Improving Solubility and Bioavailability of Breviscapine with Mesoporous Silica Nanoparticles Prepared Using Ultrasound-Assisted Solution-Enhanced Dispersion by Supercritical Fluids Method

Figures & data

Figure 1 (A) Schematic diagram of the experimental apparatus for solubility measurement of breviscapine in supercritical CO2; (B) Schematic diagram of the apparatus used for ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Note: (A): 1, CO2 cylinder; 2, High-pressure syringe pump; 3, Temperature sensor; 4, Pressure sensor; 5, Saturation cell; 6, U-sample collection tube; 7, Circulating pump; 8, Thermostat; (B): 1, CO2 cylinder; 2, Refrigerator; 3, High-pressure pump; 4, Stabilization tank; 5, Pressure sensor; 6, Temperature sensor; 7, Ultrasonic rod; 8, Nozzle; 9, View vessel; 10, Filter; 11, Thermostats; 12, High-pressure constant flow pump; 13, Graduated flask; 14, Separator; 15, Wet gas meter.

Figure 2 Solubility of breviscapine in supercritical CO₂ under various conditions. (A) Pre-saturation time; (B) pressure; and (C) temperature.

Table 1 Coded Levels and Measured Responses for the 17 Experiment Formulation Runs

NO	X1 (MPa)	X2 (W)	X3	Size (nm) (Y1)	DL (%) (Y2)
1	13	30	0.19	223.3	7.54
2	19	30	0.19	207.1	6.75
3	13	90	0.19	190.4	7.97
4	19	90	0.19	188.2	8.03
5	13	60	0.13	160.9	4.91
6	19	60	0.13	173.7	5.76
7	13	60	0.25	193.1	8.89
8	19	60	0.25	202.3	9.06
9	16	30	0.13	175.8	5.72
10	16	90	0.13	162.6	6.07
11	16	30	0.25	217.4	8.46
12	16	90	0.25	178.2	8.31
13	16	60	0.19	170.6	8.26
14	16	60	0.19	169.3	8.12
15	16	60	0.19	167.3	8.37
16	16	60	0.19	174.4	8.04
17	16	60	0.19	174.1	8.15

Notes: X₁, Pressure; X₂, Ultrasound power; X₃, value of drug: carrier.

Abbreviation: DL, drug loading.

Table 2 Comparison of the Experimental and Predicted Values of BRE-MSNs-USEDS Under Predicted Optimum Conditions

Measured Responses	Predicted Values	Experimental Values	Bias (%)
Y1(Size)	174.32nm	177.24nm	−1.69
Y2(DL)	8.86%	8.63%	2.59

Note: Bias was calculated as (predicted value − observed value)/predicted value × 100%.

Figure 3 Response surface models showing the influence of the factors on the responses.

Notes: Three-dimensional response surface plots showing the effects of (X₂) ultrasound power and (X₃) value of drug: carrier on the responses of Y1 (A) and Y2 (B). Y1 is the response of the mean particle size. Y3 is the response of drug loading.

Table 3 The Particle Size, PDI, Zeta Potential and DL of the BRE-MSNs-SIV and BRE-MSNs-USEDS (n=3)

Sample	Particle Size (nm)	PDI	Zeta Potential (mV)	DL (%)
BRE-MSNs-SIV	221.31±7.18	0.154±0.012	−25.9±2.6	5.12±0.35
BRE-MSNs-USEDS	177.24±5.72*	0.269±0.016*	−27.3±2.9	8.63±0.44*

Note: *p ≤ 0.05 compared with the BRE-MSNs-SIV.

Abbreviations: PDI, polydispersity index; DL, drug loading; BRE-MSNs-SIV, breviscapine loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Figure 4 Transmission electron micrograph of BRE-MSNs-SIV and BRE-MSNs-USEDS.

Abbreviations: BRE-MSNs-SIV, breviscapine-loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine-loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Table 4 Material Properties of MSNs Analyzed by Nitrogen Adsorption–Desorption

Sample	BET Surface Area (m^2/g)	Pore Volume (m^3/g)	Pore Size (nm)
Blank-MSNs	1029.2	1.1	4.1
BRE-MSNs-SIV	511.5	0.4	2.7
BRE-MSNs-USEDS	456.3	0.3	2.5

Abbreviations: BET, Brunauer-Emmett-Teller; MSNs, mesoporous silica nanoparticles; BRE-MSNs-SIV, breviscapine loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Figure 5 The nitrogen adsorption–desorption isotherms of the blank MSNs, BRE-MSNs-SIV and BRE-MSNs-USEDS.

Abbreviations: MSNs, mesoporous silica nanoparticles; BRE-MSNs-SIV, breviscapine-loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine-loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Figure 6 (A) Differential scanning calorimetry analyses and (B) X-ray diffraction analyses of (a) BRE, (b) MSNs, (c) physical mixtures, (d) BRE-MSNs-SIV and (e) BRE-MSNs-USEDS.

Abbreviations: BRE, breviscapine; MSNs, mesoporous silica nanoparticles; BRE-MSNs-SIV, breviscapine-loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine-loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Figure 7 The concentration of residual methanol in BRE-MSNs prepared by different methods.

Abbreviations: BRE-MSNs, breviscapine-loaded mesoporous silica nanoparticles; BRE-MSNs-SIV, breviscapine-loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine-loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Figure 8 The accelerated stability studies for BRE-MSNs prepared by different methods.

Abbreviations: BRE-MSNs, breviscapine-loaded mesoporous silica nanoparticles; BRE-MSNs-SIV, breviscapine-loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine-loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Figure 9 In vitro release of BRE,BRE-MSNs-SIV and BRE-MSNs-USEDS in phosphate buffered solution (pH =6.8).

Abbreviations: BRE, breviscapine; BRE-MSNs-SIV, breviscapine-loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine-loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Table 5 Main Pharmacokinetic Parameters of the BRE Powder, BRE-MSNs-SIV and BRE-MSNs-USEDS After Oral Administration to Rats (n = 6)

Pharmacokinetic Parameters	BRE Powder	BRE-MSNs-SIV	BRE-MSNs-USEDS
Cmax (μg/mL)	0.46±0.03	1.00±0.20*	0.98±0.15*
Tmax (h)	1.17±0.26	0.96±0.29	1.17±0.41
MRT0-∞ (h)	7.65±1.79	5.13±0.45*	5.51±0.49*
AUC0–∞ (μg/h·mL)	3.07±1.17	5.21±0.81*	6.02±1.01*

Note: *p ≤ 0.05 compared with the pure BRE powder.

Abbreviations: BRE, breviscapine; MSNs, mesoporous silica nanoparticles; BRE-MSNs-SIV, breviscapine loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids; C_max, peak plasma concentration; T_max, time peak plasma concentration; MRT_0-∞, mean retention time; AUC_0-∞, area under the plasma concentration-time curve.

Figure 10 In vivo plasma concentration-time profiles. Levels of BRE following oral administration of BRE powder suspension, BRE-MSNs-SIV and BRE-MSNs-USEDS (n=6).

Abbreviations: BRE, breviscapine; BRE-MSNs-SIV, breviscapine-loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine-loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.

Figure 11 Results of the MTT assay with Caco-2 cells. Data are given as mean ± SD (n=6).

Abbreviations: BRE, breviscapine; MSNs, mesoporous silica nanoparticles; BRE-MSNs-SIV, breviscapine loaded mesoporous silica nanoparticles prepared by the solution impregnation-evaporation method; BRE-MSNs-USEDS, breviscapine loaded mesoporous silica nanoparticles prepared by the ultrasound-assisted solution-enhanced dispersion by supercritical fluids.