The physicochemical properties, especially pH value of dental medicines, have significant influence on the health of oral cavity tissues. The pH of formulations should correspond to the value of saliva pH (5.5–8.0). For carbomer-based gels, the required pH value is obtained by neutralizing them with alkaline components, which leads to their structuring (thickening). This affects the physical properties of the gel, its residence time at the application site and the rate of release of active pharmaceutical ingredient. Therefore, the main purpose of this study is to evaluate the rheological, textural, and biopharmaceutical properties of Carbomer Polacril^® 40P-based dental gel depending on the pH value. Evaluation of the rheological properties of gel preparations were performed by measuring the structural viscosity of the samples as a function of pH and temperature. The textural properties of the gel were evaluated by performing tests regarding back extrusion and spreadability. Carbomer Polacril^® 40P-based gels haven’t shown noticeable thixotropic behavior, and were characterized by plastic flow in the whole studied pH range. The structural viscosity at the selected average pH value hasn’t differed at storage (25 °C) and application (37 °C) temperature. Texture studies of dental gels have shown a strong correlation with rheoparameters. Their rheological behavior and textural properties haven’t changed significantly between the pH range of 5.5–6.6. The relatively narrow range of working pH values does not affect the change in the viscosity of the preparation significantly and, consequently, does not affect the release of APIs from the developed Carbomer Polacril^® 40P-based dental gel.

Black, brown, and light peat and sapropel were analyzed as natural sources of organic and humic substances. These specific substances are applicable in industry, agriculture, the environment, and biomedicine with well-known and novel approaches. Analysis of the organic compounds fulvic acid, humic acid, and humin in different peat and sapropel extracts from Lithuania was performed in this study. The dominant organic compound was bis(tert-butyldimethylsilyl) carbonate, which varied from 6.90% to 25.68% in peat extracts. The highest mass fraction of malonic acid amide was in the sapropel extract; it varied from 12.44% to 26.84%. Significant amounts of acetohydroxamic, lactic, and glycolic acid derivatives were identified in peat and sapropel extracts. Comparing the two extraction methods, it was concluded that active maceration was more efficient than ultrasound extraction in yielding higher amounts of organic compounds. The highest amounts of fulvic acid (1%) and humic acid and humin (15.3%) were determined in pure brown peat samples. This research on humic substances is useful to characterize the peat of different origins, to develop possible aspects of standardization, and to describe potential of the chemical constituents.

The increased interest in functional materials of natural origin has resulted in a higher market demand for preservative-free, “clean label”, or natural ingredients-based products. The gummy bear food supplements are more acceptable to consumers and have fewer limitations compared to other dosage forms. The aim of our study was to produce natural ingredients-based gummy bear composition, and evaluate the influence of the selected ingredients on the product’s textural properties, its acceptance in vivo, and the gummy bear’s quality. The optimal base composition was determined using a surface response design: gelatin 4.3 g and agave syrup 6.3 g. The investigated sweeteners did not affect the textural properties (p > 0.05). However, further studies demonstrated that a 100% increase of agave results in up to 27% higher flexibility (p < 0.05). The addition of calcium and cholecalciferol reduced firmness by 59.59 ± 1.45% (p < 0.05). On the other hand, acai berry extract had no significant effect. The presence of calcium resulted in a decreased smell and taste; however, the data indicated that experimental texture analysis is a more accurate technique than in vivo evaluation. The acai berry extract did not improve all of the tested sensory properties. We can conclude that the suggested gummy bear base can be supplemented with various active ingredients and commercialized, though further studies are needed to investigate the other natural sources to mask the unpleasant taste of active ingredients and avoid water loss.

The formulation of biphasic gels as potential semi-solid carriers for hydrophilic and lipophilic active substances is promising for the development of pharmaceutical preparations. The aim of this study was to design a stable bigel composition and to determine the influence of the organogel/hydrogel ratio on the gel’s physical-chemical and structural-mechanical properties. The investigated compositions of organogel/hydrogel remained stable at ratios ranging from 5/95 to 40/60. After texture and microstructure analysis, bigels with 20/80 and 25/75 ratios were selected as carriers for the active ingredients, sodium diclofenac and camphor, for use as topical preparations for the treatment of muscle-joint inflammation and pain. Although other researchers have published data on the preparation and evaluation of bigels, there are no scientific results on the development of a two-phase gel with our proposed combination of APIs. Sodium diclofenac release was found to be higher when combined with camphor, which revealed the advantages of the biphasic formulation. The pseudoplastic behavior, thixotropy, and thermal stability of flow of the studied bigel samples was investigated by rheological analysis. Ongoing stability studies confirmed the minimal 6-month period.

Essential oils are volatile liquids which evaporate and lose their pharmacological effect when exposed to the environment. The aim of this study is to protect nutmeg essential oil from environmental factors by encapsulation (shell material, sodium alginate) and determine the influence of crosslinker concentration (2%, 5% calcium chloride), different emulsifiers (polysorbate 80, sucrose esters), and magnesium aluminometasilicate on microcapsule physical parameters, encapsulation efficiency (EE), swelling index (SI), and other parameters. Nutmeg essential oil (NEO)-loaded calcium alginate microcapsules were prepared by extrusion. The swelling test was performed with and without enzymes in simulated gastric, intestinal, and gastrointestinal media. This study shows that the crosslinker concentration has a significant influence on EE, with 2% calcium chloride solution being more effective than 5%, and capsules being softer with 2% crosslinker solution. Using sucrose esters, EE is higher when polysorbate 80 is used. The swelling index is nearly three times higher in an intestinal medium without enzymes than in the medium with pancreatin. Microcapsule physical parameters depend on the excipients: the hardest capsules were obtained with the biggest amount of sodium alginate; the largest with magnesium aluminometasilicate. Sucrose esters and magnesium aluminometasilicate are new materials used in extrusion.

Medicated chewing gums (MCGs) represent a beneficial platform for realizing drugs intended for dental prophylaxis and treatment. The present study aimed to investigate the impact of compression force on the mechanical, textural, release, and chewing perception characteristics of compressible MCGs with the combination of lysozyme hydrochloride (LH) and ascorbic acid (AsA). Four batches of MCGs were obtained on a laboratory single-punch tablet machine applying different forces, i.e., 5, 7, 10, and 15 kN, and evaluated by their geometrical parameters, mechanical resistance, surface and internal structure characteristics, texture profile, release behavior, and perception attributes during mastication. It was found that increasing compression force slightly affected resistance to crushing and friability of MCGs, but resulted in surface smoothing and formation of a thicker layer with highly compacted particle arrangement. According to the texture analysis, increasing compression force led to harder and more adhesive gums, indicating possible difficulties in chewing and, therefore, impairment of their consumer properties. Lower compression forces were also found to be preferable in terms of better drug release from the obtained chewing gums. The volunteers’ assessment showed that an increase of compression force led to significantly raising the initial hardness and crumbliness as well as to decreasing the rate of the integral gum mass formation during mastication, which may negatively affect perceptive sensations when using MCGs. Based on the results obtained, the optimal compressing force was selected to be 7 kN, which allows obtaining MCGs with good organoleptic, mechanical, textural, and release properties.