Modulyo freeze dryer

FNPs were obtained by following an already reported process, the HPH [15 (link),33 (link)]. Briefly, a PHEA-RhB-PLA-PEG dispersion in dichloromethane at a concentration of 17 mg/mL (6 mL) was used as organic phase and mixed by stirring at 20,500 rpm with an aqueous phase (50 mL). After dilution by addition of bidistilled water (50 mL), the o/w emulsion was homogenized one time at 7500 psi by using an EmulsiFlex TM-C5 as homogenizer (Avestin Inc., Ottawa, ON, Canada). Evaporation of organic solvent under reduced pressure by using a evaporation system constituted by a water bath B-480, a rotavapor R-114, a Recirculating Chiller F-105 and a Vacuum Controller V-800 (Buchi) allows to obtain FNPs. Finally, each FNP batch was dried by using a Modulyo freeze-dryer (Labconco Corporation, Kansas City, MO 64132, USA) after the addition of PVP as cryoprotectant at a nanoparticle/PVP weight ratio equal to 1:1, and stored as fluffy powder at −20 °C for successive characterization.

Drying of the nanoparticle dispersion, containing 1 wt% Man, was carried out by freeze-drying using a Modulyo freeze-dryer (Labconco Corporation, Kansas City, MO, USA), and by spray-drying using a Büchi Nano Spray Dryer B-90 (Büchi, Milan, Italy).
The morphology of spray-dried particles was evaluated using a Phenom™ ProX Desktop SEM microscope.

High-pressure homogenization (HPH) was used as procedure to obtain PHEA-PLA-PEG₂₀₀₀ based nanoparticles (NPs) [13 (link)]. Based on this method, a PHEA-PLA-PEG₂₀₀₀ dispersion in dichloromethane at a concentration of 16.7 mg/mL (6 mL) was used as organic phase and mixed by stirring at 20,500 rpm with an aqueous phase (50 mL) containing Pluronic F68 (15 mg). After addition of bidistilled water (25 mL), the oil in water (o/w) emulsion was homogenized four times at 7500 psi by using an EmulsiFlexTM-C5 as a homogenizer (Avestin Inc., Ottawa, ON, Canada). Evaporation of organic solvent under reduced pressure by using a evaporation system constituted by a water bath B-480, a rotavapor R-114, an F-105 recirculating chiller and a V-800 vacuum controller (Buchi) allows obtaining empty NPs. FP-loaded NPs were prepared by dissolving the drug in the organic phase at a copolymer/drug weight ratio of 100:8.7 before starting, and then following the procedure described above. Once obtained, the NP dispersion was centrifuged at 8000 rpm for 10 min. Finally, each NP batch was dried by using a Modulyo freeze-dryer (Labconco Corporation, Kansas City, MO 64132, USA) after the addition of trehalose as a cryoprotectant at a nanoparticle/trehalose weight ratio equal to 1:1, and stored at −20 °C for successive characterization.