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2 Acta Chromatographica

2 2008

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Impurity profile study of capecitabine

Hiriyanna S. G., Basavaiah K.

Acta Chromatographica

2008

Vol. 20, no. 4

609-624

Five new peaks of potential impurities, ranging from 0.05 to 0.12% on an area-percent basis, have been observed in reversed-phase high-performance liquid chromatography of capecitabine drug substance. On the basis of comparison of relative retention times and mass values two of the impurities were identified as intermediates in the process used for synthesis of capecitabine and were characterized as (2-(4-amino-5-fluoro-2-oxopyrimidin-1(2 H )-yl)-5-methyltetrahydrofuran-3,4-diyl diacetate and 2-(5-fluoro-2-oxo-4-(pentyloxycarbonylamino)pyrimidin-1(2 H )-yl)-5-methyl tetrahydrofuran-3,4-diyl diacetate. The area percentages of two of the other peaks increased substantially when the drug was treated with acid and base. The three compounds other than the two intermediates were isolated by preparative HPLC with gradient elution and were characterized by use of spectroscopic techniques, viz. MS-MS, FTIR, and NMR ( 1 H, 13 C and DEPT). On the basis of the spectral data, the structures 5?-deoxy-5-fluorocytidine, 5?-deoxy-5-fluorouridine, and 2-(4-(bis(pentyloxycarbonyl)amino)-5-fluoro-2-oxopyrimidin-(2 H )-yl)-5-methyltetrahydrofuran-3,4-diyl diacetate were proposed for the three impurities.

Identification and characterization of olanzapine degradation products under oxidative stress conditions

Hiriyanna S. G., Basavaiah K., Goud P. S. K., Dhayanithi V., Raju K., Pati H. N.

Acta Chromatographica

2008

Vol. 20, no. 1

81-93

Studies of the degradation of olanzapine bulk drug under hydrolytic (acidic and alkaline), oxidising, and photolytic conditions are reported in this paper. Olanzapine is almost completely stable under photolytic and hydrolytic (acidic and alkaline) conditions. The major degradation products formed when olanzapine bulk drug was exposed to oxidative stress conditions were isolated by preparative reversed-phase highperformance liquid chromatography and characterized by FTIR, LC-MS-MS, and 1H, 13C, and DEPT NMR. On the basis of results from spectroscopy the degradation products were characterized as 10-hydroxy-2-methyl-5,10-dihydro-4H-benzo[b]thieno [2,3- e][1,4]diazepin-4-one, 2-methyl-5,10-dihydro-4H-benzo[b]thieno[2,3-e][1,4]diazepin-4- one, and 2-methyl-10-(2-methyl-10H-benzo[b]thieno[2,3-e][1,4] diazepin-4-yloxy)-5,10- dihydro-4H-benzo[b]thieno[2,3-e]diazepin-4-one. Identification, isolation, and characterization of these oxidative degradation products are discussed in detail.