Cumulative CAMAG Bibliography Service CCBS

Our CCBS database includes more than 11,000 abstracts of publications. Perform your own detailed search of TLC/HPTLC literature and find relevant information.

The Cumulative CAMAG Bibliography Service CCBS contains all abstracts of CBS issues beginning with CBS 51. The database is updated after the publication of every other CBS edition. Currently the Cumulative CAMAG Bibliography Service includes more than 11'000 abstracts of publications between 1983 and today. With the online version you can perform your own detailed TLC/HPTLC literature search:

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      131 066
      Identification of 5‑methylisoxazole‑4‑carboxylic acid and 4‑(trifluoromethyl)aniline degradation products for leflunomide by high‑performance thin‑layer chromatography coupled with high‑resolution mass spectrometry
      M. GHANTE*, S. SAWANT, V. BHUSARL, S. SAWANT, S. JAGTAP (*Department of Pharmaceutical Quality Assurance, Sinhgad Technical Education Society’s, Smt. Kashibai Navale College of Pharmacy, Kondhwa (Bk), Pune, India, mrghante@gmail.com)

      J. Planar Chromatogr. 35, 635-641 (2022). HPTLC of leflunomide on silica gel with toluene - chloroform - ethanol 2:2:1. Quantitative determination by absorbance measurement at 266 nm. The hRF value for leflunomide was 53. Linearity was between 100 and 600 ng/zone. Intermediate precisions were below 2 % (n=6). LOD and LOQ were 4 and 13 ng/zone, respectively. Recovery was between 100.8 and 103.8 %.

       

      Classification: 32a
      131 007
      Principal component analysis and DoE-Based AQbD Approach to Multipurpose HPTLC method for synchronous estimation of multiple FDCs of metformin HCl, repaglinide, glibenclamide and pioglitazone HCl
      P. PRAJAPATI*, K. RADADIYA, S. SHAH (*Department of Quality Assurance, Maliba Pharmacy College, Uka Tarsadia University, Tarsadi, Gujarat, India; pintu.prajapati@utu.ac.in)

      J Chrom Sci, bmad055 (2022). Standards of antiglycemic drugs were metformin hydrochloride (S1, a biguanide), glibenclamide (S2 = glyburide, a sulfonylurea), pioglitazone hydrochloride (S3, a thiazolidinedione), repaglinide (S4, a glinide). Samples were methanolic solutions of commercial tablets of S1 with each of the other molecules. The following method was developed by a software-assisted AQbD approach (analytical quality by design): (1) Several TLC separations were tried with toluene together with other solvents and with acidic or basic modifiers, with also variations of 24 method or instrumental parameters. (2) Principal component analysis (PCA) was performed in order to identify two principal components (PCs) responsible for 98 % of the observed variations: namely, resolution and tailing factor. Three critical method parameters (CMPs) had a statistically significant impact on the PCs: mobile phase (MP) composition, ammonium acetate concentration in MP, and saturation time. (3) To optimize these CMPs, the Box–Behnken design was implemented in 15 software-proposed experiments; the impacts of the 3 CMPs on the 2 PCs were evaluated by ANOVA, multiple regression analysis, and 2D and 3D contour plots. (4) The optimal CMPs ranges were determined by defining a MODR (method operable design region) on the superposed contour plots, and one TLC condition was selected as analytical control point.
      TLC on silica gel pre-washed with 10 mL methanol, dried and activated 10 min at 100° C. Separation with toluene – ethyl acetate – methanolic solution of 4 % ammonium acetate 7:7:6 after 15 min pre-saturation with 35 % relative humidity. Absorption emasurement at UV 254 nm. The hRF values were 13 for S1, 72 for S2, 82 for S3, 38 for S4. LOQ were 263, 387, 73 and 35 ng/zone, respectively. Linearity range was 25–75 µg/zone for S1, 100–300 ng/zone for S2 and S4, 750–2250 ng/zone for S3. Intermediate precision was below 2 %. For accuracy tests, recovery rates were between 97.6–101.4 %.

      Classification: 2e, 5c, 7, 8b, 17a, 17c, 23d, 23e, 24, 32a
      131 006
      Application of Taguchi OA and Box–Behnken design for the implementation of DoE-based AQbD approach to HPTLC method for simultaneous estimation of azilsartan and cilnidipine
      P. PRAJAPATI*, P. TAILOR, A. SHAHI, A. ACHARYA, S. SHAH
      (*Department of Quality Assurance, Maliba Pharmacy College, Uka Tarsadia University, Tarsadi, Mahuva, Surat, Gujarat, India; pintu21083@gmail.com)

      J Chrom Sci, bmad045 (2022). Standards were azilsartan medoxomil (AZL) and cilnidipine (CLN). Samples were acetonitrile solutions of commercial tablets of AZL and CLN, and purified human blood plasma as biological fluid spiked with AZL and CLN. The following method was developed by a software-assisted AQbD approach (analytical quality by design): (1) Taguchi orthogonal array design was implemented in 8 screening experiments in order to identify the 3 critical method variables (CMVs), which were: volume ratio of toluene – ethyl acetate, volume of methanol and saturation time. These CMVs had statistically significant impact (one-way ANOVA and Pareto charts) on the 3 critical analytical attributes (CAAs, they were: resolution between AZL and CLN and their hRF values). (2) To optimize these CMVs, the Box–Behnken design was implemented in 15 software-proposed experiments; the impacts of the 3 CMVs on the 3 CAAs were evaluated by ANOVA, multiple regression analysis, and 2D and 3D contour plots; the response surface analysis allowed the software to find a mathematical (quadratic or linear) equation for each CAA, based on the CMVs values. (3) The optimal CMVs ranges were determined by defining an analytical design space (ADS) on the superposed contour plots, and one TLC condition was selected as analytical control point.
      TLC on silica gel pre-washed with 10 mL methanol, dried and activated 15 min at 110° C. Separation with toluene – ethyl acetate – methanol 13:3:4 after 15 min pre-saturation with 35 % relative humidity. Absorption measurement at UV 254 nm. The hRF values were 49–51 for AZL and 70–71 for LRT. Linearity range was 400–2000 ng/zone for AZL and 100–500 ng/zone for CLN. Intermediate precision was below 1.6 % (n=3). LOQ were 121 ng/zone for AZL and 34 ng/zone for CLN. Recovery rates were 99.3–99.7 % for AZL and 98.1–99.5 % for CLN. Recovery rates from spiked plasma were 83.3 % for both molecules.

      Classification: 2e, 7, 8b, 16, 23d, 23e, 32a
      131 004
      Simultaneous determination of montelukast sodium and loratadine by eco-friendly densitometry and spectrophotometric methods
      Shimaa A. MAHMOUD*, A.M. EL-KOSASY, F.A. FOUAD
      (*Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt; shimaa.ahmed22@azhar.edu.eg)

      J Chrom Sci, bmad025 (2023). Standards (separated and mixed) were montelukast sodium (MKT) and loratadine (LRT). Samples were methanolic solutions of commercial tablets, and purified blood plasma as biological fluid, from patients taking MKT or LRT as oral treatment. TLC on silica gel with ethyl acetate – ethanol 9:1. Visualization under UV 254nm. The hRF values were 80 for MKT and 71 for LRT. Densitometric absorbance measurement at 260 nm (20 mm/s scanning speed). System suitability was verified by resolution, selectivity, capacity and absence of tailing. The method was validated for linearity range (0.3–3.6 μg/zone for MKT, 0.2–4 µg/zone for LRT), for precision, for reproducibility, for robustness, and for accuracy expressed as average recovery values (100 % overall mean) at different concentrations. The TLC-densitometric method was also found statistically equivalent (Student’s t-test and F-test) to a previously described method (HPLC – spectrophotometry), but was better in terms of environmental and health impacts, using green analytical procedure index (GAPI) and analytical eco-scale (scores based on solvents/reagents, energy consumption, occupational hazard and waste generation). The TLC method was also compared to three (equally “green”) different analytical methods of spectrophotometry (without chromatography): response correlation, absorptivity-centering and LRT-MKT ratio derivatives. The TLC method was more sensitive (LOQ values were 82 ng/zone for MKT, 20 ng/zone for LRT).

      Classification: 5c, 7, 17c, 23d, 23e, 24, 32a, 32c
      131 005
      Green TLC-densitometric method for simultaneous determination of antazoline and tetryzoline: application to pharmaceutical formulation and rabbit aqueous humor
      O.G. HUSSEIN, Yasmin ROSTOM*, M. ABDELKAWY, M.R. REZK, D.A. AHMED
      (*Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt; yasmin.rostom@pharma.cu.edu.eg)

      J Chrom Sci, bmad042 (2023). Standards (separated and mixed) were antazoline (ANT) and tetryzoline (TET) hydrochlorides. Samples were one commercial ophthalmic solution containing both molecules (unspiked and spiked), and aqueous humour of untreated rabbits as biological fluid, spiked with various concentrations of ANT and TET. TLC on silica gel with ethyl acetate – ethanol 1:1. Visualization under UV 254 nm. Densitometric absorbance measurement at 220 nm (20mm/s scanning speed). The hRF was 47 for TET and 71 for ANT. System suitability was verified by resolution, selectivity, capacity and absence of tailing. The method was validated for linearity range (0.2 – 18 µg/band), for precision, for reproducibility, for robustness, and for accuracy expressed as average recovery values (100 % overall mean) at different concentrations. The method was also found statistically equivalent (Student’s t-test and F-test) to the official corresponding titrimetric methods of the European Pharmacopoeia. Finally, environmental and health impacts of the methods were qualitatively and quantitatively assessed better as the other described methods, using analytical greenness (AGREE), green analytical procedure index (GAPI), national environmental method index (NEMI), and analytical eco-scale (scores based on solvents/reagents, energy consumption, occupational hazard and waste generation).

      Classification: 7, 17a, 23e, 32a, 32f
      131 071
      Development and validation of a high‑performance thin‑layer chromatography method for the estimation of bromfenac in ophthalmic solution
      M. THOMAS, V. JAIN*, B. SONAWANE, E. SOUZA, M. KUMAR, R. SINGH (*Department of Quality Assurance, Oriental College of Pharmacy, Sanpada, Navi Mumbai 400705, India, vandana.jain@ocp.edu.in)

      J. Planar Chromatogr. 35, 627-633 (2022). HPTLC of bromfenac in ophthalmic solution on silica gel with toluene - ethyl acetate - glacial acetic acid 375:175:1. Quantitative determination by absorbance measurement at 274 nm. The hRF values for bromfenac was 28. Linearity was between 60 and 270 ng/zone. Intermediate precisions were below 2 % (n=3). The LOD and LOQ were 7 and 22 ng/zone, respectively. Average recovery was 100.7 %.

      Classification: 32a
      130 037
      Quantitative thin layer chromatography for the determination of medroxyprogesterone acetate using a smartphone and open-source image analysis
      Mary E. SOWERS*, R. AMBROSE, E. BETHEA, C. HARMON, D. JENKINS** (* and ** FHI 360, Product Quality and Compliance, Durham, North Carolina, USA; *msowers@fhi360.org; ** djenkins@fhi360.org)

      J Chromatogr A, 1669, 462942 (2022). Samples were medroxyprogesterone acetate (MPA) as standards and commercial drug extracts, dissolved in dichloromethane. TLC on silica gel (preactivated by 30 min heating at 120 °C) with dichloromethane – ethyl acetate 10:1, followed by 30 min drying at 120 °C. Derivatization by spraying with sulfuric acid (50 % in ethanol). Visualization in a 3D-printed chamber designed especially for this purpose, blocking extraneous light and including a smartphone holder, a fluorescent lamp and an optical density step tablet. Pictures were taken with the smartphone digital camera, after spraying (6 background images) and after 10 min heating at 120 °C (6 foreground images). In the last case, MPA appeared as black spots (hRF 16–20). Using an image processing software program: (1) one averaged background image and one averaged foreground image were created by concatenation and were split into 3 colour channels; (2) the green colour channels were corrected to remove background noise, by subtraction of an averaged darkfield image (taken on blank plate without light) and by comparison ratio to an averaged blankfield image (taken on blank plate with light); (3) the pixel values of the MPA bands were converted to optical density values through the Robard’s function, by comparison to a reference image of a theoretical optical density step tablet; (4)  furthermore, the corrected background image was subtracted from the corrected (and denoised with a Gaussian Blur) foreground image; a triangle threshold algorithm was applied on the resulting image, and was converted to a mask (white spots on black background); (5) applying the binary mask to the original corrected images (obtained in (2)), the final integrated density values of MPA spots were obtained. This method was validated for linearity range (1.25–3.75 mg/mL), for precision, for reproducibility, for robustness, and for accuracy expressed as average recovery values (101 % overall mean) by comparison of TLC results with HPLC-DAD results.

      Classification: 3f, 13a, 32a
      130 052
      Two green chromatographic methods for the quantification of tamsulosin and solifenacin along with four of their impurities
      E. KAMEL (Pharmaceutical ChemistryDepartment, Faculty of Pharmacy, EgyptianRussian University, Badr City, ET-11829 Cairo, Egypt, Ebraam81@gmail.com)

      J. Sep. Sci. 45, 1305-1316 (2022). HPTLC of tamsulosin hydrochloride (1) and solifenacin succinate (2) along with their impurities on silica gel with ethyl acetate - butanol - glacial acetic acid 100:4:1. Quantitative determination by absorbance measurement at 225 nm. The hRF values for (1) and (2) were 61 and 26, respectively. Linearity was between 0.1 and 1.0 µg/zone for (1) and 1.0 and 15.0 µg/zone for (2). Inter-day and intra-day precisions were below 2 % (n=6). Mean recovery was 99.9 % for (1) and 99.8 % for (2). 

      Classification: 32a