc.date.issued | 2022-11 | |
| dc.description | Thesis | en_US |
| dc.description.abstract | Background: Herbal medicines are increasingly used worldwide despite the increased concern of their adulteration with conventional drugs. Non-opioid analgesics are among of the conventional drugs reported to be used in adulteration of anti-pain herbal medicines. This rise a need for developing reliable analytical method for determination of adulterated conventional drugs in herbal medicines for quality control. This study aimed at developing a high throughput Liquid Chromatography coupled with Tandem Mass Spectrometry for determination of non-opioid analgesics (acetaminophen, caffeine, acetylsalicylic acid, diclofenac, and ibuprofen) in herbal medicines in one run. The study also aimed at optimizing a sample preparation technique to enhance detection of the adulterants in herbal medicine obtained from the Tanzania market. Methodology: Solid Phase Extraction (SPE) and Ultrasonic Assisted Extraction (UAE) methods were compared in respect of recoveries, extraction time, complexity, matrix effects, and expenses for sample preparation. Waters OASIS Hydrophilic-lipophilic balance (HLB) 200 mg 6 mL, a C 18 sorbent was used in Solid Phase Extraction method optimization. The optimized parameters were effects of filters on sample filtration, sample loading pH, selection of suitable solvents for conditioning, washing, and elution. Ultrasonic bath and centrifuge were used for optimization of ultrasonic assisted extraction method parameters including effectives of organic solvent in extraction, extraction solvent content, and sample to extraction solvent volume ratio. Both methods were evaluated by calculating their matrix effects, absolute recoveries, and percentage recovery for sub- steps. The effective sample preparation method was used in development and validation of an advanced hyphenated method using an Agilent Technologies 1100 series Liquid Chromatography coupled with Waters Tandem Mass spectrometry (LC-MS/MS) with electrospray ionization. The LC-MS/MS method was validated for its selectivity, sensitivity, linearity, accuracy, precision, recovery, matrix effects, and stability. It was then used to analyse 132 samples collected from the markets of four regions in Tanzania. Results and Discussion: The Ultrasonic Assisted Extraction method showed to be efficient to Solid Phase Extraction method for extraction of selected non-opioid analgesics. This was clearly evidenced by high recoveries, minimum extraction time, good peak shape, its simplicity in procedures, and use of less expensive consumables. The absolute recoveries for Ultrasonic Assisted Extraction were at acceptable range (> 60%) ranging from 60 % to 107 % while for Solid Phase Extraction method showed poor recovery except for diclofenac and ibuprofen having 83% and 67%, respectively. The matrix effect expressed as signal suppression/enhancement ranged from 70% - 122% for Ultrasonic Assisted Extraction method and 3% to 124% for Solid Phase Extraction method. From the results the Ultrasonic Assisted Extraction method was chosen for sample extraction for analysis of Herbal Samples. The developed LC-MS/MS method was linear with coefficient of determination of R 2 ≥ 0.9931. The Limit of Detection (LOD) and Limit of Quantification (LOQ) for selected non-opioid analgesics were within the range of 0 – 3.7 μg/mL. The intra-precision of the LC-MS/MS method was expressed as Relative Standard deviation and was less than 9.5% with varying matrix effect among analytes. Twenty one percent (21%) of 132 collected herbal medicines were adulterated with caffeine and acetylsalicylic acid. 1,029.22 μg/mL was one of the highest concentration of caffeine detected in one of the analysed herbal medicines. Conclusion and recommendation: This is the first study in Tanzania to report an analytical method for analysis of five (5) non opioid analgesics in herbal medicines in Tanzania. The developed LC-MS/MS method is suitable for the identification and quantification of 5 non opioid analgesics explored adulterants. The method can be adopted by the regulatory authorities for routine analysis of herbal medicines for monitoring its quality and safety. Further studies are recommended for Ultrasonic Assisted Extraction method using additional internal standards. | en_US |
| dc.description.sponsorship | Danish Ministry of Foreign Affairs through Danida Fellowship Centre (DFC), The Green Resources Innovation for Livelihood Improvement (GRILI) project with DFC file number 18-3-TAN | en_US |
| dc.identifier.uri | http://www.suaire.sua.ac.tz/handle/123456789/5172 | |
| dc.language.iso | en | en_US |
| dc.publisher | Sokoine University of Agriculture | en_US |
| dc.subject | Herbal medicines | en_US |
| dc.subject | Adulteration | en_US |
| dc.subject | Analgesics | en_US |
| dc.subject | Solid Phase extraction | en_US |
| dc.subject | Ultrasonic assisted extraction | en_US |
| dc.subject | LC-MS/MS | en_US |
| dc.title | Development and validation of LC-MS/MS method for determination of non-opioid analgesics in adulterated herbal medicines | en_US |
| dc.type | Thesis | en_US |