IPC 56th 2004, Abstract No. CP-32. A stability indicating HPTLC method has been developed for the analysis of solid dosage forms containing beta-carotene. HPTLC of beta-carotene on silica gel with petrol ether (40-60 °C) - methanol - toluene 4:8:1. Rf value of beta-carotene was 0.65-0.70. Quantification by densitometric evaluation at 460 nm. The method was validated for accuracy, precision, linearity, and stability, and can be adopted for routine analysis of beta-carotene in formulations.

J. Pharm. Biomed. Anal. 38, 180-185 (2005). A stability indicating HPTLC method is reported for estimation of cyclophosphamide in pharmaceutical preparations. HPTLC on silica gel with dichloromethane - methanol - acetic acid 97:3:2. Detection with alcoholic phosphomolybdic acid solution followed by heating at 190 °C for 10 min. Quantitative determination by absorbance measurement at 700 nm. Linearity was obtained between 0.40-1.20 mg/mL with recovery rates of 99.5 %. The method was validated for selectivity, specificity, accuracy, precision, and found to be stable for 28-70 days.

The Pharma Review, Dec, 106-108 (2005). HPTLC of hexane, petroleum ether, chloroform, and methanol extracts of Arnebia nobilis (Ratanjot) roots on silica gel with n-hexane - methanol 9:1 and toluene - chloroform - methanol 14:5:1. Detection by spraying with anisaldehyde sulphuric acid reagent and densitometric fingerprint analysis by absorbance measurement at 366 nm. HPTLC fingerprinting profile provided the most reliable method for correct identification of the root.

J. Planar Chromatogr. 18, 194-198 (2005). HPTLC of rosuvastatin calcium (with aceclofenac as internal standard) on silica gel with toluene - methanol - ethyl acetate - formic acid 60:10:30:1. Quantitative determination by absorbance measurement at 265 nm. A good determination coefficient (r2 = 0.9999) was obtained for the linearity in the range of 1.0 to 15.0 µg of sample. For formulation and bulk drug the mean percentage assay was 100.09 +/- 0.20 and 100.07 +/- 0.48, respectively. The accuracy of the method was found to be 100.62 % and precision was found to vary from 0.01 to 0.77 %.

J. Planar Chromatogr. 19, 151-156 (2006). Investigation of the reversed-phase TLC retention behavior of a series of structurally diverse drugs, mostly basic compounds, with different aqueous mobile phase components. Phosphate buffer, phosphate-buffered saline, and morpholinepropanesulfonic acid, with or without the addition of n-decylamine, at pH 7.4, and phosphate buffer at pH 11.0 were used with different portions of methanol as mobil phase. TLC of amitriptyline, chlorpromazine, diltiazem, fluoxetine, nifedipine, nimesulide, norfluoxetine, nortriptyline, phenazine, pindolol, promethazine, propanolol, protriptyline, tioconazole, and trimethoprim on RP18 with phosphate buffer pH 7.4, phosphate-buffered saline, 3-morpholinopropanesulfonic acid pH 7.4, 3-morpholinepropanesulfonic acid + 0.2 % n-decylamine pH 7.4, and phosphate buffer pH 11.0 in pre-saturated chambers. Detection under UV light at 254 nm.

J. Liq. Chrom. & Rel. Technol. 27, 785-798 (2004). TLC of methyl, ethyl, isopropyl, butyl, hexyl, and benzyl nicotinate on silica gel and a mixture of silica gel and kieselguhr (heated at 120 °C for 20 min) with mixtures of n-hexane and acetone in the volume proportions 9:1, 4:1, 7:3, 3:2, 1:1, 2:3, 3:7, 1:4. Detection under UV light at 254 nm.

J. Planar Chromatogr. 19, 443-448 (2006). HPTLC of diclofenac sodium and paracetamol (with aceclofenac as internal standard) on silica gel, pre-washed with methanol, in a presaturated twin-trough chamber with toluene - ethyl acetate - methanol - formic acid 50:40:10:1. Quantitative determination by absorbance measurement at 260 nm. The method was validated regarding accuracy and precision.

Acta Chrom. 17, 292-301 (2006). TLC of ibuprofen and naproxen on silica gel pre-washed with methanol - water 9:1 and dryed at ambient temperature for 3 h. The plates were impregnated with a 0.03 M solution of L-arginine in methanol. Development with acetonitrile - methanol - water 5:1:1 containing several drops of glacial acetic acid for S-(+)-ibuprofen, and acetonitrile - methanol - water 10:2:3 containing several drops of glacial acetic acid for S-(+)-naproxen. Densitometry at 200, 205, and 210 nm for S-(+)-ibuprofen and at 202, 215, and 225 nm for S-(+)-naproxen. The investigations were performed by using three independent measurement techniques, all based on UV absorption: HPLC–UV, HPLC–DAD, and TLC–densitometry.