Formulation and optimization of nanoemulsion using antifungal lipid and surfactant for accentuated topical delivery of Amphotericin B

Figures & data

Figure 1. The solubility of AmB in various lipids and surfactants.

Figure 2. Photographs of the zone of inhibition: (A–C) the Petri plates revealing control, capmul PG8 (CPG8) and capmul MCM C8 (C8), respectively against C. albicans. (D–F) the Petri plates showing control, CPG8 and C-8, respectively against A. niger. The data represents the mean ± SD, (n = 3).

Table 1. Antifungal activities (zone of inhibition) against C. albicans and A. niger.

	ZOI (mm)
	Lipids and surfactants	A. niger	C. albicans
Capmul MCM L	17.0 ± 1.0	17.5 ± 0.5
Capmul MCM	12.0 ± 0.8	12.25 ± 0.9
Capmul MCM C8	13.4 ± 1.2	14.75 ± 1.4
Capmul PGMC	11.0 ± 0.6	15.5 ± 1.0
Capmul PG8	17.75 ± 1.2	22.25 ± 1.8
Miglyol 829	Nil	Nil
Labrasol	11.0 ± 0.4	12.2 ± 0.6
Transcutol P	Nil	Nil
Tween-80	Nil	Nil
Acconon C80	Nil	Nil
Cremophor-EL	Nil	Nil
PEG-400	Nil	Nil

The reported are mean ± sd (n = 3).

Figure 3. Pseudo-ternary phase diagrams of the optimized nanoemulsions delineated in different combinations of S_mix as (A) and (B) reveal S_mix ratio of 1:2 and 1:3, respectively.

Table 2. Composition and characterization of developed nanoemulsion with their size, zeta potential, polydispersity index and ZOI (zone of inhibition) values.

Formulation code	^aOil (% w/w)	^bSmix ratio	Aqueous (% w/w)	Mean droplet size (nm)	Polydispersity index	Zeta potential (mV)	ZOI (mm) A. niger	ZOI (mm) C. albicans
NE1	15	2:1	61	179.8 ± 5.5	0.54	−36.37	13.8 ± 1.0	15.3 ± 1.2
NE2	10	2:1	70	116.3 ± 4.7	0.68	−33.74	10.7 ± 0.8	13.4 ± 1.0
NE3	10	1:2	70	78.8 ± 2.0	0.36	−29.23	11.9 ± 0.8	14.5 ± 1.1
NE4	10	1:3	60	60.6 ± 1.3	0.31	−32.98	14.3 ± 1.2	16.2 ± 1.0
NE5	15	1:3	49	37.2 ± 1.2	0.29	−29.23	18.7 ± 1.5	20.9 ± 1.8
NE6	15	1:2	61	49.5 ± 1.5	0.33	−24.59	19.1 ± 1.4	22.6 ± 2.0

The value represented as mean ± SD (n = 3)

^a Capmul-PG8 as oil;

^b S_mix, lipid:surfactants ratio. Labrasol and PEG-400,  polyethylene glycol are surfactant and co-surfactant, respectively in each formulations.

Figure 4. Particle size, zeta potential and morphological studies of NE6: (A) particle size (nm) analysis, (B) zeta potential (mV), (C) transmission electron micrograph (TEM) of blank nanoemulsion and (D) TEM of drug-loaded nanoemulsion (AmB-NE6).

Figure 5. In vitro cumulative amount of Amphotericin B release through a dialysis membrane.

Figure 6. The cumulative amount of Amphotericin B across the albino rat skin using various formulations.

Table 3. Ex vivo permeation profile of different Amphotericin B formulations across the albino rat skin after 24 h of study.

Formulations	Jss^1(μg/cm^2/h)	ER^2	ER^3
AmB-NE6	22.88 ± 1.7	8.73	2.02
Fungisome (0.1%w/w)	11.05 ± 1.0	4.04	−
Ampotericin B solution	2.73 ± 0.02	−	−

Value represented as mean ± SD (n = 3).

Jss¹, transdermal flux, calculated from the slop of Cartesian plot of the cumulative amount of drug present in receptor compartment versus time; ER², enhancement ratio; it is the ratio of transdermal flux from formulation to drug solution. ER³, enhancement ratio; it is the ratio of transdermal flux from formulation to commercial cream fungisome.

Figure 7. The amount of drug deposited into the rat skin after ex vivo permeation study of various formulations and compared against commercial product Fungisome^® (0.01% w/w).

Figure 8. CLSM representative images depicting the penetration and distribution of Rhodamine-123 (Rh123) across albino rat skin after treatment: (A) Control Rh123 dye, (B) NE-Rh123 and (C) AmB-NE Rh123 after being applied for 8 h.