GEL FORMATION IN THE KAOLIN SYSTEM - SODIUM ALGINATE - CALCIUM SULFATE - SODIUM PYROPHOSPHATE

Представлены результаты исследований изменений происходящих при формировании наполненных альгинатных гелей при внутреннем диффузионном гелеобразовании. Исследование проводилось для систем, состоящих из каолина и альгината натрия с системой отверждения из сульфата кальция и пирофосфата натрия. Установлено, что применение реологических методов исследования позволяют получать данные о показателях качества альгинатных гелей и их составе, и механизме гелеобразования. Установлено, что для системы каолин – альгинат натрия – сульфат кальция – пирофосфат натрия при формировании альгинатного геля целесообразно использовать сульфат кальция с массовой долей от 5 до 6,5, а пирофосфат натрия с массовой долей от 1,5 до 3 % при гидромодуле 1 к 3 и температуре воды 20 °С.Эти данные можно использовать при разработке рецептуры альгинатных масок и подготовки нормативной технической документации. The results of studies of changes occurring during the formation of filled alginate gels during internal diffusion gelation are presented. The study was carried out for systems consisting of kaolin and sodium alginate with a curing system of calcium sulfate and sodium pyrophosphate. It has been established that the use of rheological research methods makes it possible to obtain data on the quality indicators of alginate gels and their composition, and the mechanism of gelation. It was found that for the system kaolin-sodium alginate-calcium sulfate-sodium pyrophosphate when forming an alginate gel, it is advisable to use calcium sulfate with a mass fraction of 5 to 6.5, and sodium pyrophosphate with a mass fraction of 1.5 to 3% at a hydromodule 1 to 3 and a water temperature of 20 °C. This data can be used in the development of the formulation of alginate masks and the preparation of regulatory technical documentation.

Study of structural and mechanical properties of sodium alginate gels

Rheological parameters are an important characteristic of semisolid dosage forms. Structural and mechanical characteristics have a noticeable effect on the processes of release and absorption of drugs from ointments, as well as on their consumer properties: spreadability, adhesion, the ability to squeeze out of the tubes. The aim: to study the rheological parameters of aqueous solutions of sodium alginate in various concentrations to create medicinal hydrogel compositions. Materials and methods: sodium alginate (Shandong Topsea Seaweed Industrial Co., Ltd., China) was used as a gelling agent. The physicochemical properties of the samples were studied according to generally accepted methods of the State Pharmacopoeia of Ukraine. Rheological studies of experimental samples were carried out using a rotational viscometer «Rheolab QC», by Anton Paar (Austria) with coaxial cylinders C-CC27/SS at a temperature 20–25 °С. Results and discussion: the rheological profiles of sodium alginate gels have a non-Newtonian type of flow, which makes it possible to characterize them as systems with plastic-viscous properties. Gels with a sodium alginate concentration of 1.5–2 % have the best indicators of yield stress, hysteresis loop area, mechanical stability and dynamic flow coefficients. This indicates a low degree of destruction of the structural grid in the process of mechanical action and the presence of thixotropic bonds. Conclusions: sodium alginate gel base at 0.5 % and 1 % concentration is less stable under stress compared to sodium alginate bases at 1.5 % and 2 % concentration. The gel base of sodium alginate at a concentration of 2 % has the optimal mechanical stability value.

Subtle influence on alginate gel properties through host–guest interactions between covalently appended cyclodextrin and adamantane units

Alginate gels have been explored in relevant domains for daily life such as pharmaceutics and environmental. The structural features of alginate allow functionalization which, in extension, can modify the gel...

Alginate gels crosslinked with chitosan oligomers – a systematic investigation into alginate block structure and chitosan oligomer interaction

Three alginates with different block structures, poly-M, poly-G, and poly-MG, were investigated upon ionic crosslinking with chitosan oligomers, using circular dichroism, rheology, and simulations, revealing a unique high gel strength poly-MG chitosan gelling system.

Industrial kinetic resolution of d,l-pantolactone by an immobilized whole-cell biocatalyst

Immobilized whole-cells of Pichia pastoris harboring recombinant d-lactonase were entrapped in calcium alginate gels and used as an efficient biocatalyst for catalytic kinetic resolution of d,l-pantolactone.