Hydrogel delivery systems are popular dosage forms that have a number of advantages, such as ease of use, painlessness, increased efficiency due to prolongation of rheological, swelling and sorption characteristics, regulation of drug release, and stimulus sensitivity. Particular interest is shown in hydrogels of cellulose ether derivatives due to the possibility of obtaining their modified forms to vary the solubility, the degree of prolonged action, and the release of the active substance, as well as their widespread availability, affordability, and the possibility of sourcing raw materials from different sources. Hydroxypropyl methylcellulose (HPMC, “hypromellose”) is one of the most popular cellulose ethers in the production of medicines as a filler, coating and carrier. Research on hydrogel carriers based on polymer complexes and modified forms of HPMC using acrylic, citric, and lactic acids, PVP, chitosan, Na-CMC, and gelatin is of particular interest, as they provide the necessary rheological and swelling characteristics. There is growing interest in medical transdermal hydrogels, films, capsules, membranes, nanocrystals, and nanofibers based on HPMC with the incorporation of biologically active substances (BASs), especially those of plant origin, as antibacterial, wound-healing, antimicrobial, mucoadhesive, anti-inflammatory, and antioxidant agents. The aim of this article is to review modern research and achievements in the field of hydrogel systems based on cellulose ethers, particularly HPMC, analyzing their properties, methods of production, and prospects for application in medicine and pharmacy.

It is shown that a more than significant amount of experimental data obtained in the field of studying systems based on thermosensitive hydrophilic polymers and reflected in the literature over the past decades makes the issue of their systematization and classification relevant. This, in turn, makes relevant the question of choosing the appropriate classification criteria. It is shown that the basic classification feature can be the number of phase transition stages, which can vary from one to four or more depending on the nature of the temperature-sensitive system. In this work, the method of inverse phase portraits is proposed for the first time. It was intended, among other things, to identify the number of phase transition stages. Moreover, the accuracy of this method significantly exceeds the accuracy of the previously used method of direct phase portraits since, for the first time, the operation of numerical differentiation is replaced by the operation of numerical integration. A specific example of the application of the proposed method for the analysis of a previously studied temperature-sensitive system is presented. It is shown that this method also allows for a quantitative comparison between the results obtained by the differential calorimetry method and the turbidimetry method. Issues related to increasing the resolution of the method of direct phase portraits are discussed.

A new type of household/therapeutic air freshener is proposed, in which beneficial components are released from compositions containing plant raw materials through induction heating under an alternating-frequency electromagnetic field. The composition is heated by metal elements (e.g., pieces of metal foil) included in its composition. The advantage of the proposed air freshener is the possibility of using a wide range of plant raw materials without prior additional processing. Another advantage of this air freshener is the possibility of controlling it via a smartphone, which is in line with the concept of a ‘smart home.’ The proposed approach bypasses labour-intensive production of simple oils, reduces the product cost, and expands the number of plants (helpful for small-scale cultivation in countries such as Kazakhstan). At the same time, however, it remains possible to use traditional compositions based on industrially produced aromatic oils. Specific examples of the implementation of the proposed method are presented. Prospects include programme-controlled emission of odours from polymer matrices, Internet of Things applications, implementation of sound–visual effects (colour–aroma–music), and even integration with neuromorphic materials.

This article examines the effect of two types of polypropylene (H030 and H350) and petroleum residue on the bitumen modification process. Bitumen modification is one of the key methods for improving its physical and mechanical properties and enhancing the quality of road pavement. Currently, bitumen modification is widely used in road construction, playing a crucial role in improving its quality and energy efficiency. Studying the effect of polymers on the mechanical stability of bitumen is a relevant issue in increasing the durability of road surfaces. During the study, six different concentrations of polypropylene H030 and H350 were introduced into bitumen samples, and their main characteristics were compared. The obtained results demonstrated that polypropylene significantly alters the properties of bitumen, contributing to increased strength and durability of road pavements. Furthermore, the addition of petroleum residue enhances the rheological properties of the bitumen mixture, improving its adhesion. These studies provide essential data for improving bitumen used in road construction. The research results indicate that the use of polymer-modified bitumen increases the wear resistance of road surfaces, reduces crack formation, and enhances resistance to climatic factors. This, in turn, extends the service life of road pavements and reduces road maintenance costs. Long-lasting pavements help decrease energy consumption for bitumen production and road construction. The obtained data expand the possibilities for the effective use of polymer-modified bitumen mixtures in asphalt concrete production. Thus, the compatibility of bitumen and polypropylene has been studied, and their optimal compositions have been determined.