Klucel ef

API: GML-3 (Federal Research Center for Innovator and Emerging Biomedical and Pharmaceutical Technologies, Moscow, Russia). Release series: 14122023. Date of manufacture: 14 December 2023. Figure 1 shows the structural formula of GML-3.
Excipients (Es): Hydroxypropyl cellulose (Klucel LF, Klucel EF) were obtained from (Ashland GH Inc., Wilmington, DE, USA). Graft copolymer polyvinyl caprolactam-polyvinyl acetate polyethylene glycol (Soluplus^®) was obtained from (BASF AG, Ludwigshafen, Germany). PEG 4000 MW, powder, was obtained from (Merck Lifesciences, Budapest, Hungary).
Solvents: distilled water was obtained on the PE-2205 apparatus (Ecroskhim Ltd., St. Petersburg, Russia), and ethanol HP (99.5%, 0.005% maximum water) was obtained from (Merck KGaA AG, Darmstadt, Germany).

NAR ((2S)-5,7-dihydroxy-2-(4-hydroxyphenyl)-2,3-dihydro-4H-chromen-4-one, purity ≥ 98%, lot MKCD1056) was obtained from Sigma-Aldrich (St. Louis, MO, USA). The polymer Parteck^® MXP (PVA, polyvinyl alcohol, lot F1952064) was donated by Merck (Darmstadt, Germany). Klucel EF (HPC, hydroxypropylcellulose, lot 40915) and Soluplus^® (SOL, polyvinyl-caprolactam-polyvinyl-acetate-polyethyleneglycol, lot 844143368EO) were donated by Ashland Specialty Ingredients (Covington, LA, USA) and BASF (Ludwigshafen, Germany), respectively. Glycerin (GLY, lot 58591) and Tween 80 (polysorbate, lot 105896) were obtained from Dinâmica^® (Sao Paulo, Brazil). Skin from porcine ears was obtained from a local slaughterhouse (Via Carnes Indústria e Comércio, Brasilia, Brazil). The whole skin was removed from the outer region of the ear, separated from its underlying layer, and used full thickness.

The SRV-MMF varnish was formulated according to methods previously described by Friedman et al. [27 (link)], with the pharmaceutical adaptations of dissolving 31.79 mg of mometasone furoate (MMF) (M2354, Tokyo Chemical Industry, Tokyo, Japan), 2.1749 g of Eudragit RL (Hercules Inc., Wilmington, DE, USA), 0.3209 g of polyethylene glycol 400 (PEG400; 202398; Sigma, St. Louis, MO, USA), and 0.649 g of hydroxypropylcellulose (Klucel EF, Ashland Specialty Ingredients, Switzerland) in 5 mL of absolute ethanol, resulting in the formation of a dry film containing 1.0% mometasone furoate, 10.1% PEG400, 68.5% Eudragit RL, and 20.4% Klucel EF. The placebo varnish (SRV-Placebo) was prepared identically to the experimental SRV, omitting the active ingredient from the formulation.