title: Smart polymeric nanofibers for topical delivery of levothyroxine.
abstract: Topical administration of levothyroxine (T₄) helps to reduces deposits of adipose tissue on skin. The question is whether topical application of T₄ could lead to systemic effects. In the present study a series of nanofibrous membranes were electrospun into blends of poly vinyl alcohol (PVA) and poly-N-isopropylacrylamide (PNIPAM) to develop a sustained topical delivery of T₄. The polymeric nanofiber mats were characterized by field emission scanning electron microscopy (FESEM) and fourier transform infrared (FTIR) spectroscopy. In vitro permeation of the drug from the polymeric nanofibers was studied using excised human skin and the permeation mechanism investigated using confocal microscopy. It was observed that polymeric nanofibers were able to sustain the penetration of T₄ to the skin and help maintain the effective drug concentration in the skin layers for longer period of time. These formulations may have potential uses in topical skin products and can help to increase the accumulation of the active compound on the skin surface thus minimize the adverse side effects which may be caused by systemic absorption. This may result in great improvement in consumer compliance, avoid frequent dosing and enhance the therapeutic effectiveness.
authors.affiliation: Department of Pharmacy, National University of Singapore, 18, Science Drive 4, 117543, Singapore.
authors.forename: Anahita Fathi
authors.initials: AF
authors.lastname: Azarbayjani
authors.forename: Jayarama Reddy
authors.initials: JR
authors.lastname: Venugopal
authors.forename: Seeram
authors.initials: S
authors.lastname: Ramakrishna
authors.forename: Perry Fung Chye
authors.initials: PF
authors.lastname: Lim
authors.forename: Yew Weng
authors.initials: YW
authors.lastname: Chan
authors.forename: Sui Yung
authors.initials: SY
authors.lastname: Chan
mesh_terms: D000180:Acrylic Resins; D000287:Administration, Topical; D019793:Fluorescein; D020249:Hormone Replacement Therapy; D006801:Humans; D007211:Indoles; D008855:Microscopy, Electron, Scanning; D057139:Nanofibers; D011142:Polyvinyl Alcohol; D012867:Skin / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013974:Thyroxine / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D000180:Acrylic Resins; D007211:Indoles; C052970:poly-N-isopropylacrylamide; C007293:DAPI; D011142:Polyvinyl Alcohol; D013974:Thyroxine; D019793:Fluorescein