Formulation and clinical evaluation of silymarin pluronic-lecithin organogels for treatment of atopic dermatitis

Figures & data

Table 1 Composition of different PLO gels loaded with silymarin

Ingredients	Formulation code
	F1	F2	F3	F4	F5	F6	F2*
Silymarin (gm)	0.2	0.2	0.2	0.2	0.2	0.2	0.2
Lecithin (gm)	3	3	3	5	7	9	3
Isopropyl myristate (mL)	100	100	100	100	100	100	100
Pluronic 127 (gm)	10	20	30	20	20	30	20
Water (mL)	100	100	100	100	100	100	100
Ascorbic acid (gm)	0.2	0.2	0.2	0.2	0.2	0.2	0.2

Notes: F1 to F6: using 30% ethyl alcohol as a solvent; F2*: using 3% DMSO as a solvent. All formulas contained 20% oil phase (lecithin and Isopropyl myristate) and 80% aqueous phase (pluronic and water/solvent).

Abbreviations: PLO, pluronic-lecithin organogel; DMSO, dimethyl sulfoxide.

Figure 1 FTIR spectroscopy.

Notes: Silymarin (A), PLO gel free base (B), drug loaded PLO gel (C).
Abbreviations: FTIR, Fourier transform infrared spectroscopy; PLO, pluronic-lecithin organogel.

Table 2 Physicochemical properties of different PLO gels loaded with silymarin

Parameters	Formulation code
	F2	F3	F4	F5	F6	F2*
(%) Drug content	98.3	101.2	99.4	99.2	99.6	99.1
pH	6.1	6.4	6.4	6.8	6.6	6.3
Drug content (%) after 3-month storage	98.2	100.9	99.1	98.5	99.4	99.2
Viscosity (cps)	2,350	4,420	3,070	3,330	3,530	2,365
Viscosity after relaxation (cps)	2,730	4,270	3,130	3,400	3,730	2,770

Notes: F2 to F6: using 30% ethyl alcohol as a solvent; F2*: using 3% DMSO as a solvent.

Abbreviations: PLO, pluronic-lecithin organogel; DMSO, dimethyl sulfoxide.

Figure 2 Rheology behaviors of different PLO gels loaded with silymarin.

Notes: F2 to F6: using 30% ethyl alcohol as a solvent; F2*: using 3% DMSO as a solvent.
Abbreviations: PLO, pluronic-lecithin organogel; DMSO, dimethyl sulfoxide.

Figure 3 In vitro release of silymarin from different formulations of PLO gels.

Notes: F2 to F6: using 30% ethyl alcohol as a solvent; F2*: using 3% DMSO as a solvent.
Abbreviations: PLO, pluronic-lecithin organogel; hr, hours; DMSO, dimethyl sulfoxide.

Figure 4 Ex vivo permeability release (XF2, XF2*) compared with the in vitro release (F2, F2*) of silymarin from PLO gels.

Note: F2, F2*, XF2, and XF2*: using 30% ethyl alcohol as a solvent.
Abbreviations: PLO, pluronic-lecithin organogel; hr, hours.

Table 3 Clinical phase, severity, and distribution of AD lesions among patients

Clinical phase	Infantile	Childhood	Adulthood
Number of cases	5 (33.3%)	7 (46.6%)	3 (20%)
Severity	Mild	Moderate	Severe
Number of cases	4 (26.7%)	6 (40%)	5 (33.3%)
Distribution	Face	Limbs	Trunk
Number of cases	10 (66.6%)	5 (33.3%)	2 (13.3%)

Abbreviation: AD, atopic dermatitis.

Figure 5 Photographs of different AD patients before and after treatment with silymarin loaded PLO gels.

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Figure 6 Comparison between control side and treated side with regards to itching.

Figure 7 Patient’s skin histology.

Notes: Before (A) and after (B) treatment with silymarin loaded PLO gels. Magnification= 100×; Scale bar= 200 μm.
Abbreviation: PLO, pluronic-lecithin organogel.