Transdermal delivery of forskolin from emulsions differing in droplet size.

Transdermal delivery of forskolin from emulsions differing in droplet size.

Colloids and surfaces. B, Biointerfaces (2015-01-27)

Elżbieta Sikora, Meritxell Llinas, Maria Jose Garcia-Celma, Elvira Escribano, Conxita Solans

PMID25620442

ABSTRACT

The skin permeation of forskolin, a diterpene isolated from Coleus forsholii, was studied using oil in water (O/W) emulsions as delivery formulations and also an oil solution for comparative purposes. Two forskolin-loaded emulsions of water/Brij 72:Symperonic A7/Miglyol 812:Isohexadecane, at 0.075 wt% forskolin concentration were prepared with the same composition and only differing in droplet size (0.38 μm and 10 μm). The emulsions showed high kinetic stability at 25 °C. In vitro study of forskolin penetration through human skin was carried out using the MicroettePlus(®) system. The concentration of the active in the receptor solution (i.e. ethanol/phosphate buffer 40/60, v/v) was analyzed by high performance liquid chromatography with UV detection. The obtained results showed that forskolin permeation from the emulsions and the oil solution, through human skin, was very high (up to 72.10%), and no effect of droplet size was observed.

MATERIALS

Product Number

Brand

Product Description

02857

Sigma-Aldrich

Ethanol, purum, fine spirit, denaturated with 4.8% methanol, F25 METHYL¹, ~96% (based on denaturant-free substance)

02882

Sigma-Aldrich

Ethanol, purum, absolute ethanol, denaturated with 2% 2-butanone, A15 MEK¹, ≥99.8% (based on denaturant-free substance)

110086

Sigma-Aldrich

Acetonitrile, ReagentPlus^®, 99%

P0662

Sigma-Aldrich

Potassium phosphate monobasic, ACS reagent, ≥99.0%

04243

Sigma-Aldrich

Potassium phosphate monobasic, meets analytical specification of Ph. Eur., NF, E340, anhydrous, 98-100.5% (calc. to the dried substance)

02870

Sigma-Aldrich

Ethanol, ACS reagent, prima fine spirit, without additive, F15 o¹

34998

Sigma-Aldrich

Acetonitrile, HPLC Plus, ≥99.9%

439134

Sigma-Aldrich

Acetonitrile, suitable for HPLC, gradient grade, ≥99.9%

34851

Sigma-Aldrich

Acetonitrile, suitable for HPLC, gradient grade, ≥99.9%

34881

Sigma-Aldrich

Acetonitrile, suitable for HPLC-GC, ≥99.8% (GC)

1601340

USP

Residual Solvent Class 2 - Acetonitrile, United States Pharmacopeia (USP) Reference Standard

1551139

USP

Monobasic potassium phosphate, United States Pharmacopeia (USP) Reference Standard

34442

Sigma-Aldrich

Acetonitrile, suitable for DNA synthesis, ≥99.9% (GC)

32221

Sigma-Aldrich

Ethanol, puriss. p.a., absolute, ≥99.8% (GC)

459844

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, ACS reagent, ≥99.5%

493546

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, meets USP testing specifications

494445

Sigma-Aldrich

Acetonitrile, biotech. grade, ≥99.93%

60220

Sigma-Aldrich

Potassium phosphate monobasic, buffer substance, anhydrous, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., 99.5-100.5%

01-0645

Sigma-Aldrich

Acetonitrile, for chromatography

09-0851

Sigma-Aldrich

Ethanol, ≥99.5%, suitable for HPLC

24-5290

Sigma-Aldrich

Potassium phosphate monobasic, ≥99.5%

01-0620

Sigma-Aldrich

Acetonitrile, ≥99.8%, for residue analysis, JIS 300

09-0830

Sigma-Aldrich

Ethanol, JIS 300, ≥99.5%, for residue analysis

01-0590

Sigma-Aldrich

Acetonitrile, JIS special grade, ≥99.5%

09-0832

Sigma-Aldrich

Ethanol, JIS 1000, ≥99.5%, for residue analysis

01-0600

Sigma-Aldrich

Acetonitrile, SAJ first grade, ≥99.0%

09-0850

Sigma-Aldrich

Ethanol, ≥99.5%, suitable for absorption spectrum analysis

09-0852

Sigma-Aldrich

Ethanol, ≥99.5%

01-0622

Sigma-Aldrich

Acetonitrile, ≥99.8%, for residue analysis, JIS 1000

09-0853

Sigma-Aldrich

Ethanol, ≥99.5%, suitable for fluorescence