Determination of propranolol hydrochloride in pharmaceutical preparations using near infrared spectrometry with fiber optic probe and multivariate calibration methods.

A method for determination of propranolol hydrochloride in pharmaceutical preparation using near infrared spectrometry with fiber optic probe (FTNIR/PROBE) and combined with chemometric methods was developed. Calibration models were developed using two variable selection models: interval partial least squares (iPLS) and synergy interval partial least squares (siPLS). The treatments based on the mean centered data and multiplicative scatter correction (MSC) were selected for models construction. A root mean square error of prediction (RMSEP) of 8.2 mg g(-1) was achieved using siPLS (s2i20PLS) algorithm with spectra divided into 20 intervals and combination of 2 intervals (8501 to 8801 and 5201 to 5501 cm(-1)). Results obtained by the proposed method were compared with those using the pharmacopoeia reference method and significant difference was not observed. Therefore, proposed method allowed a fast, precise, and accurate determination of propranolol hydrochloride in pharmaceutical preparations. Furthermore, it is possible to carry out on-line analysis of this active principle in pharmaceutical formulations with use of fiber optic probe.

Casca de ovo como fonte de cálcio para humanos: composição mineral e análise microbiológica / Eggshell as calcium source for humans: mineral composition and microbiological analysis

Este estudo teve como objetivo avaliar a composição mineral de diferentes tipos de cascas de ovo, bem como a segurança microbiológica de amostras submetidas a diferentes métodos de higienização. Para a obtenção do pó de casca de ovo, as cascas foram lavadas, higienizadas, secas em estufa e trituradas em moinho. Cascas de ovo de granja (criação confinada), de coloração branca e vermelha, e cascas de ovo coloniais (caipira), provenientes da região central do Rio Grande do Sul, foram comparadas quanto a sua composição mineral. O Ca, mineral predominante na casca de ovo, se manteve em concentrações semelhantes nas diferentes amostras (cerca de 365mg g-1). As cascas de ovo de granja apresentaram maior concentração de Mg e menor concentração de Sr que as cascas de ovo coloniais. Não foram encontradas quantidades significativas de Fe, Cr, Mn, Mo, Ni, Se, Al, Cd e Pb nas amostras analisadas. Adicionalmente, tanto amostras higienizadas com imersão em hipoclorito e posterior fervura em água, quanto amostras nas quais a imersão em hipoclorito foi suprimida, não apresentaram contaminação por coliformes, estafilococos ou salmonela. Os resultados indicam que a casca de ovo pode ser utilizada na nutrição humana, já que é rica em Ca, não apresenta contaminação por metais tóxicos e, se processada de forma adequada, apresenta boa qualidade higiênico-sanitária.

This study aimed to evaluate the mineral composition of different kinds of eggshell, as well as the microbiological safety of samples submitted to different sanitization procedures. To obtain the eggshell powder, the shells were washed, sanitized, oven dried and grinded in a mill. White- and brown-colored eggshells from confined laying hens and eggshells from free-ranged laying hens from the central region of Rio Grande do Sul were compared for their mineral composition. Ca, the predominant mineral in eggshells, remained at similar concentrations in the different samples (approximately 365mg g-1). Eggshells from confined laying hens had higher Mg concentration and lower Sr concentration than the shells from free-ranged laying hens. No significant amounts of Fe, Cr, Mn, Mo, Ni, Se, Al, Cd or Pb were found in the samples. Additionally, both samples that were sanitized by immersion in hypochlorite and subsequently boiled in water as well as samples in which hypochlorite immersion was suppressed did not show coliform, staphylococcus or salmonella contamination. The results indicate that eggshell can be used in human nutrition since it is rich Ca source, shows no contamination by toxic metals and has good sanitary quality when properly processed.

A single consumption of high amounts of the Brazil nuts improves lipid profile of healthy volunteers.

Background. This study investigates the effects of Brazil nut ingestion on serum lipid profile in healthy volunteers. Methods. Ten healthy subjects were enrolled in the study. Each subject was tested 4 times in a randomized crossover in relation to the ingestion of different serving sizes of the Brazil nut: 0, 5, 20, or 50 g. At each treatment point, peripheral blood was drawn before and at 1, 3, 6, 9, 24, and 48 hours and 5 and 30 days. Blood samples were tested for total cholesterol, high- and low-density lipoprotein cholesterol (HDL-c and LDL-c, resp.), triglycerides, selenium, aspartate and alanine aminotransferases, albumin, total protein, alkaline phosphatase, gamma GT, urea, creatinine, and C-reactive protein. Results. A significant increase of the plasma selenium levels was observed at 6 hours within the groups receiving the nuts. Serum LDL-c was significantly lower, whereas HDL-c was significantly higher 9 hours after the ingestion of 20 or 50 g of nuts. The biochemical parameters of liver and kidney function were not modified by ingestion of nuts. Conclusions. This study shows that the ingestion of a single serving of Brazil nut can acutely improve the serum lipid profile of healthy volunteers.

Simultaneous diffuse reflectance infrared determination of clavulanic acid and amoxicillin using multivariate calibration techniques.

A method for simultaneous determination of clavulanic acid (CA) and amoxicillin (AMO) in commercial tablets was developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and multivariate calibration. Twenty-five samples (10 commercial and 15 synthetic) were used as a calibration set and 15 samples (10 commercial and 5 synthetic) were used for a prediction set. Calibration models were developed using partial least squares (PLS), interval PLS (iPLS), and synergy interval PLS (siPLS) algorithms. The best algorithm for CA determination was siPLS model with spectra divided in 30 intervals and combinations of 2 intervals. This model showed a root mean square error of prediction (RMSEP) of 5.1 mg g(-1). For AMO determination, the best siPLS model was obtained with spectra divided in 10 intervals and combinations of 4 intervals. This model showed a RMSEP of 22.3 mg g(-1). The proposed method was considered as a suitable for the simultaneous determination of CA and AMO in commercial pharmaceuticals products.

Total sulfur determination in residues of crude oil distillation using FT-IR/ATR and variable selection methods.

Total sulfur concentration was determined in atmospheric residue (AR) and vacuum residue (VR) samples obtained from petroleum distillation process by Fourier transform infrared spectroscopy with attenuated total reflectance (FT-IR/ATR) in association with chemometric methods. Calibration and prediction set consisted of 40 and 20 samples, respectively. Calibration models were developed using two variable selection models: interval partial least squares (iPLS) and synergy interval partial least squares (siPLS). Different treatments and pre-processing steps were also evaluated for the development of models. The pre-treatment based on multiplicative scatter correction (MSC) and the mean centered data were selected for models construction. The use of siPLS as variable selection method provided a model with root mean square error of prediction (RMSEP) values significantly better than those obtained by PLS model using all variables. The best model was obtained using siPLS algorithm with spectra divided in 20 intervals and combinations of 3 intervals (911-824, 823-736 and 737-650 cm(-1)). This model produced a RMSECV of 400 mg kg(-1) S and RMSEP of 420 mg kg(-1) S, showing a correlation coefficient of 0.990.