Smart Polymeric Nanofibers for Topical Delivery of Levothyroxine

Anahita Fathi Azarbayjani1, Jayarama Reddy Venugopal2, Seeram Ramakrishna2, Fung Chye Lim3, Yew Weng Chan4, Sui Yung Chan3

1National University of Singapore
2Division of Bioengineering, National University of Singapore
3Department of Pharmacy, National University of Singapore
4Department of Anaesthesiology, Singapore General Hospital


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.

J Pharm Pharm Sci, 13 (3): 400-410, 2010

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