Improved antibacterial function of Rifampicin-loaded solid lipid nanoparticles on Brucella abortus

Figures & data

Table 1. Physicochemical properties of some formulations.

Test	Stearic acid (mg)	Poloxamer 407 (mg)	Lipoid S-100 (mg)	Size (nm)	Sonication time (min)	PDI	ZP	Stability
F1	100	40	75	607.2	10	0.493	−25	Drug-leakage
F2	150	75	100	365.7	10	0.336	−24.3	Drug-leakage
F3	150	50	100	408.3	10	0.393	−25.1	Drug-leakage
F4	150	100	150	633	10	0.706	−22.8	Moderate stability
F5	200	100	150	374.9	10	0.335	−23	Moderate stability
F6	200	150	50	488.3	5	0.283	−15.8	Moderate stability
F7	250	100	150	346.9	5	0.423	−52	Moderate stability
F8	150	75	100	362.2	5	0.347	−41	Moderate stability
F9	300	100	50	430.9	3	0.267	−16.7	Stable
F10	400	150	50	319.7	3	0.204	−18.4	Stable

Table 2. Spectral numbers of each substance and Rif-SLNs.

Spectral numbers in Stearic acid	933–528	1311–1099	–	–	–	–	1704	2917–2849
Spectral numbers in free Rifampicin	941–528	1243–1000	1331	1375	1455–1425	1644	1726	2938–2880	3401
Spectral numbers in Pploxamer 407	963–522	1281–1060	1468–1343			–	–	2890	–
Spectral numbers in Lipoid S-100	969–722	1245–1090	1466–1377			1735–1651		2933–2854	3397
Spectral numbers in Rif-SLNs	997–538	1311–1030	1332	1355	1463	–	1702	2917–2849	3501–3351

Table 3. Rif-SLNs dispersion stability trend in different times and temperatures based on size, PDI, ZP and appearance form.

Time and temperature	Zero time	1 month 25 °C	3 months 4 °C	6 months 4 °C	9 months 4 °C	Average
Size (nm)	321.7	347.1	387.5	387.7	384.3	365.66
PDI (diameter)	0.204	0.257	0.258	0.323	0.327	0.273
Zp (mV)	−18.4	−14.5	−9.3	−19.0	−23.3	−16.9
Appearance (color and turbidity)	Orange, no turbidity	Orange, no turbidity	Orange, no turbidity	Orange, no turbidity	Orange, no turbidity	Desirable

Figure 1. Size and PDI optimum formulation (F10).

Figure 2. ZP of optimum formulation (F10).

Figure 3. Agar Well Diffusion test on B. abortus 544; Rif- SLNs (A–C), free Rifampicin (D,E), Blank SLN (C–F) and Rifampicin 5-μg disk (C).

Figure 4. Rifampicin standard internal curve.

Figure 5. Retention time of Rif-SLNs peak.

Figure 6. Rif-SLNs thermograms and its constituent ingredients.

Figure 7. Comparison of spectral numbers of raw materials with Rif-SLNs.

Figure 8. Image of Rif-SLNs electron microscope.

Figure 9. Release test of Rif-SLNs and free Rifampicin.

Figure 10. Toxicity test of Rif-SLNs.

Figure 11. Toxicity test of free Rifampicin.

Figure 12. The effect comparison of free Rifampicin and Rif-SLNs on J774 A(0).1 infected with B. abortus 544.

Figure 13. Free Rifampicin MIC after 24 h (A) and 72 h (B).

Figure 14. Rif-SLNS MIC after 24 h (C) and 72 h (D).

Table 4. Comparing results at different times (24, 48 and 72 h) in two groups (free Rifampicin and Rif-SLNs).

Free Rifampicin and Rif-SLNs
24 h	48 h	72 h
p = .001	p = .001	p = .002

Table 5. Variations process at different times (24, 48 and 72 h) in two groups (free Rifampicin and Rif-SLNs).

Group 1 (Rif-SLNs)		Group 2 (free Rifampicin)
Absorbance (h)	p value	Absorbance (h)	p value
24 and 48	p = .11*	24 and 48	p = .02*
24 and 72	p = .17	24 and 72	p < .01
48 and 72	p = .03*	48 and 72	p = .01*