Wyniki wyszukiwania - BazTech

1

Wykorzystanie chromatografii HPTLC w analizie produktów pszczelich

Miłek Michał

Przemysł Spożywczy

|

2023

|

T. 77, nr 9

15--19

PL

Wysokosprawna chromatografia cienkowarstwowa (HPTLC) jest techniką chromatograficzną często wykorzystywaną w analizie żywności. Może być stosowana do analiz jakościowych (np. profilowanie składu próbki) i ilościowych, a szczególnie przydatna jest w analizie porównawczej wielu próbek rozdzielanych jednocześnie na płytce. Wśród wielu zastosowań tej techniki analitycznej znajduje się ocena jakości produktów pszczelich, zwłaszcza miodu, propolisu i pyłku pszczelego, ale także mniej popularnych produktów, jak pierzga, mleczko pszczele czy czerw trutowy. Wśród najczęściej badanych tą metodą parametrów są: profil polifenolowy, cukrowy czy aminokwasowy, istnieje też możliwość oznaczania konkretnych związków, odpowiedzialnych za bioaktywność produktów pszczelich lub stanowiących substancje niepożądane (np. HMF). Zaletami metody HPTLC są jej prostota, możliwość analizy nawet kilkunastu próbek jednocześnie, brak konieczności specjalnego przygotowania próbki oraz stosunkowo niewielki koszt pojedynczej analizy.

EN

High-performance thin-layer chromatography (HPTLC) is a chromatographic technique that is increasingly used in food analysis. Suitable for qualitative (sample composition profiling) and quantitative analyses, it is particularly useful in the comparative analysis of multiple samples separated simultaneously on the plate. Among the many applications is the assessment of the quality of bee products, especially honey, propolis and bee pollen, but also less popular products such as bee bread, royal jelly or drone brood. Among the parameters most often tested with this method is the polyphenol, sugar or amino acid profile, it is also possible to determine specific compounds responsible for the bioactivity of bee products or undesirable substances (e.g. HMF). The advantages of the HPTLC method are its simplicity, the ability to analyze multiple samples simultaneously, no need for special sample preparation and the relatively low cost of a single analysis.

2

Simultaneous densitometric determination of β-sitosterol and lupeol through validated HPTLC method in different plant parts of Uraria picta (Jacq.) Desv. ex DC. – A dashmool species

Saxena Hari Om, Parihar Samiksha, Pawar Ganesh, Rao G. Rajeshwar

Acta Chromatographica

|

2023

|

Vol. 35, no. 1

99--105

EN

β-sitosterol (BS) and lupeol (LU) exhibit a number of biological activities and are the important bioactive marker compounds in pharmaceutical science. In the present study, a simple, precise, accurate and validated high performance thin layer chromatographic (HPTLC) method was developed for simultaneous quantification of these two compounds in leaves, stem and roots of Uraria picta, a critically endangered medicinal plant and one of the important constituents of ten plants ayurvedic formulation called Dashmoola. Standards and test samples were applied on TLC aluminum plate precoated with 0.2 mm layer of silica gel 60F254. The plate was run in a twin glass chamber comprising toluene: methanol: chloroform (8:1:1, v/v/v) as a mobile phase. The plates were immersed in anisaldehyde-sulfuric reagent and then heated at 105 °C for 5 min in CAMAG TLC plate heater for appearance of bands. Densitometric scanning was performed at λmax = 525 nm using tungsten light source in CAMAG TLC Scanner4 armed with WinCATS software. RF values of BS and LU standards and those of test samples were found to be 0.53 ± 0.01 and 0.63 ± 0.01 respectively. The method was further validated by following the International Conference of Harmonization (ICH) guidelines. For BS and LU, the linear regression data for the calibration plots revealed a satisfactory linear association with r2 = 0.995 and 0.998, respectively. Linear range for both BS and LU was 200–600 ng/band. Accuracy of the method was evaluated by performing recovery study at three different levels by standard addition methods with an average recovery of 99.86% and 101.07%. The results revealed that the leaf samples of U. picta contained highest concentration of BS (0.150 ± 0.02%) while its root samples confined the highest concentration of LU (0.149 ± 0.01%). The developed method can be applied for routine and quality control analysis in different herbal formulations containing U. picta species.

3

Quality risk assessment and DoE – Practiced validated stability-indicating chromatographic method for quantification of Rivaroxaban in bulk and tablet dosage form

Palandurkar Kamlesh, Bhandre Richie, Boddu Sai H. S., Harde Minal, Lakade Sameer, Kandekar Ujjwala, Waghmare Prashant

Acta Chromatographica

|

2023

|

Vol. 35, no. 1

10--20

EN

A systematic DoE and Analytical Quality by Design (AQbD) approach was utilized for the development and validation of a novel stability indicating high-performance thin–layer chromatographic (HPTLC) method for Rivaroxaban (RBN) estimation in bulk and marketed formulation. A D-optimal design was used to screen the effect of solvents, volume of solvents, time from spotting to development and time for development to scanning. ANOVA results and Pareto chart revealed that toluene, methanol, water and saturation time had an impact on retention time. The critical method and material attributes were further screened by Box-Behnken design (BBD) to achieve optimal chromatographic condition. A stress degradation study was carried out and structure of major alkaline degradant was elaborated. According to the design space, a control strategy was used with toluene: methanol: water (6:2:2) and the saturation time was 15 min. A retention factor (RF) of 0.59 ± 0.05 was achieved for RBN using chromatographic plate precoated with silica gel at detection wavelength 282 nm with optimized conditions. The linear calibration curve was achieved in the concentration range of 200–1,200 ng/band with r2 > 0.998 suggesting good coordination between analyte concentration and peak areas. The quadratic model was demonstrated as the best fit model and no interaction was noted between CMAs. The optimized HPTLC method was validated critically as stated in International Conference on Harmonization (ICH) Q2 (R1) guideline and implemented successfully for stress degradation study of RBN. The developed HPTLC method obtained through AQbD application was potentially able to resolve all degradants of RBN achieved through forced degradation study. The obtained results demonstrate that a scientific AQbD approach implementation in HPTLC method development and stress degradation study drastically minimizes the number of trials in experiments, ultimately time and cost of analysis could be minimized.

4

High performance thin layer chromatography (HPTLC) method development and validation for the simultaneous determination of paracetamol, caffeine, chlorpheniramine and phenylepherine in tablet formulation

Arage Almaz, Layloff Thomas, Hymete Ariaya, Ashenef Ayenew

Acta Chromatographica

|

2023

|

Vol. 35, no. 2

170--178

EN

A rapid, selective, and precise high performance thin layer chromatographic method was developed and validated for the simultaneous analysis of paracetamol, caffeine, phenylephrine and chlorpheniramine in tablets. The chromatographic analysis was carried out on glass plates pre-coated with silica gel 60 F254 as a stationary phase. The optimized mobile phase was methanol : n-butanol : toluene : acetic acid (8:6:4:0.2 v/v). TLC chamber of 10 × 20 cm was used with saturation time of 15 min. The retardation factor (RF) for chlorpheniramine, phenylephrine, caffeine and paracetamol was found to be 0.15 ± 0.02, 0.29 ± 0.02, 0.50 ± 0.02, 0.68 ± 0.02 respectively. Detection was carried out at 212 nm. Validation study was done following ICH Q2 (R1) guideline. The regression data for the calibration plots showed good linear relationship with R2 = 0.997 over the concentration range of 300–1,500 ng band⁻¹ for caffeine, R2 = 0.996 over the concentration range of 100–500 ng band⁻¹ for phenylephrine, R2 = 0.996 over the concentration range of 200–600 ng band⁻¹ for chlorpheniramine, R2 = 0.998 over the concentration range of 400–2,400 ng band⁻¹ for paracetamol. The method was validated for precision, accuracy and recovery. Minimum detectable amounts were found to be 304.9 ng band⁻¹, 87.88 ng band⁻¹, 117.18 ng band⁻¹ and 143.06 ng band⁻¹ for caffeine, phenylephrine, chlorpheniramine, and paracetamol respectively while the limit of quantification was found to be 923.95 ng band⁻¹, 266.32 ng band⁻¹, 355.11 ng band⁻¹, and 433.53 ng band⁻¹ in the same order. The method was successfully applied to analyze two marketed tablets in a selective and reproducible manner.

5

High performance thin layer chromatography (HPTLC) method development and validation for determination of doxycycline hyclate in capsule and tablet formulations

Kumssa Lensi, Layloff Thomas, Hymete Ariaya, Ashenef Ayenew

Acta Chromatographica

|

2022

|

Vol. 34, no. 3

287--295

EN

According to World Health Organization (WHO) 10% of the medicines in the Low and Middle Income Countries (LMICs) are of poor quality posing a major public health threat. One way to circumvent such problem is the development and deployment of rapid, economical and efficient analytical methods. Hence this research aims to develop a High-Performance Thin Layer Chromatography (HPTLC) method for the determination of doxycycline hyclate. A rapid and simple HPTLC method with densitometry detection at 360 nm to determine doxycycline hyclate in capsules and tablet formulations was developed and validated. HPTLC was performed on glass plates coated with C18 reverse phase silica gel 60 F₂₅₄ and pretreated with 0.27 M ethylenediaminetetraaceticacid (EDTA) solution. The mobile phase was dichloromethane: methanol: acetonitrile: 1% aqueous ammonia in the ratio of 10:22:53:15 (v/v). The linearity range lies between 200 and 1,000 ng/spot with correlation coefficient of 0.997. The Rf value is 0.5 ± 0.02%. Recoveries were in the range of 94.50–100.5%. Limit of detection and limit of quantitation values for doxycycline hyclate were 40 and 160 ng/spot respectively. The developer method was validated as per ICH guidelines. Thus, it was found to be accurate, precise, specific and robust. In forced degradation study, doxycycline hyclate was found to degrade in acidic and alkaline media, and through oxidative stress. The drug was found to be relatively stable to heat and photo degradation. The method was successfully applied for the routine quantitative analysis of dosage forms containing doxycycline hyclate. The developed method offered comparable results (as confirmed by F-test) with that of the HPLC pharmacopoeial (BP) analysis method.

6

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

Gu Y., Zeng B., Sherma J.

Acta Chromatographica

|

2020

|

Vol. 32, no. 3

199--202

EN

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.

7

Validated stability-indicating HPTLC method for cefixime and azithromycin with preparative isolation, identification, and characterization of degradation products

Gawande V. T., Bothara K. G., Satija C. O.

Acta Chromatographica

|

2018

|

Vol. 30, no. 4

212--218

EN

Stability-indicating High-Performance Thin-Layer Chromatography (HPTLC) method for simultaneous estimation of cefixime trihydrate and azithromycin dihydrate was developed. Both the drugs were subjected to different stress conditions recommended by International Conference on Harmonization (ICH) guideline Q1A (R2). Forced degradation was carried out for hydrolytic, oxidative, photolytic, and thermal degradation conditions. Cefixime was susceptible for degradation under all stress conditions showing four degradation products (CI–IV). However, azithromycin formed only one degradation product (AI) under acid hydrolysis. Aluminum plates precoated with silica gel 60F254 were used as the stationary phase while mixture of ethyl acetate–methanol–acetone–toluene–ammonia (1:5:7:0.5:0.5, v/v) was used as mobile phase. Detection wavelength used was 235 nm for CEFI and CI–IV. AZI and AI were detected by post development derivatization, spraying with sulfuric acid–ethanol (1:4, v/v) followed by heating at 100 °C for 5 min. Degradation products were isolated by preparative HPTLC and characterized by MS/MS. The developed method was validated for linearity, precision, accuracy, specificity, and robustness and has been successfully applied in the analysis of these drugs in tablet dosage form.

8

Quantitative determination of glycerol in antarctic krill (Euphausia superba Dana) by high-performance thin-layer chromatography

Han X., Liu D.

Acta Chromatographica

|

2018

|

Vol. 30, no. 4

274--277

EN

In this reported study, a direct high-performance thin-layer chromatographic (HPTLC) method was developed to qualitatively detect and quantitatively determine glycerol in Antarctic krill for the first time. This procedure was based on the extraction of glycerol by ultrasonic solvent extraction with anhydrous ethanol, silica-gel column chromatographic separation, HPTLC detection and quantification using methylene chloride–methanol (5:1, v/v) as the developing solvent and alkaline potassium permanganate as chromogenic agent. The content of glycerol was 1.3725 ± 0.218 mg/g in freeze-dried Antarctic krill. The structure of glycerol in the Antarctic krill was subsequently determined by gas chromatography–mass spectrometry (GC–MS) which verified the presence of the material in the krill. The HPTLC method exhibited excellent accuracy with a recovery of 90.1–103.3% and good precision with a relative standard deviation (RSD) of 1.59–4.84%. The results clearly exhibited the applicability of the proposed for quantifying glycerol in Antarctic krill.

9

A Validated Reverse Phase HPLC Technique for the Determination of TATB Assay

Bhattacharyya S. C., Patil R. S., Santosh M. S. S. N. M., Bhattacharya B., Malik R. K., Mehra A.

Central European Journal of Energetic Materials

|

2016

|

Vol. 13, no. 3

641--657

EN

The main hurdle for the estimation of the purity of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is its insolubility in most of the known organic solvents. In the conventional method, TATB is digested with steam in a modified Kjeldahl digester and the ammonia evolved is estimated quantitatively. To do away with this cumbersome method, a simple, rapid HPLC technique using a reverse phase C-18 column has been established for quantitative determination of the purity of TATB. A sharp and symmetrical peak with a retention time of 2.92 min at 355 nm is obtained for pure TATB when the flow rate is 2.0 mL/min. The linearity of the detector response has been studied with sample concentrations ranging from 10 to 50 mg/L. The method addresses two important issues of sample preparation and the precision of measurement. Unlike the previously reported HPLC techniques which mainly aimed at the detection of TATB, the present work is a validated account of a quantitative estimation of purity. Regular production batch samples have been assayed by this method and the results are compared with those obtained from the conventional analysis. The HPLC method is convenient and reliable for quality control of the product at the plant level.

10

Chromatographic Methods for Simultaneous Determination of Moxifloxacin Hydrochloride and Difluprednate in Ophthalmic Dosage Form

Mangukiya R. P., Patel R. A., Shah P. A., Patel K. G.

Acta Chromatographica

|

2015

|

Vol. 27, no. 3

495--508

EN

Two simple, accurate, specific, and precise chromatographic methods, reversed phase high-performance liquid chromatography (RP-HPLC) and highperformance thin-layer chromatography (HPTLC), have been developed and validated for the determination of moxifloxacin hydrochloride and difluprednate in ophthalmic dosage form according to International Conference on Harmonization (ICH) guidelines. The separation of moxifloxacin hydrochloride and difluprednate in HPLC was performed on reverse phase (C18, 5 μm, 250 × 4.6 mm) column using isocratic condition, with acetonitrile, 5 mM disodium hydrogen phosphate buffer adjusted to pH 5, and methanol (50:25:25, v/v/v) as mobile phase. The flow rate for analysis was 1.0 mL min−1, and the selected chromatographic conditions effectively separated moxifloxacin hydrochloride and difluprednate with retention time of 3.6 and 6.6 min, respectively, at a detection wavelength of 254 nm. Chromatographic development in HPTLC was performed on precoated silica gel 60F254 aluminium plates with n-hexane, 6 M ammonia, and acetone (5:1.8:2, v/v/v) as mobile phase. The detection wavelength for simultaneous estimation of both drugs was 232 nm in HPTLC, and the Rf values for moxifloxacin hydrochloride and difluprednate were 2.2 and 7.1, respectively. The linear concentration range for HPLC method was 5 to 50 μg Ml-1 and 1 to 10 μg Ml-1; and for HPTLC method was 1200 to 2200 ng band-1 and 200 to 1200 ng band-1 for moxifloxacin hydrochloride and difluprednate, respectively. Moreover, Bartlett's test applied on the calibration peak areas revealed homoscedasticity of variance for both the methods. Both methods were validated with respect to system suitability, specificity, linearity, precision, accuracy, and robustness. The mean percentage recoveries for marketed formulation in terms of accuracy were found to be 100.53 and 100.58 for HPLC; and 100.56 and 100.30 for HPTLC for moxifloxacin hydrochloride and difluprednate, respectively. The pooled percent relative standard deviation (% RSD) value for repeatability, intermediate precision, accuracy, and robustness studies for both the methods were found to be less than 2. Result of paired t-test at 95% confidence level reveals that there is no significant difference between recoveries of drugs, using both methods. The results of the developed chromatographic methods were acceptable assuring that these methods can be successfully applied for routine quality control testing of both bulk and ophthalmic dosage forms, without any interference from the excipients.

11

Development and validation of stability-indicating high-performance thin-layer chromatography method for estimation of sitagliptin phosphate monohydrate in bulk and in pharmaceutical formulation

Jain P. S., Chaudhari A. J., Surana S. J.

Acta Chromatographica

|

2014

|

Vol. 26, no. 2

309--319

EN

A simple, selective, precise, and stability-indicating high-performance thinlayer chromatographic method for analysis of sitagliptin phosphate both in a bulk and in pharmaceutical formulation has been developed and validated. The method employed high-performance thin-layer chromatography (HPTLC) aluminium plates precoated with silica gel 60 RP-18 F254 as the stationary phase. The solvent system consisted of methanol-water-triethylamine (8:2:0.05 v/v). The system was found to give compact spot for sitagliptin phosphate (Rf value of 0.55 ± 0.03). Densitometric analysis of sitagliptin phosphate was carried out in the absorbance mode at 267 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.998±0.0015 with respect to peak area in the concentration range 1000–6000 ng per spot. The mean value ± SD of slope and intercept was 0.723 ± 0.043 and 17.24 ± 18.78 with respect to peak area. The method was validated for precision, recovery, and robustness. The limits of detection and quantification were 85.80 and 265.42 ng per spot, respectively. Sitagliptin phosphate was subjected to acid and alkali hydrolysis, oxidation, and photo and thermal degradation. The drug undergoes degradation under acidic, basic, and oxidative conditions. This indicates that the drug is susceptible to acid and base, and oxidation. The degraded product was well resolved from the pure drug with significantly different RF value. Statistical analysis proves that the method is repeatable, selective, and accurate for the estimation of investigated drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of sitagliptin phosphate in bulk drug and pharmaceutical formulation.

12

Determination of some psychotropic drugs in human plasma by HPTLC

Wróblewski K., Petruczynik A., Waksmundzka-Hajnos M.

Acta Chromatographica

|

2014

|

Vol. 26, no. 2

297--307

EN

Psychotropic drugs: desipramine, olanzapine and mitrazapine were chromatographed on cyanopropyl-silica and Diol-silica thin layers using various nonaqueous and aqueous eluents.The best results were obtained with addition of ammonia to nonaqueous eluent on both adsorbents. On the basis of the optimization, systems for extraction from human plasma and quantitative determination of investigated drugs were selected.RP18 encaped SPE columns conditioned and pre-eluted with acetonitrile:water:ammonium buffer at pH 8.6 (5:5:2) and eluted with methanol:water (9:1) containing 2% acetic acid were used for sample preparation with high recoveries of all investigated drugs. Diol and CN plates with mixture of 15% methanol in diisopropyl ether + 1% ammonia were used for quantitative analysis by a calibration curve method.

13

Quantification of piperine and 18-β glycyrrhetinic acid in herbal formulation “Eladi Gutika”

Rode S., Bhujbal P., Sandhya P.

Acta Chromatographica

|

2013

|

Vol. 25, no. 1

135--146

EN

Eladi Gutika is a polyherbal formulation official in “Ayurvedic formulary of India” and used for dry cough and throat infection. A simple, specific and precise high-performance thin-layer chromatography (HPTLC) method has been developed for quantification of piperine and 18-β glycyrrhetinic acid in Eladi Gutika. We report the extraction and estimation of these compounds in a laboratory prepared sample of Eladi Gutika and two of its marketed formulations. The compounds were chromatographed on precoated silica gel G 60254 plates in the mobile phase comprising of toluene, ethyl acetate, and glacial acetic acid. Under the optimized chromatographic conditions, the calibration plot was found to be linear in the range of 0.2–1 g mL-1 with a correlation coefficient R2 = 0.9902 for piperine and 0.9904 for 18-β glycyrrhetinic acid. Mean recovery for piperine was 99.75% w/w and for 18-β glycyrrhetinic acid was 101.36% w/w.

14

HPTLC/HPLC and gravimetric methodology for the identification and quantification of gymnemic acid from Gymnema sylvestre methanolic extracts

Ahmed A. B. A., Rao A. S., Rao M. V., Taha R. M.

Acta Chromatographica

|

2013

|

Vol. 25, no. 2

339--361

EN

Gymnemic acid (GA), a well known anti-diabetic compound has been detected in methanol extracts of intact leaves and in vitro callus cultures derived from leaf explants of Gymnema sylvestre. Callus biomass was developed in MS medium with optimum plant growth regulators (OPGRs) of 2,4-D (1.5 mg L-1) + KN (0.5 mg L-1) under abiotic stress conditions at 45 days determined by growth curve analysis. GA detection and quantification were carried out using thin-layer chromatography (TLC), highperformance thin-layer chromatography (HPTLC), high-performance liquid chromatography (HPLC), and gravimetric techniques. GA detection peak area and their absorption spectra were evaluated through HPTLC and HPLC with the standard GA. Quantification of GA had showed the linearity, accuracy, robustness and precision by HPLC. GA content was significantly higher in gravimetric method than HPLC. All these methods were found to be simple, accurate, selective and rapid and could be successfully applied for the determination of GA. It could have potential as a pharmaceutical drug for Type 1 diabetes mellitus (IDDM) and obesity.

15

Development and validation of stability-indicating high-performance thin-layer chromatography method for estimation of repaglinide in bulk and in pharmaceutical formulation

Jain P. S., Patel M. K., Surana S. J.

Acta Chromatographica

|

2013

|

Vol. 25, no. 3

531--544

EN

A simple, selective, precise, and stability-indicating high-performance thin-layer chromatographic method for analysis of repaglinide both in a bulk and in pharmaceutical formulation has been developed and validated. The method employed high-performance thin-layer chromatography (HPTLC) aluminum plates precoated with silica gel 60 RP-18 F254 as the stationary phase. The solvent system consisted of chloroform-methanol-ammonia (4.5:0.8:0.05, v/v). The system was found to give compact spot for repaglinide (RF value of 0.55 ± 0.03). Densitometric analysis of repaglinide was carried out in the absorbance mode at 288 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.998 ± 0.0015 with respect to peak area in the concentration range 600–1600 ng per spot. The mean value ± SD of slope and intercept were 3.38 ± 1.47 and 986.9 ± 108.78, with respect to peak area. The method was validated for precision, recovery, and robustness. The limits of detection and quantification were 22.64 and 68.84 ng per spot, respectively. Repaglinide was subjected to acid and alkali hydrolysis, oxidation, and thermal degradation. The drug undergoes degradation under acidic and basic conditions. This indicates that the drug is susceptible to acid and base. The degraded product was well resolved from the pure drug with significantly different RF value. Statistical analysis proves that the method is repeatable, selective, and accurate for the estimation of investigated drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of repaglinide in bulk drug and pharmaceutical formulation.

16

Development and validation of HPTLC method for estimation of gymnemic acid in microencapsulated antidiabetic polyherbal formulations

Patil A. N., Nirmal S. A., Chavan A. K.

Acta Chromatographica

|

2013

|

Vol. 25, no. 4

601--612

EN

Gymnemic acid (GA) is one of the phytoconstituents present in Gymnema sylvestre. Estimation of GA was carried out first time from microencapsulated polyherbal formulation. Microencapsulated polyherbal formulations (F1 and F2) contain various plant extracts; hence, proper resolution of GA peak in high-performance thin-layer liquid chromatography (HPTLC) analysis of F1 and F2 is the problem. Hence, HPTLC analysis method for F1 and F2 is developed and validated for quantitative determination of GA. HPTLC analysis of F1 and F2 was carried out using TLC aluminum plates precoated with silica gel 60F254 eluted with chloroform-methanol-water (6.5 mL + 4.5 mL + 1.0 mL), and densitometric analysis was carried out at 580 nm. Complete validation was performed using standard methods. This HPTLC method was found to be reproducible, accurate, and can detect GA at microgram level. The new optimized mobile phase gave good resolution of GA peak for its proper quantification in microencapsulated polyherbal formulation.

17

Quantitative analysis of marker constituent swertisin in Enicostemma hyssopifolium verdoon by RP-HPLC and HPTLC

Patel M. B, Mishra S. H.

Acta Chromatographica

|

2012

|

Vol. 24, no. 1

85--95

EN

Methods based on RP-HPLC and HPTLC with UV detection for rapid quantitative determination of marker component in Enicostemma hyssopifolium, swertisin are described. The recovery of the compound was between 96.3–101.5% by HPTLC method and 98.9–100.2% by HPLC assay. The relative standard deviations ranged between 1.53–1.81 (intra-day) and 1.33–1.96 (inter-day) for HPTLC and 0.60–1.11 (intra-day) and 0.80–1.20 (inter-day) for HPLC. The methods were used for routine analysis of swertisin in the aerial parts of the plant. HPTLC method was found to be more economic and less time consuming than HPLC. Reproducibility and recovery in HPLC method were better than that in HPTLC method.

18

Chromatographic identification of two biologically important triterpenoids from the chloroform extract of Rhizophora mucronata

Hridya V. K, Godson P. S, Chandrasekar N.

Acta Chromatographica

|

2012

|

Vol. 24, no. 1

123--129

EN

Mangroves are the source of several bioactive secondary metabolites and have proven activity against human, animal and plant pathogens. Rhizophora mucronata is a mangrove species belonging to the family Rhizophoraceae. Betulin and lupeol are two naturally occurring pentacyclic triterpenoids having excellent biological properties. Chloroform extract of R. mucronata, collected from Pitchavaram, Muthupett and Manakudy regions of Tamilnadu, was chromatographed on silica gel 60F254 plates with nhexane and ethyl acetate (80:20) (v/v) as the mobile phase. Derivatizations were done using anisaldehyde and sulfuric acid reagents. The triterpenoids such as betulin and lupeol were identified through HPTLC method. This is the first report for the thin layer chromatographic (TLC) identification of triterpenoids such as betulin and lupeol from R. mucronata, which will be the most valuable information to identify the antimalarial and antiviral activities.

19

A model procedure for the transfer of TLC pharmaceutical product screening methods designed for use in developing countries to quantitative HPTLC-densitometry methods

O’sullivan C, Sherma J.

Acta Chromatographica

|

2012

|

Vol. 24, no. 2

241--252

EN

Transfer of four rapid thin-layer chromatography (TLC) screening methods used to detect substandard and counterfeit pharmaceutical products to quantitative high-performance TLC (HPTLC)-densitometry methods is demonstrated. These methods for acetaminophen, acetylsalicylic acid, ibuprofen, and chlorpheniramine maleate are contained in a Compendium of methods developed by Kenyon and Layloff for use in countries with limited resources. The new quantitative methods use Merck HPTLC silica gel 60 F254 glass plates, automated standard and sample application, and automated densitometry for detection, identification, and quantification. Standard and sample solution preparation and application procedures for obtaining calibration curves and bracketed samples are described. The HPTLC plates give 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 Compendium TLC procedures to support regulatory compliance actions. These transferred methods can be fully validated according to International Conference on Harmonization (ICH) guidelines or by interlaboratory studies if their applications require. The approach described can be used to transfer the remaining Compendium methods as well as the GPHF [Global (formerly German) Pharma Health Fund E.V.] Minilab kit TLC screening methods.

20

Quantification of triazine herbicides using chloroplasts in conjunction with thin-layer chromatography

Broszat M., Ernst H., Spangenberg B.

Environmental Biotechnology

|

2011

|

Vol. 7, No. 2

47-52

EN

We present a video-densitometric quantification method for the triazine herbicides atraton, terbumeton, simazine, atrazine and terbutylazine. Triazine herbicides were separated on silica gel using methyl-t-butyl ether, cyclohexane (1+1, v/v) as mobile phase. The quantification was based on a bioeffective-linked analysis using chloroplast and 2,6-dichlorophenolindophenol. Within 1-2 minutes HILL-reaction inhibitor substances show blue-grey zones on a pale yellowgreen background. To increase the contrast, the moist plate can be dipped into a solution of PEG-600 (10% PEG-600 in methanol) for 2s. Measurements were carried out using a 16 bit ST-1603ME CCD camera with 1.56 megapixels (from Santa Barbara Instrument Group, Inc., Santa Barbara, USA). A white LED was used for illumination purposes. The range of linearity covers more than one magnitude using the (1/R) - 1 expression data transformation. The method can be used for herbicide screenings in environmental samples, because not spectral sensitivity but herbicide activity is measured. The separation method is cheap, fast and reliable.