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

Abstract

Summary.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 F 254 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.

Development of Quantitative HPTLC-Densitometry Methods Following a Model Approach for Transfer of TLC Screening Methods for Pharmaceutical Products of Metformin HCL, Potassium Clavulanate, Caffeine, Fluoxetine HCL, and Gabapentin

“…General preparation procedures were carried out as described earlier [1][2][3] unless otherwise specified. All standards and ground (by mortar and pestle) tablets or capsule contents were dissolved with the aid of 10 min each of magnetic stirring and sonication before syringe filtration to remove undissolved excipients prior to further dilution or direct application.…”

“…Detailed HPTLC-densitometry methods and instruments were described earlier [1][2][3][6][7][8][9][10][11][12]. Silica gel 60 F 254 Premium Purity HPTLC glass plates (20 x10 cm; EMD Millipore Corp., Billerica, MA, a division of Merck KGaA, Darmstadt, Germany; Part No.…”

“…A model process was previously described [1][2][3] for transfer of qualitative/semiquantitative thin-layer chromatography (TLC) screening methods for pharmaceutical products with quality defects contained in the Global Pharma Health Fund E.V. (GPHF) Minilab manual [4] or U.S. Food and Drug Administration Compendium of Unofficial Methods for Rapid Screening of Pharmaceuticals by Thin Layer Chromatography [5] to quantitative highperformance TLC (HPTLC)-densitometry methods.…”

“…(GPHF) Minilab manual [4] or U.S. Food and Drug Administration Compendium of Unofficial Methods for Rapid Screening of Pharmaceuticals by Thin Layer Chromatography [5] to quantitative highperformance TLC (HPTLC)-densitometry methods. The model process was applied earlier to formulations containing acetylsalicylic acid, acetaminophen, ibuprofen, and chlorpheniramine maleate [1]; mebendazole, diphenhydramine HCl, amodiaquine, and artesunate [2]; amodiaqine and diazepam [3]; lumefantrine + artemether [6]; albendazole, amodiaquine + artesunate [7]; pyrazinamide + ethambutol + isoniazid + rifampicin [8]; quinine sulfate, mefloquine, and dihydroartemisinin + piperaquine phosphate [9]; azithromycin, imipramine HCl, and sulfadoxine + pyrimethamine [10]; clarithromycin, azithromycin, and amodiaquine + artesunate [11]; and cefixime, cefuroxime axetil, cephalexin hydrate, ciprofloxacin HCl, levofloxacin, and metronidazole [12].…”

Development of Quantitative HPTLC-Densitometry Methods for Analysis of Fake and Substandard Pharmaceutical Products Following a Model Approach for Transfer of TLC Screening Methods: Albendazole, Amodiaquin + artesunate, Aciclovir, and Amoxicillin

“…[1] The TLC screening methods have been published in a U.S. Food and Drug Administation Compendium by Kenyon and Layloff [2] and in Minilab manuals published by the Global Pharma Health Fund E.V. (GPHF) [3] primarily for use in developing countries to help detect mislabeled, substandard, and fake products.…”