Authors: K. Nguyen1 and J. Sherma1
View More View Less
  • 1 Department of Chemistry, Lafayette College, Easton, PA, USA
Open access

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.

Abstract

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.

Introduction

The model process developed earlier [13] has allowed for the transfer of visual, qualitative TLC drug screening methods, which are published in the Global Pharma Health Fund (GPHF) Minilab manual [4] and US Food and Drug Administration (FDA) Compendium of Unofficial Methods for Screening of Pharmaceuticals by TLC [5], to quantitative HPTLC–densitometry methods that can be used in support of regulatory sanctions. Use of this model process has been reported for the development and validation of HPTLC–densitometry methods for analyzing a variety of drugs in pharmaceutical products [114]. In addition to the methods that were transferred from the Minilab manual or FDA Compendium method, the model process has been used to develop and validate quantitative methods for amitriptyline HCl [2]; acyclovir [7]; naproxen sodium, loperamide HCl, and loratidine [12]; caffeine, fluoxetine HCl, and gabapentin [14]; and desloratadine, etodolac, famotidine, omeprazole, oxaprozin, and phenazopyridine HCl [15], for which no TLC screening methods exist in these sources. This article details the development and validation of HPTLC–densitometry methods for the following additional pharmaceutical products for which no Minilab manual or FDA Compendium methods have been published: the anti-arrhythmic agent amiodarone HCl (CAS No. 19774-82-4); the β blockers carvedilol (CAS No. 72956-09-3), metoprolol succinate (CAS No. 98418-47-4), and nebivolol HCl (CAS No. 152520-56-4); the antihistamine doxylamine succinate (CAS No. 562-10-7); and the analgesics magnesium salicylate (CAS No. 18917-89-0) and salicylamide (CAS No. 65-45-2). Qualitative TLC screening methods corresponding to these new HPTLC–densitometry methods were subsequently developed and published online with open access in a supplement to the FDA Compendium on the Website of Dr. Thomas Layloff.

The model process includes standard and sample solution preparation, establishment of linear and second order polynomial regression calibration curves by applying standards representing 70–130% of the product's label value, assay of three individual tablets or capsules in triplicate for comparison of the label value, peak purity and identity tests, and validation of the method by standard addition analysis of 50%, 100%, and 150% spike levels. Only the “green” solvents and reagents acetone, concentrated ammonium hydroxide, ethanol, ethyl acetate, glacial acetic acid, hydrochloric acid, methanol, sulfuric acid, and toluene specified in the Minilab manual were considered for use in the development of these methods. This eliminates the use of many common TLC solvents and reagents for sample and standard solutions and mobile phases, such as hexane, butanol, chloroform, dioxane, methylene chloride, acetonitrile, formic acid, and triethylamine

Experimental

Standard and Sample Preparation

Preparation of standard and sample solutions followed the procedures described previously [13], unless otherwise noted. Standards and tablets ground by mortar and pestle were dissolved in their respective solvents by 10 min of magnetic stirring followed by 10 min of sonication. Metoprolol succinate sample solutions were sonicated for 15 min to obtain sufficient dissolution. All sample solutions, before further dilution or direct application onto the plates, were syringe-filtered to remove excipients. Nebivolol HCl sample solutions, at a concentration of 10.9 mg/mL, were allowed to stand for 15 min prior to filtration to allow excipients to settle to the bottom of the vial. This allowed for less difficult filtration and more plentiful filtrate of a relatively concentrated solution. If necessary to the preparation of a working solution, volumetric flasks, measuring pipets, and volumetric pipets of appropriate volume designation were used. Solutions were refrigerated in Parafilm-sealed glass vials. Table 1 describes the source of the pharmaceutical products as well as the methods employed to prepare the 100% standard and sample solutions for each drug analysis.

Table 1.

Preparation of 100% standard and 100% sample solutions

Pharmaceutical product100% Standard solution100% Sample solutiona
Amiodarone HCl (200 mg; Zydus Pharmaceuticals, Pennington, NJ, USA)0.500 μg 10.0 μL−1: Dissolve 25.0 mg standard (Sigma-Aldrich, St. Louis, MO, USA, No. A8423) in 50.0 mL of ethanol and then dilute 1.00 mL with 9.00 mL of ethanol, for a total volume of 10.0 mL.0.500 μg 10.0 μL−1: Dissolve a tablet in 100 mL of ethanol, then dilute 1.00 mL with 3.00 mL ethanol for a total of 4.00 mL, and dilute 1.00 mL further with an additional 9.00 mL of ethanol for a total volume of 10.0 mL.
Carvedilol (25.0 mg; Aurobindo Pharma Limited, Hyderabad, India)10.0 μg 10.0 μL−1: Dissolve 25.0 mg standard (Sigma-Aldrich, No. PHR1265) in 50.0 mL of methanol and then dilute 1.00 mL with 4.00 mL of methanol for a total volume of 5.00 mL.10.0 μg 10.0 μL−1: Dissolve a tablet in 50.0 mL of methanol and then dilute 1.00 mL with 4.00 mL of methanol for a total volume of 5.00 mL.
Doxylamine Succinate (25.0 mg; Perrigo, Allegan, MI, USA)2.50 μg 10.0 μL−1: Dissolve 25.0 mg standard (Sigma-Aldrich, No. PHR1420) in 100 mL of ethanol.2.50 μg 10.0 μL−1: Dissolve a tablet in 100 mL of ethanol.
Magnesium Salicylate (467.2 mgb; Ciba Self-Medication, Inc., Woodbridge, NJ, USA)4.67 μg 10.0 μL−1: Dissolve 43.2 mg salicylic acid standard (Sigma-Aldrich, No. S-6271) in 100 mL of ethanol. 4.32 μg salicylic acid 10.0 μL−1 is equivalent to 4.67 μg magnesium salicylate 10.0 μL−1.4.67 μg 10.0 μL−1: Dissolve a tablet in 100 mL of ethanol and then dilute 1.00 mL with 9.00 mL of ethanol for a total volume of 10.0 mL.
Metoprolol Succinate (47.5 mg; Mylan Pharmaceuticals Inc., Morgantown, WV, USA)9.50 μg 10.0 μL−1: Dissolve 50.0 mg metoprolol tartrate standard (Sigma-Aldrich, No. PHR1076) in 50.0 mL of methanol. 10.0 μg metoprolol tartrate 10.0 μL−1 is equivalent to 9.50 μg metoprolol succinate 10.0 μL−1.9.50 μg 10.0 μL−1: Dissolve a tablet in 50.0 mL of methanol.
Nebivolol HCl (5.45 mg; Forest Pharmaceuticals, Inc. Subsidiary of Forest Laboratories, LLC, Cinncinnati, OH, USA)10.9 μg 10.0 μL−1: Dissolve 10.9 mg of standard (Sigma-Aldrich, No. N1915) in 10.0 mL of methanol.10.9 μg 10.0 μL−1: Dissolve a tablet in 5.00 mL of methanol.
Salicylamide (152 mgc; First Aid Only Inc., Vancouver, WA 98682)4.56 μg 10.0 μL−1: Dissolve 76.0 mg of standard (Sigma-Aldrich, No. S-0750) in 50.0 mL of ethanol and then dilute 3.00 mL with 7.00 mL of ethanol for a total volume of 10.0 mL.4.56 μg 10.0 μL: Dissolve a tablet in 100 mL of ethanol and then dilute 3.00 mL with 7.00 mL of ethanol for a total volume of 10.0 mL.

Concentrations indicated for all 100% sample solutions are theoretical concentrations based on label values.

580 mg of magnesium salicylate tetrahydrate equivalent to 467.2 mg anhydrous magnesium salicylate.

Coformulated with 162 mg aspirin, 110 mg acetaminophen, and 32.4 mg caffeine.

HPTLC

Premium Purity silica gel 60 F254 plates (20 × 10 cm; Merck KGaA, Darmstadt, Germany; Catalog No. 1.05648.0001) were used without prewashing. Calibration curves were generated by applying 7.00, 9.00, 11.0, and 13.0 μL of the 100% sample solution, representing 70–130% of the label value of the active pharmaceutical ingredient. Assays were carried out by applying 10.0 μL of each sample solution in triplicate. A CAMAG (Wilmington, NC, USA) Linomat 4 equipped with a 100 μL syringe was used for semi-automated, bandwise, zone application. An application rate of 4 s/μL was used for all solutions. The band length was 6 mm; table speed, 10 mm/s; distance between bands, 4 mm; distance from the left edge of the plate, 17 mm; and distance from the bottom of the plate, 1 cm. Development was carried out for a distance of 7 cm beyond the bottom of the plate in a mobile phase vapor saturated CAMAG twin-trough chamber; the mobile phases and their respective Rf values are listed in Table 2. A CAMAG Scanner 3 controlled by winCATS software was used for automated HPTLC–densitometry with 4.00 × 0.45 mm microslit dimensions and a 20 mm/s scan rate. All drugs for which the analytical methods are detailed in this article quenched the fluorescence of the phosphor in the layer and were scanned with 254 nm ultraviolet (UV) radiation. The winCATS scanner software generated two calibration curves (linear and second-order polynomial regressions) for each sample, by determining the relationship between the scan areas and the weights of standards applied. Sample weights were interpolated from calibration curves based on the bracketed scan areas of samples. Spectral comparison was used to test peak purity and identity. Validation of the developed methods was performed using standard addition with spiking at 50%, 100%, and 150% levels, as described by Popovic and Sherma [3].

Table 2.

Mobile phases used for the analysis of pharmaceutical products containing amiodarone HCl, carvedilol, doxylamine succinate, magnesium salicylate, metoprolol succinate, nebivolol HCl, and salicylamide

Pharmaceutical productMobile phaseaRf
Amiodarone HClAcetone–toluene–glacial acetic acid (10:10:1)0.24
CarvedilolEthyl acetate–toluene–methanol–concentrated ammonium hydroxide (50:30:15:5)0.62
Doxylamine SuccinateEthyl acetate–methanol–concentrated ammonium hydroxide (24:3:1)0.54
Magnesium SalicylateEthyl acetate–glacial acetic acid (95:5)0.58
Metoprolol SuccinateEthyl acetate–toluene–methanol–concentrated ammonium hydroxide (50:30:15:5)0.50
Nebivolol HClEthyl acetate–methanol–concentrated ammonium hydroxide (8.5:1:0.5)0.42
SalicylamideEthyl acetate–acetone–glacial acetic acid (18:4:0.1)0.60

All solutions are shown in volume proportions.

Results

Calibration curve r values for the assays and validations were all greater than 0.99, all pharmaceutical products were assayed within 85–115% of the label value as is required by the United States Pharmacopeia (USP) for single tablet or capsule analysis (Table 3), all standard addition recoveries in the method validations were within ± 5% (Table 4), peak purity and identity r values were greater than 0.99, and all relative standard deviation (RSD) values were no higher than 3% in accordance with the requirements of the model process. The preferred regression mode was determined based on whether polynomial or linear regression gave better r values for the calibration curve, assay and standard addition recovery values closer to 100%, and lower RSD values for the triplicate analyses.

Table 3.

Assay results for pharmaceutical products containing amiodarone HCl, carvedilol, doxylamine succinate, magnesium salicylate, metoprolol succinate, nebivolol HCl, and salicylamide

Pharmaceutical productRegression modeTablet 1Tablet 2Tablet 3
Assay (%)RSD (%)Assay (%)RSD (%)Assay (%)RSD (%)
Amiodarone HClPolynomial1061.121070.5681080.913
CarvedilolPolynomial1090.3181100.4561080.694
Doxylamine succinatePolynomial94.40.4881031.351011.23
Magnesium salicylateLinear97.91.141021.011011.05
Metoprolol succinateLinear1011.021001.051030.872
Nebivolol HClLinear92.22.3491.91.3894.40.786
SalicylamideLinear1000.6781021.271061.07
Table 4.

Validation results for pharmaceutical products containing desloratadine, etodolac, famotidine, omeprazole, oxaprozin, and phenazopyridine HCl

Pharmaceutical productRegression mode50% Spike100% Spike150% Spike
Rec.a (%)RSD (%)Rec. (%)RSD (%)Rec. (%)RSD (%)
Amiodarone HClPolynomial1030.5251010.64297.82.21
CarvedilolPolynomial1030.5951031.151010.316
Doxylamine succinatePolynomial1020.4451001.0996.90.965
Magnesium salicylateLinear95.21.781031.161011.88
Metoprolol succinateLinear1001.001050.2011020.581
Nebivolol HClLinear1000.5921000.85696.91.61
SalicylamideLinear1022.3399.00.61896.51.96

Rec. = recovery.

Discussion

The model process for directly transferring Minilab manual or Compendium TLC methods to HPTLC–densitometry methods involves use of the same solvents for sample and standard solution preparation, weight of sample and standard applied (in 10.0 μL for the densitometry methods, instead of 2.00 μL or 3.00 μL as in the Minilab manual or Compendium, respectively), mobile phase, and detection method. As no Minilab manual or Compendium method had been published for the pharmaceutical products included in this article, our extensive previous experience in drug product analysis and exhaustive literature searches through SciFinder® (Chemical Abstracts), ISI Web of Science, and Google Scholar were employed to guide our method development and validation research.

For the amiodarone quantification method, the mobile phase ethyl acetate–methanol–concentrated ammonium hydroxide (85:10:15) used for this drug in a study of the identification of drugs using chemometrics [16] was tested first, but this ternary solution was cloudy. The solvent proportions were adjusted to (34:6:6) to achieve the necessary clear solution, but this mobile phase produced an Rf value that was too high (0.87) to give symmetrical peak scans on a flat baseline and a calibration curve with an adequately high r value. Additional mobile phases from our previously published drug product analysis articles were tested, and acetone–toluene–glacial acetic acid (10:10:1) [13] gave ideal results satisfying all model process guidelines. The published article [16] did not specify the amount of drug applied to the plates for TLC, and a trial and error process was necessary to determine that 100% standard and sample solutions with concentrations of 0.500 μg 10.0 μL−1 met the model process guidelines.

In the development of the method for analyzing carvedilol, the use of methanol as the solvent for sample and standard solution preparation was transferred from the methods of Abdel-Gawad et al. [17] and Patel et al. [18] for assay of pharmaceutical formulations of carvedilol. However, the mobile phases used in these methods, acetone–toluene–ethanol–ammonia (45:45:10:1) [17] and ethyl acetate–toluene–methanol (1:4:3.5) [18], both gave broad, streaked zones that could not be successfully scanned. The mobile phase described by Ramadan et al. [19] for determination of metoprolol phosphate and hydrochlorthiazide mixed pharmaceutical product was successfully used to develop our method for carvedilol (Table 2).

Ethanol as the solvent for the 100% standard and sample solutions for doxylamine succinate product analysis was suggested by DiGregorio and Sherma [20]. Their mobile phase, ethyl acetate–methanol–concentrated ammonium hydroxide (85:10:5), gave an Rf value of 0.66 and acceptable calibration curve r value, but zones were found to be unequally spaced after development on the Premium Purity plates and could not be scanned accurately. The mobile phase from our previously published HPTLC–densitometry method for loperamide HCl [12] (Table 2) was found to give excellent results for the doxylamine succinate determination according to the model process.

Based on DiGregorio and Sherma's study [21], the magnesium salicylate quantification method used ethanol as the solvent for sample and standard solution preparation, ethyl acetate–glacial acetic acid (95:5) as the mobile phase, and 100% sample and standard solutions with a concentration of 4.67 μg 10.0 μL−1. An additional pharmaceutical product, Diurex® Water Pills, contains magnesium salicylate (162.5 mg) and caffeine (50 mg). It was verified that this formulation could be successfully analyzed by the developed method because the two active ingredients are well separated by the mobile phase used (Table 2) with Rf values of 0.58 and 0.18, respectively.

For the metoprolol succinate quantification method, the mobile phase ethyl acetate–toluene–methanol–concentrated ammonium hydroxide (50:30:15:5) and methanol as the solvent for standard and sample solution preparation were used as reported earlier [19]. A method for a 23.75-mg formulation of metoprolol succinate (equivalent to 25.0 mg of metoprolol tartrate, Dr. Reddy's Laboratories Limited, Bachupally, 500090, India) was also developed and validated successfully according to the model process (data not given). The tablet is dissolved in 25.0 mL of methanol to give a 100% sample solution concentration of 9.50 μg 10.0 μL−1, with all other method parameters identical to those of the metoprolol succinate 47.5 mg tablet quantification method described above. Both metoprolol succinate products gave two well-resolved zones on the plate after development (Figure 1): a faint satellite zone (Rf = 0.27) and the primary zone (Rf = 0.50) used for quantification.

Figure 1.
Figure 1.

Densitogram of 10.0 μL of the 100% sample solution of metoprolol succinate showing the main peak used for quantification (Rf = 0.50) and peak from a satellite zone (Rf = 0.27)

Citation: Acta Chromatographica Acta Chromatographica 30, 4; 10.1556/1326.2017.00367

In the development of the nebivolol HCl 5.45 mg tablet method, the mobile phase ethyl acetate–methanol–concentrated ammonium hydroxide (8.5:1:0.5) and methanol as the solvent for the sample and standard solutions were used as recommended by Bhat et al. [22]. Nebivolol HCl is also available as a 10.9-mg tablet that could be analyzed using the method described above except for dissolving the tablet in 10.0 mL of methanol to give a 100% sample solution concentration of 10.9 μg 10.0 μL−1.

The use of ethanol as the solvent for salicylamide 100% sample and standard solution preparation was based on the method of Sullivan and Sherma [23]; their employment of a calibration curve centered at 5.00 μg influenced the decision to prepare these solutions at 4.56 μg 10.0 μL−1, which was a convenient concentration given the 152 mg tablet label value. The mobile phase of the earlier method [23], dichloromethane–acetone (4:1), could not be employed because dichloromethane is not on the list of solvents approved for the model process. The mobile phase used for the developed method (Table 2), which gave good separation of salicylamide from the three coformulants in the analyzed product (32.4 mg caffeine, 162 mg aspirin, and 110 mg acetaminophen; see Figure 2), was taken from a previously published method for the analysis of artesunate pharmaceutical products [7].

Figure 2.
Figure 2.

Densitogram of 10.0 μL of the 100% sample solution of salicylamide, showing the salicylamide peak (Rf = 0.60), acetaminophen/aspirin peak (Rf = 0.44), and caffeine peak (Rf = 0.21)

Citation: Acta Chromatographica Acta Chromatographica 30, 4; 10.1556/1326.2017.00367

Qualitative TLC screening methods based on the format of the FDA Compendium [5] were developed corresponding to the new HPTLC–densitometry methods. The qualitative methods generally employed the same solvents used in sample and standard solution preparation, weights of analytes spotted on the plate (in 3.00 μL for the qualitative method, instead of the 10.0 μL used in the quantitative method), mobile phases, and methods of detection. If necessary, parameters of the qualitative methods (mobile phase or weights spotted) were adjusted to improve visual differences among 85%, 100%, 115% of the drug product, relative Rf of coformulants, if present, and spot shape. These supplemental FDA Compendium methods, which are available online, open access [26], can be easily converted to Minilab manual methods by spotting the same drug weights in the 2.00 μL application volume specified in the Minilab manual and substitution of the Sigma-Aldrich standards we used with authentic drug products available to the GPHF.

Conclusion

HPTLC–densitometry methods for the determination of amiodarone, carvedilol, doxylamine succinate, magnesium salicylate, metoprolol succinate, nebivolol, and salicylamide in pharmaceutical preparations were developed and validated according to the previously described model procedure for transfer of qualitative TLC screening methods. The methods should be fully validated according to the International Conference on Harmonization (ICH) guidelines [24] or by interlaboratory studies [25] if future applications require. Since neither the Minilab manual nor the FDA Compendium contain qualitative TLC screening methods for these drugs that are able to used in the field, these were subsequently developed and posted online with open access as supplements to the FDA Compendium on Dr. Thomas Layloff's website [26].

Acknowledgments

J.S. thanks Dr. Thomas Layloff, Senior Quality Assurance Advisor, Supply Chain Management Systems (SCMS), Arlington, VA, USA, for his help in devising the model transfer process and its application to pharmaceutical products. The authors also thank Dr. Gerd Battermann, Head of Instrumental Analytics Franchise, Merck KGaA, Darmstadt, Germany, for providing the Premium Purity HPTLC plates used in this research. Kaitlin Nguyen was financially supported by a Camille and Henry Dreyfus Foundation Senior Scientist Mentor Program award to J.S. and by the Lafayette College EXCEL Scholars Program.

References

  • 1.

    O'Sullivan C. ; Sherma J. Acta. Chromatogr. 2012, 24, 241252.

  • 2.

    Lianza K. ; Sherma J. J. Liq. Chromatog. Relat. Technol. 2013, 36, 24462462.

  • 3.

    Popovic N. ; Sherma J. Acta. Chromatogr. 2014, 26, 615623.

  • 5.

    Kenyon A. S. ; Layloff T. P. A Compendium of Unofficial Methods for Rapid Screening of Pharmaceutical by Thin Layer Chromatography http://www.layloff.net

    • Search Google Scholar
    • Export Citation
  • 6.

    Nguyen M. ; Sherma J. Trends Chromatogr. 2013, 8, 131135.

  • 7.

    Nguyen M. ; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2014, 37, 29562970.

  • 8.

    Strock J. ; Nguyen M.; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2015, 38, 11261130.

  • 9.

    Strock J. ; Nguyen M.; Sherma J. Acta. Chromatogr. 2016, 28, 363372.

  • 10.

    Zhang D. ; Strock J.; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2016, 39, 277280.

  • 11.

    Armour E. ; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2017, 40, 282286.

  • 12.

    Zhang D. ; Strock J.; Sherma J. Trends Chromatogr. 2016, 10, 15.

  • 13.

    Zhang D. ; Armour E.; Sherma J. Acta Chromatogr. 2017, DOI: 10.1556/1326.2016.29409, accepted for publication in Volume 29, Issue 4, in press.

    • Search Google Scholar
    • Export Citation
  • 14.

    Nguyen K. ; Zhang D.; Sherma J. Studia UBB Chemia LXII, 2017, 2, 918.

  • 15.

    Nguyen K. ; Zhang D.; Sherma J. Trends Chromatogr. 2017, accepted for publication, in press.

  • 16.

    Romano G. ; Caruso G.; Musumarra G.; Pavone D.; Cruciani G. J. Planar Chromatogr.-Mod TLC 1994, 7, 233241.

  • 17.

    Abdel-Gawad F. M. ; Issa Y. M.; Hussien E. M.; Ibrahim M. M.; Barakat S. Int. J. Res. Pharm. Chem. 2012, 2, 741748.

  • 18.

    Patel L. J. ; Suhagia B. N.; Shah P. B.; Shah R. R. Indian J Pharm Sci 2016, 68, 790793.

  • 19.

    Ramadan N. K. ; Mohamed H. M.; Mostafa A. A. J. Planar Chromatogr.-Mod TLC 2013, 26, 510516.

  • 20.

    DiGregorio D. ; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2006, 22, 15991606.

  • 21.

    DiGregorio D. ; Sherma J. J. Planar Chromatogr.-Mod TLC 1999, 12, 230232.

  • 22.

    Bhat L. R. ; Bothara K. G.; Damle M. C. Indian Drugs 2008, 45, 948951.

  • 23.

    Sullivan C. ; Sherma J. Acta Chromatogr. 2006, 16, 153163.

  • 24.

    Ferenczi-Fodor K. ; Vegh Z.; Nagy-Turak A.; Renger M.; Zeller M. J. AOAC Int. 2001, 84, 12651276.

  • 25.

    Kaale E. ; Risha P.; Reich E.; Layloff T. P. J. AOAC Int. 2010, 93, 18361843.

  • 26.

    Supplement to A Compendium of Unofficial Methods for Rapid Screening of Pharmaceuticals by Thin Layer Chromatography http://www.layloff.net

    • Search Google Scholar
    • Export Citation
  • 1.

    O'Sullivan C. ; Sherma J. Acta. Chromatogr. 2012, 24, 241252.

  • 2.

    Lianza K. ; Sherma J. J. Liq. Chromatog. Relat. Technol. 2013, 36, 24462462.

  • 3.

    Popovic N. ; Sherma J. Acta. Chromatogr. 2014, 26, 615623.

  • 5.

    Kenyon A. S. ; Layloff T. P. A Compendium of Unofficial Methods for Rapid Screening of Pharmaceutical by Thin Layer Chromatography http://www.layloff.net

    • Search Google Scholar
    • Export Citation
  • 6.

    Nguyen M. ; Sherma J. Trends Chromatogr. 2013, 8, 131135.

  • 7.

    Nguyen M. ; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2014, 37, 29562970.

  • 8.

    Strock J. ; Nguyen M.; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2015, 38, 11261130.

  • 9.

    Strock J. ; Nguyen M.; Sherma J. Acta. Chromatogr. 2016, 28, 363372.

  • 10.

    Zhang D. ; Strock J.; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2016, 39, 277280.

  • 11.

    Armour E. ; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2017, 40, 282286.

  • 12.

    Zhang D. ; Strock J.; Sherma J. Trends Chromatogr. 2016, 10, 15.

  • 13.

    Zhang D. ; Armour E.; Sherma J. Acta Chromatogr. 2017, DOI: 10.1556/1326.2016.29409, accepted for publication in Volume 29, Issue 4, in press.

    • Search Google Scholar
    • Export Citation
  • 14.

    Nguyen K. ; Zhang D.; Sherma J. Studia UBB Chemia LXII, 2017, 2, 918.

  • 15.

    Nguyen K. ; Zhang D.; Sherma J. Trends Chromatogr. 2017, accepted for publication, in press.

  • 16.

    Romano G. ; Caruso G.; Musumarra G.; Pavone D.; Cruciani G. J. Planar Chromatogr.-Mod TLC 1994, 7, 233241.

  • 17.

    Abdel-Gawad F. M. ; Issa Y. M.; Hussien E. M.; Ibrahim M. M.; Barakat S. Int. J. Res. Pharm. Chem. 2012, 2, 741748.

  • 18.

    Patel L. J. ; Suhagia B. N.; Shah P. B.; Shah R. R. Indian J Pharm Sci 2016, 68, 790793.

  • 19.

    Ramadan N. K. ; Mohamed H. M.; Mostafa A. A. J. Planar Chromatogr.-Mod TLC 2013, 26, 510516.

  • 20.

    DiGregorio D. ; Sherma J. J. Liq. Chromatogr. Relat. Technol. 2006, 22, 15991606.

  • 21.

    DiGregorio D. ; Sherma J. J. Planar Chromatogr.-Mod TLC 1999, 12, 230232.

  • 22.

    Bhat L. R. ; Bothara K. G.; Damle M. C. Indian Drugs 2008, 45, 948951.

  • 23.

    Sullivan C. ; Sherma J. Acta Chromatogr. 2006, 16, 153163.

  • 24.

    Ferenczi-Fodor K. ; Vegh Z.; Nagy-Turak A.; Renger M.; Zeller M. J. AOAC Int. 2001, 84, 12651276.

  • 25.

    Kaale E. ; Risha P.; Reich E.; Layloff T. P. J. AOAC Int. 2010, 93, 18361843.

  • 26.

    Supplement to A Compendium of Unofficial Methods for Rapid Screening of Pharmaceuticals by Thin Layer Chromatography http://www.layloff.net

    • Search Google Scholar
    • Export Citation
The author instruction is available in PDF.
Please, download the file from HERE.
 
The Open Access statement together with the description of the Copyright and License Policy are available in PDF.
Please, download the file from HERE.
 

 

Senior editors

Editor(s)-in-Chief: Kowalska, Teresa

Editor(s)-in-Chief: Sajewicz, Mieczyslaw

Editors(s)

  • Danica Agbaba (University of Belgrade, Belgrade, Serbia)
  • Ivana Stanimirova-Daszykowska (University of Silesia, Katowice, Poland)
  • Monika Waksmundzka-Hajnos (Medical University of Lublin, Lublin, Poland)

Editorial Board

  • R. Bhushan (The Indian Institute of Technology, Roorkee, India)
  • J. Bojarski (Jagiellonian University, Kraków, Poland)
  • B. Chankvetadze (State University of Tbilisi, Tbilisi, Georgia)
  • M. Daszykowski (University of Silesia, Katowice, Poland)
  • T.H. Dzido (Medical University of Lublin, Lublin, Poland)
  • A. Felinger (University of Pécs, Pécs, Hungary)
  • K. Glowniak (Medical University of Lublin, Lublin, Poland)
  • B. Glód (Siedlce University of Natural Sciences and Humanities, Siedlce, Poland)
  • A. Gumieniczek (Medical University of Lublin, Lublin, Poland)
  • U. Hubicka (Jagiellonian University, Kraków, Poland)
  • K. Kaczmarski (Rzeszow University of Technology, Rzeszów, Poland)
  • H. Kalász (Semmelweis University, Budapest, Hungary)
  • I. Klebovich (Semmelweis University, Budapest, Hungary)
  • A. Koch (Private Pharmacy, Hamburg, Germany)
  • Ł. Komsta (Medical University of Lublin, Lublin, Poland)
  • P. Kus (Univerity of Silesia, Katowice, Poland)
  • D. Mangelings (Free University of Brussels, Brussels, Belgium)
  • E. Mincsovics (Corvinus University of Budapest, Budapest, Hungary)
  • G. Morlock (Giessen University, Giessen, Germany)
  • A. Petruczynik (Medical University of Lublin, Lublin, Poland)
  • J. Sherma (Lafayette College, Easton, PA, USA)
  • R. Skibiński (Medical University of Lublin, Lublin, Poland)
  • B. Spangenberg (Offenburg University of Applied Sciences, Germany)
  • T. Tuzimski (Medical University of Lublin, Lublin, Poland)
  • Y. Vander Heyden (Free University of Brussels, Brussels, Belgium)
  • A. Voelkel (Poznań University of Technology, Poznań, Poland)
  • B. Walczak (University of Silesia, Katowice, Poland)
  • W. Wasiak (Adam Mickiewicz University, Poznań, Poland)
  • I.G. Zenkevich (St. Petersburg State University, St. Petersburg, Russian Federation)

 

KOWALSKA, TERESA
E-mail: kowalska@us.edu.pl

SAJEWICZ, MIECZYSLAW
E-mail:msajewic@us.edu.pl

Indexing and Abstracting Services:

  • Science Citation Index
  • Sci Search
  • Research Alert
  • Chemistry Citation Index and Current Content/Physical
  • Chemical and Earth Sciences
  • SCOPUS
  • GoogleScholar
  • Index Copernicus
  • CABI
2020
 
Total Cites
650
WoS
Journal
Impact Factor
1,639
Rank by
Chemistry, Analytical 71/83 (Q4)
Impact Factor
 
Impact Factor
1,412
without
Journal Self Cites
5 Year
1,301
Impact Factor
Journal
0,34
Citation Indicator
 
Rank by Journal
Chemistry, Analytical 75/93 (Q4)
Citation Indicator
 
Citable
45
Items
Total
43
Articles
Total
2
Reviews
Scimago
28
H-index
Scimago
0,316
Journal Rank
Scimago
Chemistry (miscellaneous) Q3
Quartile Score
 
Scopus
393/181=2,2
Scite Score
 
Scopus
General Chemistry 215/398 (Q3)
Scite Score Rank
 
Scopus
0,560
SNIP
 
Days from
58
submission
 
to acceptance
 
Days from
68
acceptance
 
to publication
 
Acceptance
51%
Rate

2019  
Total Cites
WoS
495
Impact Factor 1,418
Impact Factor
without
Journal Self Cites
1,374
5 Year
Impact Factor
0,936
Immediacy
Index
0,460
Citable
Items
50
Total
Articles
50
Total
Reviews
0
Cited
Half-Life
6,2
Citing
Half-Life
8,3
Eigenfactor
Score
0,00048
Article Influence
Score
0,164
% Articles
in
Citable Items
100,00
Normalized
Eigenfactor
0,05895
Average
IF
Percentile
20,349
Scimago
H-index
26
Scimago
Journal Rank
0,255
Scopus
Scite Score
226/167=1,4
Scopus
Scite Score Rank
Chemistry (miscellaneous) 240/398 (Q3)
Scopus
SNIP
0,494
Acceptance
Rate
41%

 

Acta Chromatographica
Publication Model Online only
Gold Open Access
Submission Fee none
Article Processing Charge 400 EUR/article
Regional discounts on country of the funding agency World Bank Lower-middle-income economies: 50%
World Bank Low-income economies: 100%
Further Discounts Editorial Board / Advisory Board members: 50%
Corresponding authors, affiliated to an EISZ member institution subscribing to the journal package of Akadémiai Kiadó: 100%
Subscription Information Gold Open Access
Purchase per Title  

Acta Chromatographica
Language English
Size A4
Year of
Foundation
1992
Volumes
per Year
1
Issues
per Year
4
Founder Institute of Chemistry, University of Silesia
Founder's
Address
PL-40-007 Katowice, Poland, Bankowa 12
Publisher Akadémiai Kiadó
Publisher's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
Responsible
Publisher
Chief Executive Officer, Akadémiai Kiadó
ISSN 2083-5736 (Online)

Monthly Content Usage

Abstract Views Full Text Views PDF Downloads
Aug 2021 0 15 17
Sep 2021 0 9 55
Oct 2021 0 17 7
Nov 2021 0 11 5
Dec 2021 0 8 8
Jan 2022 0 8 12
Feb 2022 0 0 0