Hiroko Otake1, Tomoyuki Okuda1, Daiki Hira1,2, Haruyoshi Kojima1, Yasuhiro Shimada3, Hirozazu Okamoto4. 1. Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya, 468-8503, Japan. 2. Department of Pharmacy, Shiga University of Medical Science Hospital, Setatsukiwa-cho, Ohtsu, 520-2192, Japan. 3. Nano Seeds Corporation, 2266-99 Anagahora, Shimoshidami, Moriyama-ku, Nagoya, 463-8560, Japan. 4. Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya, 468-8503, Japan. okamotoh@ccmfs.meijo-u.ac.jp.
Abstract
PURPOSE: The purpose of this study was to develop inhalable particles that can reach deep into the lungs efficiently independent of inhalation patterns of patients and inhalation devices. We prepared porous particles including L-leucine (Leu), a dispersive agent, by a spray-freeze-drying (SFD) method and examined the influence of inspiratory flow patterns and inhalation devices with various inhalation resistances. METHODS: Four types of SFD powder with different Leu contents (0-10%) were prepared. Scanning electron microscopy and laser diffraction were used to measure the morphology and size distribution of the powders. In-vitro inhalation characteristics were determined using a twin-stage liquid impinger equipped with an inspiratory flow pattern simulator. The effects of Leu on the adhesion force and electrostatic property of the particles were evaluated. RESULTS: The inhalation performance of the powders was improved by the addition of Leu. The powders with Leu showed a high inhalation performance regardless of inspiratory flow patterns and devices. The addition of Leu decreased the adhesion force and increased the surface potential of the powders. CONCLUSIONS: The SFD particles with Leu showed high inhalation performance regardless of the inhalation patterns and devices, which was attributed to the decreased adhesion force between particles and increased dispersibility.
PURPOSE: The purpose of this study was to develop inhalable particles that can reach deep into the lungs efficiently independent of inhalation patterns of patients and inhalation devices. We prepared porous particles including L-leucine (Leu), a dispersive agent, by a spray-freeze-drying (SFD) method and examined the influence of inspiratory flow patterns and inhalation devices with various inhalation resistances. METHODS: Four types of SFD powder with different Leu contents (0-10%) were prepared. Scanning electron microscopy and laser diffraction were used to measure the morphology and size distribution of the powders. In-vitro inhalation characteristics were determined using a twin-stage liquid impinger equipped with an inspiratory flow pattern simulator. The effects of Leu on the adhesion force and electrostatic property of the particles were evaluated. RESULTS: The inhalation performance of the powders was improved by the addition of Leu. The powders with Leu showed a high inhalation performance regardless of inspiratory flow patterns and devices. The addition of Leu decreased the adhesion force and increased the surface potential of the powders. CONCLUSIONS: The SFD particles with Leu showed high inhalation performance regardless of the inhalation patterns and devices, which was attributed to the decreased adhesion force between particles and increased dispersibility.
Authors: Francesca Ungaro; Roberta d'Emmanuele di Villa Bianca; Concetta Giovino; Agnese Miro; Raffaella Sorrentino; Fabiana Quaglia; Maria Immacolata La Rotonda Journal: J Control Release Date: 2008-12-25 Impact factor: 9.776