Haripriya Kalluri1, Ajay K Banga. 1. Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Mercer University, 3001 Mercer University Drive, Atlanta, Georgia 30341, USA.
Abstract
PURPOSE: To characterize the microchannels created in hairless rat skin by microneedles and investigate their closure following exposure to different occlusive conditions. METHODS: Maltose microneedles were characterized by scanning electron microscopy. The microchannels created and their closure when exposed to different conditions was investigated using a variety of techniques. RESULTS: Microscopic imaging indicates a pyramidal geometry of maltose microneedles with an average length of 559 ± 14 μm and tip radius of 4 μm. Upon insertion into skin, they created microchannels with an average surface diameter of 60 μm and an average depth of 160 ± 20 μm as observed by histological sectioning and confocal microscopy. Skin recovers its barrier function within 3-4 hrs, and microchannels closed within 15 hrs of poration when exposed to environment. However, when occluded, the microchannels remained open for up to 72 hrs in vivo, as observed by calcein imaging, transepidermal water loss measurements and methylene blue staining. CONCLUSION: Maltose microneedles penetrated the stratum corneum barrier and created microchannels in skin which completely close within 15 hrs after poration. However, under occluded conditions, barrier recovery can be delayed for up to 72 hrs in vivo.
PURPOSE: To characterize the microchannels created in hairless rat skin by microneedles and investigate their closure following exposure to different occlusive conditions. METHODS:Maltose microneedles were characterized by scanning electron microscopy. The microchannels created and their closure when exposed to different conditions was investigated using a variety of techniques. RESULTS: Microscopic imaging indicates a pyramidal geometry of maltose microneedles with an average length of 559 ± 14 μm and tip radius of 4 μm. Upon insertion into skin, they created microchannels with an average surface diameter of 60 μm and an average depth of 160 ± 20 μm as observed by histological sectioning and confocal microscopy. Skin recovers its barrier function within 3-4 hrs, and microchannels closed within 15 hrs of poration when exposed to environment. However, when occluded, the microchannels remained open for up to 72 hrs in vivo, as observed by calcein imaging, transepidermal water loss measurements and methylene blue staining. CONCLUSION:Maltose microneedles penetrated the stratum corneum barrier and created microchannels in skin which completely close within 15 hrs after poration. However, under occluded conditions, barrier recovery can be delayed for up to 72 hrs in vivo.
Authors: Devin V McAllister; Ping M Wang; Shawn P Davis; Jung-Hwan Park; Paul J Canatella; Mark G Allen; Mark R Prausnitz Journal: Proc Natl Acad Sci U S A Date: 2003-11-17 Impact factor: 11.205
Authors: Michel Cormier; Bonny Johnson; Mahmoud Ameri; Kofi Nyam; Luz Libiran; Dee Dee Zhang; Pete Daddona Journal: J Control Release Date: 2004-07-07 Impact factor: 9.776
Authors: Jean-Pierre Hachem; Mao-Quiang Man; Debra Crumrine; Yoshikazu Uchida; Barbara E Brown; Vera Rogiers; Diane Roseeuw; Kenneth R Feingold; Peter M Elias Journal: J Invest Dermatol Date: 2005-09 Impact factor: 8.551
Authors: Ryan F Donnelly; Karen Mooney; Maelíosa T C McCrudden; Eva M Vicente-Pérez; Luc Belaid; Patricia González-Vázquez; James C McElnay; A David Woolfson Journal: J Pharm Sci Date: 2014-03-14 Impact factor: 3.534
Authors: Ryan F Donnelly; Kurtis Moffatt; Ahlam Zaid Alkilani; Eva M Vicente-Pérez; Johanne Barry; Maelíosa T C McCrudden; A David Woolfson Journal: Pharm Res Date: 2014-02-19 Impact factor: 4.200
Authors: Yasmine A Gomaa; Martin J Garland; Fiona J McInnes; Ryan F Donnelly; Labiba K El-Khordagui; Clive G Wilson Journal: Int J Pharm Date: 2012-08-30 Impact factor: 5.875