title: Modified vibrating-mesh nozzles for advanced spray-drying applications.
abstract: This work describes uniform polymer coatings allowing for an adjustment of the orifice dimension of vibrating-mesh nozzles and therefore, size of emerging formulation droplets and dried particles, which is of general interest for diverse spray-drying applications. Chemical vapor deposition of poly(p-xylylene) (PPXN) on aperture templates of the B-90 spray-dryer (orifice diameters: ∼4.0μm) caused a reduction of the opening cross-sections of ∼50%. Thus, a more efficient formulation atomization was observed (finer droplets). Likewise, application of PPXN-coated, rather than plain nozzles, resulted in significantly smaller (particle diameter: 1.3 vs. 3.6μm) and narrower distributed (span: ∼1.4 vs. ∼1.8) sildenafil-loaded poly(lactide-co-glycolide) microparticles. Prediction of the size of spray-dried microparticles using the size results of atomized droplets ("residual core method") was shown to be in agreement with the observed values. Formulations prepared with plain and PPXN-coated nozzles exhibited a sustained sildenafil release profile with mean dissolution times of ∼1.5 and ∼4.0h, respectively. Regardless of the starting aperture template, any desired orifice dimension and therefore, dried particle size could be achieved by generating adequate polymer deposits.
authors.affiliation: Medical Clinic II, Department of Internal Medicine, Justus-Liebig-Universität, Giessen, Germany; Department of Pharmaceutics and Biopharmacy, Philipps-Universität, Marburg, Germany. Electronic address: moritz.beck-broichsitter@innere.med.uni-giessen.de.
authors.forename: Moritz
authors.initials: M
authors.lastname: Beck-Broichsitter
authors.affiliation: Department of Chemistry and Scientific Center for Materials Science, Philipps-Universität, Marburg, Germany.
authors.forename: Ilka E
authors.initials: IE
authors.lastname: Paulus
authors.affiliation: Department of Chemistry and Scientific Center for Materials Science, Philipps-Universität, Marburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Greiner
authors.affiliation: Department of Pharmaceutics and Biopharmacy, Philipps-Universität, Marburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kissel
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D003692:Delayed-Action Preparations; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding / Q000379:methods; D008863:Microspheres; D010316:Particle Size; D011098:Polyglactin 910 / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D000068677:Sildenafil Citrate / Q000008:administration & dosage* / Q000737:chemistry; D012995:Solubility; D014732:Vibration; D014992:Xylenes / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D011108:Polymers; D014992:Xylenes; C513670:poly(p-xylylene); D011098:Polyglactin 910; D000068677:Sildenafil Citrate
keywords: Chemical vapor deposition; Controlled drug delivery; Parylene coating; Polymeric microparticles; Spray-drying; Vibrating-mesh atomization