Improving chemical stability of resveratrol in hot melt extrusion based on formation of eutectic with nicotinamide

Tamarind seed polysaccharide-guar gum buccal films loaded with resveratrol-bovine serum albumin nanoparticles: Preparation, characterization, and mucoadhesiveness assessment

Mucoadhesive films based on tamarind seed polysaccharide and guar gum (TSP-GG) were formulated for buccal delivery of resveratrol. Resveratrol-bovine serum albumin nanoparticles (Res-BSA) were prepared and dispersed in TSP-GG to improve its buccal mucoadhesiveness. The impregnation of Res-BSA induced the dense internal structures of TSP-GG and improved its strength and rigidity. Structural characterization showed that resveratrol existed in an amorphous state in the films containing Res-BSA, and hydrogen bonding was formed between Res-BSA and the film matrices. The films containing Res-BSA exhibited good uniformity in thickness, weight, and resveratrol content, and their surface pH was near neutral, ranging between 6.78 and 7.09. Increasing Res-BSA content reduced the water contact angle of TSP-GG (from 75.9° to 59.6°). The swelling and erosion studies indicated the favorable hydration capacity and erosion resistance of the films containing Res-BSA. Additionally, the addition of Res-BSA imparted enhanced ex vivo mucoadhesive force, in the range of 1.53 N to 1.98 N, and extended ex vivo residence time, between 17.9 h and 18.9 h, to TSP-GG. The current study implied that the composite systems of TSP-GG and Res-BSA may be a novel platform for buccal mucosal delivery of resveratrol.

Reduced Graphene Oxide/Cellulose Sodium Aerogel-Supported Eutectic Phase Change Material Gel Demonstrating Superior Energy Conversion and Storage Capacity toward High-Performance Personal Thermal Management

By virtue of their capacity to absorb and release energy during the phase change process, phase change materials (PCMs) are ideal for personal thermal management (PTM). The combination of reduced graphene oxide/cellulose sodium aerogel (rGCA) and lauric acid/myristic acid binary eutectic phase change gel (LMG) creates a composite phase change material that possesses outstanding photothermal conversion capabilities, electro-thermal conversion capabilities, energy storage capabilities, and shape-stable performance. The results showed that rGCA had a maximum adsorption efficiency of 99.7% with a melting latent heat of 124.6 J g-1. The high absorption rate of rGCA to LMG is a result of the capillary force, pore characteristics, hydrogen bonding, and the π-π interaction. Notably, rGCA and LMG composite material (rGCG) exhibited an excellent photothermal conversion efficiency of 96.5% and electro-thermal conversion of 82.3%. Results indicate that binary eutectic phase change materials are more suitable for temperature regulation than single phase change materials, making them more suitable for PTM. It is anticipated that the innovative thermal comfort solution, which provides thermal shielding, thermal energy storage, self-supporting characteristics, and wearability, will offer new possibilities for the next generation of wearable PTMs.

A drug-drug cocrystal and a co-amorphous form, prepared from honokiol and ligustrazine, inspired by Chinese patent medicine

A drug-drug cocrystal created with two antithrombotic-active ingredients from herbs, honokiol (HON) and ligustrazine (TMP, 1:1), was synthesized and characterized. The structure of HON-TMP (1:1) was determined by single-crystal X-ray diffraction. Then co-amorphous HON-TMP was prepared by honey-assisted grinding, which was inspired by a grinding process for a Chinese patent medicine-Shijunzi honey pill. This co-amorphous drug-drug cocrystal (20% honey) exhibits improved solubility over HON and a significantly reduced sublimation tendency than TMP.

Hot Melt Extrusion for Improving the Physicochemical Properties of Polydatin Derived from Polygoni cuspidati Extract; A Solution Recommended for Buccal Applications

Three different types of solid dispersions based on polyvinyl polymers and related copolymers (Kollidon® VA64, Soluplus® and Kollicoat IR®) comprising polydatin-rich Polygoni cuspidati extract were prepared by hot melt extrusion. The systems were characterized using X-ray powder diffraction, infrared spectroscopy as well as by polydatin release and in vitro permeability. Mucoadhesive tablets were prepared from the extrudates based on Kollidon® VA64 and Soluplus® to obtain a suitable pharmaceutical form, where (hydroxypropyl)methyl cellulose was added as a mucoadhesive agent. The tablets were evaluated in terms of the kinetics of polydatin release as well as their mucoadhesive properties. The best tabletability properties, polydatin release profile and adequate mucoadhesive properties were obtained by the formulation containing the Kollidon® VA64-based extrudate, which makes it an excellent prototype for enhancing the release of poorly water-soluble compounds.

Thermal investigation on hydrated co-amorphous systems of nicotinamide and prilocaine

It is generally recognized that water, acting as a plasticizer, increases molecular mobility, leading to a decrease of the glass transition temperature (T_g) in amorphous systems. However, an anti-plasticizing effect of water was recently observed on prilocaine (PRL). This effect might be used in co-amorphous systems to moderate the plasticizing effect of water. Nicotinamide (NIC) can form co-amorphous systems with PRL. In order to investigate the effect of water on these co-amorphous systems, the T_gs and molecular mobility of hydrated co-amorphous NIC-PRL systems were compared with those of the respective anhydrous systems. Molecular mobility was estimated by considering the enthalpic recovery at the T_g using the Kohlrausch-Williams-Watts (KWW) equation. At molar ratios of NIC above 0.2, a plasticizing effect of water on co-amorphous NIC-PRL systems was observed with increasing the NIC concentration. In contrast, at molar ratios of NIC of 0.2 and below, water had an anti-plasticizing effect on the co-amorphous NIC-PRL systems, with increased T_gs and reduced mobility upon hydration.

Hot-melt extrudability of amorphous solid dispersions of flubendazole-copovidone: An exploratory study of the effect of drug loading and the balance of adjuvants on extrudability and dissolution

The FDA-approved anthelmintic flubendazole has shown potential to be repositioned to treat cancer and dry macular degeneration; however, its poor water solubility limits its use. Amorphous solid dispersions may overcome this challenge, but the balance of excipients may impact the preparation method and drug release. The purpose of this study was to evaluate the influence of adjuvants and drug loading on the development of an amorphous solid dispersion of flubendazole-copovidone by hot-melt extrusion. The drug, copovidone, and adjuvants (magnesium stearate and hydroxypropyl cellulose) mixtures were statistically designed, and the process was performed in a twin-screw extruder. The study showed that flubendazole and copovidone mixtures were highly extrudable, except when drug loading was high (>40%). Furthermore, magnesium stearate positively impacted the extrusion and was more effective than hydroxypropyl cellulose. The extruded materials were evaluated by modulated differential scanning calorimetry and X-ray powder diffraction, obtaining positive amorphization and physical stability results. Pair distribution function analysis indicated the presence of drug-rich domains with medium-range order structure and no evidence of polymer-drug interaction. All extrudates presented faster dissolution (HCl, pH 1.2) than pure flubendazole, and both adjuvants had a notable influence on the dissolution rate. In conclusion, hot-melt extrusion may be a viable option to obtain stable flubendazole:copovidone amorphous dispersions.