Journal of Chromatographic science, 49: 1-7 (2011) IF: 1.078

Two chromatographic methods were developed, optimized and validated for simultaneous determination of calcipotriol monohydrate (CPM) and betamethasone dipropionate (BMD) in the presence of two dosage form additives named; butylated hydroxytoluene (BHT) and alpha-tocopherol (TOCO). The proposed methods were accurate, sensitive and specific. The first method based on using aluminum thin-layer chromatographic plates precoated with silica gel GF254 as a stationary phase and chloroform-ethyl acetate-toluene (5:5:3, by volume) as a developing system. This was followed by densitometric measurement of the separated bands at 264 nm. Whereas the second method is RP-HPLC where OnyxMonolithic C18® column was used with a gradient profile using methanol, water and acetic acid at flow rate 2.0 mL min-1. Detection was carried out at 264 nm. The methods were validated according to ICH guidelines. The specificity of the developed methods was investigated by analyzing the pharmaceutical dosage form. The validity of the proposed methods was assessed using the standard addition technique. The obtained results were statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision at P = 0.05.

Two chromatographic methods were developed and validated for the simultaneous
determination of Mometasone furoate (MO) and Formoterol fumarate dihydrate (FOR). Combination
of MO and FOR is used for the treatment of asthma in patients suffering from reversible
obstructive airway disease. The first chromatographic method was based on using aluminum
TLC plates pre-coated with silica gel GF254 as the stationary phase and chloroform:ethyl acetate:
methanol:toluene:formic acid (5:2:2:2:0.1, by volume) as the mobile phase followed by densitometric
measurement of the separated bands at 233 nm. The second method is a high performance liquid
chromatographic method for the separation and determination of MO and FOR using reversed
phase C18 column with isocratic elution. The mobile phase composed of methanol: 0.5% ammonium
acetate pH adjusted with acetic acid (80:20, v/v) at a flow rate of 1.0 mL/min. Quantitation
was achieved with UV detection at 220 nm. The specificity of the developed methods was investigated
by analyzing the pharmaceutical dosage form. The validity of the proposed methods was
assessed using the standard addition technique. The obtained results were statistically compared
with those obtained by the reported methods, showing no significant difference with respect to accuracy
and precision at p = 0.05.