title: In vitro analysis of a novel controlled release system designed for intratympanic administration of N-acetylcysteine: a preliminary report.
abstract: The aim of this in-vitro experimental study was to design a novel drug delivery system that may permit controlled release of N-acetylcysteine (NAC) following intratympanic administration. The system was composed of two different solutions that attained a hydrogel form within seconds after getting into contact with each other. The authors performed swelling, pH and temperature tests and analysis of controlled release of NAC from this novel controlled release system. For the structure and porosity analysis of the hydrogel, an environmental scanning electron microscope (SEM) was used. The diameter of designed hydrogel showed an increase when pH was increased. In addition, in comparison to acidic values, the pore diameter of the hydrogel increased significantly especially in physiological level. The increase in the pore diameter was also directly proportional to the increase in temperature. Spectrophotometric analysis showed that the amount of NAC released into the medium was statistically significant (p=0.038, t=-2.18, 95% CI; DF: 27). SEM analysis of the samples revealed a smooth surface topography and numerous porous structures. The authors are of the opinion that the designed hydrogel may be used as an alternative method for intratympanic delivery of NAC for otoprotective purposes. The disadvantages of intratympanic injection of the drug in its liquid form, including leakage through eustachian tube, restraining the patient in an uncomfortable position, necessity for repetitive injections and dose dependent inflammation of the middle ear epithelium, may also be avoided. Further in vivo studies should be conducted to assess its tolerability and effectivity.
authors.affiliation: Department of Otorhinolaryngology, School of Medicine, Namik Kemal University, Turkey. Electronic address: zaferciftci@yahoo.com.
authors.forename: Zafer
authors.initials: Z
authors.lastname: Ciftci
authors.affiliation: Department of Otorhinolaryngology, School of Medicine, Namik Kemal University, Turkey.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Deniz
authors.affiliation: Department of Pharmacovigilance and Rational Use of Drugs, Tekirdag State Hospital, Ministry of Health, Turkey.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Yilmaz
authors.affiliation: Department of Otorhinolaryngology, Tekirdag State Hospital, Ministry of Health, Turkey.
authors.forename: Halide Gunes
authors.initials: HG
authors.lastname: Ciftci
authors.affiliation: Department of Biology, School of Arts and Sciences, Namik Kemal University, Turkey.
authors.forename: Duygu Yasar
authors.initials: DY
authors.lastname: Sirin
authors.affiliation: Department of Otorhinolaryngology, School of Medicine, Namik Kemal University, Turkey.
authors.forename: Erdogan
authors.initials: E
authors.lastname: Gultekin
mesh_terms: D000111:Acetylcysteine / Q000008:administration & dosage*; D001672:Biocompatible Materials; D001881:Borates; D048271:Chitosan; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D016166:Free Radical Scavengers / Q000008:administration & dosage*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007267:Injections; D008855:Microscopy, Electron, Scanning; D011142:Polyvinyl Alcohol; D013053:Spectrophotometry; D014432:Tympanic Membrane
chemical_list: D001672:Biocompatible Materials; D001881:Borates; D003692:Delayed-Action Preparations; D016166:Free Radical Scavengers; C062364:polyvinyl alcohol hydrogel; C018851:borax; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011142:Polyvinyl Alcohol; D048271:Chitosan; D000111:Acetylcysteine