L-Buthionine Sulfoximine Detection and Quantification in Polyurea Dendrimer Nanoformulations

L-Buthionine sulfoximine (L-BSO) is an adjuvant drug that is reported to increase the sensitivity of cancer cells to neoplastic agents. Dendrimers are exceptional drug delivery systems and L-BSO nanoformulations are envisaged as potential chemotherapeutics. The absorption of L-BSO at a low wavelength limits its detection by conventional analytical tools. A simple and sensitive method for L-BSO detection and quantification is now reported. In this study, L-BSO was encapsulated in a folate-targeted generation four polyurea dendrimer (PUREG4-FA(2)) and its release profile was followed for 24 h at pH 7.4 and 37 degrees C. The protocol uses in situ L-BSO derivatization, by the formation of a catechol-derived orto-quinone, followed by visible detection of the derivative at 503 nm. The structure of the studied L-BSO derivative was assessed by NMR spectroscopy.