RESUMEN

This study showed near Infrared (NIR) and Raman spectroscopy with a multivariate calibration approach were very effective to determine blend uniformity end-point. A set of 36 trimebutine samples containing magnesium stearate, stearic acid, colloidal silicon oxide, talc as excipients (0.9%∼1.8%) was acquired from six positions during blending processing with U-type blender from 0 to 30 min. Principle component analysis (PCA) with NIR and Raman spectral data was used to confirm the end-point of blending. After 30 min, the scores of principle component (PC) 1 and principle component (PC) 2 for samples moved into one point, which clearly indicated the mixture of sample became homogenous. In addition, NIR and Raman spectroscopy has been applied to the quantitative analysis of 20 trimebutine samples containing 2∼40% in mixture granules, which divided into a calibration set of 15 samples and a prediction set of 5 samples for NIR spectral data. The standard error of calibration (SEC) and standard error of prediction (SEP) are 0.15% and 0.13%, respectively using NIR while SEC and SEP of 0.95% and 0.91% are obtained using Raman spectroscopy. The results showed the NIR and Raman spectroscopy with a multivariate calibration such as PCA and PLS provide the possibility of real time monitoring of homogeneity and content uniformity during blending process.

Asunto(s)

Parasimpatolíticos/química , Tecnología Farmacéutica , Trimebutino/química , Inteligencia Artificial , Calibración , Química Farmacéutica , Determinación de Punto Final , Estudios de Factibilidad , Análisis de los Mínimos Cuadrados , Parasimpatolíticos/análisis , Análisis de Componente Principal , Control de Calidad , Reproducibilidad de los Resultados , República de Corea , Espectroscopía Infrarroja Corta , Espectrometría Raman , Comprimidos , Trimebutino/análisis

RESUMEN

A new quantitative calibration algorithm, called "Moment Combined Partial Least Squares (MC-PLS)", which combines the moment of spectrum and conventional PLS was proposed. Its calibration performance was evaluated for the analyses of three import petroleum and petrochemical products: gasoline, naphtha and polyol samples. The selected properties for these products included the research octane number (RON) and Reid vapor pressure (RVP) for gasoline, the distillation temperature at 10% (D 10%) for naphtha and the hydroxyl (OH) number for polyol. The major concept presented here used the moment to find the closest spectrum of a sample in a given dataset, and generate the difference spectrum and the corresponding difference in the property. These difference spectra and property differences were then used for PLS calibration. The moment has been employed in spectroscopic fields as a simple and effective "spectral feature characteristic" using just a few scalar values (moments). MC-PLS showed improved prediction performance over PLS for each case. In MC-PLS, the difference spectra generated using the moments were used as explained; therefore, additional detail in spectral variations can be utilized for calibrations. Additionally, the difference in the property was employed as reference data, so that its variation range was smaller when compared with that of the original property. Consequently, the MC-PLS performance could be better since the feature-enhanced spectra were used to model a narrower range of property variations. In the case of the D 10% prediction for naphtha, a non-linear prediction pattern that occurred in conventional PLS was effectively corrected using the MC-PLS method.

RESUMEN

The ability to monitor etching solutions using a spectroscopy directly through existing Teflon lines in electronic industries is highly beneficial and offers many advantages. A monitoring method was developed using near-infrared (NIR) measurements with Teflon tubing as a sample container for the quantification of components in the indium-tin-oxide (ITO) etching solution composed of hydrochloric acid (HCl), acetic acid (CH3COOH) and water. Measurements were reproducible and it was possible to use the same calibration model for different Teflon tubings. Even though partial least squares (PLS) calibration performance was slightly degraded for Teflon cells when compared to quartz cells of the similar pathlength, the calibration data correlated well with reference data. The robustness of Teflon-based NIR measurement was evaluated by predicting the spectra of 10 independent samples that were collected using five different Teflon tubes. Although, two Teflon tubes were visually less transparent than the other three, there was no significant variation in the standard error of predictions (SEPs) among the five Teflon tubes. Calibration accuracy was successfully maintained and highly repeatable prediction results were achieved. This study verifies that a Teflon-based NIR measurement is reliable for the monitoring of etching solutions and it can be successfully integrated into on-line process monitoring.

RESUMEN

We describe a method for determining the ambroxol content in tablets nondestructively. To obtain a reliable quantitative calibration, we prepared 20 pellet samples (ambroxol content: 8.30-16.25 wt.%) and acquired their Raman spectra while rotating the pellets. The spectra of the rotated samples reflected the compositional variations better than those that were recorded without rotation. To reduce both the baseline variations and the spectral noise simultaneously, the spectra were pre-processed using wavelet transformation (WT). Then, we used the normalization method before partial least-squares (PLS) regression to correct Raman intensity variation from laser power fluctuation. The achieved standard error of cross validation (SECV) was 0.30%. Two different datasets where Raman intensity was artificially changed were prepared and the corresponding spectra were quantitatively analyzed. The result was reproducible even if laser intensity was fairly changed. Additionally, two different commercial tablets were analyzed and the accuracy of measurement was better for a tablet that had the similar spectral features of the standard pellet samples. The proposed method can be utilized for the analysis of commercial tablets if standard tablets of various ambroxol concentrations that have the same chemical components including additives and the same physical shape of tablets are available.

Asunto(s)

Ambroxol/análisis , Espectrometría Raman/métodos , Comprimidos/análisis , Implantes de Medicamentos/análisis , Análisis de los Mínimos Cuadrados , Tecnología Farmacéutica/métodos

RESUMEN

The chemometric calibration performance was systematically investigated by two parameters (changing the chemical matrix as well as the signal-to-noise ratio) of the NIR (near-infrared) spectrum. Three different analytes (hexane, cyclohexane, toluene) were selected and heptane was used as a solvent. The degree of spectral difference significantly affected the calibration performance. The largest structural difference between the analyte and the solvent provided the best calibration result for a given signal-to-noise ratio. Additionally, the signal-to-noise ratio of the spectra also directly influenced the calibration performance. Overall, the spectral difference and signal-to-noise ratio were the major factors for governing the chemometric calibration performance, especially in the low-concentration range.