Formulation Considerations for Dry Powder Inhalers

References

• Anderson SD Rozea PJ Dolton R Lindsay DA . Inhaled and oral bronchodilator therapy in exercise induced asthma . Aust. NZ J. Med.5 ( 6 ), 544 – 550 ( 1975 ).
   PubMedGoogle Scholar
• Shaw RJS Waller JF Hetzel MR Clark TJH . Do oral and inhaled terbutaline have different effects on the lung?Br. J. Dis. Chest76 ( 0 ), 171 – 176 ( 1982 ).
   PubMedGoogle Scholar
• Onoue S Yamada S . Pirfenidone in respirable powder form for the treatment of pulmonary fibrosis: a safer alternative to the current oral delivery system?Ther. Deliv.4 ( 8 ), 887 – 889 ( 2013 ).
   PubMedGoogle Scholar
• Global Initiative for Asthma (GINA) . From the Global Strategy for Asthma Management and Prevention . www.ginasthma.org
   Google Scholar
• Global Initiative for Chronic Obstructive Lung Disease (GOLD) . Global Strategy for Diagnosis, Management, and Prevention of COPD . www.goldcopd.org
   Google Scholar
• Labiris NR Dolovich MB . Pulmonary drug delivery. Part I: Physiological factors affecting therapeutic effectiveness of aerosolized medications . Br. J. Clin. Pharmacol.56 ( 6 ), 588 – 599 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Kamin W Erdnüss F Krämer I . Inhalation solutions – which ones may be mixed? Physico-chemical compatibility of drug solutions in nebulizers – update 2013 . J. Cyst. Fibros.13 ( 3 ), 243 – 250 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Phipps PR Gonda I . Droplets produced by medical nebulizers. Some factors affecting their size and solute concentration . Chest97 ( 6 ), 1327 ( 1990 ).
   PubMed Web of Science ®Google Scholar
• Steckel H Eskandar F . Factors affecting aerosol performance during nebulization with jet and ultrasonic nebulizers . Eur. J. Pharm. Sci.19 ( 5 ), 443 – 455 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Freedman T . Medihaler therapy for bronchial asthma; a new type of aerosol therapy . Postgrad. Med.20 ( 6 ), 667 – 673 ( 1956 ).
   PubMedGoogle Scholar
• Anderson PJ . History of aerosol therapy: liquid nebulization to MDIs to DPIs . Respir. Care50 ( 9 ), 1139 – 1150 ( 2005 ).
   PubMedGoogle Scholar
• Khassawneh BY Al-Ali MK Alzoubi KH et al. Handling of inhaler devices in actual pulmonary practice: metered-dose inhaler versus dry powder inhalers . Respir. Care53 ( 3 ), 324 – 328 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Baverstock M Woodhall N Maarman V . P94 Do healthcare professionals have sufficient knowledge of inhaler techniques in order to educate their patients effectively in their use?Thorax65 ( Suppl. 4 ), A117 ( 2010 ).
   Google Scholar
• Price D Bosnic-Anticevich S Briggs A et al. Inhaler competence in asthma: Common errors, barriers to use and recommended solutions . Respir. Med.107 ( 1 ), 37 – 46 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Brand P Hederer B Austen G Dewberry H Meyer T . Higher lung deposition with Respimat Soft Mist inhaler than HFA-MDI in COPD patients with poor technique . Int. J. Chronic Obstruct. Pulm. Dis.3 ( 4 ), 763 – 770 ( 2008 ).
   PubMedGoogle Scholar
• Newman SP . Spacer Devices for Metered Dose Inhalers . Clin. Pharmacokinet.43 ( 6 ), 349 – 360 ( 2004 ).
   PubMed Web of Science ®Google Scholar
• Pitcairn G Reader S Pavia D Newman S . Deposition of corticosteroid aerosol in the human lung by Respimat® Soft Mist™ inhaler compared to deposition by metered dose inhaler or by Turbuhaler® dry powder inhaler . J. Aerosol Med.18 ( 3 ), 264 – 272 ( 2005 ).
   PubMedGoogle Scholar
• Bell JH Hartley PS Cox JSG . Dry powder aerosols I: A new powder inhalation device . J. Pharm. Sci.60 ( 10 ), 1559 – 1564 ( 1971 ).
   PubMed Web of Science ®Google Scholar
• Fisons Limited: US4161516 A ( 1979 ).
   Google Scholar
• Astra Aktlebolag: US005551489A ( 1994 ).
   Google Scholar
• Pharmatech GmbH: US 2011/0159102 A1 ( 2008 ).
   Google Scholar
• Schuster A Haliburn C Doring G Goldman MH . Safety, efficacy and convenience of colistimethate sodium dry powder for inhalation (Colobreathe DPI) in patients with cystic fibrosis: a randomised study . Thorax68 ( 4 ), 344 – 350 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Boer AH de Hagedoorn P Westerman EM Le Brun PP Heijerman HG Frijlink HW . Design and in vitro performance testing of multiple air classifier technology in a new disposable inhaler concept (Twincer®) for high powder doses . Eur. J. Pharm. Sci.28 ( 3 ), 171 – 178 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Hoppentocht M Hagedoorn P Frijlink HW Boer AH de . Design and development of a disposable high dose dry powder inhaler for aminoglycosides . Presented at: Drug Delivery To The Lungs 24: Proceedings.Edinburgh, UK , 11 – 13December 2013 .
   Google Scholar
• Young PM Crapper J Philips G Sharma K Chan H Traini D . Overcoming dose limitations using the Orbital® multi-breath dry powder inhaler . J. Aerosol Med. Pulm. Drug Deliv.27 ( 2 ), 138 – 147 ( 2014 ).
   PubMed Web of Science ®Google Scholar
• Hoppentocht M Hagedoorn P Frijlink HW Boer AH de . Developments and strategies for inhaled antibiotic drugs in tuberculosis therapy: a critical evaluation . Eur. J. Pharm. Biopharm.86 ( 1 ), 23 – 30 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Carvalho TC Peters JI Williams III RO . Influence of particle size on regional lung deposition – what evidence is there?Int. J. Pharm.406 ( 1-2 ), 1 – 10 ( 2011 ).
   PubMed Web of Science ®Google Scholar
• Usmani OS Biddiscombe MF Barnes PJ . Regional lung deposition and bronchodilator response as a function of β2-agonist particle size . Am. J. Respir. Crit. Care Med.172 ( 12 ), 1497 – 1504 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Rasenack N Müller BW . Micron‐size drug particles: common and novel micronization techniques . Pharm. Dev. Technol.9 ( 1 ), 1 – 13 ( 2004 ).
   PubMed Web of Science ®Google Scholar
• Wittmann R Schwarz E Steckel H . The Influence of Amorphous Content in Lactose on the De-agglomeration Behavior of Powders for Inhalation . Presented at: Drug Delivery To The Lungs 23: Proceedings.Edinburgh, UK , 5 – 7December 2012 .
   Google Scholar
• Mackin L Zanon R Park JM Foster K Opalenik H Demonte M . Quantification of low levels (<10%) of amorphous content in micronised active batches using dynamic vapour sorption and isothermal microcalorimetry . Int. J. Pharm.231 ( 2 ), 227 – 236 ( 2002 ).
   PubMed Web of Science ®Google Scholar
• Young PM Chiou H Tee T et al. The use of organic vapor sorption to determine low levels of amorphous content in processed pharmaceutical powders . Drug Dev. Ind. Pharm.33 ( 1 ), 91 – 97 ( 2007 ).
   PubMed Web of Science ®Google Scholar
• Kubavat HA Shur J Ruecroft G Hipkiss D Price R . Investigation into the influence of primary crystallization conditions on the mechanical properties and secondary processing behaviour of fluticasone propionate for carrier based dry powder inhaler formulations . Pharm. Res.29 ( 4 ), 994 – 1006 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Kubavat HA Shur J Ruecroft G Hipkiss D Price R . Influence of primary crystallisation conditions on the mechanical and interfacial properties of micronised budesonide for dry powder inhalation . Int. J. Pharm.430 ( 1-2 ), 26 – 33 ( 2012 ).
   PubMedGoogle Scholar
• Steckel H Brandes HG . A novel spray-drying technique to produce low density particles for pulmonary delivery . Int. J. Pharm.278 ( 1 ), 187 – 195 ( 2004 ).
   PubMedGoogle Scholar
• Littringer EM Mescher A Schröttner H Achelis L Walzel P Urbanetz NA . Spray dried mannitol carrier particles with tailored surface properties – the influence of carrier surface roughness and shape . Eur. J. Pharm. Biopharm.82 ( 1 ), 194 – 204 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Littringer EM Mescher A Eckhard S et al. Spray drying of mannitol as a drug carrier – the impact of process parameters on product properties . Drying Technol.30 ( 1 ), 114 – 124 ( 2012 ).
   Web of Science ®Google Scholar
• Chan H Chew NY . Novel alternative methods for the delivery of drugs for the treatment of asthma . Adv. Drug Delivery Rev.55 ( 7 ), 793 – 805 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Weers J Clark A Challoner Peter . High dose inhaled powder delivery: challenges and techniques . In:Respiratory Drug Delivery IX.DalbyRNByronPRPeartJSumanJDFarrSJ (Eds) . Virginia Commonwealth University , VA, USA , 281 – 288 ( 2004 ).
   Google Scholar
• Weers J Tarara TE Clark AR . Design of fine particles for pulmonary drug delivery . Expert Opin. Drug Deliv.4 ( 3 ), 297 – 313 ( 2007 ).
   PubMed Web of Science ®Google Scholar
• Jin TH Tsao E Goudsmit J Dheenadhayalan V Sadoff J . Stabilizing formulations for inhalable powders of an adenovirus 35-vectored tuberculosis (TB) vaccine (AERAS-402) . Vaccine28 ( 27 ), 4369 – 4375 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Maa Y Nguyen P Sweeney T Shire S Hsu C . Protein inhalation powders: spray drying vs spray freeze drying . Pharm. Res.16 ( 2 ), 249 – 254 ( 1999 ).
   PubMed Web of Science ®Google Scholar
• Sweeney LG Wang Z Loebenberg R Wong JP Lange CF Finlay WH . Spray-freeze-dried liposomal ciprofloxacin powder for inhaled aerosol drug delivery . Int. J. Pharm.305 ( 1-2 ), 180 – 185 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Costantino HR Firouzabadian L Hogeland K et al. Protein spray-freeze drying. effect of atomization conditions on particle size and stability . Pharm. Res.17 ( 11 ), 1374 – 1382 ( 2000 ).
   PubMed Web of Science ®Google Scholar
• Costantino HR Firouzabadian L Wu C et al. Protein spray freeze drying. 2. Effect of formulation variables on particle size and stability . J. Pharm. Sci.91 ( 2 ), 388 – 395 ( 2002 ).
   PubMed Web of Science ®Google Scholar
• Johnson OL Jaworowicz W Cleland J et al. The stabilization and encapsulation of human growth hormone into biodegradable microspheres . Pharm. Res.14 ( 6 ), 730 – 735 ( 1997 ).
   PubMed Web of Science ®Google Scholar
• Saluja V Amorij J Kapteyn J Boer AH de Frijlink HW Hinrichs W . A comparison between spray drying and spray freeze drying to produce an influenza subunit vaccine powder for inhalation . J. Control. Release144 ( 2 ), 127 – 133 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Steckel H Thies J Müller BW . Micronizing of steroids for pulmonary delivery by supercritical carbon dioxide . Int. J. Pharm.152 ( 1 ), 99 – 110 ( 1997 ).
   Google Scholar
• Shekunov BY Chattopadhyay P Seitzinger J . Supercritical Fluid Processing Techniques - Comparing Supercritical fluid processing techniques: comparing the products . In:Respiratory Drug Delivery IX.DalbyRNByronPRPeartJSumanJDFarrSJ (Eds) . Virginia Commonwealth University, VA , USA ( 2004 ).
   Google Scholar
• Chow AHL Tong HHY Chattopadhyay P Shekunov BY . Particle engineering for pulmonary drug delivery . Pharm. Res.24 ( 3 ), 411 – 437 ( 2007 ).
   PubMed Web of Science ®Google Scholar
• Shekunov BY Feeley JC Chow AHL Tong HH York P . Aerosolisation behaviour of micronised and supercritically-processed powders . J. Aerosol Sci.34 ( 5 ), 553 – 568 ( 2003 ).
   Web of Science ®Google Scholar
• Lobo JM Schiavone H Palakodaty S York P Clark A Tzannis ST . SCF-engineered powders for delivery of budesonide from passive DPI devices . J. Pharm. Sci.94 ( 10 ), 2276 – 2288 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Kellermann: US20110171141 A1 ( 2010 ).
   Google Scholar
• Hersey JA . Ordered mixing: A new concept in powder mixing practice . Powder Technol.11 ( 1 ), 41 – 44 ( 1975 ).
   Web of Science ®Google Scholar
• Steckel H Bolzen N . Alternative sugars as potential carriers for dry powder inhalations . Int. J. Pharm.270 ( 1-2 ), 297 – 306 ( 2004 ).
   PubMedGoogle Scholar
• Tee S Marriott C Zeng X Martin G . The use of different sugars as fine and coarse carriers for aerosolised salbutamol sulphate . Int. J. Pharm.208 ( 1-2 ), 111 – 123 ( 2000 ).
   PubMedGoogle Scholar
• Rahimpour Y Kouhsoltani M Hamishehkar H . Alternative carriers in dry powder inhaler formulations . Drug Discov. Today ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Kaialy W Nokhodchi A . Freeze-dried mannitol for superior pulmonary drug delivery via dry powder inhaler . Pharm. Res.30 ( 2 ), 458 – 477 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Pilcer G Amighi K . Formulation strategy and use of excipients in pulmonary drug delivery . Int. J. Pharm.392 ( 1-2 ), 1 – 19 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Telko MJ Hickey AJ . Dry powder inhaler formulation . Respir. Care50 ( 9 ), 1209 – 1227 ( 2005 ).
   PubMedGoogle Scholar
• Grasmeijer F Hagedoorn P Frijlink HW Boer AH de . Drug content effects on the dispersion performance of adhesive mixtures for inhalation . PLoS ONE8 ( 8 ), e71339 ( 2013 ).
   Web of Science ®Google Scholar
• Traini D Young PM Thielmann F Acharya M . The influence of lactose pseudopolymorphic form on salbutamol sulfate–lactose interactions in dpi formulations . Drug Dev. Ind. Pharm.34 ( 9 ), 992 – 1001 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Young PM Edge S Triani D et al. The influence of dose on the performance of dry powder inhalation systems . Int. J. Pharm.296 ( 1-2 ), 26 – 33 ( 2005 ).
   PubMedGoogle Scholar
• Staniforth JN . Performance-modifying influences in dry powder inhalation systems . Aerosol Sci. Technol.22 ( 4 ), 346 – 353 ( 1995 ).
   Web of Science ®Google Scholar
• Staniforth JN . Pre-formulation aspects of dry powder aerosols . In:Respiratory Drug Delivery V.DalbyRNByronPRFarrSJ (Eds) . Interpharm Press, Inc. , IL, USA , 65 – 73 ( 1996 ).
   Google Scholar
• Lucas P Anderson K Staniforth JN . Protein deposition from dry powder inhalers: fine particle multiplets as performance modifiers . Pharm. Res.15 ( 4 ), 562 – 569 ( 1998 ).
   PubMed Web of Science ®Google Scholar
• Lucas P Clarke MJ Anderson K Tobyn MJ Staniforth JN . The role of fine particle excipients in pharmaceutical dry powder aerosoles . In:Respiratory drug delivery VI.DalbyRNByronPRFarrSJ (Eds) . VA, USA , 243 – 250 ( 1998 ).
   Google Scholar
• Cordts E Steckel H . Capabilities and limitations of using powder rheology and permeability to predict dry powder inhaler performance . Eur. J. Pharm. Biopharm.82 ( 2 ), 417 – 423 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Jones MD Price R . The influence of fine excipient particles on the performance of carrier-based dry powder inhalation formulations . Pharm. Res.23 ( 8 ), 1665 – 1674 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Dickhoff BHJ de Boer AH Lambregts D Frijlink HW . The effect of carrier surface treatment on drug particle detachment from crystalline carriers in adhesive mixtures for inhalation . Int. J. Pharm.327 ( 1-2 ), 17 – 25 ( 2006 ).
   PubMedGoogle Scholar
• Shur J Harris H Jones MD Kaerger J Price R . The role of fines in the modification of the fluidization and dispersion mechanism within dry powder inhaler formulations . Pharm. Res.25 ( 7 ), 1631 – 1640 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• de Boer AH . Interactions in adhesive mixture dispersion . Presented at:Lactose as a Carrier for Inhalation Products.Parma, Italy , 28 September 2010 .
   Google Scholar
• Boer AH de Chan H Price R . A critical view on lactose-based drug formulation and device studies for dry powder inhalation: which are relevant and what interactions to expect?Adv. Drug Deliv. Rev.64 ( 3 ), 257 – 274 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Boer AH de Hagedoorn P Gjaltema D Goede J Frijlink HW . Air classifier technology (ACT) in dry powder inhalation: Part 1. Introduction of a novel force distribution concept (FDC) explaining the performance of a basic air classifier on adhesive mixtures . Int. J. Pharm.260 ( 2 ), 187 – 200 ( 2003 ).
   PubMedGoogle Scholar
• Cordts E Grasmeijer F van der Wel P Dekens B Boer AH de Steckel H . The influence of mixing time and intensity on blend homogeneity and dispersion performance . Presented at: Drug Delivery To The Lungs 23: Proceedings.Edinburgh, UK , 5 – 7December 2012 .
   Google Scholar
• Miller-Larsson A Selroos O . Advances in asthma and COPD treatment: combination therapy with inhaled corticosteroids and long-acting β2-agonists . Curr. Pharm. Des.12 ( 25 ), 3261 – 3279 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Nelson HS Chapman KR Pyke SD Johnson M Pritchard JN . Enhanced synergy between fluticasone propionate and salmeterol inhaled from a single inhaler versus separate inhalers . J. Allergy Clin. Immunol.112 ( 1 ), 29 – 36 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Ducharme FM Ni Chroinin M Greenstone I Lasserson TJ . Addition of long-acting beta2-agonists to inhaled steroids versus higher dose inhaled steroids in adults and children with persistent asthma . Cochrane Database Syst. Rev.4 , CD005533 ( 1996 ).
   Google Scholar
• Seyfang K Steckel H . Pulverabfüllung: Kleine Mengen richtig dosieren . TechnoPharm3 ( 6 ), 304 – 311 ( 2013 ).
   Google Scholar
• Powder Flow . In:The United States Pharmacopeia: The National Formulary.The United States Pharmacopeial Convention , MD, USA ( 2013 ).
   Google Scholar
• Freeman T Seyfang K . Enhancing dose consistency . Manufacturing Chemist Pharma,13 March ( 2010 ).
   Google Scholar
• Eskandar F Lejeune M Edge S . Low powder mass filling of dry powder inhalation formulations . Drug Dev. Ind. Pharm.37 ( 1 ), 24 – 32 ( 2011 ).
   PubMed Web of Science ®Google Scholar
• Chen X Seyfang K Steckel H . Development of a micro dosing system for fine powder using a vibrating capillary. Part 1: The investigation of factors influencing on the dosing performance . Int. J. Pharm.433 ( 1-2 ), 34 – 41 ( 2012 ).
   PubMedGoogle Scholar
• Chen X Seyfang K Steckel H . Development of a micro-dosing system for fine powder using a vibrating capillary. Part 2. The implementation of a process analytical technology tool in a closed-loop dosing system . Int. J. Pharm.433 ( 1-2 ), 42 – 50 ( 2012 ).
   PubMedGoogle Scholar
• Son Y McConville JT . Advancements in dry powder delivery to the lung . Drug Dev. Ind. Pharm.34 ( 9 ), 948 – 959 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• White S Bennett DB Cheu S et al. EXUBERA®: pharmaceutical development of a novel product for pulmonary delivery of insulin . Diabetes Technol. Ther.7 ( 6 ), 896 – 906 ( 2005 ).
   PubMedGoogle Scholar
• Mastrandrea LD Quattrin T . Clinical evaluation of inhaled insulin . Adv. Drug Deliv. Rev.58 ( 9-10 ), 1061 – 1075 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Donovan MJ Gibbons A Herpin MJ Marek S McGill SL Smyth HDC . Novel dry powder inhaler particle-dispersion systems . Ther. Deliv.2 ( 10 ), 1295 – 1311 ( 2011 ).
   PubMedGoogle Scholar
• Islam N Gladki E . Dry powder inhalers (DPIs) – a review of device reliability and innovation . Int. J. Pharm.360 ( 1-2 ), 1 – 11 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Friebel C Steckel H . Single-use disposable dry powder inhalers for pulmonary drug delivery . Expert Opin. Drug Deliv.7 ( 12 ), 1359 – 1372 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Aerosoles, nasal sprays, meterd-dose inhalers; and dry powder inhalers . In:The United States Pharmacopeia: The National Formulary.The United States Pharmacopeial Convention , MD, USA ( 2013 ).
   Google Scholar
• Zubereitungen zur Inhalation - Inhalanda . In:Europäisches Arzneibuch: amtliche deutsche Ausgabe, 7th Edition,Dt. Apotheker-Verl. , Stuttgart, Germany ( 2011 ).
   Google Scholar
• Frijlink HW Boer AH de . Trends in the technology-driven development of new inhalation devices . Drug Discov. Today: Technol.2 ( 1 ), 47 – 57 ( 2005 ).
   PubMedGoogle Scholar
• Zubereitungen zur Inhalation: Aerodynamische Beurteilung feiner Teilchen . In:Europäisches Arzneibuch: amtliche deutsche Ausgabe, 7th Edition,Dt. Apotheker-Verl. , Stuttgart, Germany ( 2011 ).
   Google Scholar
• Mitchell JP Nagel MW . Cascade impactors for the size characterization of aerosols from medical inhalers: their uses and limitations . J. Aerosol Med.16 ( 4 ), 341 – 377 ( 2003 ).
   PubMedGoogle Scholar
• Miller NC Maniaci MJ Dwivedi S Ward GW . Aerodynamic sizing with simulated inhalation profiles: total dose capture and measurement . In:Respiratory Drug Delivery VII.DalbyRNByronPRFarrSJPeartJ (Eds) . Virginia Commonwealth University , VA, USA , 191 – 196 ( 2000 ).
   Google Scholar
• Olsson B Borgström L Lundbäck H Svensson M . Validation of a general in vitro approach for prediction of total lung deposition in healthy adults for pharmaceutical inhalation products . J. Aerosol Med. Pulm. Drug Deliv.26 ( 6 ), 355 – 369 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Boer AH de Gjaltema D Hagedoorn P . Inhalation characteristics and their effects on in vitro drug delivery from dry powder inhalers Part 2: Effect of peak flow rate (PIFR) and inspiration time on the in vitro drug release from three different types of commercial dry powder inhalers . Int. J. Pharm.138 ( 1 ), 45 – 56 ( 1996 ).
   Google Scholar
• Borgström L . On the Use of Dry Powder Inhalers in Situations Perceived as Constrained . J. Aerosol Med.14 ( 3 ), 281 – 287 ( 2001 ).
   PubMedGoogle Scholar
• Ashurst I Malton A Prime D Sumby B . Latest advances in the development of dry powder inhalers . Pharm. Sci. Technol. Today3 ( 7 ), 246 – 256 ( 2000 ).
   PubMedGoogle Scholar
• Boer AH de Hagedoorn P Gjaltema D Goede J Frijlink HW . Air classifier technology (ACT) in dry powder inhalation . Int. J. Pharm.310 ( 1-2 ), 72 – 80 ( 2006 ).
   PubMedGoogle Scholar
• Boer AH de Bolhuis G Gjaltema D Hagedoorn P . Inhalation characteristics and their effects on in vitro drug delivery from dry powder inhalers . Int. J. Pharm.153 ( 1 ), 67 – 77 ( 1997 ).
   Google Scholar
• Weers J Ung K Le J et al. Dose emission characteristics of placebo PulmoSphere® particles are unaffected by a subject's inhalation Maneuver . J. Aerosol Med. Pulm. Drug Deliv.26 ( 1 ), 56 – 68 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Price R Young PM Edge S Staniforth J . The influence of relative humidity on particulate interactions in carrier-based dry powder inhaler formulations . Int. J. Pharm.246 ( 1–2 ), 47 – 59 ( 2002 ).
   PubMed Web of Science ®Google Scholar
• Zhu K Tan RB Kiong Ng W Shen S Zhou Q Heng PW . Analysis of the influence of relative humidity on the moisture sorption of particles and the aerosolization process in a dry powder inhaler . J. Aerosol Sci.39 ( 6 ), 510 – 524 ( 2008 ).
   Web of Science ®Google Scholar
• Jashnani RN Byron PR Dalby RN . Testing of dry powder aerosol formulations in different environmental conditions . Int. J. Pharm.113 ( 1 ), 123 – 130 ( 1995 ).
   Google Scholar
• Young PM Price R . The influence of humidity on the aerosolisation of micronised and SEDS produced salbutamol sulphate . Eur. J. Pharm. Sci.22 ( 4 ), 235 – 240 ( 2004 ).
   PubMed Web of Science ®Google Scholar