title: Preparation and characterization of spray-dried oxidized cellulose microparticles.
abstract: The goal of this study was to investigate the feasibility of spray drying to produce microparticles of oxidized cellulose (OC), a biocompatible and bioresorbable polymer. OCs containing 7, 13, and 20 wt% carboxylic groups were converted into stable aqueous dispersions and then spray dried using a Yamoto G-32 spray dryer equipped with a standard fluid nozzle with an orifice of 406 microm. The following operating conditions were investigated: inlet temperature 140, 170, and 190 degrees C; feed rate 3, 6, and 9 mL/min; and atomization airpressure 0.5, 1, and 1.5 kg f/cm2. The amounts of OC used in feed were 1, 2.5, and 5%. OC microparticles produced under these conditions were shrunken spheres, ranging in size between 0.98+/-0.47 and 2.05+/-0.98 microm. The different operating conditions used had no significant effect on the size and shape of particles. The use of a water-soluble plasticizer (glycerin, polyethylene glycol 400, or polyethylene glycol 6000) in the dispersion yielded microparticles with a good sphericity and a smooth surface morphology, whereas no change in the shape or size of microparticles was noted with water-insoluble plasticizers, Triacetin and dibutyl phthalate. Powder X-ray diffraction and Fourier transform infrared spectral analyses of spray-dried microparticles showed no change in the solid-state structure of OC. In conclusion, results show that OC can be converted into stable aqueous dispersions and used to produce microparticles by spray drying.
authors.affiliation: Pharmaceutics Division, College of Pharmacy, The University of Iowa, Iowa City 52242, USA. vijaykumar@uiowa.edu
authors.forename: V
authors.initials: V
authors.lastname: Kumar
authors.forename: J
authors.initials: J
authors.lastname: Kang
authors.forename: T
authors.initials: T
authors.lastname: Yang
mesh_terms: D002214:Capsules; D002483:Cellulose, Oxidized / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D006490:Hemostatics / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D010968:Plasticizers / Q000737:chemistry; D011208:Powders; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002214:Capsules; D002483:Cellulose, Oxidized; D006490:Hemostatics; D010968:Plasticizers; D011208:Powders