RESUMO
Paracetamol is an active ingredient commonly found in pharmaceutical formulations in combination with one of the following compounds: codeine, orphenadrine, promethazine, scopolamine, and tramadol. In this work, we propose a unique analytical method for determination of these active ingredients in pharmaceutical samples. The method is based on capillary electrophoresis with capacitively coupled contactless conductivity detection. The separation was achieved on a fused silica capillary (50 cm total length, 40 cm effective length, and 50 µm id) using an optimized background electrolyte composed of 20 mmol/L ß-alanine/4 mmol/L sodium chloride/4 µmol/L sodium hydroxide (pH 9.6). Each sample can be analyzed in a single run (≤2 min) and the limits of detection were 2.5, 0.62, 0.63, 2.5, 15, and 1.6 µmol/L for scopolamine, tramadol, orphenadrine, promethazine, codeine, and paracetamol, respectively. Recovery values for spiked samples were between 94 and 104%.
Assuntos
Acetaminofen/análise , Eletroforese Capilar , Codeína/análise , Composição de Medicamentos , Orfenadrina/análise , Prometazina/análise , Escopolamina/análise , Tramadol/análiseRESUMO
We report the quantification of promethazine (PMZ) using glassy carbon electrodes (GCE) modified with bamboo-like multi-walled carbon nanotubes (bCNT) dispersed in double stranded calf-thymus DNA (dsDNA) (GCE/bCNT-dsDNA). Cyclic voltammetry measurements demonstrated that PMZ presents a thin film-confined redox behavior at GCE/bCNT-dsDNA, opposite to the irreversibly-adsorbed behavior obtained at GCE modified with bCNT dispersed in ethanol (GCE/bCNT). Differential pulse voltammetry-adsorptive stripping with medium exchange experiments performed with GCE/bCNT-dsDNA and GCE modified with bCNTs dispersed in single-stranded calf-thymus DNA (ssDNA) confirmed that the interaction between PMZ and bCNT-dsDNA is mainly hydrophobic. These differences are due to the intercalation of PMZ within the dsDNA that supports the bCNTs, as evidenced from the bathochromic displacement of UV-Vis absorption spectra of PMZ and quantum dynamics calculations at DFTB level. The efficient accumulation of PMZ at GCE/bCNT-dsDNA made possible its sensitive quantification at nanomolar levels (sensitivity: (3.50±0.05)×10(8) µA·cm(-2)·M(-1) and detection limit: 23 nM). The biosensor was successfully used for the determination of PMZ in a pharmaceutical product with excellent correlation.
Assuntos
Antialérgicos/análise , Técnicas Biossensoriais/instrumentação , DNA/química , Nanotubos de Carbono/química , Prometazina/análise , Animais , Bovinos , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento , Limite de Detecção , Modelos MolecularesRESUMO
A cromatografia líquida de alto desempenho (CLAD) é uma técnica adequada para a análise de fenoriazínicos uma vez que é eficiente, rápida, precisa e sensível. Nesta pesquisa foi padronizado um método por cromatografia líquida para a análise quantitativa simultânea dos cloridratos de prometazina e clorpromazina en injetáveis. Um sistema em fase reversa foi empregado consistindo de uma coluna LiChrosorb RP-18 (5 micronn) fase estacionária e metanol-água-amônia (88:11:1) como fase móvel. Operou-se em temperatura ambiente e o fluxo foi de 1,0 mL/min. As amostras após preparaçäo e extraçäo foram injetadas na coluna (cloridrato de prometazina = 20,a microng/mL, cloridrato de clorpromazina = 10,0 microng/mL). Os compostos foram detectados a 254 nm. O método pode ser usado para controle de qualidade durante a produçäo e no produto terminado