Composites based on silicon dioxide xerogels, containing glycerin and nicotine, were prepared by means of tetraethoxysilane hydrolysis using the single-stage synthesis and two-stage sorption procedures. In the single-stage synthesis, glycerin sorption 3 : 1 by weight with respect to the sorbent was achieved. The kinetics of the release (desorption) of nicotine from an aerosol mixture with glycols has been studied. The synthesized sorbent is promising for use in aerosol generating systems, and also as carriers and means of delivery of biologically active compounds and medicines.

Журнал прикладной химии, Синтез и свойства силиконовых композитов, содержащих никотин

This article represents the initial preformulation stage of a broader project aimed at evaluating polysiloxane films as carrier matrices for the TIODIN components thiamine bromide (ThBr) and sodium iodide (NaI). The specific gap addressed in this first part is the lack of information on how these two highly water-soluble crystalline salts are incorporated into hydrophobic crosslinked PDMS-based matrices, how they are distributed within such films, what solid-state forms and interactions may arise, and how these features relate to their release behaviour. Crosslinked films were prepared from α,ω-dihydroxypolydimethylsiloxane (PDMS–OH) of different viscosities, tetraethoxysilane (TEOS), and Sn(Oct)₂ as a catalyst. Raman spectroscopy, confocal Raman depth profiling, and X-ray diffraction showed that the films contain both individual ThBr and NaI crystallites and mixed crystalline domains consistent with partial ThBr/NaI association and/or iodide-exchanged phases. The fraction of such mixed domains was higher in films prepared from lower-viscosity PDMS–OH than in films based on higher-viscosity PDMS–OH, and depth profiling extended this trend into the accessible near-surface layers from both film sides. Release into physiological saline, used here as a simple comparative aqueous release medium, remained low, reaching approximately 9% for ThBr and 20% for NaI after 72 h, while film swelling was minimal, approximately 1–1.5%. These findings are consistent with restricted water penetration and diffusion-limited release from hydrophobic, weakly swelling matrices. Because this first part of the study is restricted to matrix characterisation, depth profiling, and release into saline, the present results should be regarded as preformulation data. They do not demonstrate skin permeation, therapeutic transdermal performance, or suitability as a complete patch dosage form but establish baseline structural and release characteristics for a planned Part 2 focused on more application-oriented film optimisation, including properties required for future transdermal patch development.

Silicone elastomers are attractive matrices for transdermal drug delivery systems, but the controlled release of poorly water-soluble drugs from hydrophobic silicone networks remains challenging. Medical-grade silicone elastomers are generally regarded as chemically stable, biologically inert, and highly biocompatible polymer matrices, which supports their use in biomedical and pharmaceutical materials. Here, ibuprofen-loaded silicone/polyol composite films were prepared from hydroxyl-terminated polydimethylsiloxane (PDMS-OH) using glycerol- and 1,2-propylene glycol-derived alkoxysilane cross-linkers and amino-terminated PDMS as a metal-free room-temperature-vulcanising catalyst. The effects of cross-linker composition, glycerol, PEG 200 and selected functional additives on film formation, morphology, apparent ibuprofen release and preliminary Strat-M^® permeation were evaluated. FTIR analysis indicated no covalent reaction between ibuprofen and the silicone network, but suggested hydrogen-bonding interactions with polyol-rich domains, particularly in glycerol-containing systems. Raman mapping supported ibuprofen incorporation within the films, while SEM showed phase-separated microdomains whose morphology depended on the formulation. Apparent release into 0.9% NaCl at 37 °C was formulation-dependent over 72 h. The optimised F-9 film showed approximately 83% cumulative apparent release, whereas the F-10 film containing copper oxide nanoparticles and sea buckthorn oil showed the highest numerical cumulative apparent release, approximately 94%. Kinetic analysis of the apparent release data supported a mainly diffusion-controlled contribution, modulated by hydrophilic microdomains. These results provide preliminary materials-development evidence that silicone/polyol films can be used to tune apparent ibuprofen release and merit further optimisation for local topical or transdermal applications; however, efficient skin permeation and biological performance require dedicated validation.

Low molecular mono- and diamines (3-aminopropyltriethoxysilane, hexamethylenediamine, 1,4-diaminobutane), and high molecular weight polydimethylsiloxane with terminal amine groups were studied as catalysts in the synthesis of cross-linked composite films based on polydimethylsiloxane with terminal hydroxyl groups, tetraethoxysilane a cross-linking agent and containing sodium diclofenac as a physiologically active compound. Polyethylene glycol PEG200 was used as a hydrophilizing component for the hydrophobic silicone matrix. The chemical structure of amine catalysts and polyethylene glycol presence have significant effect on structure and properties of the composites, thereby determining the kinetics and degree of prolonged release of diclofenac from the films.