. Author manuscript; available in PMC: 2015 Mar 28.

Published in final edited form as: J Control Release. 2014 Jan 11;178:46–54. doi: 10.1016/j.jconrel.2014.01.003

Table 2.

Texture properties and drug loading efficiency of pSiO₂-CO₂H:DNR particles

Particle	Particle size, µm			Porosity, %	Pore size, nm (SEM)^a	S_BET, m²/g	D_p, nm (BJH)	V_T, cm³/g	Drug loading, µg/mg
Particle	Width	Length	Thickness	Porosity, %	Pore size, nm (SEM)^a	S_BET, m²/g	D_p, nm (BJH)	V_T, cm³/g	Drug loading, µg/mg
A	31±7	46±10	17±2	50±2	15±2	209±4	12	0.61	75±5
B	27±6	40±10	17±2	60±3	26±5	216±1	21	1.02	N/A^c
C	23±4	37±6	13±2	73±3	43±7	168±1	45	1.44	71±5
D	15±2	20±5	13±1	76±3	95±17	154±2	45^b	1.84	80±6

BET: Brunauer-Emmett-Teller method

BJH: Barrett-Joyner-Halenda method

S_BET: specific surface area

V_T: total pore volume at relative pressure (P/P₀) equal to 0.99

D_p: pore diameter calculated from the adsorption branch of the isotherm by the BJH method

Pore size calculated from scanning electron microscope (SEM) images

Pore size in particle D is beyond the mesopore range (2–50 nm), thus beyond the detection limit for this sorption technique

Drug loading studies were not performed on this particle type