title: Indomethacin electrospun nanofibers for colonic drug delivery: In vitro dissolution studies.
abstract: Generally, although the conventional drug delivery systems, such as using only pH-dependent polymers or time-dependent release systems are popular, the individuals' variations of physiological conditions usually lead to premature or imperfect drug release from each of these systems. Therefore, a combination of pH- and time-dependent polymers could be more reliable for delivering drugs to the lower GI tract such as colon. To this end, electrospinning method was used as a fabrication approach for preparing electrospun nanofibers of indomethacin aimed for colon delivery. Formulations were prepared based on a 32full factorial design. Independent variables were the drug:polymer ratio (with the levels of 3:5, 4.5:5 and 6:5w/w) and Eudragit S:Eudragit RS w/w ratio (20:80, 60:40 and 100:0). The evaluated responses were drug release at pH 1.2, 6.4, 6.8 and 7.4. Combinations of Eudragit S (ES), Eudragit RS (ERS) and drug based on factorial design were loaded in 10ml syringes. Electrospinning method was used to prepare electrospun nanofibers from electrospinning solutions. Conductivity and the viscosity of the solutions were analyzed prior to electrospinning. After collection, the nanofibers were evaluated in terms of morphology and drug release. It was shown that the ratio of drug:polymer and polymer:polymer were pivotal factors to control the drug release from nanofibers. A formulation containing Eudragit S:Eudragit RS (60:40) and drug:polymer ratio of 3:5 exhibited the most appropriate drug release as a colon delivery system with a minor release at pH 1.2, 6.4 and 6.8 and major release at pH 7.4. Nanofibers resulted from this formulation were also more uniform and contained fewer amounts of beads. It was demonstrated that the electrospinning could be regarded as a modern approach for the preparation of colon drug delivery systems leading to marketable products.
authors.affiliation: Targeted Drug Delivery Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Akhgari
authors.affiliation: Nanotechnology Research Center and School of Pharmacy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Heshmati
authors.affiliation: Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Afrasiabi Garekani
authors.affiliation: Targeted Drug Delivery Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sadeghi
authors.affiliation: Targeted Drug Delivery Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Atena
authors.initials: A
authors.lastname: Sabbagh
authors.affiliation: Nanotechnology Research Center and School of Pharmacy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Behzad
authors.initials: B
authors.lastname: Sharif Makhmalzadeh
authors.affiliation: Pharmaceutices Research Laboratory, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, UK; Drug Applied Research Center and Faculty of Pharmacy, Tabriz Medical Sciences University, Tabriz, Iran. Electronic address: a.nokhodchi@sussex.ac.uk.
authors.forename: Ali
authors.initials: A
authors.lastname: Nokhodchi
mesh_terms: D016503:Drug Delivery Systems / Q000379:methods*; D004560:Electricity; D007213:Indomethacin / Q000737:chemistry*; D057139:Nanofibers / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry
chemical_list: D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer; D007213:Indomethacin
keywords: Colon delivery; Electrospinning; Eudragit; Indomethacin; Nanofiber; Release rate