P., India) and Cadila Pharmaceutical Ltd (Dholka, Ahmedabad, Gujarat, India), respectively. LORN and PCM combined tablet (Claiming 8 mg of LORN and 500 mg of PCM per tablet) of two different brands Lornasafe-plus (B.No. LFS045, Mankind Pharma Ltd., Bosutinib CAS New Delhi) and Lorsaid-P (B.No. LOS10001, Piramal Healthcare Ltd., Mumbai) were collected from market and analyzed for the LORN and PCM content by the proposed method. All the other chemicals and reagents were of analytical grade. Selection of detection wavelength The wavelength was selected at 280 nm, at which, LORN shows high absorbance. This could be used to compensate for relatively low concentration of LORN compared to PCM in the marketed formulation. In the tablet dosage form PCM and LORN were found in the ratio of 500:8 mg/tab.

Hence, the selected wavelength was convenient to obtain good response peaks for both the drugs. Preparation of solution Standard stock solution of both drugs were prepared by dissolving 1000 mg of PCM and 16 mg of LORN in Acetonitrile to obtain 100 ml stock solution (10 000:160 ��g/ml) and further diluted to get final linear concentrations. Chromatographic condition A premix of toluene: chloroform: methanol: formic acid (3:5:1.5:0.2 v/v/v/v), respectively was optimized for thin layer chromatography plate development. The chamber was saturated with the mobile phase at room temperature for 30 min. A run distance was kept about 67 mm and 10 ml of the mobile phase was used for single development. The dosing speed of nitrogen applicator was kept 150 nl/sec with a predosage volume of 5 ��l.

Samples were applied as bands of 4 mm width with the gaps of 10 mm in between. Developed plates were dried at room temperature for 5 min. Detection was done at 280 nm using the deuterium lamp in the absorption reemission mode. The slit dimension of detection was kept to be 0.4 mm �� 0.02 mm. Method validation This optimized HPTLC method was then validated for the parameters listed below as per International Conference on Harmonisation (ICH) guidelines.[17] Linearity Different concentrations of LORN (160 to 560 ng/ band) and PCM (10 000 to 35 000 ng/band) were applied on the TLC plate and peak area were measured in densitometer. The calibration curves were constructed by plotting the peak areas vs concentrations for both drugs and the regression equation was calculated.

Each response was an average of three determinations. Precision Precision of the method was Anacetrapib determined in the terms of intraday and interday variation (%RSD). Intraday precision (%RSD) was assessed by analyzing standard drug solutions (240:15 000 ng/spot, 320:20 000 ng/spot and 400:25 000 ng/spot of LORN:PCM) within the calibration range, three times on the same day. Interday precision (%RSD) was assessed by analyzing drug solutions within the calibration range on three different days over a period of a week.