Preparation of honokiol-loaded chitosan microparticles via spray-drying method intended for pulmonary delivery

Figures & data

Table 1.  Process yield and water content of prepared powders with different formulations.

Honokiol nanoparticle (g)	Chitosan/mannitol (w/w)	Yield (%)	Drug content (%)	Water content (%)
0.15	1:2	30.4 ± 1.2	6.98 ± 0.62	4.53 ± 1.36
0.15	1:4	40.7 ± 1.8	4.17 ± 0.55	5.28 ± 0.43
0.15	1:6	42.7 ± 1.5	3.12 ± 0.30	3.82 ± 0.35
0.15	1:8	48.4 ± 2.1	2.65 ± 0.58	4.25 ± 1.06

Figure 1.  Typical scanning electron micrographs (SEM) of spray-dried powders with different formulations. (A) Honokiol nanoparticles loaded chitosan/mannitol (w/w, 1:2) microparticles, (B) Honokiol nanoparticles loaded chitosan/mannitol (w/w, 1:4) microparticles, (C) Honokiol nanoparticles loaded chitosan/ mannitol (w/w, 1:6) microparticles, (D) Honokiol nanoparticles loaded chitosan/mannitol (w/w, 1:8) microparticles.

Table 2.  Physical characterization of obtained powders with different formulations.

Chitosan/mannitol (w/w) microparticles	Mean particles size (μm)	Tapped density (g/cm^3)	Carr’s index		Aerodynamic diameter (dae, μm)
			(%)	flowability
1:2	7.25 ± 0.32	0.18 ± 0.02	34.07	Poor	3.26 ± 0.21
1:4	6.95 ± 0.37	0.15  ± 0.07	13.52	Good	2.82 ± 0.32
1:6	8.03 ± 0.66	0.15 ± 0.07	16.53	Good	2.89 ± 0.46
1:8	8.48 ± 0.11	0.14 ± 0.05	22.23	Poor	3.32 ± 0.12

Figure 2.  FTIR spectra of chitosan (A), mannitol (B), honokiol nanoparticles (C), and corresponding physical mixtures (D), and honokiol nanoparticles load microparticles (E).

Figure 3.  In vitro release profile of the spray-dried powders with different formulations in PBS (pH7.4) at 37°C. (▪) Formulation of powders with chitosan/mannitol (1:8); (•) Formulation of powders with chitosan/mannitol (1:6); (▴) Formulation of powders with chitosan/mannitol (1:4); (▾) Formulation of powders with chitosan/mannitol (1:2).