Table 1.

Particle size and specific surface area parameters for ultrasonic spray freeze-dried and lyophilized recombinant human epithelial growth factor liposomal dry powders (mean ± standard deviation; n=3)

Formulation process	Sucrose to phospholipid ratio	Mean particle size (μm)	Specific surface area (m2/g)
Ultrasonic spray freeze drying	1:1	3.37±0.41	72.5±4.87
	2:1	2.39±0.47	108.7±7.34
	3:1	5.88±0.86	54.2±4.26
	4:1	8.10±1.02	43.5±3.22
Lyophilization	1:1	7.78±0.79	1.55±0.21
	2:1	8.25±0.93	1.51±0.18
	3:1	11.24±1.21	1.20±0.10
	4:1	18.31±1.44	0.92±0.09