Niosomes gel of apigenin to improve the topical delivery: development, optimization, ex vivo permeation, antioxidant study, and in vivo evaluation

Figures & data

Table 1. Composition of various an-NS batches and experimental & predicted values of responses.

Batch Code	Independent variables			Response
	Span 60 (mg)	CHO (mg)	HT (min)	Vesicle size (nm)	Entrapment Efficiency (%)
AN-NS1	70.00	10.00	60.00	338.73 ± 15.27	82.49 ± 1.48
AN-NS2	90.00	10.00	60.00	272.50 ± 12.49	86.19 ± 1.51
AN-NS3	70.00	20.00	60.00	430.21 ± 13.82	66.99 ± 1.27
AN-NS4	90.00	20.00	60.00	399.85 ± 15.21	80.06 ± 1.11
AN-NS5	70.00	15.00	45.00	367.27 ± 17.91	70.77 ± 1.38
AN-NS6	90.00	15.00	45.00	307.22 ± 21.46	81.17 ± 1.19
AN-NS7	70.00	15.00	75.00	315.24 ± 12.38	66.53 ± 1.91
AN-NS8	90.00	15.00	75.00	280.36 ± 9.73	72.1 ± 1.15
AN-NS9	80.00	10.00	45.00	310.48 ± 11.39	83.51 ± 0.94
AN-NS10	80.00	20.00	45.00	426.71 ± 17.91	72.46 ± 1.57
AN-NS11	80.00	10.00	75.00	280.24 ± 7.27	76.88 ± 2.83
AN-NS12	80.00	20.00	75.00	385.58 ± 15.83	65.04 ± 1.25
AN-NS13	80.00	15.00	60.00	340.43 ± 23.53	72.62 ± 1.02

*Value is expressed as mean ± SD, n = 3, CHO: Cholesterol; HT: Hydration time; Exp: Experimental; Pred: Predicted.

Figure 1. 3D response surface plots representing the effects of formulation variable on (A) Particle size and (B) Entrapment efficiency.

Table 2. Statistical model summary of selected dependent variables.

Formulation parameters	Regression parameters	Models			Best fitted model
		Linear	2FI	Quadratic
Vesicle size	SD	20.51	22.82	1.55	Quadratic model
	R²	0.8709	0.8837	0.9997
	Adjusted R²	0.8356	0.7964	0.9991
	Predicted R²	0.7237	0.3817	0.9949
	% CV	–	–	0.45
	Adeq Precision	9896.28	22149.02	181.86
	P-value	< 0.0001	0.8293	<0.0001
Entrapment efficiency	SD	3.25	3.23	0.79	Quadratic model
	R²	0.8056	0.8604	0.9948
	Adjusted R²	0.7525	0.7557	0.9854
	Predicted R²	0.5941	−0.3009	0.9781
	% CV	–	–	1.05
	Adeq Precision	242.07	416.95	13.07
	P-value	0.0003	0.4227	0.0005

Table 3. Analysis of variance (ANOVA) test for the experimental response.

	Vesicle size		Entrapment efficiency
Source	Sum of the square	P-value	Sum of the square	P-value
Model	35810.02	<0.0001*	593.32	<0.0001*
A	4446.25	<0.0001*	142.30	<0.0001*
B	23925.78	<0.0001*	249.98	<0.0001*
C	2823.76	<0.0001*	88.18	<0.0001*
AB	270.60	0.0001*	26.88	0.0012*
AC	157.50	0.0005*	5.83	0.0280*
BC	30.25	0.0162*	2.500E-005	0.9952**
A^2	154.40	0.0005*	6.73	0.0217*
B^2	2643.72	<0.0001*	42.17	0.0004*
C^2	1041.08	<0.0001*	26.13	0.0013*
Residual	11.94		3.11
Lack of Fit	11.27	0.0826**	0.44	0.9464**
Pure Error	0.67		2.67
Total	35821.96		596.43

*Significant α < 0.05, **Nonsignificant p > 0.05.

Figure 2. Optimisation by BBD showing the cube desirability graphs.

Figure 3. A) VS distribution graph, B) zeta potential graph of the an-NS2.

Figure 4. FTIR spectra of A) an, B) CHO, C) sapan-60, D) an-NS2.

Table 4. Composition of different an-NS gel and result of evaluation parameters.

Formulation code	Chitosan concentration (%w/v)	pH	Viscosity (cps)	Spreadability (g.cm/sec)	Drug content uniformity (%)
AN-NS2G1	1	6.5 ± 0.3	742 ± 12	17.33 ± 0.25	99.84 ± 0.76
AN-NS2G2	1.5	6.3 ± 0.2	1094 ± 15	14.83 ± 0.14	99.75 ± 0.65
AN-NS2G3	2	6.4 ± 0.1	1400 ± 10	11.82 ± 0.23	99.68 ± 0.92
AN-NS2G4	2.5	6.5 ± 0.2	2110 ± 14	10.40 ± 0.21	99.65 ± 0.53
AN-NS2G5	3	6.4 ± 0.1	3580 ± 25	7.74 ± 0.32	97.03 ± 1.21

Figure 5. A) Invitro release of an from the an-NS2, an-NS2G4, and an-gel, B) kinetic release models for an-NS2G4.

Figure 6. Ex-vivo rat skin permeation profile of an from the an-NS2G4 and an-gel.

Figure 7. Shows the A) antioxidant graph of pure an and an-NS2G4, (*p < 0.05, **p < 0.001 than pure an), and, B) antibacterial activity of pure an, an-gel, and an-NS2G4 against S. aureus and E. coli.

Figure 8. Shows the anti-inflammatory activity of pure an-gel, an-oral and an-NS2G4 in wistar albino rats. Bar showing the SD, **p < 0.001 compared diseases control ***p < 0.0001 compared to pure an-oral.

Table 5. Storage stability study results of optimised gel (an-NS2G4) at different storage conditions.

4 ± 1^○C
Duration (days)	pH	Colour	Viscosity (cps)	Spreadability (g.cm/sec)	Drug content (%)
0	6.5 ± 0.2	No change	2110 ± 17	10.40 ± 0.21	99.65 ± 0.53
30	6.3 ± 0.1	No change	2117 ± 14	10.38 ± 0.24	99.49 ± 0.43
60	6.4 ± 0.2	No change	2119 ± 13	10.38 ± 0.17	99.24 ± 0.65
90	6.2 ± 0.2	No change	2122 ± 10	10.36 ± 0.16	99.06 ± 0.72
25 ± 2^○C/60%RH
0	6.5 ± 0.1	No change	2110 ± 17	10.40 ± 0.21	99.65 ± 0.63
30	6.4 ± 0.1	No change	2106 ± 12	10.40 ± 0.19	99.54 ± 0.32
60	6.5 ± 0.2	No change	2108 ± 14	10.43 ± 0.13	99.40 ± 074
90	6.3 ± 0.2	No change	2100 ± 13	10.45 ± 0.15	99.23 ± 0.92

Data availability statement

All the data is present in the manuscript and available on request