In the present investigation, an attempt was made for the development, validation, forced degradation and pharmacokinetic application of sitagliptin in the human plasma spiking studies by UV - HPLC method. The experimentation was developed based on the extensive literature survey and ascertained by the statistical parameters of the sampling. A simplified, accurate method was created by the liquid chromatographic system from Shimadazu LC 20AD consisting of manual injection. The optimized chromatogram was obtained with acetonitrile in the isocratic mobile phase method at a 1.0 mL/min flow rate. A thermo C-8 column (4.6X250mm,5μm) was used as a stationary phase, and 265.0nm was selected as the detection wavelength with the aid of a UV-Vis detector. The proposed method was validated as per ICH guidelines. The technique was linear in the range of 10-50μg/mL with correlation coefficient R2 = 0.9746, respectively. Recovery studies postulated that % RSD 19.14, 3 & 9.95 respectively. Injection repeatability values were found to be % RSD 17 & 10.63 for intraday and interday, respectively. Stress degradation studies revealed that sitagliptin degrades more rapidly when subjected to 0.1 NaoH. Human plasma spiking studies reported 3.02 ng/mL at 3.02+/-60 min of C and T max, respectively. Keywords: Sitagliptin, Method development, HPLC, Validation, Stress degradation studies, Human plasma spiking studies