title: Influence of process parameters on the preparation of pharmaceutical films by electrostatic powder deposition.
abstract: Electrostatic powder deposition (ESPD) has been developed as a solvent-free method to prepare pharmaceutical films. The aim of this work was to investigate the influence of process parameters during (1) electrostatic powder deposition, (2) curing, and (3) removal of the film from the substrate on the properties of the film. Polyethylene oxide (PEO) was used as the model polymer and stainless steel 316 as the substrate. Deposition efficiency (i.e. deposited weight) was measured with varying charging voltage, gun tip to substrate distance, and environmental humidity. Scanning electron microscopy was utilized to assess film formation, and adhesive and mechanical strength of films were measured with varying cure temperature and time. Adhesive strength was measured for films prepared on substrates of varying surface roughness. When deposition was performed at low humidity conditions, 25%RH, process parameters did not significantly affect deposition behavior. At 40%RH, increasing deposition efficiency with decreasing gun tip to substrate distance and increasing voltage (up to 60kV) was observed. Complete film formation was seen by 30min at 80°C, compared to lower curing temperatures and times. All films were readily removed from the substrates. The results show the ESPD process can be modified to produce films with good mechanical properties (e.g. tensile strength>0.06MPa), suggesting it is a promising dry powder process for preparing pharmaceutical films.
authors.affiliation: College of Pharmacy, The University of Texas at Austin, 2409 University Avenue, Campus Mail Code A1920, Austin, TX 78712, USA. Electronic address: leena.prasad@utexas.edu.
authors.forename: Leena Kumari
authors.initials: LK
authors.lastname: Prasad
authors.affiliation: College of Pharmacy, The University of Texas at Austin, 2409 University Avenue, Campus Mail Code A1920, Austin, TX 78712, USA.
authors.forename: Justin S
authors.initials: JS
authors.lastname: LaFountaine
authors.affiliation: College of Pharmacy, The University of Texas at Austin, 2409 University Avenue, Campus Mail Code A1920, Austin, TX 78712, USA.
authors.forename: Justin M
authors.initials: JM
authors.lastname: Keen
authors.affiliation: College of Pharmacy, The University of Texas at Austin, 2409 University Avenue, Campus Mail Code A1920, Austin, TX 78712, USA.
authors.forename: Robert O
authors.initials: RO
authors.lastname: Williams
authors.affiliation: College of Pharmacy, The University of Texas at Austin, 2409 University Avenue, Campus Mail Code A1920, Austin, TX 78712, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: McGinity
mesh_terms: D000269:Adhesives / Q000737:chemistry; D006813:Humidity; D008855:Microscopy, Electron, Scanning / Q000379:methods; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011208:Powders / Q000737:chemistry*; D055672:Static Electricity; D013696:Temperature; D013718:Tensile Strength
chemical_list: D000269:Adhesives; D004364:Pharmaceutical Preparations; D011108:Polymers; D011208:Powders; D011092:Polyethylene Glycols
keywords: Adhesion; Dry powder process; Electrostatic powder coating; Pharmaceutical films; Polyethylene oxide