Preparation and evaluation of ofloxacin-loaded palmitic acid solid lipid nanoparticles

Figures & data

Table 1 Physicochemical characteristics of ofloxacin-loaded solid lipid nanoparticles (mean ± SD, n = 3)

EE (%)	LC (%)	MD (nm)	PDI	ZP (mv)	RP (%)
41.36 ± 1.50	4.40 ± 0.16	156.33 ± 7.51	0.26 ± 0.04	−22.70 ± 1.40	1.28 ± 0.12

Abbreviations: EE, encapsulation efficiency; LC, loading capacity; MD, mean diameter; PDI, polydispersity index; ZP, zeta potential; RP, residual PVA.

Figure 1 Photographs of ofloxacin-loaded solid lipid nanoparticles: A) optical microscope (magnification ×400); B) scanning electron microscope.

Figure 2 In vitro release of native ofloxacin solution and ofloxacin-loaded solid lipid nanoparticles (SLN) (mean ± SD, n = 3).

Table 2 Minimal inhibitory concentrations (MIC) of ofloxacin (n = 3)

Ofloxacin	MIC (μg/mL)
	12 h	24 h	36 h	48 h
Native	0.2	0.4	0.5	0.5
Released	0.2	0.4	0.5	0.5
SLN-loaded	0.2	0.3	0.3	0.3

Abbreviation: SLN, solid lipid nanoparticles.

Figure 3 Plasma ofloxacin concentration–time curves after oral administration of ofloxacin-loaded solid lipid nanoparticles (SLN) and ofloxacin solution in mice (mean ± SD, n = 5). A) within 8 hours; B) from 8 to 72 hours.

Table 3 Pharmacokinetic parameters of ofloxacin after oral administration in mice (mean ± SD, n = 5)

Formulation	MRT (h)	AUC0–∞ (mg/h/L)	Cmax (μg/mL)	Tmax (h)	T1/2 ab (h)	T1/2el (h)
SLN	43.44 ± 13.36a	12.24 ± 1.50a	3.64 ± 0.48a	0.33a	0.06 ± 0.03a	28.72 ± 9.66a
Solution	10.50 ± 2.81	5.39 ± 0.45	1.12 ± 0.12	0.60 ± 0.22	0.17 ± 0.05	9.10 ± 1.63

Notes:

a Statistical significance compared with solution, P < 0.05.

Abbreviations: MRT, mean residence time; AUC_0–∞ area under the concentration–time curve from zero to infinity; C_max, maximal ofloxacin concentration in plasma; T_max, time to reach C_max; T_1/2ab, absorption half-life; T_1/2el, elimination half-life.

Figure 4 Percentage survival of mice infected with different inoculations of S. aureus (CCVCC2248). Inoculations: low dose: 3 × 10⁹ cfu/mL; medium dose: 6 × 10⁹ cfu/mL; high dose: 12 × 10⁹ cfu/mL.

Figure 5 Percentage survival of lethal dose infection mice treated with a single dose of ofloxacin-loaded solid lipid nanoparticles (SLN) or ofloxacin solution; A) 5 mg/kg; B) 10 mg/kg; C) 20 mg/kg. Ten mice were used for each treatment group.