Enabling the Tablet Product Development of 5-Fluorocytosine by Conjugate Acid Base Cocrystals.

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.

Physicochemical conversion of human exometabolites for the NaCl involvement into the mass exchange in closed life support systems.

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.

Synthesis of hydrochloric acid solution for total mercury determination in natural waters.

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) → (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).

[New polymer-drug systems based on natural and synthetic polymers]. / Noi sisteme polimer-medicament pe baza de polimeri naturali si sintetici.

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.

Unravelling the reactivity of antisymmetric stretch-excited CH4 with Cl by-product pair-correlation measurements.

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.

Photocatalysis by tetraphenylporphyrin of the decomposition of chloroform.

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.

[Synthesis of polyamine hydrochlorides and their oxidative deamination by diamine oxidase from rapidly growing tissues]. / Sintez khlorgidratov poliaminov i ikh okislitel'noe dezaminirovanie diaminoksidazoi iz bystrorastushchikh tkanei.

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.