Development of a simple paste for 3D printing of drug formulations containing a mesoporous material loaded with a poorly water-soluble drug.

Poorly soluble drugs represent a substantial portion of emerging drug candidates, posing significant challenges for pharmaceutical formulators. One promising method to enhance the drug's dissolution rate and, consequently, bioavailability involves transforming them into an amorphous state within mesoporous materials. These materials can then be seamlessly integrated into personalized drug formulations using Additive Manufacturing (AM) techniques, most commonly via Fused Deposition Modeling. Another innovative approach within the realm of AM for mesoporous material-based formulations is semi-solid extrusion (SSE). This study showcases the feasibility of a straightforward yet groundbreaking hybrid 3D printing system employing SSE to incorporate drug-loaded mesoporous magnesium carbonate (MMC) into two different drug formulations, each designed for distinct administration routes. MMC was loaded with the poorly water-soluble drug ibuprofen via a solvent evaporation method and mixed with PEG 400 as a binder and lubricant, facilitating subsequent SSE. The formulation is non-aqueous, unlike most pastes which are used for SSE, and thus is beneficial for the incorporation of poorly water-soluble drugs. The 3D printing process yielded tablets for oral administration and suppositories for rectal administration, which were then analyzed for their dissolution behavior in biorelevant media. These investigations revealed enhancements in the dissolution kinetics of the amorphous drug-loaded MMC formulations. Furthermore, an impressive drug loading of 15.3 % w/w of the total formulation was achieved, marking the highest reported loading for SSE formulations incorporating mesoporous materials to stabilize drugs in their amorphous state by a wide margin. This simple formulation containing PEG 400 also showed advantages over other aqueous formulations for SSE in that the formulations did not exhibit weight loss or changes in size or form during the curing process post-printing. These results underscore the substantial potential of this innovative hybrid 3D printing system for the development of drug dosage forms, particularly for improving the release profile of poorly water-soluble drugs.

Chitosan nanocomposite coatings with enhanced corrosion inhibition effects for copper.

A biopolymer coating on copper was prepared based on chitosan nanocomposite and its corrosion inhibition efficiency was investigated. Inclusion of silica nanoparticles substantially reduces swelling ratio of chitosan coating while enhancing its thermal stability. The corrosion resistance of chitosan-based coatings is improved by introducing 2-mercaptobenzothiazole and silica in the matrix. It is found that upon crosslinking the chitosan coatings, a higher corrosion resistance could be achieved and the highest inhibition efficiency for chitosan nanocomposite coatings is calculated as 85%. The corrosion mechanism is found closely related to mass transition and diffusion process, and also the polarization resistance contributes to the impedance. Calculated impedance using Kramers-Kronig transformation shows good agreement with experimental values, thus validating the impedance measurements. This study exhibits the enhanced efficiency of nanocomposite and potential of chitosan coatings in corrosion prevention for copper.