A validated stability indicating HPLC method for determination of sitagliptin

A comparative and stability-indicating reversed phase high performance liquid chromatographic study have been developed and validated for sitagliptin phosphate. The liquid chromatographic determination was achieved isocratically on Poroshell 120 EC-C18 (100 × 4.6 mm, i.d.; particle size, 2.7 µm), Pursuit 5PFP (150 × 4.6 mm, i.d.; particle size, 5 µm) and Chromolith performance RP-18e (100 × 4.6 mm, i.d.; macropore diameter, 2 µm) columns using a mobile phase consisting of methanol:water:triethylamine:acetic acid (60:40:0.1:0.1; v:v:v:v), at a flow rate 0.5 mL/min and UV detection at 268 nm. The method was linear over the concentration range of 100-1000 µg/mL (r = 0.9998) with a limit of detection and quantitation of 10 and 30 µg/mL, respectively. All the validation parameters and stability indicating study were studied on Poroshell 120 EC-C18 column, which achieved the best separation. The proposed method has been found to have the required accuracy, selectivity, sensitivity, and precision to assay sitagliptin phosphate in bulk form and in a pharmaceutical dosage form. Degradation products resulting from the stress studies did not interfere with the detection of sitagliptin phosphate that indicates that the assay are stability-indicating assay

Synthesis and preliminary biological screening of certain 5-aralkyl pyrrolidine-3-carboxylic acids as anticonvulsants

Synthesis of a series of 5-aralkyl pyrrolidine-3-carboxylic acid derivatives namely, 1-acetyl-4-hydroxy-5-benzyl or 5-(4-alkoxy-benzyl)-pyrrolidine-3-carboxylic acids (3a-e), 1-H-4-hydroxy-5-benzyl or 5-(4-alkoxy-benzyl)-pyrrolidine-3-carboxylic acids (4a-e), 1-acetyl-5-benzyl or 5-(4-alkoxy-benzyl)-pyrrolidine-3-carboxylic acids (8a-e), 1-H-5-benzyl or 5-(4-alkoxy-benzyl)-pyrrolidine-3-carboxylic acids (9a-e) have been accomplished. The structures of the new compounds were assigned from IR, 1H NMR, 13C NMR and elemental analyses. Compounds 3a-e, 4a-e, 8a-e and 9a-e were biologically screened for their anticonvulsant potential using the subcutaneous pentylenetetrazole seizures (scPTZ) assay and Gabapentin as reference standard. The 1-H-4-hydroxy-5-benzyl or 5-(4-alkoxy-benzyl)-pyrrolidine-3-carboxylic acids (4a-e) showed the highest anticonvulsant activity. Compound 4b was found to be the most potent one which exhibited 100% protection

Lipase Catalysed Kinetic Resolution of Stiripentol

Kinetic resolution of rac-Stiripentol, catalysed by lipase A from Candida antarctica by esterification with vinyl butanoate was performed with an E-value of 24. This allowed isolation of (3S)-Stiripentol with an ee of 86 % and the corresponding (3R)-butanoate with an ee of 87 %. Enzymatic hydrolysis of the ester product gave (3R)-Stiripentol with 94 % ee