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Powder Inhalers (powder + inhaler)
Kinds of Powder Inhalers Selected AbstractsFactors affecting the deposition of inhaled porous drug particlesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2002Cynthia J. Musante Abstract Recent findings indicate that the inhalation of large manufactured porous particles may be particularly effective for drug delivery. In this study, a mathematical model was employed to systematically investigate the effects of particle size, particle density, aerosol polydispersity, and patient ventilatory parameters on deposition patterns of inhaled drugs in healthy human lungs. Aerodynamically similar particles with densities of 0.1, 1.0, and 2.0 g/cm3 were considered. Particle size distributions were defined with mass median aerodynamic diameters (MMADs) ranging from 1 to 3 ,m and geometric standard deviations ranging from 1.5 to 2.5, representing particles in the respirable size range. Breathing rates of 30 and 60 L/min with tidal volumes of 500 to 3000 mL were assumed, simulating shallow to deep breaths from a dry powder inhaler. Particles with a high density and a small geometric diameter had slightly greater deposition fractions than particles that were aerodynamically similar, but had lower density and larger geometric size (typical of manufactured porous particles). This can be explained by the fact that particles with a small geometric diameter deposit primarily by diffusion, which is a function of geometric size but is independent of density. As MMAD increased, the effect of density on deposition was less pronounced because of the decreased efficiency of diffusion for large particles. These data suggest that polydisperse aerosols containing a significant proportion of submicron particles will deposit in the pulmonary airways with greater efficiency than aerodynamically similar aerosols comprised of geometrically larger porous particles. © 2002 Wiley-Liss Inc. and the American Pharmaceutical Association J Pharm Sci 91:1590,1600, 2002 [source] Assessment of inhaled corticosteroid treatment response in asthma using hypertonic histamine challenge-induced coughTHE CLINICAL RESPIRATORY JOURNAL, Issue 2 2010Minna Purokivi Abstract Background and Aims:, Bronchial provocation tests may be utilised to monitor the efficacy of the corticosteroid treatment. Unfortunately, these measurements necessitate good patient cooperation during the spirometry. Coughing during such tests is related to the degree of the bronchoconstriction and occurs involuntarily, i.e. independent of patient cooperation. This study aimed to evaluate the utility of a hypertonic histamine challenge-induced cough in assessing the efficacy of inhaled corticosteroid treatment. Methods:, A total of 16 steroid-naïve asthmatics and 10 non-asthmatic, symptomatic controls received 800-µg beclomethasone (Beclomet Easyhaler®, Orion Ltd., Orion Pharma, Helsinki, Finland) via powder inhaler per day for 8 weeks. Videoed inhalation challenge with hypertonic histamine solution was performed before and after the treatment. Symptom questionnaire was completed before both challenges. The airway responsiveness to hypertonic histamine was expressed as the cumulative number of coughs divided by the final histamine concentration administered [coughs/concentration ratio (CCR)] and as the provocative concentration of histamine to induce a 20% fall in FEV1(PC20). Results:, CCR [geometric mean; 95% confidence interval (CI)] of the asthmatic subjects decreased from 494 (209,1168) to 73.6 (29.8,182) coughs per mg/mL (P = 0.002). Their PC20 levels were 1.31 (1.07,1.60) and 1.91 (1.33,2.74) mg/mL over the treatment period (P = 0.01). The symptom frequency also decreased significantly in the asthmatics (P = 0.039). There were no significant changes in PC20 level, in CCR level or in symptom frequency in non-asthmatic subjects during the treatment. Conclusions:, Hypertonic histamine challenge-induced cough and PC20 are sensitive measures in assessing the treatment effect in asthma. The cough response may be especially useful in subjects who cannot perform spirometry reliably. Please cite this paper as: Purokivi M, Koskela H, Koistinen T, Peuhkurinen K and Kontra KM. Assessment of inhaled corticosteroid treatment response in asthma using hypertonic histamine challenge-induced cough. The Clinical Respiratory Journal 2010; 4: 67,73. [source] Laryngeal Findings in Users of Combination Corticosteroid and Bronchodilator Therapy,THE LARYNGOSCOPE, Issue 9 2004Natasha Mirza MD Educational Objective: At the conclusion of this article, the readers should be able to 1) describe the laryngeal findings in patients who use combination therapy for asthma, 2) discuss the mechanism of laryngeal irritation from the use of inhalers, and 3) describe possible mechanisms for reducing laryngeal irritation and secondary dysphonia from the use of inhalers. Objectives: To describe voice changes and laryngeal findings in patients who are started on combination corticosteroid and bronchodilator therapy in the form of a dry powder inhaler (DPI). Study Design: Retrospective, single-subject design. Methods: Retrospective review of 10 consecutive patients meeting inclusion criteria, who presented at the voice center with more than 4 weeks of dysphonia after being started on a combination form of asthma medication for control and maintenance therapy. All patients were nonsmokers and without history of previous identification or excision of vocal pathology. All patients were treated previously with a proton pump inhibitor for gastroesophageal reflux. Laryngeal videostroboscopic evaluations were performed on all patients. Patients were asked to complete a questionnaire regarding their perceived voice change and history of medical maintenance therapy for asthma. Results: Dysphonia was present in the patients selected for greater than 4 weeks. Patients had been switched to combination therapy after previously using traditional two-drug asthma regimens. In eight of nine patients, the vocal folds demonstrated areas of hyperemia, with plaque-like changes on the surface mucosa. Reduced amplitude of vibration and a reduction in mucosal wave propagation were present on videostroboscopy. Questionnaires revealed that all patients were initiated on combination DPI treatment within the last 6 months. Conclusions: Dysphonia caused by a change in the surface mucosa is a side effect from the use of DPI therapy for asthma. The high-impact force during inhalation of the medication and carrier leads to deposition of particles in the upper airway. We believe the extent of mucosal irritation can be minimized by patient education in the proper delivery of DPI. In some cases, however, return of the two medications delivered separately was necessary. The irritation of the laryngeal mucosa and return of normal vibratory parameters occurred in all patients. [source] Use of dry powder inhalers in COPDINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 12 2007D. S. Wilson Summary Introduction:, This was a study of 30 chronic obstructive pulmonary disease (COPD) patients to assess the ease of use and preference of four dry powder inhalers , accuhaler, aerolizer, handihaler, turbohaler , the accuhaler and turbohaler are multidose devices, whereas the aerolizer and handihaler are single dose devices. Method:, None of the subjects had previous experience of dry powder inhalers. The correct technique for each inhaler was divided into 12 steps including one critical step that if not performed would result in no drug delivery. Subjects were shown the correct technique for each inhaler in a random order and were assessed immediately and 1 h later. Each subject was asked to rank the four devices for preference and ease of use, as well as to assess how comfortable it felt to inhale through the device using a visual analogue scale. Results:, The numbers of perfect scores were not significantly different between devices, but the number of fatal errors that would result in no drug delivery was significantly more common in single dose devices (p < 0.01). There were significant differences in the rankings of each device (Friedman test, p < 0.005) with the turbohaler being ranked first most often and the handihaler last. The turbohaler scored highest for comfort of inhalation and the accuhaler lowest, but differences were small. Conclusions:, In COPD patients starting on dry powder inhalers, multidose devices appear to be preferred, have fewer problems and are easier to use effectively. [source] Foreword: Can dry powder inhalers be used interchangeably?INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2005D. Price No abstract is available for this article. [source] Could interchangeable use of dry powder inhalers affect patients?INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2005D. Price Summary The aim of asthma treatment is optimal disease control. Poor asthma control results in considerable patient morbidity, as well as contributing to the considerable burden placed by the disease on healthcare budgets. There is a need for costs to be carefully scrutinised, with the switching of patients to inhaler devices with lower acquisition costs likely to be increasingly considered. However, before such practice becomes widespread, it is important to establish whether or not this could adversely impact on patients and the level of disease control. For approval to have been given, all marketed inhalers must have satisfied current regulatory requirements for devices. Full preclinical and clinical development programmes are not required when application is made for authorisation to market a new inhaler containing an existing chemical entity, although clinical equivalence testing must be used. Both beneficial and adverse effects should be tested, and the limits of equivalence must be clearly defined, based on therapeutic relevance. It should be noted that equivalence studies are invalid when the end point is not responding (i.e. at the top of the dose,response curve) and when equivalence limits approach or are equal to the magnitude of the drug effect. Approval on the basis of regulations designed to safeguard quality of dry powder inhalers does not mean that devices are interchangeable. When using an inhaler, there are many stages between the patient and the therapeutic effect, involving device design, pharmaceutical performance and patient behaviour. Regulations governing new devices cover only a few of the many factors affecting disease control. Furthermore, clinical trials to assess equivalence may not take into account factors in patient behaviour or variations in patient inhaler technique that may affect use of devices in real-life situations. When assessing the consequences of interchangeable use of dry powder inhalers on healthcare costs, it is important to ensure that the acquisition cost of the devices is not the only cost considered. Other costs that should be considered include the cost of time spent demonstrating to the patient how to use the new device, the cost of additional physician visits to address patient concerns and the management costs if disease control is adversely affected. [source] Physical characterization of component particles included in dry powder inhalers.JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2007Abstract Characteristics of particles included in dry powder inhalers is extended from our previous report (in this journal) to include properties related to their dynamic performance. The performance of dry powder aerosols for pulmonary delivery is known to depend on fluidization and dispersion which reflects particle interactions in static powder beds. Since the solid state, surface/interfacial chemistry and static bulk properties were assessed previously, it remains to describe dynamic performance with a view to interpreting the integrated database. These studies result in complex data matrices from which correlations between specific properties and performance may be deduced. Lactose particles were characterized in terms of their dynamic flow, powder and aerosol electrostatics, and aerodynamic performance with respect to albuterol aerosol dispersion. There were clear correlations between flow properties and aerosol dispersion that would allow selection of lactose particles for formulation. Moreover, these properties can be related to data reported earlier on the morphological and surface properties of the carrier lactose particles. The proposed series of analytical approaches to the evaluation of powders for inclusion in aerosol products has merit and may be the basis for screening and ultimately predicting particle performance with a view to formulation optimization. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 1302,1319, 2007 [source] Electrostatics of pharmaceutical inhalation aerosolsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2009Philip Chi Lip Kwok Abstract Objectives This review focuses on the key findings and developments in the rapidly expanding research area of pharmaceutical aerosol electrostatics. Key findings Data from limited in-vivo and computational studies suggest that charges may potentially affect particle deposition in the airways. Charging occurs naturally in the absence of electric fields through triboelectrification, that is contact or friction for solids and flowing or spraying for liquids. Thus, particles and droplets emitted from pulmonary drug delivery devices (dry powder inhalers, metered dose inhalers with or without spacers, and nebulisers) are inherently charged. Apparatus with various operation principles have been employed in the measurement of pharmaceutical charges. Aerosol charges are dependent on many physicochemical parameters, such as formulation composition, device construction, relative humidity and solid-state properties. In some devices, electrification has been purposefully applied to facilitate powder dispersion and liquid atomisation. Summary Currently, there are no regulatory requirements on characterising electrostatic properties of inhalation aerosols. As research in this area progresses, the new knowledge gained may become valuable for the development and regulation of inhalation aerosol products. [source] Sensitivity of Turbutester and Accuhaler tester in asthmatic children and adolescentsPEDIATRICS INTERNATIONAL, Issue 1 2010Wiparat Manuyakorn Abstract Background:, Dry powder inhalers (DPI) are alternative devices for delivering medication for treatment of asthma. The amount of drug delivery to the lungs is directly influenced by peak inspiratory flow rate (PIFR). A minimum PIFR of ,30 L/min is needed for the Turbuhaler and Accuhaler. Methods:, In order to evaluate the sensitivity of the Turbutester and Accuhaler tester in detecting the minimum and optimum PIFR for the Turbuhaler and Accuhaler in asthmatic children, PIFR was measured using the In-Check Dial through the internal resistance of the Turbuhaler and Accuhaler and compared according to the child's ability to make a whistle sound via both testers. Results:, A total of 259 asthmatic children were studied: 20 pre-school children, aged 5,6 years; 174 school-age children, aged 7,12 years; and 65 adolescents, aged 13,18 years. The sensitivity of the Turbutester and Accuhaler tester to detect optimum PIFR were 98.40% and 97.2%, respectively. In the comparison among age groups, the sensitivity of the Accuhaler tester to detect optimum or minimum PIFR for the Accuhaler was 95%, 97.7% and 95.4%, respectively. The sensitivity of the Turbutester to detect optimum PIFR for the Turbuhaler was 94.4%, 98.8% and 98.5%, respectively. The sensitivity of the Turbutester to detect minimum PIFR for the Turbuhaler was 94.7%, 100% and 100%, respectively. There were no significant differences in percentage of having optimum or minimum PIFR among asthma severity and current device usage in all age groups. Conclusions:, Most children aged at least 5 years could generate enough PIFR to use dry powder inhaler devices. Both the Turbutester and Accuhaler tester were found to have high sensitivity in detecting optimum and minimum required PIFR. [source] Ability of preschool children to use dry powder inhalers as evaluated by In-Check MeterPEDIATRICS INTERNATIONAL, Issue 1 2006YOKO S ADACHI Abstract Background: Although current guidelines recommend the pressurized metered-dose inhaler with a spacer for preschool children with asthma, dry powder inhalers (DPI) may be a valuable treatment alternative. Methods: To evaluate the ability of preschool children to inhale through DPI, peak inspiratory flow rates (PIFR) of 57 healthy children aged 3,6 years were measured with In-Check Meter after practising with an instructor. Two different calibrated resistances were attached to the Meter to mimic the internal resistance of each inhaler; Diskus and Turbuhaler. Results: The ability of children to generate adequate inspiratory flow increased with age. The percentages of the 3-, 4-, 5-, and 6-year-old children who were able to inhale reliably through the devices were 30% (3/10), 79.0% (15/19), 100% (16/16), and 100% (12/12), respectively. In these children, 100%, 93.3%, 100%, and 100% achieved an adequate PIFR for the Diskus (30 L/min). In contrast, 66.7%, 66.7%, 62.5%, and 91.7% generated an adequate PIFR for the Turbuhaler (60 L/min). Conclusions: The In-Check Meter is a useful device to assess the ability of preschool children to generate adequate PIFR for each inhaler. Most children aged ,5 years could use DPI. [source] | ||||||||||