Development of sulconazole-loaded nanoemulsions for enhancement of transdermal permeation and antifungal activity

Figures & data

Figure 1 Solubility of SCZ in different oils, surfactants and co-surfactants. Results are represented as the mean±SD (n=3).

Abbreviations: IPM, isopropyl myristate; MCT, medium chain triglycerides; OP-10, octaphenyl polyoxyethyiene-10; PEG400, polyethylene glycol 400.

Figure 2 Pseudo-ternary phase diagrams of SCZ-NEs with different Km values (1:2, 1:1 and 2:1).

Abbreviations: SCZ-NEs, sulconazole-loaded nanoemulsions; Smix, mixed-surfactants; Km, surfactant: co-surfactant ratio.

Table 1 Particle size, PDI and appearance stability of SCZ-NEs with different O:S ratios

Formulations	Capryol 90 (%)	Smix (%) (Km=2:1)	Aqueous (%)	Particle size (nm)	PDI	Appearance
NE1	5	45	50	54.2±3.4	0.205±0.02	Limpid
NE2	10	40	50	86.5±5.7	0.256±0.07	Limpid
NE3	15	35	50	154±11.2	0.353±0.06	Limpid
NE4	20	30	50	236±15.6	0.523±0.12	Turbid
NE5	25	25	50	315±19.3	0.696±0.14	Turbid

Note: Results are represented as mean±SD (n=3).

Abbreviations: PDI, polydispersity index; O:S, oil/mixed-surfactant; SCZ-NEs, sulconazole-loaded in nanoemulsions; Smix, mixed-surfactant; km, surfactant:co-surfactant ratio.

Table 2 Particle size, PDI and appearance stability of SCZ-NEs with different proportions of aqueous phase

Formulations	Oil (%)	Smix (%) (Km=2:1)	Aqueous (%)	Particle size (nm)	PDI	Appearance
NE 6	7	63	30	92.1±4.6	0.323±0.05	limpid
NE 7	5	45	50	52.3±3.8	0.213±0.04	limpid
NE 8	3	27	70	36.7±2.7	0.137±0.02	limpid

Note: Results are represented as mean±SD (n=3).

Abbreviations: PDI, polydispersity index; SCZ-NEs, sulconazole-loaded in nanoemulsions; Smix, mixed-surfactant.

Table 3 Range of variables and their levels used in CCD

Independent variables	Unit	Code level
		−1.41	−1	0	1	1.41
Oil/mixed-surfactants ratio	w/w	1/9	1/8	1/6	1/4	1/3
Proportion of aqueous phase	%	50	55	60	65	70

Note: Optimization experiment was constructed by 2 factors and 5 levels.

Abbreviation: CCD, central composite design.

Table 4 Scheme of the central composite design: independent values, experimental values of the response variables and overall desirability (D)

Runs	Coded values		Responses				Desirability (D)
	X1	X2	Y1	Y2	Y3	Y4
1	−1	1	82.18	0.41	62.1	23.2	0.69
2	1	−1	88.53	0.36	82.6	15.3	0.38
3	0	0	93.87	0.39	68	19.3	0.63
4	0	−1.41	94.54	0.45	74	18.6	0.69
5	0	0	94.23	0.42	65.6	16.6	0.66
6	−1.41	0	86.57	0.43	45.3	27.3	0.92
7	1.41	0	79.11	0.33	90.7	12.6	0.16
8	−1	−1	84.8	0.41	59.4	25.9	0.77
9	0	0	92.15	0.4	67.3	15.9	0.58
10	1	1	74.3	0.32	73.7	17.2	0.27
11	0	1.41	60.2	0.32	61.3	20.5	0.30
12	0	0	96.2	0.4	69.6	16.4	0.61

Note: Experimental batch included 4 factorial runs, 4 axial runs and 4 center points.

Abbreviations: X₁, oil/mixed-surfactants ratio; X₂, proportion of aqueous phase; Y₁, encapsulation efficiency (%); Y₂, drug loading (%); Y₃, particle size (nm); Y₄, zeta potential (mV).

Table 5 ANOVA of quadratic model for the EE%, DL%, particle size and zeta potential responses

Factors	Y1		Y2		Y3		Y4
	Coefficient	P-value	Coefficient	P-value	Coefficient	P-value	Coefficient	P-value
Model	-	<0.05*	-	<0.05*	-	<0.01**	-	<0.01**
X1	−1.84	0.34	−0.04	<0.01**	12.38	<0.01**	−4.67	<0.0001***
X2	−8.18	<0.01**	−0.03	<0.05*	−3.02	0.13	0.24	0.65
X1X2	−2.9	0.29	<0.01	0.38	−2.9	0.27	1.15	0.15
X1^2	−5.05	<0.05*	−0.01	0.18	0.59	0.76	1.61	<0.05*
X2^2	−7.78	<0.01**	−0.01	0.18	0.42	0.83	1.41	<0.05*
R^2	0.8764		0.8692		0.9057		0.9466

Notes: The significance of the effect of independent variables on responses: *P<0.05; **P<0.01; ***P<0.0001.

Abbreviations: X₁, oil/mixed-surfactants ratio; X₂, proportion of aqueous phase; Y₁, encapsulation efficiency (%); Y₂, drug loading (%); Y₃, particle size (nm); Y₄, zeta potential (mV).

Figure 3 3D surface map of the responses from the central composite design calculations. (A) The effects of X₁ and X₂ on EE%. (B) The effects of X₁ and X₂ on DL%. (C) The effects of X₁ and X₂ on particle size. (D) The effects of X₁ and X₂ on zeta potential.

Abbreviations: X₁, oil/mixed-surfactant ratio; X₂, proportion of the aqueous phase; EE, encapsulation efficiency (%); DL, drug loading (%)

Figure 4 Particle size and morphology of the optimized SCZ-NE. (A) Particle size of the optimized SCZ-NE measured by DLS. (B) Morphology of the optimized SCZ-NE observed by TEM.

Abbreviations: SCZ-NEs, sulconazole-loaded nanoemulsions; DLS, dynamic light scattering; TEM, transmission electron microscopy.

Table 6 The particle size, zeta potential, DL% and EE% of the SCZ-NE during 14 days of storage at room temperature

Stability parameters	0th day	7th day	14th day
Particle size (nm)	50.23±3.3	53.51±3.2	51.16±3.6
Zeta potential (mV)	24.62±1.4	23.67±1.6	24.12±1.5
DL%	0.49±0.06	0.48±0.05	0.50±0.03
EE%	88.5±2.3	90.5±2.1	90.9±2.4

Note: Results are represented as mean±SD (n=3).

Abbreviations: DL, drug loading; EE, encapsulation efficiency.

Table 7 The Js, Qn and Kp of SCZ-NE, MCZ cream and SCZ-DMSO solution after permeating for 12 hrs

Parameters	SCZ-DMSO solution	MCZ cream	SCZ-NEs
Qn (μg/cm^2)	57.0±15.6	91.4±14.5	171.7±20.6**^,#
Js (μg/cm^2/h)	4.6±0.4	7.7±1.1	13.7±1.9**^,#
Kp×10^−3 (cm/h)	0.9±0.1	1.5±0.2	2.7±0.4**^,#

Notes: Results are represented as mean±SD (n=3); ^#P<0.05 vs MCZ cream; **P<0.01 vs SCZ DMSO solution.

Abbreviations: Qn, cumulative penetration quality; Js, penetration rate; Kp, permeability coefficient.

Figure 5 Ex vivo permeation profiles of the SCZ-NE, MCZ cream and SCZ DMSO solution. Results are represented as the mean±SD (n=5).

Abbreviations: SCZ-NEs, sulconazole-loaded nanoemulsions; MCZ cream, miconazole commercial reference.

Table 8 ZOIs against C. albicans and T. rubrum for the SCZ-NEs, MCZ cream, SCZ-DMSO solution and Blank NEs after incubation at 30°C for 48 hrs

Groups	Formulations	ZOI (mm)
		C. albicans	T. rubrum
A	SCZ-NEs	23.5±2.4*^, ##	20.4±2.5^#
B	MCZ cream	17.0±2.2	16.8±2.2
C	SCZ-DMSO solution	12.5±1.9	13.5±1.2
D	Blank NEs	0	0

Notes: Results are represented as mean±SD (n=3); *P<0.5 vs Group B; ^#P<0.5, ^##P<0.01 vs Group C.

Abbreviations: ZOI, zone of inhibition; SCZ-NEs, sulconazole-loaded in nanoemulsion; MCZ cream, miconazole commercial reference.

Figure 6 The zones of inhibition for the SCZ-NE, MCZ cream and SCZ DMSO solution. (A) The zones of inhibition for the SCZ-NE, MCZ cream and SCZ DMSO solution against C. albicans. (B) The zones of inhibition for the SCZ-NE, MCZ cream and SCZ DMSO solution against T. rubrum. The SCZ concentration in each formulation was 5 mg/ml. The results are represented as the mean±SD (n=3).

Abbreviations: SCZ-NEs, sulconazole-loaded in nanoemulsion; MCZ cream, miconazole commercial reference.