T. K. Ravi

Arbutin and quercetin are anti-cancer agents, extracted from leaves and flowers of Origanum majorana L which can be simultaneously estimated using a rapid, specific and sensitive high – performance thin layer chromatographic technique using silica gel G60F254 as the stationary phase and butyl acetate: methanol: formic acid: toluene (8: 1.5: 5: 0.5) as mobile phase for the separation. The method was validated for linearity, precision and recovery. Linearity was established in the range 300-900 ng/spot for arbutin and 150-450 ng/spot for quercetin, respectively. The % RSD values of repeatability of application, repeatability of measurement, intra-day and inter day precision studies of arbutin and quercetin were found to be below 1 for 500 and 250 ng/spot of arbutin and quercetin, respectively. The recovery of the drugs were found to be 99.8 and 100.2%, proves that the developed method was highly accurate. Hence the proposed validated method could be applied for the simultaneous analysis of arbutin and quercetin in methanolic extract of Origanum majorana L as well as for its marketed formulation.

A simple, specific, sensitive, precise and stability-indicating reversed phase high performance liquid chromatographic method was developed and validated for the simultaneous determination of thiocolchicoside and aceclofenac, using a RP-18 column and a mobile phase composed of 0.1% trifluoroacetic acid: acetonitrile (45:55). The retention time of thiocolchicoside and aceclofenac were found to be 2.35 and 13.2 min, respectively. Linearity was established for both thiocolchicoside and aceclofenac in the range of 0.08-0.8 and 1-10 µg/ml. Both the drugs were subjected to acid, alkali and neutral hydrolysis, oxidation, dry heat, and photolytic degradation. The degradation studies indicated that both thiocolchicoside and aceclofenac were susceptible to acid, alkaline and neutral hydrolysis. The degradation products of thiocolchicoside and aceclofenac were well resolved from the pure drugs with significant differences in the retention time values. This method can be successfully employed for simultaneous quantitative analysis of thiocolchicoside and aceclofenac in bulk drugs and formulations.

A simple, specific, accurate and stability-indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of thiocolchicoside  and lornoxicam, using a RP-18 column and a mobile phase composed of 10mM ammonium acetate : methanol(50:50), pH7 adjusted with 1%triethyl amine. The retention time of thiocolchicoside and lornoxicam were found to be 4.6 and 10.2 min, respectively. Linearity was established for both thiocolchicoside and lornoxicam in the range of 1-10 µg/ml. The percentage recoveries of thiocolchicoside and lornoxicam were found to be 100.45±0.4489 and 100.70±0.5111, respectively. Both the drugs were subjected to acid, alkali and neutral hydrolysis, oxidation, dry heat, and photolytic degradation. The degradation studies indicated thiocolchicoside to be susceptible to acid, alkaline and neutral hydrolysis while lornoxicam showed degradation under acid and alkali. The degradation products of thiocolchicoside and lornoxicam were well resolved from the pure drugs with significant differences in the retention time values. This method can be successfully employed for simultaneous quantitative analysis of thiocolchicoside and lornoxicam in bulk drugs and formulations.