Table 1.

Textural Parameters of pSi Microparticle Formulations

Sample	SBET, m2/g	VT, cm3/g Exp	CBET	Drug Loaded,* μg/mg
pSi†	458 ± 4	1.30	31	NA
pSi-COOH	385 ± 2	1.31	52	NA
pSi-C12	356 ± 2	0.82	27	NA
pSiO2-C8	260 ± 2	0.62	32	NA
pSiO2‡	217 ± 1	0.61	80	NA
pSi-COOH-RAP	268 ± 1	0.92	48	68 ± 8
pSi-C12-RAP	236 ± 2	0.56	24	36 ± 6
pSiO2-C8-RAP	204 ± 1	0.48	27	105 ± 18

C_BET, constant related to the affinity between the N₂ adsorbate molecules and the pSi surface; S_BET, specific surface area calculated at (P/P₀) 0.03–0.24; V_T, total pore volume at relative pressure (P/P₀) equal to 0.99.

^* Drug-loading capacity calculated by LC-MS analysis.

^† Freshly etched pSi.

^‡ Porous Si converted to fully oxidized to porous silica (SiO₂) by thermal oxidation in air at 800°C for 1 hour.