title: Development of thiolated poly(acrylic acid) microparticles for the nasal administration of exenatide.
abstract: The purpose of this study was to develop a microparticulate formulation for nasal delivery of exenatide utilizing a thiolated polymer. Poly(acrylic acid)-cysteine (PAA-cys) and unmodified PAA microparticles loaded with exenatide were prepared via coprecipitation of the drug and the polymer followed by micronization. Particle size, drug load and release of incorporated exenatide were evaluated. Permeation enhancing properties of the formulations were investigated on excised porcine respiratory mucosa. The viability of the mucosa was investigated by histological studies. Furthermore, ciliary beat frequency (CBF) studies were performed. Microparticles displayed a mean size of 70-80 µm. Drug encapsulation was ∼80% for both thiolated and non-thiolated microparticles. Exenatide was released from both thiolated and non-thiolated particles in comparison to exenatide in buffer only within 40 min. As compared to exenatide dissolved in buffer only, non-thiolated and thiolated microparticles resulted in a 2.6- and 4.7-fold uptake, respectively. Histological studies performed before and after permeation studies showed that the mucosa is not damaged during permeation studies. CBF studies showed that the formulations were cilio-friendly. Based on these results, poly(acrylic acid)-cysteine-based microparticles seem to be a promising approach starting point for the nasal delivery of exenatide.
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University Innsbruck, CCB-Center for Chemistry and Biochemistry , Innsbruck, Austria , Europe and.
authors.forename: Gioconda
authors.initials: G
authors.lastname: Millotti
authors.forename: Anja
authors.initials: A
authors.lastname: Vetter
authors.forename: Katharina
authors.initials: K
authors.lastname: Leithner
authors.forename: Federica
authors.initials: F
authors.lastname: Sarti
authors.forename: Gul
authors.initials: G
authors.lastname: Shahnaz Bano
authors.forename: Patrick
authors.initials: P
authors.lastname: Augustijns
authors.forename: Andreas
authors.initials: A
authors.lastname: Bernkop-Schnürch
mesh_terms: D000180:Acrylic Resins / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000281:Administration, Intranasal; D000818:Animals; D002478:Cells, Cultured; D000077270:Exenatide; D006801:Humans; D008863:Microspheres; D009297:Nasal Mucosa / Q000187:drug effects / Q000378:metabolism; D010316:Particle Size; D010455:Peptides / Q000008:administration & dosage* / Q000493:pharmacokinetics; D013438:Sulfhydryl Compounds / Q000008:administration & dosage* / Q000493:pharmacokinetics; D013552:Swine; D014688:Venoms / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D000180:Acrylic Resins; D010455:Peptides; D013438:Sulfhydryl Compounds; D014688:Venoms; C006903:carbopol 940; D000077270:Exenatide
keywords: Exenatide; microparticles; nasal delivery; thiolated polymers