Determination of the physical and mechanical indicators of the polymer base and the optimal method of introducing active pharmaceutical ingredients into the base composition
Authors: Solomennyi A. M. , Drozdova A. O. , Davtyan L. L. 
Published: February 2023

Treatment of wounds and wound infection remains an urgent medical problem today, especially in conditions of constant hostilities. Hydrogel bandages are quite effective means for local treatment of wounds, which are able to have a complex therapeutic effect and do not require frequent replacement in the process of medical supply to military personnel. Taking into account the relevance of this topic, our research is aimed at developing a hydrogel bandage with lidocaine hydrochloride, ceftriaxone and metronidazole.
Aim. To study the physical and mechanical parameters of the polymer base and determine the optimal method for introducing active pharmaceutical ingredients (APIs) into the base composition.
Materials and methods. The study materials were APIs (lidocaine hydrochloride, ceftriaxone, metronidazole) and excipients. Physical and mechanical research methods were used in the work.
Results and discussion. In order to develop the optimal technology for obtaining the polymer mass and determining technological indicators, we studied the indicators of physical and mechanical properties. Indicators of breaking force and relative elongation depend on such technological characteristics as homogeneity, uniformity of application on the substrate, the absence of air bubbles. It was found that the higher the physical and mechanical parameters, the higher the quality of the polymer mass applied to the substrate. Therefore, after obtaining a homogeneous mass it is necessary to deaerate air bubbles by centrifugation (No. 1-5) at 3000 rpm for 5-10 min. During the study of the ease of application of the polymer mass on the polyethylene terephthalate substrate, it was found that the drying process was affected by the thickness of the layer. It was proven that samples No. 1-5 had a uniform, adhesive layer and could be used for further research. The main technological indicators were the layer thickness of 0.40 mm, the centrifugation time of 5-10 min at 3000 rpm, homogeneity (mixing for 15 min at 36 rpm, an anchor stirrer). It was experimentally found that to obtain a layer thickness of 0.40 mm, it was necessary to apply 0.03 g of the sample per 1 cm2 of the substrate. We proved that polymers in the concentration of 10 % provided the optimal technological indicators. To confirm this, the dependence of the viscosity of the forming solution on the concentration / ratio of polymers was studied. We found that the technological indicators of homogeneity and uniformity directly affected the quality of the resulting product. Taking into account the fact that it was possible to introduce poorly soluble substances into the composition of model samples we conducted an experiment on their sedimentation in a polymer solution. It was found that APIs introduced into the polymer solution had different values of the sedimentation rate (time), which was probably related to the degree of solubility. In addition, the polymer concentration in the forming solutions also affected the sedimentation rate of API. The higher the viscosity, the slower the API particles settled.
Conclusions. It has been found in the course of the study that satisfactory indicators of physical and mechanical parameters can ensure the quality of the polymer mass production technology as the base for choosing a polymer coating for obtaining a hydrogel with anesthetic, antibacterial, and antimicrobial effects. The main technological indicators determined are the layer thickness (0.40 mm), the centrifugation time (5-10 min at 3000 rpm), homogeneity (mixing for 15 min at 36 rpm, anchor stirrer). The results obtained will be used to develop the composition and the manufacturing technology for a pharmaceutical composition with lidocaine hydrochloride, ceftriaxone and metronidazole.