J. Planar Chromatogr. 20, 331-334 (2007). HPTLC of tizoxanide (with nitazoxanide as internal standard) on silica gel prewashed with methanol in a twin-trough chamber with toluene - ethyl acetate - acetic acid 62:134:4. UV detection and quantitation at 313 nm for the internal standard and at 410 nm for tizoxanide.

59th Indian Pharmaceutical congress F-10, 392, (2007). HPTLC of olmesartan medoxomil and hydrochlorothiazide on silica gel with acetonitrile - chloroform - glacial acetic acid 14:4:1 with chamber saturation for 30 min. Densitometric evaluation at 254 nm. Linearity was between 480 and 900 ng/zone for olmesartan and 150 and 600 ng/zone for hydrochlorothiazide. Recovery was 99.7 - 100.4 % . The method can be used for routine quality control of formulations.

Pharmazie 63, 102-106 (2008). TLC of benzyl 2-acetamido-6-O-acetyl-3-O-[(R)-1-carboxyethyl]-2-deoxy-alpha-D-glucopyranoside 1’,4-lactone, 2-acetamido-6-O-acetyl-3-O-[(R)-1-carboxyethyl]-2-deoxy-alpha-D-glucopyranoside 1’,4-lactone, and 2-acetamido-6-O-acetyl-3-O-[(R)-1-carboxyethyl]-2-deoxy-alpha-D-glucopyranoside-1-alpha-(diphenyl phosphate) 1’,4-lactone on silica gel with ethyl acetate - acetone 2:1. TLC of triethylammonium muramyl phosphate on silica gel with isopropanol - water - 25 % ammonia 6:1:3. Evaluation under UV light and by heating the plate at 250 °C.

Ind. J. Pharm. Sci. 70(3), 398 - 400 (2008). HPTLC of ibuprofen and pseudoephedrine HCl on silica gel with tert-butanol - ethyl acetate - acetic acid - water 7:4:2:2. Quantitative determination by absorbance measurement at 254 nm. The hRf value of pseudoephedrine was 68 and of ibuprofen 91. The method was linear in the concentration range of 45.6 - 75.6 µg/mL for ibuprofen and 6.8 - 11.3 µg/mL for pseudoephedrine. The recovery was between 100.7 and 101.0 % for both compounds. The method was suitable for routine quality control.

CBS 101, 12-13 (2008). During a drug substance stability study a mass imbalance was discovered in light degraded samples. HPTLC on silica gel first with ethyl acetate - heptane, then, after drying, with tetrahydrofuran in a horizontal developing chamber. Detection under UV 254 nm and by densitometry at 240 nm. During another project differences in color between batches of a drug substance were observed. HPTLC on amino phase with methanol in a horizontal developing chamber. Detection under white light and under UV 366/>400 nm.

J. Liq. Chromatogr. Relat. Technol. 30, 2369-2383 (2007). TLC of 2-arylpropionic acids, namely ibuprofen and naproxen, on silica gel and silica gel impregnated with a 0.03 mol/L solution of L-arginine in methanol by dipping for 2 s, with ethanol and ethanol containing several drops of acetic acid. Quantitative determination by absorbance measurement at 254 nm. It was demonstrated that the crystalline chirality of the silica gel adsorbent is most probably responsible for the horizontal enantioseparation, whereas the molecular chirality of L-arginine deposited on the silica gel layer is responsible for the vertical enantioseparation.

Asian J. Chem. 18(4), 2669-2672 (2006). TLC of lamivudine and zidovudine on silica gel with toluene - methanol - n-hexane 14:3:2. Quantitative determination by absorbance measurement at 275 nm. Linearity for lamivudine and zidovudine was in the range of 0.8-2.0 and 1.5-4.0 µg/zone, respectively. The average recovery was 99.4 - 100.3 % for both drugs. The method can be applied for routine simultaneous estimation in combined dosage form.

J. Planar Chromatogr. 22, 201-206 (2009). TLC of ambroxol hydrochloride and doxycycline hyclate on silica gel with ethyl acetate - ethanol - glacial acetic acid - water 90:40:5:10 with chamber saturation for 1 h. Detection under UV 254 nm. Quantitative determination by absorbance measurement at 254 nm for ambroxol hydrochloride and 270 nm for doxycycline hyclate.