J. Planar Chromatogr. 5, 184-191 (1992). RM values of some basic drugs (used mainly against Parkinson’s disease) and related compounds have been measured by RPTLC with a variety of ion pair reagents in the mobile phase or stationary phases. Retention and separation selectivity were readily controlled by changes in the eluent pH, methanol (modifier) content, or type and concentration of the ion pair reagent. - The strongest effect on the retention of the compounds was obtained when ion pair reagent was incorporated into the stationary phase.

Indian Drugs 31 (4), 139-143 (1994). TLC of different analgesics in combined dosage form on silica in phosphate buffer (pH 6.0) with ethyl acetate - chloroform - methanol NH3 110:80:10:1. Determination after elution by spectrophotometry at 242 nm for paracetamol, 258 nm for dextropropoxyphene, 265 nm for oxyphenbutazone and ibuprofen.

J. Chin. Trad. Med. (Zhongguo Zhongyao Zazhi) 29, 486-488 (1994). TLC of encainide-HCl on silica with chloroform - DMF - acetone 4:3:3. Detection under 254 nm. The TLC method is used for product quality control. Quantification by HPLC.

J. Planar Chromatogr. 9, 61-64 (1996). TLC of sulfonamides and degradation products (e.g. 2-amino-4,6-dimethylpyrimidine, sulfanilamide, sulfadimidine, 2-hydroxy-4,6-dimethylpyrimidine, sulfanilic acid) on silica with 1,2-dichloroethane - 2-propanol - NH3 (25%) - methanol 26:13:2:13. Detection under UV 254 and 366 nm and after spraying with Bratton-Marshall reagent or with p-dimethylaminobenzaldehyde solution.

J. Planar Chromatogr. 9, 456 - 458 (1996). HPTLC of pseudoephedrine hydrochloride or guaifenesin on silica with ethyl acetate - methanol - NH3 conc. 17:2:1. Quantification by densitometry at 210 nm for pseudoephedrine hydrochloride and 276 nm for guaifenesin. Visual detection sensitivity by fluorescence quenching were about 5 and 1.5 mg. Simple, rapid quantitative HPTLC method.

J. Planar Chromatogr. 10, 222-224 (1997). HPTLC of R-(+)- and S-(-)-pindolol enantiomers (after derivatization with 2,3,4,6-tetra-O-acetyl-b-D-glucopyranosylisothiocyanate) on RP-8 silica with distilled water - 2-propanol 7:3. Quantification by densitometry at 256 nm (absorbance).

Part II: Quantitation and evaluation of ceftriaxone J. Planar Chromatogr. 11, 258-262 (1998). HPTLC of ceftriaxone (without prior solvent elution) on reversed-phase hydrocarbon-impregnated silica gel with water for plate washing and as spotting solvent. Evaluation of the spots at different wavelengths by densitometry. The direct sample determination (DSD), i.e. sample spotting coupled with densitometric quantitation, has a great advantage over GC or HPLC when the need for separation is absent and high sample throughput is required.

J. Planar Chromatogr. 11, 428-432 (1998). New TLC method HPTLC-OPLC and conventional TLC on silica gel with n-hexane - butyl acetate - ethyl acetate - chloroform 12:3:3:4; OPLC, and 6:3:3:4, TLC. Evaluation at 233 nm by densitometry. Development and validation of a quantitative OPLC purity test for phthaloyl-amlodipine and comparison of the validation characteristics (specificity characterized by retention factor, resolution, and asymmetry factors; linearity; detection limit and quantitation limit; and precision) with those of a similar TLC method.