Journal of Pharmacy Research 2(1), 189-195 (2009). A validated HPTLC method has been developed for simultaneous estimation of valdecoxib and tizanidine in dosage form. HPTLC on silica gel with toluene - methanol - ethyl acetate 2:2:1. The compounds were well separated as compact bands. The method was linear in the range of 10-100 ng/band for tizanidine and 100-1000 ng/band for valdecoxib. The recovery was in the range of 99.3-101.2 %. Densitometric quantification at 254 nm. The method is suitable for quality control of combined dosage form.

var hirsuta. 62nd Indian Pharmaceutical Congress Abstract No. F-238 (2010). TLC of the two marker compounds bebeerine and oleanolic acid from the roots of Cissampelos pareira Linn. on silica gel with toluene – ethyl acetate – diethylamine 7:2:1 for bebeerine and toluene – ethyl acetate – formic acid 70:30:3 for oleanolic acid. The hRf value was 20 (bebeerine) and 56 (oleanolic acid). Quantitative determination by absorbance measurement at 254 nm and under visible light after spraying with dragendorff’s reagent (bebeerine) or anisaldehyde sulfuric acid reagent (oleanolic acid).

J. Planar Chromatogr. 28, 119-125 (2015). The goal of this quantitative structure-retention relationship study was to investigate the retention behavior and to characterize the lipophilicity of 16 guanidine and imidazoline derivatives by TLC on RP-8 with methanol–water–ammonia (in different volume ratios), simulating the n-octanol–water partition system. Detection by absorbance measurement at 254 nm. Three different modeling methodologies (stepwise MLR, PLR, ANN) were tested. The stepwise MLR could be used as the most reliable model for prediction of retention behavior in the examinated RP-TLC system.

Chinese J. Med. Industry 17, 422-423 (1986) (Yiyao Gongye). TLC on silica with butanol - isopropanol - 38% NH3 3:1:0.5. Quantification by densitometry at 460 nm.

J. Chromatogr. 499, 361-371 (1990). Studies of reverse-phase retention behavior of 18 benzodiazepine derivatives using TLC on paraffin-impregnated silica with a solution containing 0 – 32.5 Vol-% of acetonitrile in steps of 2.5 % and 6, 12, 30, 60, and 90 mM KHPO4 solution. Detection by their UV absorption spectra. Linear dependence of RM value on organic phase concentration and logarithmically on buffer concentration in mobile phase. Prediction of HPLC retention behavior.

Anal. Letters 27, 723-729 (1994). TLC of phenytoin on silica with chloroform - isopropylether - methanol - NH3 75:25:20:1. Quantification by densitometry at 254 nm.

J. Planar Chromatogr. 15, 38-41 (2002). Study of the effect of impregnating TLC plates with some synthetic peptides and aspartic acid on the speed of migration of 3-(w-aminoalkyl)-5,5-dialkyl-(or spirocycloalkyl-1',5)hydantoin derivatives of phenylpiperazines and comparison of the results with the affinity of the impregnants for 5-HT 1A and 5-HT 2A receptors. TLC of 10 5-HT 1A and 5-HT 2A compounds on silica gel impregnated with H-Asp-OH, H-Asp-Ile-OH, H-Leu-Asp-Val-Leu-OH, and H-Ala-Asp-Val-Leu-OH with chloroform - methanol 10:1. Visualization under UV and by use of an iodine chamber.

Coll.czechoslov.chem.comm. 46, 312-318 (1983). TLC on silica with chloroform - ethanol - triethylamine 92:6:2. Detection by UV 254 and 366 nm; with 0.5 % p-dimethylaminobenzaldehyde solution in cyclohexane; or HCl vapours.