High performance cyclone

2 g of DA form II
and PRO was dissolved at a stoichiometric molar ratio of 1:1 (1.440
g of DA and 0.560 g of PRO), either solely or codissolved with 20,
60, and 100 mg of polymer, respectively (Table 1), in 40 mL of ethanol at 65 °C in a
50 mL DURAN closed bottle (DWK LIFE SCIENCE, Mainz, Germany). The
bottle with the suspension was kept in a water bath at 65 °C,
heated by a hot plate. The suspension in the bottle was stirred at
600 rpm. Once the suspension became clear, the solution was kept at
65 °C and spray-dried using a Büchi Mini Spray Dryer B-290
(Büchi, Flawil, Switzerland) with a high-performance cyclone
(Büchi, Flawil, Switzerland) running in open mode. A two-fluid
nozzle with a 1.5 mm nozzle cap and a 0.7 mm nozzle tip was used.
Solutions were spray-dried at an inlet temperature of 78 °C,
an aspirator rate of 100% (35 m³/h), an atomization rate
of 667 L/h, and a liquid feed rate of 10% (3 mL/min). The outlet temperature
was in the range of 48–54 °C.

Spray-dried formulation of 3-IAld, containing mannitol as excipient at 2:1 w/w ratio, was prepared using a mini spray-dryer model B-290 (Büchi, Switzerland). Solution of 3-IAld:mannitol was prepared in water/ethanol (50:50 v/v). Spray-drying was performed, in co-current mode, by a spray-dryer equipped with a 2-fluid nozzle having a 0.7 mm nozzle tip and a 1.5 mm diameter nozzle cap. The operating spray drying parameters were as follows: inlet temperature 75 °C, air flow rate 301 L/h, 2.4 mL/min feed rate and aspirator rate of 20 m³/h. Briefly, 3-IAld was dispersed in the ethanol solvent and allowed to solubilize under magnetic stirring before adding into mannitol water solution. The obtained dried powders were recovered by using a high-performance cyclone (Büchi, Switzerland).

Synthesis of nano-Ca(OH)₂ was performed by the addition of 3 M NaOH aqueous solution to a 1.5 M CaCl₂ aqueous solution dropwise under high power ultrasound radiation for 1 h while an inert gas (Helium) was flowing into the solution. After the synthesis, the precipitate was centrifuged and washed, by using deionized water three times to eliminate NaCl residues. An ultrasound generator used for the synthesis is a titanium horn type 750 W (20 kHz), Sonics and materials VCX750, with a tip diameter of 13 mm and with amplitude of 50%. The Ultrasound generator has a power of 750 Watt and for 1 h of synthesis produces 0.313 kg of CO₂, according to the method IPCC GWP 100 YEARS. CaCl₂ and NaOH were purchased from Sigma-Aldrich and used as received without further purification. The synthesized nano-Ca(OH)₂ solution was nebulized by using the Mini Spray-dryer model B-290 (BUCHI Italia s.r.l, Cornaredo (MI), Italy) to obtain a dried nano-Ca(OH)₂ powder. The spry-drying operating parameters were set as follows: inlet temperature of 135 °C, aspiration of 65%, air flow of 40 bar, and a feed rate of 10%. Ca(OH)₂ particles were separated from the drying gas by a high-performance cyclone (Büchi, Italy).

NPs were incorporated into nanocomposite microparticles (NCMPs) by spray-drying, as previously described by Kunda et al. [30 (link)]. Briefly, NPs were suspended in l-leucine solution at a NPs-to-carrier ratio of 1:1.5 w/w and spray-dried at a feed rate of 10% with an atomizing air flow of 400 L/h, aspirator capacity of 100%, and an inlet temperature of 100 °C (outlet temperature of 45–47 °C). A Büchi B-290 mini spray-dryer (Büchi Labortechnik, Flawil, Switzerland) with a nozzle atomizer diameter of 0.7 mm and a high-performance cyclone (Büchi Labortechnik) were used to separate the dry particles (NCMPs) from the air stream. The NCMPs were collected and stored in a desiccator until further use.

The enteric MPs were prepared using Eudragit^® L100-to-S100 (Rohm Pharma GmbH, Darmstadt, Germany) ratio of 1:2 with the addition EC (30% w/w, ETHOCEL std. 7, Dow Chemical Company, Milan, Italy) as described [19 (link)]. The 3-IAld (Sigma-Aldrich, Milan, Italy) and the polymers were dissolved in ethanol at a feedstock concentration of 3% w/v and spray-dried, at the inlet temperature of 75 °C, using a mini spray-dryer model B-290 (Büchi, Italy) in co-current mode, equipped with a two-fluid nozzle having a 0.7 mm nozzle tip and a 1.5 mm diameter nozzle cap. Aspirator capacity was maintained at 20 m³/h, air flow rate was 301 L/h, and feed rate 2.4 mL/min. The obtained dried MP were recovered by using a high-performance cyclone (Büchi, Milan, Italy).