donepezil (E 2022 / TK023 / TK 023)

Donepezil nanocrystals-incorporated carboxymethyl cellulose nanopaste for high-payload transdermal delivery with improved skin compatibility.

Yang In Gyu IG, Heo Jae Yoon JY, Myung Jin Hyuk JH, Jeong Min Young MY et al.

Donepezil (DPZ), an acetylcholinesterase inhibitor for Alzheimer's disease, suffers from skin irritation during transdermal delivery. Herein, a drug high-payload nanopaste (NP) system was designed employing carboxymethyl cellulose (CMC) to enhance transdermal delivery of DPZ while mitigating cutaneous irritation. DPZ NPs (10, 20, and 27.5% w/v) were fabricated via wet bead-milling with low-molecular-weight CMC (90 K) to obtain submicron particles, followed by incorporation into high-molecular-weight CMC (700 K) matrix. The drug nanocrystals were uniformly distributed in the CMC matrix, preserving crystal size (505.6-563.8 nm), zeta potential (-48.93 to -51.95 mV), and crystallinity. Fourier-transform infrared analysis revealed the electrostatic interaction between the anionic polymers and drug nanocrystals. Pharmacokinetic evaluations in rats revealed that while the 10% NP achieved systemic absorption comparable to the commercial patch, the 20% NP provided a 2.1-fold higher transdermal absorption. Level A IVIVC analysis established a robust correlation (R2 > 0.96) between in vitro dissolution profile and in vivo absorption. Crucially, the CMC-based NPs showed markedly improved dermal tolerability, showing minimal hyperplasia and inflammation compared to acrylic-based commercial patches. Additionally, NPs were chemically stable under accelerated conditions without antioxidants. These findings suggest that CMC-based NP system of DPZ represents a biocompatible transdermal platform for long-term Alzheimer's therapy.

sQUIZ your knowledge! A long-lasting hypopigmented patch on a young adult.

Fialho Maria Cristina MC, Ferreirinha Ana A, Fernandes Cândida C

Symptomatic Inlet Patch as a Cause of Chronic Cough and Dysphagia: A Case Report.

Aznar Ruiz Elena E, Zataraín Vallés Ana A, Aparicio Cabezudo Marta M, García Pravia Laura L et al.

A Flexible PPDO-co-PEG-Based Copolymer Tissue Patch with High Interfacial and Cohesive Strength for Reliable Sealing and Rapid Closure of Wet Tissue.

Yan Lan-Xi LX, Zhang Jie J, Chen Xiao-Hu XH, Cao Yu-Tao YT et al.

Tissue patches have gained widespread attention for their ability to rapidly and effectively close tissue wounds. Nevertheless, maintaining robust adhesive strength under physiological conditions remains a significant challenge for current tissue adhesion materials. Herein, a tissue patch material based on a poly(p-dioxanone)-co-poly(ethylene glycol) (PPDO-co-PEG) copolymer is reported. This copolymer is engineered to exhibit a rigid-to-flexible transition property, with N-hydroxysuccinimide (NHS) groups grafted onto its backbone as adhesive functional moieties. The semi-crystalline structure of the PPDO segments enhances cohesive strength, while PEG segments provide segmental mobility under physiological conditions, enabling NHS to penetrate irregular tissue interfaces and react with surface primary amine groups. Therefore, the patch exhibits excellent tissue adhesion performance, with dry and wet adhesive strength of 2.59 MPa and 189.6 kPa, respectively. Furthermore, the patch has the potential for multifunctional applications, such as effectively sealing wounds in multiple organs with outstanding pressure-resistant stability (326 mmHg), while also offering rapid hemostasis and accelerated tissue healing. In summary, this study presents a feasible design strategy for flexible, high-adhesion tissue patches, which show promising potential for clinical applications in wound management and tissue repair.