Design and development of solid lipid nanoparticles for topical delivery of an anti-fungal agent

Figures & data

Table 1.  Composition of various SLN formulations.

Formulation code	Composition				Parameters
	Tristearin:Soya Lecithin (%w/v)	Drug (mg)	Tween80 (%w/v)	Sonicationtime (min)	Particle size (nm)	Polydispersity index	% Drugentrapment
A	1:0.25	—	0.1	2	425.58 ± 10.5	0.38 ± 0.051	—
B	1:0.5	—	0.1	2	389.39 ± 8.74	0.34 ± 0.038	—
C	1:0.75	—	0.1	2	341.72 ± 5.48	0.29 ± 0.023	—
D	1:1	—	0.1	2	311.24 ± 7.20	0.24 ± 0.011	—
E	1:1.25	—	0.1	2	360.24 ± 8.29	0.44 ± 0.074	—
D1	1:1	5	0.1	2	322.20 ± 5.35	0.28 ± 0.020	87.62 ± 2.51
D2	1:1	10	0.1	2	326.63 ± 5.93	0.29 ± 0.031	89.35 ± 3.49
D3	1:1	15	0.1	2	328.84 ± 4.91	0.26 ± 0.019	92.74 ± 2.11
D4	1:1	20	0.1	2	352.79 ± 6.82	0.41 ± 0.081	84.95 ± 3.08
D31	1:1	15	0.5	2	305.57 ± 5.39	0.18 ± 0.011	92.81 ± 2.46
D32	1:1	15	1	2	292.53 ± 5.48	0.46 ± 0.051	88.47 ± 3.12
D33	1:1	15	2	2	255.27 ± 7.22	0.56 ± 0.072	83.68 ± 2.82
D311*	1:1	15	0.5	4	206.39 ± 9.37	0.21 ± 0.060	90.86 ± 5.20
D312	1:1	15	0.5	6	198.42 ± 11.48	0.45 ± 0.120	80.40 ± 3.40

* Optimized formulation, values represent mean ± SD (n = 3).

Figure 1.  SEM image of MN-loaded SLN.

Figure 2.  TEM image of MN-loaded SLN.

Figure 3.  In vitro dug release studies of different formulations.

Table 2.  Amount of MN permeated and retained in hairless rat skin from different formulations (tape stripping experiments).

S.No.	Formulation	Amount of MN permeated (µg/cm^2)	MN in tape strips (µg/cm^2)	% MN in skin after tape stripping
1	MN suspension	U.D.	11.4 ± 2.95	4.1 ± 1.18
2	MN hydrogel	U.D.	13.2 ± 3.52	5.8 ± 2.73
3	MN-loaded SLN-bearing hydrogel	U.D.	145.5 ± 6.84	65.3 ± 3.18

U.D. = Undetectable, values represent mean ± SD (n = 3).

Table 3.  Mean erythemal scores observed for various formulations.

Formulation	Erythemal scores (n = 3)
	24 hrs	48 hrs	72 hrs
Control (Group I)	0	0	0
MN suspension (Group II)	2	3	3
MN hydrogel (Group III)	1	2	2
MN-loaded SLN-bearing hydrogel (Group IV)	0	1	1

Table 4.  Colony forming unit of Candidia albicans in skin of rats after treatment with different formulations.

Treatment	No. of animals with positive culture/total no. of animals	Log CFU/infected sites
Control (Group I)	6/6	3.84 ± 0.47
MN suspension (Group II)	4/6	3.11 ± 0.34
MN hydrogel (Group III)	3/6	2.46 ± 0.21
MN-loaded SLN-bearing hydrogel (Group IV)	1/6	1.28 ± 0.09

Figure 4.  (a) Skin texture of rat skin for control at initiation of experiment, (b) Skin texture of rat skin for control after 6 days.

Figure 5.  Skin texture of rat skin after 6 days treatment with developed formulations: (a) MN suspension, (b) MN hydrogel, (c) MN-loaded SLN-bearing hydrogel.