Chitosan is a promising naturally derived polysaccharide to be used in hydrogel forms for pharmaceutical and biomedical applications. The multifunctional chitosan-based hydrogels have attractive properties such as the ability to encapsulate, carry, and release the drug, biocompatibility, biodegradability, and non-immunogenicity. In this review, the advanced functions of the chitosan-based hydrogels are summarized, with emphasis on fabrications and resultant properties reported in literature from the recent decade. The recent progress in the applications of drug delivery, tissue engineering, disease treatments, and biosensors are reviewed. Current challenges and future development direction of the chitosan-based hydrogels for pharmaceutical and biomedical applications are prospected.

Cellulose-based materials have attracted great attention due to the demand for eco-friendly materials and renewable energy alternatives. An increase in the use of these materials is expected in the coming years due to progressive decline in the supply of petrochemicals. Based on the limitations of cellulose in terms of dissolution/processing, and focused on green chemistry, new cellulose production techniques are emerging, such as dissolution and functionalization in ionic liquids which are known as green solvents. This review summarizes the recent ionic liquids used in processing cellulose, including pretreatment, hydrolysis, functionalization, and conversion into bio-based platform chemicals. The recent literatures investigating the progress that ILs have made in their transition from academia to commercial application of cellulosic biomass are also reviewed.

Chito-oligosaccharides (COSs) are the partially hydrolyzed products of chitin, which is abundant in the shells of crustaceans, the cuticles of insects, and the cell walls of fungi. These oligosaccharides have received immense interest in the last few decades due to their highly promising bioactivities, such as their anti-microbial, anti-tumor, and anti-inflammatory properties. Regarding environmental concerns, COSs are obtained by enzymatic hydrolysis by chitinase under milder conditions compared to the typical chemical degradation. This review provides updated information about research on new chitinase derived from various sources, including bacteria, fungi, plants, and animals, employed for the efficient production of COSs. The route to industrialization of these chitinases and COS products is also described.

A gel-based floating matrix tablet was formulated and evaluated using the sublimation technique to enhance gastroretentive drug delivery. Anhydrous theophylline was employed as the active pharmaceutical ingredient, combined with sublimation agents and hydroxypropyl methylcellulose as the gel-forming polymer. The resulting tablets exhibited high porosity, immediate floatation, and sustained buoyancy for over 8 h. Optimization of the floating behavior and drug release profiles was achieved by adjusting the viscosity of and hydroxypropyl methylcellulose and the concentration of sublimation agents, specifically ammonium carbonate and menthol. These agents were selected for their effectiveness in creating a porous structure, thus reducing tablet density and enhancing floatation. Higher HPMC viscosity resulted in increased floating force, slower drug release, and improved swelling properties due to a slower erosion rate. A critical assessment of the balance between tablet porosity, mechanical strength, and drug release kinetics indicates that ammonium carbonate provided superior tablet hardness and lower friability compared to menthol, favoring a controlled release mechanism. The release dynamics of theophylline were best described by the anomalous (non-Fickian) diffusion model, suggesting a combined effect of diffusion and erosion. This research advances the development of gastroretentive drug delivery systems, highlighting the potential of sublimation-based floating matrix tablets for sustained drug release.

This study investigated the formulation and performance characteristics of compressed toothpaste tablets incorporating magnolia bark extract and varying concentrations of hydrated silica. The tablets were prepared using a direct compression method. The effects of hydrated silica content on key performance parameters, including physicochemical properties, cleaning efficacy, antimicrobial activity, and stability, were evaluated. Increasing concentrations of hydrated silica in the powder formulation reduced its flowability, as evidenced by decreases in the compressibility index, Hausner's ratio, and angle of repose. Upon compression into tablets, higher silica content resulted in reduced tablet hardness without significantly affecting friability or foaming properties. All formulations complied with pharmacopoeial standards for weight variation, hardness, and friability. The tablet containing 15% w/w hydrated silica demonstrated a cleaning efficacy of 50.31%, closely comparable to conventional paste-based toothpaste (54.99%). The optimized formulation exhibited a Relative Dentin Abrasivity (RDA) of 84.15 and a Relative Enamel Abrasivity (REA) of 8.23, indicating a medium abrasive level suitable for daily use. Accelerated stability testing showed no changes in the tablet's physical properties; however, a slight reduction in flavor intensity was observed over time. Antimicrobial assessments revealed that tablets containing magnolia bark extract produced inhibition zones against Streptococcus mutans comparable to those achieved with chlorhexidine. These findings offer valuable insights into the development of environmentally sustainable oral care products that maintain therapeutic efficacy while incorporating natural antimicrobial agents.