J. Liq. Chromatogr. Relat. Technol. 30, 2103-2115 (2007). TLC of five derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-dione on silica gel with n-butanol - 2-propanol - cyclohexane - acetic acid 6:3:2:1 in the first dimension and chloroform - 2-propanol - acetic acid 40:15:6 or chloroform - cyclohexane - 2-propanol - acetic acid 20:20:15:6 in the second dimension. Quantitative determination by absorbance measurement at 254 nm.

Ind. J. Pharm. Sci. 70(2), 251-255 (2008). HPTLC of olanzapine and fluoxetine on silica gel with methanol - toluene 2:1. Quantitative determination by absorbance measurement at 233 nm. The method was linear in the range of 100-800 ng/spot for olanzapine and 1000-1200 ng/spot for fluoxetine. Recovery was 99.4-100.4 % for both compounds. Forced degradation studies (acid, base, oxidation, photolyses and thermal) revealed that all the degradation products were well resolved from the principal compound. The method was suitable for routine quality control.

Asian J. Chem. 18(2), 1078-1084 (2006). TLC of nimesulide and diclofenac sodium on silica gel with n-hexane - ethyl acetate - chloroform - acetic acid 16:2:3:1. Quantitative determination by absorbance measurement at 256 nm. The hRf value of nimesulide was 3 and of diclofenac sodium 57. Linearity was between 1.0 and 3.2 µg/zone for nimesulide and 0.5 and 1.6 µg/zone for diclofenac sodium. The recoveries (by standard addition method) were in the range of 99.1 and 101.0 for both drugs. The proposed method is precise and accurate and can be used for routine analysis of nimesulide and diclofenac sodium capsule formulation.

Indian Drugs 46(2), 150-153 (2009). HPTLC of hydrochlorthiazide (HZ) in combination with quinapril (QP) or candensartan (CD) on silica gel with toluene - ethyl acetate - glacial acetic acid 2:12:1 (for HZ and QP), or 20:50:1 (for HZ and CD), with chamber saturation for 30 min at room temperature. Quantitative determination by absorbance measurement at 273 nm. The method was linear in the range of 480-960 (HZ), 400-800 (QP) and 50-250 ng/spot (CD).

J. Planar Chromatogr. 22, 207-210 (2009). HPTLC of dexibuprofen on silica gel (prewashed with methanol) in a twin trough chamber with hexane - ethyl acetate - glacial acetic acid 15:5:1. Quantitative determination by absorbance measurement at 217 nm.

Chromatographia 65 (3-4), 239-243 (2007). TLC of solasodine in various Solanum species on silica gel with a developing solvent containing an organic acid to form ion pair complexes of solasodine with the acid dye. The resulting colored complex was quantified by absorbance measurement at 461 nm. Linearity was between 79 and 495 ng/spot with a correlation coefficient of 0.995. The method eliminates post derivatization steps and the problem of background interference. Application of the method to determine solasodine content in various herb samples, herb extract and their formulations showed an accuracy of 98.5 ± 2.8 % without matrix interference.

Asian J. of Chem. 21(9), 6999-7004 (2009). HPTLC of ursolic acid in methanolic and aqueous extracts of Ocimum sanctum (Tulsi) on silica gel with toluene - ethyl acetate - acetic acid 55:45:2 with chamber saturation. Detection by treatment with Liebermann Burchard’s reagent. Quantitative determination by absorbance measurement at 550 nm. The method was linear in the range of 100-400 ng/band. The amount of ursolic acid in aqueous and methanolic extracts was in the range of 0.2 and 0.4 %. Samples collected from different geographical regions were compared, samples from Kerala contained the highest levels of ursolic acid.

Chinese J. Pharm. Anal. 26 (2), 221-224 (2006). HPTLC of gentamycin and related compounds on silica gel with chloroform – methanol – 25 % ammonia 5:7:6. The main compound is well separated from the impurities. Quantification by densitometry at 485 nm. Linearity was between 4.0 – 40 ng/spot (r2 = 0.99) and the limit of detection was at the low ng level.