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1.
Scand J Gastroenterol ; 52(2): 230-237, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27806647

RESUMO

INTRODUCTION: Helicobacter-induced atrophic gastritis with a hypochlorhydric milieu is a risk factor for gastric cancer. Microbes colonising acid-free stomach oxidise ethanol to acetaldehyde, a recognised group 1 carcinogen. OBJECTIVE: To assess gastric production of acetaldehyde and its inert condensation product, non-toxic 2-methyl-1,3-thiazolidine-4-carboxylic acid (MTCA), after alcohol intake under treatment with slow-release L-cysteine or placebo. METHODS: Seven patients with biopsy-confirmed atrophic gastritis, low serum pepsinogen and high gastrin-17 were studied in a cross-over single-blinded design. On separate days, patients randomly received 200 mg slow-release L-cysteine or placebo with intragastric instillation of 15% (0.3 g/kg) ethanol. After intake, gastric concentrations of ethanol, acetaldehyde, L-cysteine and MTCA were analysed. RESULTS: Administration of L-cysteine increased MTCA (p < .0004) and decreased gastric acetaldehyde concentrations by 68% (p < .0001). The peak L-cysteine level was 7552 ± 2687 µmol/L at 40 min and peak MTCA level 196 ± 98 µmol/L at 80 min after intake. Gastric L-cysteine and MTCA concentrations were maintained for 3 h. The AUC for MTCA was 11-fold higher than acetaldehyde, indicating gastric first-pass metabolism of ethanol. With placebo, acetaldehyde remained elevated also at low ethanol concentrations representing 'non-alcoholic' beverages and food items. CONCLUSIONS: After gastric ethanol instillation, slow-release L-cysteine eliminates acetaldehyde to form inactive MTCA, which remains in gastric juice for up to 3 h. High acetaldehyde levels indicate a marked gastric first-pass metabolism of ethanol resulting in gastric accumulation of carcinogenic acetaldehyde. Local exposure of the gastric mucosa to acetaldehyde can be mitigated by slow-release L-cysteine capsules.


Assuntos
Acetaldeído/análise , Carbolinas/metabolismo , Cisteína/administração & dosagem , Etanol/administração & dosagem , Gastrite Atrófica/metabolismo , Adulto , Carbolinas/análise , Carcinogênese/efeitos dos fármacos , Estudos Cross-Over , Preparações de Ação Retardada/administração & dosagem , Feminino , Suco Gástrico/microbiologia , Mucosa Gástrica/metabolismo , Gastrinas/sangue , Gastrite Atrófica/microbiologia , Helicobacter/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , Neoplasias Gástricas/metabolismo , Suécia
2.
AAPS PharmSciTech ; 18(2): 293-302, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27738876

RESUMO

Printing technologies were recently introduced to the pharmaceutical field for manufacturing of drug delivery systems. Printing allows on demand manufacturing of flexible pharmaceutical doses in a personalized manner, which is critical for a successful and safe treatment of patient populations with specific needs, such as children and the elderly, and patients facing multimorbidity. Printing of pharmaceuticals as technique generates new demands on the quality control procedures. For example, rapid quality control is needed as the printing can be done on demand and at the point of care. This study evaluated the potential use of a handheld colorimetry device for quality control of printed doses of vitamin Bs on edible rice and sugar substrates. The structural features of the substrates with and without ink were also compared. A multicomponent ink formulation with vitamin B1, B2, B3, and B6 was developed. Doses (4 cm2) were prepared by applying 1-10 layers of yellow ink onto the white substrates using thermal inkjet technology. The colorimetric method was seen to be viable in detecting doses up to the 5th and 6th printed layers until color saturation of the yellow color parameter (b*) was observed on the substrates. Liquid chromatography mass spectrometry was used as a reference method for the colorimetry measurements plotted against the number of printed layers. It was concluded that colorimetry could be used as a quality control tool for detection of different doses. However, optimization of the color addition needs to be done to avoid color saturation within the planned dose interval.


Assuntos
Química Farmacêutica/métodos , Colorimetria/métodos , Sistemas de Liberação de Medicamentos/métodos , Impressão/métodos , Cor , Espectrometria de Massas/métodos , Controle de Qualidade , Tecnologia Farmacêutica/métodos , Complexo Vitamínico B/química
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