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

Simultaneous quantification of simvastatin and excipients in liposomes using near infrared spectroscopy and chemometry

This work describes the development and validation of a near infrared (NIR) spectroscopy method coupled with an appropriate multivariate calibration algorithm for the simultaneous quantification of encapsulated drug, simvastatin (SIM) and excipients, L-α-phosphatidylcholine (LPC) and cholesterol (CHO) in liposomes. The development of calibration models for each compound was based on a D-optimal experimental design consisting of 63 standard mixtures containing LPC, CHO and SIM in chloroform. For each compound, different spectral pretreatment methods were applied in association with selected spectral regions. Partial least-square regression (PLS) was performed using OPUS 6.5 software. Calibration set and cross-validation was carried out in order to select the best model to be used further. Straight line subtraction (SLS) was the best pre-treatment method for each compound, although the selected spectral regions were different. The method developed for each compound was validated in terms of linearity, trueness, precision and accuracy. Finally, the method has been successfully used for simultaneous quantification of SIM and excipients in liposomes. The encapsulation efficiency of SIM determined by this method was similar with that obtained by the use of reference HPLC method.

FT-NIR spectroscopy and Whittaker smoother applied to joint analysis of duel-components for corn

Protein and total fat are two ingredients to measure the quality of corn. The aim of this study is to evaluate the quality of corn by the dual-component join determination through Fourier transform near infrared (FT-NIR) spectroscopic analysis. The calibration models were established by the systematic study performed respectively in the four regions of the whole range, the second overtone, the first overtone, and the combination. Whittaker smoother was introduced as an attractive alternative data preprocessing method. With the optimized parameters, Whittaker smoother indicates its priority for improving modeling results in any of the four regions. The predictive abilities were compared between the joint analysis of protein and total fat and the separate analysis of each single component by partial least squares (PLS) modeling. The uncertainty in parameter was further estimated for the linear models. It is suggested that the joint analysis of dual-component always leads to better predictive results, and also provided good evaluation results for the independent validation samples. For the joint analysis, the optimal region for protein was the combination (5400-4000 cm(-1)), and the optimal region for total fat was the first overtone (7200-5400 cm(-1)). The optimal PLS models also provided appreciate predictive performance for both protein and total fat. And the parameter uncertainty determination provided an acceptable estimate of the measured uncertainty for the FT-NIR analysis of corn. In general, the joint analysis of dual-component is a better strategy for FT-NIR analysis of corn, and it is hoped to be tested for other objects.

Quantification of ascorbic acid and sodium ascorbate in powder blends for tableting and in vitamin C chewable tablets by NIR-chemometry

The paper proposes a near infrared method able to directly and simultaneously quantify ascorbic acid and sodium ascorbate in powder blends for tableting and in vitamin C chewable tablets without any sample preparation. In the first step, calibration models for the quantification of ascorbic acid and sodium ascorbate in powder blends for tableting and subsequently in chewable vitamin C tablets (corresponding to 80-120 % active substance) were developed according to an experimental design with 2 variables and 5 levels. Then, using the best calibration models, the methods were fully validated in terms of recovery, precision and accuracy for both powder blends and vitamin C chewable tablets. The validated concentration range was 15.14-18.51 % for ascorbic acid and 12.06-14.49 % for sodium ascorbate in powder blends and 91.85-111.03 mg per tablet for ascorbic acid and 71.01-84.50 mg per tablet for sodium ascorbate in tablets. Validation results showed good precision and accuracy.