A importância da escolha dos excipientes na manipulação de medicamentos / The importance of the choice of excipients in drug manipulation

Para o desenvolvimento de uma formulação, estável, eficaz e segura é necessário considerar as características de todos os componentes utilizados na manipulação de um medicamento. A biodisponibilidade dos fármacos é influenciada por diversos fatores, como a solubilidade e permeabilidade, sendo necessário minimizar esta influência através da introdução de substâncias que os melhorem. O Sistema de Classificação Biofarmacêutica classificou os fármacos em quatro classes, a classe I com alta solubilidade e permeabilidade, classe II com baixa solubilidade e alta permeabilidade, classe III com alta solubilidade e baixa permeabilidade e classe IV com baixa solubilidade e permeabilidade. Sendo assim, os excipientes apresentam finalidade específica nas formulações, podendo atuar como diluentes, lubrificantes, aglutinantes, desintegrantes, entre outros, na forma farmacêutica. O presente trabalho tem por objetivo atentar para a importância da escolha correta dos excipientes na manipulação de medicamentos, pois eles podem ser incompatíveis com certos princípios ativos e com isso resultar em um medicamento ineficaz e sem segurança de uso A metodologia seguida foi levantamento bibliográfico sobre as diversas classes de excipientes, suas funções e compatibilidades. Para a coleta de informações foram utilizados artigos publicados em periódicos, contidos nas bases de dados Scientific Electronic Library Online- ScIELO, National Library of Medicine - PUBMED, bem como artigos técnicos de entidades como a Agência Nacional de Vigilância Sanitária – ANVISA. Conclui-se, portanto, que a escolha correta dos excipientes na manipulação de medicamentos favorece a liberação e absorção de fármacos, sendo de extrema importância para um bom desempenho terapêutico

Mid Infrared Spectroscopy and Multivariate Analysis Evaluation of Adulteration in Whey Protein Powder

Mid infrared (MIR) spectroscopy was combined with multivariate approaches Principal Component Analysis (PCA) and Partial Least Squares (PLS) regression to assess modifications in spectral profile of whey protein concentrate (WPC) powder due to changes in formulation level using caffeine, creatine and lactose, simulating fraud. Adulterations were made by replacing WPC in different levels from 5 to 50% (w/w - 5% steps) with three adulterants in separate. The spectra comparison of the samples allowed the identification of peaks associated to characteristic chemical bonds of each adulterant. PCA was carried out and 89% of the total variability of the spectral data was explained by three principal components, which allowed the confirmation of variables influencing each sample mixture and validating the spectral observations. Above 20% decrease in WPC content (20% adulteration), it was possible to differentiate all the three substances used. Predictions of percentage of WPC substitution were made through PLS regressions. The best prediction models were: lactose > creatine > caffeine. However, predictions resulted in overall good accuracy, low relative errors and coefficients of determination of fitting of calibration and validation curves above 0.97 in all cases. Therefore, techniques employed here aid the quality assessment of food products as alternative analytical tools. &nbsp

Mathematical models for correlating electrical parameters and milk adulterants

This work presents mathematical models obtained from electrical measurements to control of milk quality and detection of adulterations, especially by ethanol, sodium chloride and sodium bicarbonate. These substances may cause changes in the electrical properties of raw milk. Electrical measurements are non-destructive and fast techniques. The proposed models correlate the addition of the mentioned substances with measurements of conductance and phase angle at a fixed frequency of 100 Hz. Linear models were proposed from the data and the independence, normality, lack of adjustment and homoscedasticity were verified. The detection limits obtained based on conductance were 0.01 %, 0.03 g/L and 2.1 g/L for samples adulterated with ethanol, sodium chloride and sodium bicarbonate, respectively. The limits for measurements based on the phase angle were 0.4%, 1.3 g/L and 16.4 g/L, respectively. The results demonstrated that the proposed models may be a powerful tool to improve milk analysis methodologies.Este trabalho apresenta modelos matemáticos obtidos a partir de medidas elétricas para controle da qualidade do leite e detecção de adulterações, principalmente por etanol, cloreto de sódio e bicarbonato de sódio. Essas substâncias podem causar alterações nas propriedades elétricas do leite cru. As medições elétricas são técnicas não destrutivas e rápidas. Os modelos propostos correlacionam a adição das substâncias mencionadas com medições de condutância e ângulo de fase a uma frequência fixa de 100 Hz. Modelos lineares foram propostos a partir dos dados e verificou-se independência, normalidade, falta de ajuste e homocedasticidade. Os limites de detecção obtidos com base na condutância foram de 0,01%, 0,03 g / L e 2,1 g / L para amostras adulteradas com etanol, cloreto de sódio e bicarbonato de sódio, respectivamente. Os limites para medições baseadas no ângulo de fase foram de 0,4%, 1,3 g / L e 16,4 g / L, respectivamente. Os resultados demonstraram que os modelos propostos podem ser uma ferramenta poderosa para aprimorar as metodologias de análise do leite

Protein characterization of pasteurized milk, cheese whey and their mixtures by using the CEM SprintTM analyzer

In this work, the protein analyzer SprintTM was assessed regarding its capacity of predicting addition of whey in milk. This type of practice is relatively common in dairy plants, since whey, as it is a protein component, may be added with little loss of milk protein content. Besides,its incorrect elimination contributes to environmental pollution. Mixtures of milk and whey were prepared in different levels of addition and two methods of milk partition were tested. The results indicated that the concentration of trichloroacetic acid (TCA) from the selected method was not suitable for the present purpose while the chosen method using glacial acetic acid (GAA) has presented a satisfactory separation of the soluble and insoluble milk components. Even though the concentration of whey protein and casein are the essential parameters for determining whey addition in milk, the use of measurements from total protein was important in order to improve the linearity of the method due to the fact that the rates whey protein/total protein and casein/total protein presented the best results concerning fraud prediction capacity. Therefore, as the equipment is a rapid, safe and efficient platform, it can be used as an alternative to be implemented in laboratories of food quality control which perform or plan to perform assays to verify the whey addition in fluid milk

Long-Term Ripening Evaluation of Ewes’ Cheeses by Fourier-Transformed Infrared Spectroscopy under Real Industrial Conditions

The ripening changes over time of special cheeses (Pecorino, ewes’ ripe, and Gouda) made with ewes’ milk were evaluated using FTIR/ATR spectroscopy during approximately one year. The midinfrared FTIR/ATR analyses were carried out in different ripening times between the cheese varieties and processed by means of multivariate statistical approaches. Overall, during the maturation, we observed a downward trend of the absorbance intensity of the amide group peaks (1700 to 1500 cm−1), which is linked to the breakdown of peptide bonds. Similar behavior was obtained for the lipidic region (3000 to 2800 cm−1 and 1765 to 1730 cm−1). Hierarchical cluster analysis and principal component analysis allowed the evaluation of the physicochemical changes of the cheeses. The proteolysis occurs in a fast pace during the first trimester of the ripening process, and the lipids are converted to smaller species as the times goes by. Our results indicate that infrared spectroscopy can be a useful tool in determining optimal temporal parameters in stages involving the development, production, and even a possible estimation of shelf life of cheeses

Capillary zone electrophoresis for fatty acids with chemometrics for the determination of milk adulteration by whey addition

Adulteration of milk with whey is difficult to detect because these two have similar physical and chemical characteristics. The traditional methodologies to monitor this fraud are based on the analysis of caseinomacropeptide. The present study proposes a new approach to detect and quantify this fraud using the fatty acid profiles of milk and whey. Fatty acids C14:0, C16:0, C18:0, C18:1, C18:2 and C18:3 were selected by gas chromatography associated with discriminant analysis to differentiate milk and whey, as they are present in quite different amounts. These six fatty acids were quantified within a short time by capillary zone electrophoresis in a set of adulterated milk samples. The correlation coefficient between the true values of whey addition and the experimental values obtained by this technique was 0.973. The technique is thus useful for the evaluation of milk adulteration with whey, contributing to the quality control of milk in the dairy industry

ASPECTOS COMPOSICIONAIS, PROPRIEDADES FUNCIONAIS, NUTRICIONAIS E SENSORIAIS DO LEITE DE CABRA: UMA REVISÃO

O objetivo deste trabalho foi realizar uma revisão de literatura sobre aspectos composicionais e propriedades funcionais, nutricionais e sensoriais do leite de cabra aplicados à sua tecnologia de processamento. A escassez de publicações contendo informações específicas sobre o leite de cabra motivou a realização deste artigo. Para a realização da revisão bibliográfica foi feita uma busca de artigos científicos nas bases de dados da SpringLink, Nature, Scientific Electronic Library Online, principalmente, acessados através do portal de periódicos da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior por intermédio do Sistema Integrado de Gestão Acadêmica da UFJF. As principais palavras-chave utilizadas como descritor do assunto foram "leite de cabra" em português, em inglês "goat milk" e em espanhol "leche de cabra". O leite de cabra tem um importante papel como fonte de cálcio, de gordura de elevada digestibilidade, de proteína de alto valor biológico e hipoalergenicidade. Comparando o leite caprino com o leite bovino em relação aos aspectos composicionais, observou-se que os leites das duas espécies são distintos. Informações específicas sobre o leite de cabra facilitam o seu processamento e desenvolvimento de novos produtos a partir deste. As propriedades nutricionais e funcionais do leite de cabra justificam sua singularidade e demonstram que o leite caprino e seus produtos representam um nicho promissor para diversificar e inovar a indústria láctea. As propriedades sensoriais relativas ao sabor e odor do leite de cabra representam dificuldades para a sua aceitação, sendo necessárias pesquisas para melhorar estas características

Electrical characterization of milk samples by Electrical Impedance Spectroscopy (EIS)

This work presents a study of electrical impedance spectroscopy (EIS) as an alternative to characterize milk, aiming to develop an analysis methodology. The behavior of the electrical impedance module, the real part and the imaginary part (reactance), and the derived quantities such as admittance, phase and diffusion coefficient (D) were also analyzed and will be discussed. Comparisons of the measured spectra with theoretical models of equivalent circuits were carried out in order to understand the electrical behavior of the samples. Understanding this electrical phenomenon will help in the development of future analysis methodologies and applications. The results indicated that milk is a solution with predominantly resistive behavior with resistance of approximately 500 Ohms, capacitance of about of 0.5 MicroFarad (μF) and admittance of the order of MiliSiemens (mS), presenting small storaged charge due to low viscosity. The best-fitting equivalent circuit was a mixed RC model consisting of a series resistor coupled with a resistor in parallel with a capacitor