J Chromatogr A, 1619, 460945 (2020). Samples were lamotrigin as standard, or extracted with an oil-in-water microemulsion (10 µL butyl acetate, 4 mL n-butanol, 925 mg sodium dodecyl sulphate, 8.6 mL water) either from patients’ raw plasma (for separation from blood proteins) after spiking, or from commercial tablets dissolved in methanol. TLC on silica gel with a water-in-oil microemulsion of 9 mL butyl acetate, 1 mL n-butanol, 250 mg sodium dodecyl sulphate, 250 µL water. Both optimal microemulsions were predicted using Taguchi orthogonal array and Plackett-Burman design. Evaluation in UV 254 nm, quantification from the digital picture using four image processing software programs. For lamotrigin (hRF 24), limits of quantification were 170 ng for pure drug and 10 ng for spiked plasma. Linearity (in range 20–200 ng/spot) was directly obtained for the calibration curve in spiked plasma; however, for pure drug, linearity was obtained only when using log values of the calculated densities (300–3000 ng/spot).

Pharm. Res. 38, 127-140 (2021). HPTLC of [11C]metoclopramide in plasma, kidney, urine and liver extracts on silica gel with ethyl acetate - ethanol - 25 % ammonium hydroxide 16:4:1. Detection using a multisensitive phosphor screen. The hRF value for [11C]metoclopramide was 60. The method allowed kinetic analysis in different organs after radiotracer injection in mice.

J. Planar Chromatogr. 33, 169-177 (2020). HPTLC of berberine (1) and 5-fluorouracil (2) in rabbit plasma on silica gel with toluene - methanol - ethyl acetate - formic acid 6:2:6:1. Quantitative determination by absorbance measurement at 266 nm. The hRF values for (1) and (2) were 28 and 57, respectively. Linearity was between 20 and 300 ng/zone for both (1) and (2). Intermediate precisions were below 7 % (n=3). The LOQ was 29 ng/zone for (1) and 26 ng/zone for (2), respectively. Average recovery was 86.5 % for (1) and 87.2 % for (2).

J. of Chromatogr. Sci. 57 (2), 130-138 (2019). Development of a method for the simultaneous determination of thalidomide (THD) and dexamethasone (DEX) in rat plasma using paracetamol as an internal standard by HPTLC on silica gel with methylene chloride - acetone - ethyl acetate 7:4:1. Detection by absorption measurement at 235 nm. Linearity was in the range of 0.02 - 100 µg/zone for THD and 0.02 - 3 µg/zone for DEX. LOD and LOQ were 7 and 20 ng/zone both for THD and DEX. Validation by testing all parameters using quality control samples as per FDA guidelines. Successful application of the method to study the pharmacokinetic parameters of both THD and DEX after their intra-peritoneal administration.

J. Planar Chromatogr. 32, 401-409 (2019). HPTLC of losartan potassium in plasma on silica gel with toluene - ethyl acetate - acetone - formic acid 8:8:2:1. Quantitative determination by absorbance measurement at 240 nm. The hRF value for losartan was 57. Linearity was between 50 and 1200 ng/mL. Intermediate precision was below 3 % (n=6). Recovery rate was between 95 and 99 %.

59th Indian Pharmaceutical Congress C-100, 248, (2007). An HPTLC method has been developed for the estimation of flavonoids tannin and saponin in Caesalpinia bonduc. The dried powdered leaves of the plant were extracted with methanol and used for evaluation. HPTLC on silica gel with ethyl acetate - formic acid - glacial acetic acid - water 20:2:2:5 for flavonoids, chloroform - glacial acetic acid - methanol - water 16:8:3:2 for saponin, and ethyl acetate - toluene - formic acid 6:6:1 for tannin. Detection by spraying with 5 % methanolic sulphuric acid for saponin, 5 % alcoholic aluminium chloride solution for flavonoids, and 5 % ferric chloride solution for tannin. Densitometric evaluation at 254 nm and 366 nm.

Whole Plant Powder by HPTLC. Chromatographia 65 (11-12), 767-769 (2007). HPTLC of rutin in the whole plant powder of Amaranthus spinosus Linn. on silica gel with ethyl acetate - formic acid - methanol - distilled water 100:9:11:17. Quantification by densitometry at 363 nm. Linearity was between 10 and 60 µg/mL for rutin. The concentration of rutin in the whole plant powder was found to be 0.15 %.

Acta Chromatographica 21 (1), 83-93 (2009). HPTLC of quetiapine fumarate on silica gel with toluene - methanol 4:1. The hRf value of quetiapine fumarate was 37. Quantitative determination by absorbance measurement at 254 nm. There was no chromatographic interference from tablet excipients. The drug is susceptible to treatment with acid and alkaline hydrolysis, oxidation, and photodegradation. The method was able to separate the degradation products from the pure drug, it can be used for stability tests.