Development and validation of UV-spectrophotometric method for estimation of pterostilbene in Pterocarpus marsupium

Aim: To develop and validate a simple, precise and cost effective UV-visible spectrophotometric method for the estimation of pterostilbene in Pterocarpus marsupium extract. All the parameters of the analysis were chosen as per ICH Q2 (R1) guideline.
Methods: Pterostilbene solution was scanned over UV-visible range for its wavelength of maximum absorbance. Various calibration standards of pterostilbene were prepared. Calibration curve of concentration vs. absorbance was plotted and developed UV – visible spectrophotometry method was used for estimation of pterostilbene in standardized Soxhlet assisted extract (SAE)as well as ultrasound assisted extracts (UAE) of Pterocarpus marsupium.
Results: The maximum wavelength of pterostilbene was found to be 306 nm. The correlation coefficient of developed UV-Visible spectrophotometric method over the concentration range of 1-6 μg/ml was found to be 0.999. The validation study of the said method was carried out in terms of linearity, accuracy, precision, robustness, ruggedness, limit of detection and limit of quantitation studies. Developed UV – visible method was found to be precise for the intra- and inter- day studies and showed standard deviation in the range of 0.83 to 1.912&0.762 to 1.542respectively. The pterostilbene content in Pterocarpus marsupium extract was found to be 4.5% using the proposed UV – visible spectrophotometry method.
Conclusion: A simple, precise and cost-effective UV- visible spectrometry method was developed for the estimation of pterostilbene in standardized extract of Pterocarpus marsupium. The method was developed using solvent containing economical percentage of organic phase in aqueous media. Said validated UV- visible method can be efficiently used for the estimation of pterostilbene in extracts of Pterocarpus marsupium.