Mucopenetrating polymer - Lipid hybrid nanovesicles as subunits in alginate beads as an oral formulation.

Crossing the intestinal mucus layer remains a great hurdle in oral drug delivery. The viscous mucus gel protects the body from pathogens but simultaneously traps many types of delivery vehicles, limiting their therapeutic efficacy. We report the assembly of mucopenetrating PEG-based polymer-lipid hybrid vesicles encapsulated in mucoadhesive alginate carriers aiming to increase their residence time in the intestine. The stability of the formulations was evaluated in simulated gastrointestinal conditions, showing negligible subunit leakage in the gastric fluid but a substantial release in the intestinal fluid. Mucopenetration of the free and encapsulated subunits was first demonstrated in vitro in a microfluidic set-up filled with reconstituted porcine mucus and in a mucus-covered co-culture of Caco-2 cells and HT29-MTX-E12 cells. Finally, the free and encapsulated subunits remained adhered in close proximity to the intestinal epithelium after oral administration to rats while the alginate carriers were washed away. In conclusion, the double-encapsulated system with combined mucoadhesive and mucopenetrating properties is a promising alternative drug carrier for oral delivery.

Process development of continuous glycerolysis in an immobilized enzyme-packed reactor for industrial monoacylglycerol production.

Continuous and easily operated glycerolysis was studied in different lipase-packed columns to evaluate the most potential process set-ups for industrial monoacylglycerol (MAG) production. Practical design-related issues such as enzyme-filling degree, required reaction time, mass transfer investigations, and capacity and stability of the enzyme were evaluated. A commercially available immobilized Candida antarctica lipase B was used to catalyze the glycerolysis reaction between glycerol and sunflower oil dissolved in a binary tert-butanol: tert-pentanol medium. Considering easy handling of the enzyme and measured expansion when wetted with a reaction mixture, a filling degree of 52 vol % dry enzymes particles per column volume seemed appropriate. Twenty minutes was required to reach equilibrium conditions with a MAG content of 50-55 wt %. Only insignificant indications of mass transfer limitations were observed. Hence, the commercial lipase seemed adequate to use in its available particle size distribution ranging from 300 to 900 microm. A column length-to-diameter ratio of less than 25 did not interfere with the transfer of the fluid mixture through the column. Under the tested conditions, the enzyme could be active for approximately 92 days before enzyme renewal was needed. This corresponds to a very high enzyme capacity with approximately 2000 L pure MAG produced per kg enzyme.