RESUMO
5-Fluorocytosine (FC) is a high-dose antifungal drug that challenges the development of a tablet product due to poor solid-state stability and tabletability. Using 2 pharmaceutically acceptable conjugate acid base (CAB) cocrystals of FC with HCl and acesulfame, we have developed commercially viable high loading FC tablets. The tablets were prepared by direct compression using nano-coated microcrystalline cellulose Avicel PH105 as a tablet binder, which provided both excellent tabletability and good flowability. Commercial manufacturability of formulations based on both CAB cocrystals was verified on a compaction simulator. The results from an expedited friability study were used to set the compaction force, which yielded tablets with sufficient mechanical strength and rapid tablet disintegration. This work demonstrates the potential value of CAB cocrystals in drug product development.
Assuntos
Antifúngicos/síntese química , Química Farmacêutica/métodos , Flucitosina/síntese química , Cristalização/métodos , Ácido Clorídrico/síntese química , Comprimidos , Resistência à Tração , Tiazinas/síntese química , Difração de Raios X/métodosRESUMO
The results of the original physicochemical method of NaCl recovery out of the mineralized human metabolites' solution obtained after their oxidation in H2O2 aqueous solution under the influence of alternating electric current are presented. The technological stages of the newly developed method are described, and its efficiency at each stage is demonstrated. The possibility to efficiency isolate Na from the NaHCO3 solution by applying electrodialysis technology and temperature separation is demonstrated. The HCl synthesis from Cl2 and H2 released during electrolysis is stable, allowing its combining with electrodialysis aimed at NaCl production under the conditions of a closed life support system.
Assuntos
Líquidos Corporais/química , Diálise/métodos , Sistemas de Manutenção da Vida/instrumentação , Cloreto de Sódio/química , Diálise/instrumentação , Eletrólise/métodos , Humanos , Ácido Clorídrico/síntese química , Peróxido de Hidrogênio/química , Oxirredução , Bicarbonato de Sódio/química , AstronaveRESUMO
Total mercury (Hg(T)) determination requires the addition of concentrated hydrochloric acid solution (≥10 mol L(-1) HCl) in relatively high amounts to preserve the samples and to prepare reagent solutions. A method for the preparation of concentrated HCl with Hg(T) concentration of lower than 5 ng L(-1) is described in this article. It is based on the well-known chemical reaction: 2 NH(4)Cl + H(2)SO(4) â (NH(4))(2)SO(4) + 2 HCl. This method is validated thanks to the US Environmental Protection Agency method 1631 and standard reference materials BCR-579 (mercury in coastal seawater).
Assuntos
Ácido Clorídrico/síntese química , Mercúrio/análise , Água/química , Ácido Clorídrico/química , Água do Mar/química , SoluçõesRESUMO
The great versatility of polymers makes them very useful in the biomedical and pharmaceutical fields. The combination of natural and synthetic polymers leads to new materials with tailored functional properties. The aim of this work consists in the preparation of new drug delivery system based on chitosan (natural polymer) and polybetaines (synthetic polymers), by a simple process, well known in the literature as complex coacervation methods. Also, the adsorption and release studies of two antibiotics as well as the preservation of their bactericidal capacities were performed.
Assuntos
Acrilatos/síntese química , Antibacterianos/síntese química , Betaína/síntese química , Materiais Biocompatíveis/síntese química , Quitosana/síntese química , Lipotrópicos/síntese química , Adesivos Teciduais/síntese química , Ácido Acético/síntese química , Antibacterianos/farmacologia , Biopolímeros/biossíntese , Sistemas de Liberação de Medicamentos/métodos , Ácido Clorídrico/síntese químicaRESUMO
The vibrational branching ratio [CH(3)(v=0) + HCl(v'=1)]/[CH(3)(v=0) + HCl(v'=0)] of two correlated product pairs from the title reaction shows a dramatic E(c)-dependence, in sharp contrast to the previously observed behavior in Cl + CHD(3)(v(1)=1), while the vibrational enhancement factors in reactivity of the two reactions are remarkably similar.
Assuntos
Cloro/química , Metano/química , Ácido Clorídrico/síntese química , Ácido Clorídrico/química , Metano/análogos & derivados , Metano/síntese química , Análise Espectral , VibraçãoRESUMO
Irradiation of solutions of tetraphenylporphyrin (H2TPP) in chloroform causes decomposition of the chloroform at UV wavelengths higher than those that decompose chloroform directly. The catalytic cycle involves photooxidation of the porphyrin followed by thermal reduction. Photocatalysis continues after H2TPP has been completely protonated by the HCl produced during decomposition, and the rate of HCl production accelerates as a second pathway, in which CCl3OOH oxidizes the porphyrin, becomes important.
Assuntos
Clorofórmio/química , Clorofórmio/efeitos da radiação , Porfirinas/química , Porfirinas/efeitos da radiação , Raios Ultravioleta , Catálise , Radicais Livres/química , Radicais Livres/efeitos da radiação , Ácido Clorídrico/síntese química , Cinética , Fotoquímica , Fotólise , Soluções/química , Fatores de TempoRESUMO
A simple, highly effective and economical method is developed for conversion of polyamines/putrescine, spermidine and spermine into their chlorhyndrates with a yield about 100%. The melting points of the preparations obtained and those available from "Serva" /FRG/ were identical; all the preparations were oxidized by diamine oxidase from rat liver tissue at the same rate. Tissues of transplanted hepatomas and malignant liver exhibited an absolute inability to oxidative deamination. The diamine oxidase activity in regenerating liver tissue was similar to the rate of deamination, estimated in liver tissue of sham-operated animals.