Microemulsions for oral delivery of insulin: Design, development and evaluation in streptozotocin induced diabetic rats

Sharma, G., Wilson, K. , van der Walle, C.F., Sattar, N. , Petrie, J.R. and Ravi Kumar, M.N.V. (2010) Microemulsions for oral delivery of insulin: Design, development and evaluation in streptozotocin induced diabetic rats. European Journal of Pharmaceutics and Biopharmaceutics, 76(2), pp. 159-169. (doi: 10.1016/j.ejpb.2010.07.002) (PMID:20655382)

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Insulin loaded microemulsions were developed adopting a low shear reverse micellar approach using didoceyldimethylammonium bromide (DMAB) as the surfactant, propylene glycol (PG) as the co-surfactant, triacetin (TA) as the oil phase and insulin solution as the aqueous phase. A ternary phase diagram was constructed based on multiple cloud point titration to highlight the reverse micellar region. The droplet sizes of the microemulsions were 161.7 ± 24.7 nm with PDI of 0.447 ± 0.076 and insulin entrapment of 85%. Transmission electron microscopy (TEM) revealed the spherical nature and size homogeneity of the microemulsion droplets. The conformational stability of the entrapped insulin within microemulsions was confirmed by fluorescence spectroscopy and circular dichroism. The microemulsions displayed a 10-fold enhancement in bioavailability compared with plain insulin solution administered per oral in healthy rats. The short-term in vivo efficacy in STZ induced diabetic rats provided the proof of concept by a modest glucose reduction at a dose of 20 IU/kg. Together this preliminary data indicate the promise of microemulsions for oral delivery of insulin.

Item Type:Articles
Additional Information:K.W. was supported by an EPSRC MRes studentship and G.S. by a University of Strathclyde Ph.D. studentship. Start-up funds from University of Strathclyde to M.N.V.R.K. are gratefully acknowl- edged, along with instrument support from the EPSRC, Grant Ref. EP/E036244/1.
Glasgow Author(s) Enlighten ID:Wilson, Dr Kathryn and Petrie, Professor John and Sattar, Professor Naveed
Authors: Sharma, G., Wilson, K., van der Walle, C.F., Sattar, N., Petrie, J.R., and Ravi Kumar, M.N.V.
College/School:College of Medical Veterinary and Life Sciences
College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
Journal Name:European Journal of Pharmaceutics and Biopharmaceutics
ISSN (Online):1873-344
Published Online:22 July 2010
Copyright Holders:Copyright © 2010 Elsevier
First Published:Fisrt published in European Jpurnal of Pharmaceutics and Biopharmaceutics 76 (2010)

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