I have encapsulated Paclitaxel inside a polymer. The polymer is attached to different functional groups. I am getting higher values for optical density. Those values are not lying within the standard curve of paclitaxel. The only way to quantify the Paclitaxel amount which is conjugated with the polymer is through Beer's Law. In literature i haven't found the extinction coefficient value in 10 % DMSO at wavelength of 239 nm. Regards NABEELA JABEEN