Novel biodegradable polyesteramide microspheres for controlled drug delivery in Ophthalmology



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Andrés Guerrero, Vanessa and Zong, Mengmeng and Ramsay, Eva and Rojas López, Blanca and Sarkhel, Sanjay and Gallego Collado, Beatriz Isabel and Hoz Montañana, Rosa de and Ramírez Sebastián, Ana Isabel and Salazar Corral, Juan José and Triviño Casado, Alberto and Ramirez Sebastian, Jose Manuel and Amo, Eva M. del and Cameron, Neil and Las Heras Polo, Beatriz de and Urtti, Arto and Mihov, George and Dias, Aylvin and Herrero Vanrell, Rocío (2015) Novel biodegradable polyesteramide microspheres for controlled drug delivery in Ophthalmology. Journal of Controlled Release, 211 . pp. 105-117. ISSN 0168-3659

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Most of the posterior segment diseases are chronic and multifactorial and require long-term intraocular medication. Conventional treatments of these pathologies consist of successive intraocular injections, which are associated with adverse effects. Successful therapy requires the development of new drug delivery systems able to release the active substance for a long term with a single administration. The present work involves the description of a new generation of microspheres based on poly(ester amide)s (PEA), which are novel polymers with improved biodegradability, processability and good thermal and mechanical properties. We report on the preparation of the PEA polymer, PEA microspheres (PEA Ms) and their characterization. PEA Ms (~ 15 μm) were loaded with a lipophilic drug (dexamethasone) (181.0 ± 2.4 μg DX/mg Ms). The in vitro release profile of the drug showed a constant delivery for at least 90 days. Based on the data from a performed in vitro release study, a kinetic ocular model to predict in vivo drug concentrations in a rabbit vitreous was built. According to the pharmacokinetic simulations, intravitreal injection of dexamethasone loaded PEA microspheres would provide release of the drug in rabbit eyes up to 3 months. Cytotoxicity studies in macrophages and retinal pigment epithelial cells revealed a good in vitro tolerance of the microsystems. After sterilization, PEA Ms were administered in vivo by subtenon and intravitreal injections in male Sprague–Dawley rats and the location of the microspheres in rat eyes was monitored. We conclude that PEA Ms provide an alternative delivery system for controlling the delivery of drugs to the eye, allowing a novel generation of microsphere design.

Item Type:Article
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Received 3 March 2015, Revised 18 May 2015, Accepted 19 May 2015, Available online 21 May 2015

Uncontrolled Keywords:Ocular drug delivery; Microspheres; Poly(ester amide); Tolerance; Dexamethasone; Intraocular injection
Subjects:Sciences > Chemistry > Chemistry, Organic
Medical sciences > Medicine > Pharmacology
Medical sciences > Medicine > Ophtalmology
ID Code:42046
Deposited On:03 Apr 2017 10:47
Last Modified:03 Apr 2017 15:49

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