title: Preparation and evaluation of a timolol maleate drug-resin ophthalmic suspension as a sustained-release formulation in vitro and in vivo.
abstract: The aim of this work was to assess the performance of resin as an ocular delivery system. Timolol maleate (TM) was chosen as the model drug and an ion exchange resin (IER) as the carrier. The drug-resin complex was prepared using an oscillation method and then characterized regarding particle size, zeta potential, morphology, and drug content. After in vitro drug release study and corneal permeation study were performed, in vivo studies were performed in New Zealand albino rabbits using a suspension with particles sized 4.8 ± 1.2 μm and drug loading at 43.00 ± 0.09%. The results indicate that drug released from the drug-resin ophthalmic suspension permeated the cornea and displayed a sustained-release behavior. Drug levels in the ocular tissues after administration of the drug-resin ophthalmic suspension were significantly higher than after treatment with an eye drop formulation but were lower in body tissues and in the plasma. In conclusion, resins have great potential as effective ocular drug delivery carriers to increase ocular bioavailability of timolol while simultaneously reducing systemic drug absorption.
authors.affiliation: a Department of Pharmacy , The Second Affiliated Hospital of Zhengzhou University , Zhengzhou , Henan , China .
authors.forename: Fuhong
authors.initials: F
authors.lastname: Qin
authors.affiliation: b School of Pharmaceutical Sciences, Zhengzhou University , Zhengzhou , Henan , China .
authors.forename: Li
authors.initials: L
authors.lastname: Zeng
authors.affiliation: b School of Pharmaceutical Sciences, Zhengzhou University , Zhengzhou , Henan , China .
authors.forename: Yongtao
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: c Department of Pharmacy , Henan Provincial People's Hospital , Zhengzhou , Henan , China , and.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Cao
authors.affiliation: d Department of Pharmacy , Luohe Central Hospital , Luohe , Henan , China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Wang
authors.affiliation: b School of Pharmaceutical Sciences, Zhengzhou University , Zhengzhou , Henan , China .
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000138:chemical synthesis / Q000378:metabolism; D000818:Animals; D002626:Chemistry, Pharmaceutical; D003315:Cornea / Q000187:drug effects* / Q000378:metabolism; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000378:metabolism; D004337:Drug Carriers / Q000008:administration & dosage / Q000138:chemical synthesis / Q000378:metabolism; D007475:Ion Exchange Resins / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000378:metabolism; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D013535:Suspensions; D013999:Timolol / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000378:metabolism
chemical_list: D000319:Adrenergic beta-Antagonists; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D007475:Ion Exchange Resins; D009883:Ophthalmic Solutions; D013535:Suspensions; D013999:Timolol
keywords: Ion exchange resin; ophthalmic drug delivery; pharmacokinetics; sustained-release; tissue distribution toxicity