title: Drug delivery into the skin by degradable particles.
abstract: Recently, it was demonstrated that particles could be utilized as carrier systems for drugs into the hair follicles. In the present study, a two-component drug delivery system is presented consisting of degradable particles loaded with fluorescein isothiocyanate and a separate protease formulation for degradation. The particles were applied alone, 30 min previous to the protease application and simultaneously with the protease onto porcine skin. Subsequently, biopsies were removed, and the penetration depths of the particles were analyzed using laser scanning microscopy. The obtained results demonstrate that the particles alone achieved a penetration depth of around 900 μm. Similar results were obtained for the successive application of particles and protease, whereas a release of the fluorescent dye was only observed in the upper 250 μm corresponding to the penetration depth of the protease. In the case of the simultaneous application, the particles were partly dissolved before application, leading to a reduced particle size and diminished penetration depth. The results revealed that degradable particles are a promising tool for drug delivery into the skin.
authors: Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong, China.
authors: Wing Cheung
authors: WC
authors: Mak
authors: Heike
authors: H
authors: Richter
authors: Alexa
authors: A
authors: Patzelt
authors: Wolfram
authors: W
authors: Sterry
authors: Kwok Kei
authors: KK
authors: Lai
authors: Reinhard
authors: R
authors: Renneberg
authors: Jürgen
authors: J
authors: Lademann
mesh_terms: D000818:Animals; D002119:Calcium Carbonate / Q000737:chemistry; D002417:Cattle; D003432:Cross-Linking Reagents / Q000737:chemistry; D004339:Drug Compounding; D016503:Drug Delivery Systems; D004353:Drug Evaluation, Preclinical; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism*; D018859:Hair Follicle / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D008405:Massage; D010316:Particle Size; D010447:Peptide Hydrolases / Q000737:chemistry / Q000378:metabolism; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption; D013552:Swine; D013997:Time Factors
chemical_list: D003432:Cross-Linking Reagents; D005456:Fluorescent Dyes; D010447:Peptide Hydrolases; D002119:Calcium Carbonate; D016650:Fluorescein-5-isothiocyanate