This solution was applied to TLC plate precoated with silica gel 60 F254 as band of 4 mm at a distance of 20 mm from x-axis and 15 mm from y-axis. It was developed in the chamber using optimized mobile phase consisting of Toluene : Chloroform : Methanol in the ratio of 5 : 5 : 1.5 v/v. The plate was developed up to 90 cm and dried in the air and scanned at 260 nm. Sample solution To measure ITZ clearly content of capsule (label claim 100 mg ITZ per capsule, Itaspor capsules), 20 capsules were weighed. The mean weight was determined. A weight of the powder equivalent to 100 mg ITZ was transferred to a 100-ml volumetric flask containing 50 ml methanol and the mixture was sonicated for 30 minutes, then diluted to 100 ml with methanol (1 000 ��g/ml).

The solution was filtered and 1 ml of filtered solution was diluted five-fold to furnish a concentration of 200 ��g/ml. This solution (20 ��l, 4 000 ng/band) was applied to a TLC plate which was developed and scanned as described above. The analysis was repeated in triplicate. The possibility of interference of excipients with the analysis was also examined. Forced degradation studies Forced degradation of drug substance was carried out under photolytic, UV degradation, elevated temperature and humidity, acid/base/neutral hydrolytic and oxidative conditions. After the degradation, 6 000 ng ITZ per spot was applied. Acid degradation For acid degradation study, 10 mg of drug was weighed accurately and transferred into 10 ml volumetric flask. 1N methanolic HCl was added and made up to the mark. The solution was refluxed for 2 hour at 75��C.

After this, it was neutralized using 1N NaOH and from this solution, an appropriate dilution was made and 6 000 ng/spot was applied. Alkali degradation For alkali degradation study, 10 mg of drug was weighed accurately and transferred into 10 ml volumetric flask. 1N Methanolic NaOH was added and made up to the mark. The solution was refluxed for 2 hour at 75��C. After this, it was neutralized using 1N HCl and from this solution an appropriate dilution was made and 6 000 ng/spot was applied. Neutral degradation For neutral degradation study, 10 mg of drug was weighed accurately and transferred into 10 ml volumetric flask. After that, volume was made up to the mark with methanol and water (80 : 20 v/v). The solution was refluxed for 1 hour at 75��C. After this, an appropriate dilution was made and 6 000 ng/spot was applied. Oxidation degradation For oxidative degradation study, 10 mg of drug was weighed accurately and transferred into 10 ml volumetric flask. 1 ml of 30% hydrogen peroxide was added and made up to the mark with methanol. After this, Entinostat an appropriate dilution was made and 6 000 ng/spot was applied.