Simultaneous quantification of l-α-phosphatidylcoline and cholesterol in liposomes using near infrared spectrometry and chemometry

This paper describes the development and validation of a multivariate method based on transmittance NIR spectroscopy for simultaneous quantification of l-α-phosphatidylcoline (LPC) and cholesterol (CHO). Method development was based on a D-optimal experimental design consisting of 16 LPC–CHO mixtures. Calibration models were generated by partial least-squares (PLS) and principal component regression (PCR) method followed by leave-one-out cross-validation. Among the spectra pretreatment methods tested, Norris Gap first derivative was the best for both LPC and CHO quantification, combined with PLS multivariate method. The method was validated (trueness, precision, accuracy) for the concentration range 50–150% of the expected concentration in liposomes. This method was successfully applied for the characterization of liposomes prepared using the two excipients.