Thin-layer Chromatographic Screening Research Articles

Coupling thin layer chromatography with mass spectrometry for detection and identification of sertraline and its metabolite in the urine

The aim of the study was to detect sertraline and its metabolites in urine under standardized thin layer chromatography (TLC) screening conditions and identify the metabolites using the mass spectrometry method. Materials and methods. Urine samples, collected within 30 hours in portions of 20–50 mL, commenced from the seventh hour after the administration of a single therapeutic dose of the drug. The sample preparation process involved dilute acid hydrolysis, followed by the extraction of the native compound and metabolites with chloroform at a pH of 8–9. Thin layer chromatography studies of the extracts were conducted using four unified TLC systems recommended by The International Association of Forensic Toxicologists for general drug screening. Chromatograms were subjected to color reactions with a variety of chromogenic reagents. For the analysis of eluates from chromatograms, a Varian 1200 L mass spectrometer (Netherlands) equipped with a dual quadrupole mass analyzer was employed. Identification was performed through direct sample introduction into the ion chamber, electron-impact ionization (70 eV), and full ion scanning mode. Results. The spot of the native drug on the chromatogram was identified by the Rf, value. Metabolite of sertraline was identified as N-desmethyltrihydroxysertraline by the molecular ion peak in the mass spectrum. Conclusions. The study demonstrated the ability of TLC to detect sertraline and its metabolite, N-desmethyltrihydroxysertraline, in urine after the administration of a single therapeutic dose of the drug. The chromatographic mobility of the native compound and N-desmethyltrihydroxysertraline in the unified TLC screening systems, along with the results of their visualization using chromogenic reagents for toxicological drug screening, was determined. Furthermore, the potential of coupling TLC with mass spectrometry for the separation, detection, and confirmatory identification of sertraline and its metabolic products in urine was established.

Investigation of Chemical Components of Hexane Extract from the Stem of Arcangelisia flava via Phytochemical Test, GC-MS Analysis, FTIR Fingerprinting, and In Vitro Antioxidant Activity

Arcangelisia flava, also known as yellow root, is a woody vine indigenous to the Philippines. It has been established that it possesses medicinal properties, and several of its bioactive compounds have been identified. However, most of its possible bioactive nonpolar chemical compounds remain unidentified. In this study, the stem of A. flava was investigated for its chemical components, FTIR fingerprinting, and antioxidant activity. The stem of A. flava was chopped, ground, and then extracted with hexane per gram of A. flava. Thin-layer chromatography (TLC), phytochemical screening, GC-MS and FTIR analyses, cupric-reducing antioxidant capacity (CUPRAC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays were performed to evaluate the chemical components of A. flava hexane extract. TLC and phytochemical screening revealed the presence of some organic acids, triterpenes, sterols, essential oils, phenols, and flavonoids. Further characterization using GC-MS analysis revealed 64 chemical components classified into hydrocarbon, ketone, alcohol, aromatic compounds, aldehyde, ester, organosilicon, and other chemicals. The most abundant compound was hexacosane with a relative abundance of 43.17%. This was followed by tetracosane (8.85%), o-xylene (8.09%), and hexatriacontane (5.72%). The FTIR spectrum also revealed the presence of hydrocarbons such as alkanes and alkenes, confirming the 60% abundance of such class of compounds as revealed by GC-MS. Meanwhile, based on the CUPRAC and DPPH assay conducted, the hexane extract from the stem of A. flava had low antioxidant capacity. Based on the literature search, this is the first time the chemical composition of A. flava hexane extract has been evaluated and its chemical compounds identified. The findings presented in this paper should be taken into account for any future research on the species’ therapeutic properties.

Chemical and Toxicological Diagnosis of Acute Poisoning with Doxylamine, Zaleplon, and Phenazepam

BACKGROUND The market of hypnotic and sedative drugs is being updated due to the high toxicity of barbiturates and the limitations of their use. Currently, safer drugs such as Z-drugs, Doxylamine, and some benzodiazepine derivatives are often prescribed for the treatment of anxiety and insomnia, but they can cause acute poisoning if overdosed or in case of nonmedical use.AIM To establish an affordable express thin-layer chromatography (TLC) technique for preliminary screening detection of Doxylamine, Phenazepam and Zaleplon in order to diagnose acute poisoning.MATERIAL AND METHODS Thin-layer chromatography (TLC) and gas chromatography with mass selective detection (GC-MS) methods were used. Urine samples from patients with symptoms of acute Doxylamine, Zaleplon, Phenazepam poisoning, and model urine samples were prepared by liquid-liquid extraction at pH 9.0 with chloroform for TLC analysis, with ethyl acetate-diethyl ether mixture (1:1) for GC-MS.RESULTS We developed the TLC method of Doxylamine, Zaleplon and Phenazepam detection which helps reveal their presence in the patient’s urine, as well as distinguish one from another in case of similar toxic symptoms. The GC-MS method was used for confirmatory analysis. Compared to confirmatory methods, the developed technique of TLC screening is expressive, does not require expensive high-tech equipment, while allowing to differentiate Doxylamine, Zaleplon and Phenazepam from each other and from other toxicologically significant psychoactive substances detected in general screening.

ANTI-BACTERIAL, CYTOTOXICITY, AND ANTIOXIDANT PROPERTIES OF THE ISOLATED FLAVONOIDS EXTRACT FROM WHITE DRAGON FRUIT (HYLOCEREUS UNDATUS) PEELS AND FLESH

The presence of flavonoids in white pitaya’s flesh and peel was confirmed using the Thin Layer Chromatography Screening method. Flavonoid was extracted using solvent fractionation and then subjected to the three assays. Using the Kirby-Bauer method, better antibacterial activity against E. coli was found using 100% peel extract, partially active at 10.28 mm. The flesh flavonoid extract was inactive against both E. coli and S. aureus at concentrations of 100%, 75%, and 50%. The flavonoid peel and flesh have the potential as anticancer agents since they are active, toxic, and potent, with LC50 of less than 1000 ppm in Brine Shrimp Lethality Assay. Using a UV VIS spectrophotometer at 517 nm, both the flesh flavonoid extract and the peel flavonoid extract have antioxidant potential. However, the flesh with a percent Radical Scavenging Activity close to the catechin control is a better antioxidant. This study proved that the peel and flesh of White Pitaya, particularly its flavonoid, have medical benefits, can be a potential source of income for farmers, and decrease waste in the environment.

Qualitative and Quantitative Evaluation of Rosavin, Salidroside, and p-Tyrosol in Artic Root Products via TLC-Screening, HPLC-DAD, and NMR Spectroscopy

Artic root is a well-known plant adaptogen with multipotential pharmacological properties. Thin-layer chromatography (TLC)-screening followed by diode-array high-performance liquid chromatography and nuclear magnetic resonance spectroscopy proved to be a reliable and convenient method for the simultaneous determination of the quality of various herbal raw materials and supplements. This combination allowed for comparing and differentiating arctic root samples as well as defining their authenticity. The study provided information on the chemical and biological properties of the seven chosen samples as well as qualitative and quantitative evaluation of the quality markers: rosavin, salidroside, and p-tyrosol. The absence of rosavin, salidroside, and p-tyrosol in three samples was detected using TLC screening and confirmed by HPLC-DAD and NMR. The paper highlighted the importance of quality control and strict regulation for herbal medicine supplements and preparations.

Pharmacognostical Aspects and Phytochemical Screening of Powdered Rosa centifolia Petal

Objective: This study would be useful to complement the information regarding pharmacognostical characteristics, physicochemical evaluation, micrometric analysis, and phytochemical exploration in the Ayurvedic system of medicine for its identification and pharmacological use of herbal drug Rosa centifolia Petals.
 Material and Methods: The flowers of Rosa centifolia were collected, authenticated and shade dried. Rosa centifolia petals were then undergone morphological, physiochemical exploration, micrometric investigation, and Phytochemical analysis. The dried Rosa centifolia Petals were then extracted with different solvents alcohol, ethyl acetate, and petroleum ether, and their extractive values were calculated. The secondary metabolites were found in ethanol and ethyl acetate extract of the crude drug. Thin Layer chromatography (TLC) was performed for important phytochemicals flavonoids and polyphenol of the ethanol, ethyl acetate, and petroleum ether extract. The presence of Flavonoids and phenolics showed in various extracts with one spot in individual extracts of the crude drug.
 Result and discussion: The Physicochemical evaluation of powder crude drug showed values for moisture content, ash values, swelling index, foreign matter, and extractive values which are within the limits of World Health Organization standards for medicinal plants. Micromeritic analysis of rose petal powder discloses good flowability. The preliminary examination of the crude extract indicated the presence of carbohydrates, glycosides, alkaloids, flavonoids, and amino acids. TLC Rf values for flavonoid and phenolic were found for ethanolic extract at 0.78 and 0.77, ethyl acetate extract at 0.81 and 0.78, and petroleum ether extract at 0.81 0.78 respectively.
 Conclusions: The current study was to explore the crude drug that would be useful to complement the information regarding pharmacognostical features, physicochemical determination, micrometric exploration for the standardization of Rosa centifolia Petals.
 Keywords: Rosa centifolia, Macromorphological study, Physicochemical exploration, Phytochemical analysis, micrometric investigation, TLC screening.

Green Synthesis Characterization In Vitro Cytotoxicity and Antioxidant Activity of Stem Extract Mediated Gold Nanoparticles from Tinospora Cordifolia

The aim of this study was to investigate the ability of Tinospora cordifolia mediated synthesis of gold nanoparticle at room temperature and to study the properties of the nanoparticles thus produced. The synthesized nanoparticles were characterized and investigated by ultraviolet-visible spectroscopy spectrophotometry, high-performance thin-layer chromatography screening, Fourier transform infrared, transmission electron microscope, scanning electron microscope, X-ray diffraction, zeta potential, in vitro cytotoxicity test and antioxidant activity. Ultraviolet-visible spectrum of the aqueous medium containing, gold nanoparticles showed a peak at 546 nm. The hexagonal shaped nanoparticles were well dispersed with particle size ranging from 30-60 nm, that were confirmed by transmission electron microscope and scanning electron microscope respectively. Fourier transform infrared showed shift in position and intensity of the peaks. High-performance thin-layer chromatography screening showed that even after forming gold nanoparticles, it retains most of its phytochemical constituents. In vitro stability studies have confirmed that gold nanoparticles are stable in biological fluids at physiological pH and also in salt solutions. X-ray diffraction studies confirmed crystalline nature of the synthesized nanoparticles. Zeta potential value of the synthesized gold nanoparticles is -29 mV at 25° showing good stability of nanoparticles. From in vitro cytotoxicity test it is seen that gold nanoparticles formed are biocompatible. In vitro antioxidant study showed that 2,2-diphenyl- 1-picrylhydrazyl activity increased in a dose dependent manner. The potential of this biosynthesized nanoparticles for the development of value-added products can be used to a good advantage in drug delivery.

Physiochemical Evaluation and Determination of Chemical Constituent in Rose Petal (Rosa centifolia)

Objectives: The purpose of the present study was to explore the Pharmacognostic parameters for the standardization of Rosa centifolia Petals. 
 Material and Methods: The flowers of Rosa centifolia were authenticated and shade dried. Rosa centifolia petals were collected then macromorphological, physiochemical assessment, and the micrometric study was carried out. The dried powder form of the Rosa centifolia Petals was then extracted with different solvent systems alcoholic, ethyl acetate, and petroleum ether, and their extractive values were calculated. Most of the phytochemicals were found in ethanol and ethyl acetate fractions. Thin Layer chromatography (TLC) of the ethanol, ethyl acetate, and petroleum ether extract was performed for important phytochemicals flavonoids and polyphenol. Flavonoids and phenolics showed their presence in all extracts with one spot in each extract for ethanol, ethyl acetate, and petroleum ether.
 Result: The Physicochemical exploration showed values for moisture content, moisture sorption capacity, ash values, and extractive values which are within the limits of World Health Organization standards for the crude drug from medicinal plants. Micromeritic analysis of petal powder reveals good flowability. Ethanolic extractive values were found to be higher when compared to extractive values of, ethyl acetate and petroleum ether. Preliminary Phytochemical examination for the sample indicated the presence of carbohydrates, glycosides, alkaloids, flavonoids, and amino acids. Rf value for flavonoid and phenolic on TLC were found to be for ethanol 0.78 and 0.77, for ethyl acetate 0.81 and 0.78, for petroleum ether 0.81 and 0.78 respectively.
 Conclusions: The current research would be useful to supplement the information regarding pharmacognostical characteristics, physicochemical evaluation, micrometric analysis, and phytochemical exploration in the Ayurvedic system of medicine for its identification and medicinal use. 
 Keywords: Rosa centifolia, Macromorphological description, Physicochemical evaluation, Phytochemical screening, TLC screening.

Syzygium aromaticum L.: phytochemical investigation and comparison of the scavenging activity of essential oil, extracts and eugenol

Syzygium aromaticum L. is a popular flavor and fragrance spice used in cooking, traditional and modern therapy. No work has compared between the scavenging capacity of the essential oil, extracts and eugenol, or studied that of the hexane extract, as well as its phenolic and flavonoid contents. To reveal more details on phytochemical and scavenging characteristics of Syzygium aromaticum spice, we estimated the scavenging activity of the essential oil, each extract of water, ethanol, ethyl acetate and hexane obtained from clove buds, based on their effective concentration able to scavenge 50% (EC50) of 2,2′-diphenyl-1-picrylhydrazyl, and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt free radicals. The essential oil showed high scavenging activity (EC50 of 0.40 ± 0.06 and 0.42 ± 0.02 mg/ml), and comprises 13 identified compounds. Eugenol, β-Caryophyllene, eugenyl acetate and α-Humulene are the major components. Comparing extracts, those of ethanol and hexane exhibited the greatest phenolic content (351.83 ± 17.90 and 348.04 ± 24.54 mg of gallic acid equivalent/gextract respectively) and the potent scavenging activities (EC50 of 0.41 ± 0.03 and 0.37 ± 0.00 mg/ml respectively). A moderate flavonoid content was observed, and aqueous extract was the best (21.90 ± 0.16 mg of quercetin equivalent/gextract). According to thin layer chromatography screening, all extracts content eugenol except that of water, this phenol contributes mainly on the scavenging activity and seems to be more active in mixture with terpenes, like in essential oil.

Development of quantitative HPTLC methods for dolutegravir, lamivudine, and tenofovir disproxil fumarate in a combination pharmaceutical product using a model process published earlier for transfer of minilab TLC screening methods to HPTLC-densitometry

High-performance thin-layer chromatography (HPLTC)–densitometry methods are described for the analysis of the anti(retro)virals dolutegravir (D), lamivudine (L), and tenofovir disoproxil fumarate (TDF) in a pharmaceutical tablet product. To the best of our knowledge, no previous quantitative planar chromatography method has been reported in the literature for this combination formulation. The method for L was transferred from a thin-layer chromatography (TLC) screening method published in the Global Pharma Health Fund (GPHF) Minilab Manual designed for identification of counterfeit and substandard drug products using a model process published earlier. D and TDF are not included in the list of drugs for which TLC screening methods are published for the Minilab, but HPTLC–densitometry procedures were developed for them using the transfer process guidelines. L was analyzed simultaneously with TDF on Merck Premium Purity silica gel 60 F plates using the mobile phase ethyl acetate–methanol–acetone–concentrated ammonium hydroxide (30:7:3:1) and densitometric scanning at 254 nm. D was analyzed on a second plate by scanning at 366 nm after chromatography with the chloroform–methanol–formic acid (32:8:2) mobile phase. Data for all three drugs are shown to meet the requirements of the model transfer process for calibration curve r values, assay of tablets relative to their label values, peak purity/peak identity tests, and validation by standard addition analysis of samples spiked at 50%, 100%, and 150% of the label value of active ingredients. A TLC screening method for TDF in the combination product was developed and published online with open access.

Advances in the thin layer chromatographic analysis of counterfeit pharmaceutical products: 2008–2019

Publications reporting thin layer chromatography (TLC) screening and high performance TLC (HPTLC)-densitometry quantification analyses of counterfeit pharmaceutical products are reviewed for the 2008–2019 period. Screening using TLC methods published in the Global Pharma Health Fund (GPHF) Minilab Manual and U.S. Food and Drug Administration (FDA) Compendium, as well as in other sources, are covered. Also included are publications on TLC analysis hyphenated with Raman and mass spectrometry; analyses of counterfeit traditional herbal medicines; earlier published reviews; transfer of screening methods for counterfeit pharmaceutical products in the Minilab Manual and FDA Compendium to HPTLC-densitometry using a model process; development of HPTLC-densitometry methods for pharmaceutical products not included in the Minilab Manual or FDA Compendium using the model process followed by development of corresponding Supplemental FDA Compendium TLC screening methods; and modified Minilab methods with simplified detection based on heating of silica gel F layers to produce fluorescence quenching zones (thermochemical activation) rather than detection using spray, dip, or vapor phase derivatization reagents. Some thoughts on future prospects for the field are also offered.

Development of quantitative HPTLC-densitometry methods following a model process for transfer of TLC screening methods for pharmaceutical products containing moxifloxacin HCl, ofloxacin, amoxicillin trihydrate, acetylsalicylic acid + acetaminophen + caffeine, nimesulide, irbesartan, and pantoprazole

Transfer of thin-layer chromatography (TLC) Global Pharma Health Fund E.V. Minilab Manual and U.S. Food and Drug Administration (FDA) Compendium protocols for detecting falsified or substandard drugs in pharmaceutical products to quantitative high-performance TLC (HPTLC)-densitometry methods suitable for support of regulatory authorities was performed following a previously published model process for moxfloxacin HCl, ofloxacin, and amoxicillin trihydrate. In addition, the guidelines of the process were followed to develop and validate HPTLC-densitometry methods for pharmaceutical products containing acetylsalicylic acid + acetaminophen + caffeine, nimesulide, irbesartan, and pantoprazole that are not included in the Minilab Manual or FDA Compendium. The new methods involved silica gel 60 F254 plates; semiautomated bandwise sample and standard solution application; ascending mobile phase development of plates in a glass chamber; and automated slit scanning densitometry for detection, identification, and quantification. Data for standard and sample solution preparation, calibration curves, assay of pharmaceutical products compared to label declarations, standard addition validation, and peak purity and peak identity are provided. Supplemental FDA Compendium screening methods corresponding to the HPTLC-densitometry methods for caffeine, nimesulide, irbesartan, pantoprazole, and acetylsalicylic acid co-formulated with acetaminophen and caffeine were developed and published online with open access on the website www.layloff.net.

Inter-organ transport of secologanin allows assembly of monoterpenoid indole alkaloids in a Catharanthus roseus mutant

The medicinal value of the monoterpenoid indole alkaloids (MIAs) such as 3′,4′-anhydrovinblastine, as well as their chemical complexity have stimulated extensive efforts to understand the biochemical and molecular pathways involved in their biosynthesis in plants such as Catharanthus roseus, Rawvolfia serpentina and others. Ethyl methane sulphonate (EMS) mutagenesis has been used successfully together with simple MIA thin layer chromatography screening to identify C. roseus mutants with altered MIA profiles. This study describes the isolation of very low iridoid and MIA containing C. roseus mutant (M2-1582) that accumulates MIAs when the plant is provided with secologanin by feeding mutant roots or by grafting the mutant scion onto wild type roots. The observed low iridoid and MIA content was correlated with lowered expression of BIS1/BIS2 transcription factors and several genes involved in secologanin biosynthesis that are expressed in internal phloem parenchyma cells of leaves. When exogenous secologanin was applied to the roots of the mutant plant, secologanin levels rose more than 13-fold, while two major MIAs catharanthine and vindoline rose more than 8- and 4- fold, respectively. Grafting the mutant on WT stocks led to 27-, 11- and 27-fold increases in secologanin, catharanthine and vindoline, respectively in leaves of the scion one week after graft initiation. Other minor MIAs (serpentine, anhydrovinblastine, vindolidine, deacetylvindoline, tabersonine and 16-methoxytabersonine) that were not detected in the mutant, became detectable in leaves of the scion. These results provide strong evidence for a secologanin transport mechanism that mobilizes this iridoid between different plant organs in C. roseus and that secologanin transport to the mutant across the graft union permits the formation of MIAs in leaves of the mutant.

Development of quantitative HPTLC–Densitometry methods for the analysis of amiodarone HCl, carvedilol, doxylamine succinate, magnesium salicylate, metoprolol succinate, nebivolol HCl, and salicylamide using a model process developed earlier for the transfer of TLC screening methods

A model process, previously developed in a series of studies, allows for the transfer of thin-layer chromatography (TLC) methods for qualitative screening of counterfeit drug products published in the Global Pharma Health Fund (GPHF) Minilab manual and US Food and Drug Administration (FDA) Compendium of Unofficial Methods for Screening of Pharmaceuticals by TLC to quantitative high-performance TLC (HPTLC)–densitometry methods. This article describes HPTLC–densitometry methods developed and validated according to this model process for pharmaceutical products of amiodarone HCl, carvedilol, doxylamine succinate, magnesium salicylate, metoprolol succinate, nebivolol HCl, and salicylamide, for which qualitative screening methods have not been published in the Minilab manual or FDA Compendium. These methods use relatively inexpensive and nontoxic “green solvents” for sample and standard solution and mobile phase preparation, Merck Premium Purity silica gel 60 F254 plates, automated standard and sample solution bandwise application, and automated densitometry for the assessment of peak purity and identity and quantification. Corresponding to the quantitative HPTLC–densitometry methods, qualitative TLC screening methods for these drug products were developed and posted online with open access as supplements to the FDA Compendium.

Development of quantitative HPTLC-densitometry methods following a model approach for transfer of TLC screening methods for pharmaceutical products of atenolol, chloramphenicol, furosemide, glibenclamide, penicillin V potassium, and praziquantel

ABSTRACTTransfer of six thin-layer chromatography (TLC) Global Pharma Health Fund E.V. Minilab manual protocols for detecting fake drugs in pharmaceutical products to quantitative high-performance TLC (HPTLC)-densitometry methods was performed following a previously published model process. The developed and validated methods for tablets or capsules containing atenolol, chloramphenicol, furosemide, glibenclamide, penicillin V potassium, and praziquantel involved use of a limited list of inexpensive, relatively nontoxic, readily available solvents and other reagents; silica gel 60 F254 plates; automated bandwise sample and standard solution application; ascending mobile phase development of plates in a chamber; and automated slit scanning densitometry for detection, identification, and quantification. Validation data for methods developed in an early version of the transfer model process that did not include standard addition validation are reported for pharmaceutical products containing amitriptyline HCl, amodiaquine, diphenhydramine HCl, and mebendazole.

TLC Screening Profile of Secondary Metabolites and Biological Activities of Salisapilia tartarea S1YP1 Isolated from Philippine Mangroves.

The Salisapilia species are estuarine oomycetes of the mangrove and saltmarsh ecosystem. To date, reports on the secondary metabolites and biological activities of these microorganisms are wanting. In this study, secondary metabolites in broth ethyl acetate extracts (BEAE) and mycelial ethyl acetate extracts (MEAE) of Salisapilia tartarea S1YP1 isolated from yellow senescent mangrove leaves were screened by Thin Layer Chromatography (TLC). Extracts were assayed for antioxidant, antibacterial, α- glucosidase inhibition, and cytotoxic activity. The TLC detected anthraquinones, anthrones, flavonoids, phenols, and triterpenes in both BEAE and MEAE. Coumarins were detected in BEAE but not in MEAE. Quantifying the total phenolics and total flavonoids content of the extracts in terms of gallic acid and quercetin equivalents, respectively shows that BEAE has higher total phenolic and flavonoid contents than MEAE. BEAE exhibited significant antioxidant activities through measurements of free radical scavenging activity against DPPH, hydroxyl, nitric oxide, and superoxide anion radicals as well as the ability to chelate Fe2+ metal ion. BEAE significantly inhibited in a dose-dependent manner α-glucosidase activity and selectively inhibited HepG2 cell proliferation. Antioxidant, α- glucosidase inhibitory, and cytotoxic activities have not been observed for MEAE. Both BEAE and MEAE do not have antibacterial activity.

Development of quantitative HPTLC–densitometry methods following a model approach for transfer of TLC screening methods for pharmaceutical products of cefixime, cefuroxime axetil, cephalexin⋅H2O, ciprofloxacin HCl, levofloxacin, and metronidazole

Transfer of six thin-layer chromatography (TLC) Global Pharma Health Fund Minilab kit protocols for detecting fake or markedly substandard drugs in pharmaceutical products in the field to quantitative high-performance TLC (HPTLC)–densitometry methods was carried out using a model process published earlier. The developed and validated methods for tablets or capsules containing cefixime, cefuroxime axetil, cephalexin·H2O, ciprofloxacin HCl, levofloxacin, and metronidazole involved use of EMD Millipore Premium Purity silica gel 60 F254 plates, automated sample and standard solution application with a CAMAG Linomat 4, and automated densitometry with a CAMAG Scanner 3 for detection, identification, and quantification.

Transfer of silica gel TLC screening methods for clarithromycin, azithromycin, and amodiaquine + artesunate to HPTLC–densitometry with detection by reagentless thermochemical activation of fluorescence quenching

ABSTRACTA previously published model process was used for the transfer of silica gel thin-layer chromatography (TLC) screening methods for clarithromycin, azithromycin, and amodiaquine + artesunate pharmaceutical formulations published in the Global Pharma Health Fund E.V. Minilab manual for the identification of counterfeit drugs to high-performance TLC–densitometry quantitative methods that can be used in support of regulatory compliance actions. In these new methods, detection of clarithromycin, azithromycin, and artesunate was achieved by thermochemical activation involving simple reagent-free heating of the layer to produce derivatives of the drugs that quench fluorescence under 254 nm ultraviolet light. Additional drugs with TLC screening methods published in the Minilab manual and/or Compendium of Unofficial Methods for Rapid Screening of Pharmaceuticals by Thin Layer Chromatography that do not naturally quench fluorescence were studied and also found to be detectable by thermochemical activation on silica gel layers. The conditions of the thermochemical activation were studied, and in situ spectra of drug zones before and after heating were obtained. Heat activation of fluorescence quenching seems to be a widely applicable detection method that is safer and more convenient than the use of chemical spray, dip, or vapor phase reagents.

Use of a model process for transfer of minilab TLC screening methods for quinine sulfate, mefloquine, and dihydroartemisinin—piperaquine phosphate tablets to quantitative HPTLC—densitometry methods

Transfer of four thin-layer chromatography (TLC) Global Pharma Health Fund Minilab mobile kit protocols for detecting fake pharmaceutical products to quantitative high-performance TLC (HPTLC)—densitometry methods was carried out using a model process published earlier. The developed and validated methods were for the drugs quinine sulfate, mefloquine, dihydroartemisinin, and piperaquine phosphate. EMD Millipore Premium Purity silica gel 60 F254 glass plates, automated standard and sample solution application with a CAMAG Linomat 4, and automated densitometry with a CAMAG Scanner 3 for detection, identification, and quantification were used. Sample peak identity and purity validation were carried out by spectral comparison checks available in the winCATS software, and accuracy was estimated by the standard addition approach. HPTLC gives better efficiency, selectivity, and resolution than TLC, and the new methods overcome the deficiencies in technology related to manual application and visual zone comparison that do not allow the Minilab TLC procedures to support regulatory compliance actions. These new methods should be fully validated according to International Conference on Harmonization guidelines or by interlaboratory studies if required by their applications. In addition, a previously reported transferred simultaneous HPTLC–densitometry method for lumefantrine and artemether was used to analyze a new combination tablet to demonstrate its applicability.

TLC Screening and Evaluation of Antioxidant, Antibacterial Activity of Onopordon Macrocephalum by Bioautography Method

TLC screening and Evaluation of antioxidant, antibacterial activity of Onopordon macrocephalum by bioautography methodOnopordon known as scotch thistle is a medicinal plant of the Asteraceae family that is widely distributed in Europe and Asia, also it has many valuable medicinal properties as hypotensive and antitumor. Thin layer chromatography (TLC) is wildly used in natural product extract analysis as a finger print which can be used for identification and quality control of medicinal preparations. Performing Thin-layer chromatography TLC tests on the plant show the presence of flavonoids, coumarins and bitter principles. Planar chromatographic analysis hyphenated with the biological detection method is known as bioautography which is an effective and inexpensive technique for the phytochemical analysis of plant extracts. Thin-layer chromatography-direct bioautography links separation on the adsorbent layer with biological tests performed directly on it in order to identify antimicrobial and antioxidant activities. Bioautography revealed that Staphylococcus aureus was inhibited by most of the flavonoids separated on the TLC plates. Similarly, growth of the Bacillus cereus was also inhibited by one flavonoid band on TLC. Antioxidant bioautography shows the strong antioxidant activity of one flavonoid band, whereas no activity detected of bitter principles. Bioautography showed that the antimicrobial and antioxidant activity was probably due to flavonoids.