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Simplifying the assessment of patients with chronic airflow limitation for home nebulizer therapy.

One-hundred nebulizer trials were performed in 98 adult patients with chronic airflow limitation who had remained symptomatic despite regular use of bronchodilators by metered dose or dry powder inhalation. Mean baseline FEV1 was 0.9 (SD = 0.41) 1, FVC -2.0 (0.74) 1 and PEFR 169 (77) 1 min-1. After laboratory measurements of reversibility to inhaled salbutamol (5 mg) and ipratropium bromide (0.5 mg), patients were supplied with a compressor and a peak flow meter to make twice daily measurements at home for 3 weeks. They nebulized normal saline, salbutamol (5 mg) and salbutamol (5 mg) ipratropium (0.5 mg) mixture 6-hourly, each for 1 week. A positive nebulizer trial was defined as a 15% increase in mean PEFR over a week on an active treatment compared to the week on saline. Twenty-eight patients had positive trials based on these criteria. Of these nine responded to both active treatments and 16 to the salbutamol/ipratropium mixture. Although no laboratory measurements predicted a positive domiciliary trial, the patients' subjective assessment of benefit had a 93% sensitivity and 87% negative predictive value. We conclude that an appropriate protocol for assessing the value of long-term nebulized bronchodilators is for patients to measure their PEFR during a week of nebulized saline and a week of nebulized beta-agonist/ipratropium mixture. Those with an increase of 15% in mean PEFR in the week on active treatment and who experienced subjective benefit should be supplied with a compressor. Had we conducted our 100 trials in this way we would have started 25 of our 98 patients on long-term home nebulized bronchodilators.

Adult↗

Dose of nebulized ipratropium bromide in acute severe asthma.

The aim of the study was to determine the maximum effective dose of nebulized ipratropium bromide, 0.5 or 1.0 mg, in the treatment of acute severe attacks of asthma. Thirty-two patients (ten males, 19-53 years) who were admitted with acute severe asthma were, in a double-blind trial, randomized to receive either 0.5 or 1.0 mg of isotonic, preservative-free ipratropium bromide nebulized in saline. Ear oxygen saturation, peak flow and heart rate were measured on admission and regularly following nebulization. Two hours after nebulization of the ipratropium, terbutaline (5 mg) was administered by nebulizer and further measurements taken 30 min later. Twenty-six patients completed the study, 13 in each group. Peak expiratory flow (PEF) increased by 51% [1211 min-1 increasing to 1831 min-1 (mean)] in the 0.5-mg ipratropium group, and by 37% (1551 min-1 to 2071 min-1) in the 1.0-mg group. There were no significant differences in heart rate or ear oxygen saturation changes between the groups. Nebulized terbutaline led to a small further rise in peak flow in both groups (341 min-1 in the 0.5-mg group; 411 min-1 in the 1.0-mg group). No side-effects were noticed in either group. We conclude that 0.5 mg of nebulized ipratropium is as effective as 1.0 mg in the treatment of acute severe asthma.

Acute Disease↗

Home nebulizers: can optimal therapy be predicted by laboratory studies?

Twenty patients (six severe asthma, 14 chronic obstructive pulmonary disease, COPD) were referred for consideration of domiciliary nebulized treatment. A double blind laboratory assessment demonstrated similar subjective and objective responses to nebulized salbutamol (5 mg), ipratropium bromide (IB) (0.5 mg) or a mixture of these medications in both groups of patients. The patients subsequently self-administered each treatment four times daily for one month. Fourteen patients requested long-term home nebulizer treatment (three salbutamol, four ipratropium bromide, seven mixture), and nine of these had their highest domiciliary peak flow recordings during home nebulizer treatment. However, subjective and objective laboratory assessments did not clearly predict the patients long-term choice of therapy in any case. There was little overall correlation between the laboratory response and the domiciliary response to treatment (Spearman correlation coefficient; subjective score, laboratory vs. home, r = 0.27, P = 0.03; peak flow response 30 min after treatment, laboratory vs. home, r = 0.31, P less than 0.02). The hospital study was also unreliable in predicting side effects during domiciliary nebulizer use. We conclude that prospective laboratory studies are of little value in the assessment of patients for home nebulizer therapy; these assessments must be made by carefully supervised domiciliary trials of nebulized treatment.

Adult↗

The use and misuse of domiciliary nebulizer therapy on the Isle of Wight.

Domiciliary nebulizer use is evaluated in a well-defined population on the Isle of Wight covering all ages. A questionnaire was administered to 167 known users and all were completed. The indication for nebulizer therapy was asthma (137), bronchitis (32) and emphysema (30). Twenty-three had never had a simple inhaler device prescribed and, of the others, 13 had never had instruction in its use. One hundred and fifty-three had used the nebulizer within the previous year and, of these, instruction was provided by physiotherapist (87), general practitioner (30), nurse (19) and hospital doctor (6). Nine received no advice. The drugs used comprised mostly salbutamol (140) and sodium cromoglycate (51). Twenty-six mixed medicines for use in the nebulizer and 24 admitted to exceeding the recommended dose. Twenty-three patients had a peak flow meter available at home. With treatment failure, 108 would call a doctor or report to hospital, while 25 would persist with nebulizer therapy. Thirty-two patients had no help at home in the event of an emergency. Most patients thought that they benefited greatly from nebulizer treatment at home, but better selection of patients and monitoring of treatment is needed. Comparison with previous studies suggests that there has been little improvement in the domiciliary use of nebulizers.

Adolescent↗

The use of home nebulizers in adult asthma.

Nebulization therapy is an approach for the treatment of respiratory diseases such as asthma which was not anticipated in the international recommendations for the treatment of asthma and which merits study. Even if the place of nebulizers in the treatment of asthma exacerbations has been validated, this is not the case for adult asthmatic subjects with chronic asthma. While asthma control for most patients can be achieved using metered-dose inhaler and dry powder inhaler therapy, some patients may require regular home nebulized therapy. Before determining the objectives and therapeutic characteristics of nebulization in the treatment of chronic asthma in the adult patient, we shall first describe the pathophysiological elements involved in the treatment of asthma and of the couple 'nebulized substance-nebulizer' leading to an optimal nebulization.

Adult↗

Monitoring nebulizer use in children: comparison of electronic and asthma diary data.

BACKGROUND: Measurement of nebulizer medication adherence that relies on self-report of medication use is subject to recall bias and increased patient burden. Electronic monitoring of nebulizer medication use is relatively new technology and provides an objective measure of nebulizer use. OBJECTIVE: To examine levels of agreement for nebulizer use between self-report on diary cards and electronic monitor data in young inner-city children with asthma. METHODS: Of 221 enrolled children with persistent asthma, 157 (71%) provided 12 weeks of diary card and nebulizer monitor recordings that were matched by date across days and by patient. Concordance, sensitivity, specificity, and kappa coefficients were calculated between self-report and electronic data. RESULTS: The children were predominantly African American (89%) and male (66%), with a mean age of 4.6 years. Their persistent asthma was categorized as mild (61%) or moderate to severe (35%). Concordance between diary and electronic data was 85%, with overreporting on diary cards noted on 15% of the total days. Sensitivity of the diary data relative to the electronic data ranged from 0.80 to 0.91 during the 12-week study. Diary return rates decreased from 75% during the initial 3 weeks to 44% at 12 weeks. CONCLUSIONS: Electronic monitoring of nebulizer use provides a more precise measure of long-term medication use than does self-report on diary cards, and it is feasible for use in high-risk populations. However, diary cards seem to be a valid alternative for short-term monitoring of nebulizer use, resulting in only a slight overestimation of medication use.

Administration, Inhalation↗

Contamination of nebulizer equipment with cockroach allergen: there's a bug in the system!

BACKGROUND: Physicians often have anecdotal reports of patients describing increased asthma symptoms after the use of nebulizers; however, there are few published reports of nebulizer-associated exacerbations. OBJECTIVE: To present 2 cases of asthmatic children who experienced a life-threatening exacerbation of their symptoms after nebulizer use. METHODS: Case 2's nebulizer was tested for cockroach allergen by washing the medication reservoir with 2 mL of sterile filtered 1% phosphate-buffered saline, 0.05% bovine serum albumin, and Tween 20 overnight with rotation. The patient's sealed albuterol nebulizer medication was used as a control. The control albuterol and test solutions were analyzed for Blattella germanica 1 and 2 allergens using a monoclonal antibody-based immunoenzymetric assay. RESULTS: The reservoir from case 2 was found to have measurable levels of both Bla g 1 and Bla g 2. The control albuterol solution had no measurable cockroach allergen. An insect found in the nebulizer box of case 2 was identified as an infantile German cockroach. CONCLUSIONS: Nebulizer use provides an opportunity for antigen exposure directly to small airways, which may lead to severe allergic reactions in patients using contaminated equipment.

Adolescent↗

Systemic availability and lung deposition of budesonide via three different nebulizers in adults.

BACKGROUND: Budesonide is an inhaled corticosteroid widely used in the treatment of asthma. The local and systemic availability of budesonide has been determined in adults via pressurized metered-dose inhaler and dry-powder inhaler. OBJECTIVE: To estimate lung deposition and systemic availability of budesonide inhalation suspension in healthy adults. METHODS: Twelve adult volunteers entered an open, randomized, five-way crossover study and received the following treatments, with 1-week washout between treatments: separate 2-mg (nominal dose) budesonide doses via the Pari Inhalierboy (Inhalierboy; Pari GmbH, Starnberg, Germany), Pari LC Jet Plus (Jet Plus, Pari GmbH), and Maxin MA-2 (MA-2; Clinova Medical AB, Malmö, Sweden) jet nebulizers, 4 mg budesonide orally, and 0.5 mg budesonide intravenously. The plasma concentration of budesonide was measured up to 8 hours postadministration. Lung deposition and systemic availability of nebulized budesonide were estimated using pharmacokinetic evaluation. RESULTS: In this first study of the bioavailability of budesonide inhalation suspension in adults, there were no differences between nebulizers in lung deposition (14 to 16%) or systemic availability (15 to 17%) relative to the nominal budesonide dose. Relative to the actual dose inhaled (dose-to-subject), lung deposition and systemic availability were statistically significantly higher for the Jet Plus (58 and 63%, respectively) and MA-2 (59 and 64%, respectively) nebulizers than the Inhalierboy (36 and 44%, respectively). The Inhalierboy produced larger aerosol droplets than Jet Plus or MA-2 nebulizers (7-, 5-, and 3-microm mass median diameters, respectively) and delivered a higher dose-to-subject than the other two nebulizers. CONCLUSION: Relative to the nominal dose, lung deposition and systemic availability of budesonide were similar via the three nebulizers tested.

Administration, Inhalation↗

Comparison of inhaled metaproterenol via metered-dose and hand-held nebulization in prehospital treatment of bronchospasm.

INTRODUCTION: Although the efficacy of the administration of beta-adrenergic bronchodilators has been demonstrated, the best method available for the delivery of these drugs in the prehospital setting has not been defined. This paper compares the effects of administration of metaproterenol when administered by paramedics using either a metered-dose inhaler (MDI) or a hand-held nebulizer (HHN). HYPOTHESIS: There is no difference in the effects produced in patients suffering from smooth bronchiolar muscle spasm by metaproterenol when delivered either by a standard metered-dose inhaler or with a hand-held nebulizer. PARTICIPANTS: Consecutive prehospital patients complaining of difficulty breathing with clinical evidence of bronchospasm and with a history of asthma, chronic obstructive pulmonary disease, or emphysema who were not in extremis. METHODS: Prior to the administration of metaproterenol, a peak expiratory flow rate (PEFR) was obtained. This measurement was repeated five minutes following the conclusion of the administration of metaproterenol. Patients in Burbank, California, received the treatment using a standard metered-dose inhaler, and those in Madison, Wisconsin, received the drug using a hand-held nebulizer. Peak expiratory flow rates were compared using Student's t-tests with Bonferroni's correction. Statistical significance was set at p < 0.05. RESULTS: Data were collected from 36 consecutive patients by the paramedics of the Burbank Fire Department and from 32 consecutive patients by the paramedics of the Madison Fire Department. For the metered-dose inhaler group, the mean value for peak expiratory flow rate for the pre-treatment test was 95.4 +/- 88.1 l/min, and after treatment was 109.4 +/- 89.3 l/min (p < 0.001). For the hand-held nebulizer group, the mean value for peak expiratory flow rate before the administration of the metaproterenol was 96.1 +/- 76.3 l/min and following the treatment was 149.1 +/- 92.9 l/min (p < 0.001). The mean values for the differences between the control peak expiratory flow rate and the post-treatment peak expiratory flow rate for the metered-dose inhaler group was + 140.0 +/- 27.4 l/min, and for the hand-held nebulizer group was + 53.0 +/- 69.1 l/min (p < 0.003). CONCLUSIONS: In the prehospital setting, the administration of metaproterenol using a hand-held nebulizer is more effective than delivering the drug using a metered-dose inhaler. The hand-held nebulizer is easier to use and delivers a higher dose of the drug than is convenient using the metered-dose inhaler.

Administration, Inhalation↗

Efficient delivery to the lungs of flunisolide aerosol from a new portable hand-held multidose nebulizer.

In order to provide asthmatic patients with an inhaler that does not use chlorofluorocarbon propellants, a novel multidose hand-held nebulizer (RESPIMAT, Boehringer Ingelheim Ltd.) has been developed. This device delivers 200 x 15 microL metered doses of drug solution, but does not use propellants of any kind. In this study of 10 healthy volunteers, the deposition pattern in the lungs and oropharynx of an ethanolic solution of flunisolide delivered via a prototype III multidose nebulizer has been determined by gamma scintigraphy. A comparison was made with the same dose (250 micrograms) of flunisolide delivered by a pressurized metered dose inhaler (MDI) and MDI plus Inhacort spacer. Mean (SD) whole lung deposition from the multidose nebulizer (39.7 (9.9) % of the metered dose) was significantly higher than that from either MDI (15.3 (5.1) %, P < 0.01) or MDI plus spacer (28.0 (7.0) %, P = 0.01). A mean 10.4% of the dose was recovered from an exhaled air filter for the multidose nebulizer, but less than 2% of the dose for MDI or MDI plus spacer. Oropharyngeal deposition was significantly reduced for the multidose nebulizer (39.9 (9.4) %) compared to MDI (66.9 (7.1) %), but was reduced further for the MDI plus spacer (27.3 (11.3) %). The multidose nebulizer delivers an unusually high percentage of an aerosol dose to the lungs, and it "targets" flunisolide to the lungs more effectively than the MDI. The multidose nebulizer could constitute a viable alternative to MDIs in asthma maintenance therapy.

Adult↗

Characterization of aerosols of human recombinant deoxyribonuclease I (rhDNase) generated by jet nebulizers.

Recombinant human deoxyribonuclease I (rhDNase) is a new therapeutic agent developed to improve clearance of purulent sputum from the human airways. It is delivered by inhalation. Four jet nebulizers, T Up-Draft II (Hudson), Customized Respirgard II (Marquest), Acorn II (Marquest), and Airlife Misty (Baxter), were evaluated in vitro for their ability to deliver aerosols of rhDNase. The aerosols were generated from 2.5-mL aqueous solutions of rhDNase, at concentrations of either 1 or 4 mg/mL. In all experiments, the Pulmo-Aide Compressor (De Vilbiss) was used to supply the air to the nebulizers. Between 20 and 28% of the rhDNase dose initially placed in the nebulizers was delivered to the mouthpiece in the respirable range (1-6 microns). Evaluation of the rhDNase following nebulization in all four devices indicated that there was no loss in enzymatic activity and no increase in aggregation. Circular dichroism spectrophotometry indicated there was no change in either the secondary or the tertiary structure in rhDNase following nebulization. These results show that all four nebulizers are essentially equivalent in their ability to deliver respirable doses of rhDNase in an intact, fully active form. Changing the concentration of the solution in the nebulizer from 4 to 1 mg/mL rhDNase leads to a proportional reduction in the respirable dose delivered to the mouthpiece.

Aerosols↗

Aerosolization of cationic lipid:pDNA complexes--in vitro optimization of nebulizer parameters for human clinical studies.

Previously, we have described the optimization of the aerosol delivery of a nonviral gene therapy vector to the lungs of rodents (Eastman et al., 1997b). Although aerosolizing cationic lipid:pDNA complexes into a whole-body exposure chamber resulted in high levels of reporter gene expression in the lungs of BALB/c mice, the conditions employed were not optimal for the delivery of lipid:pDNA complexes to the lungs of human patients. That is, the consumption rate of the material in the nebulizer, and thus the delivery time, were very slow and the aerosol was delivered in a continuous flow. Here we describe in vitro experiments used to develop a cationic lipid:pDNA aerosol with characteristics more suitable for delivery to the lungs of humans, as a necessary prerequisite for conducting a clinical study with human cystic fibrosis patients. Using cascade impactors and all-glass impingers, we have screened several commercially available nebulizers for their ability to deliver intact, respirable, active lipid:pDNA complexes in the shortest time possible, and have identified the Pari LC Jet Plus nebulizer as the optimal nebulizer that meets these criteria. Using this nebulizer in an intermittent mode to mimic breath actuation, consumption rates of approximately 0.6 ml/min of the cationic lipid:pDNA complexes (6 mM cationic lipid:8 mM pDNA) were obtained. The plasmid DNA remained intact and the complexes were shown to maintain activity throughout the nebulization run. Based on measurements of the nebulized dose and the mass median aerodynamic diameter, we calculate a delivered dose of approximately 22 micromol (7.2 mg) of pDNA for each 8 ml of cationic lipid:pDNA complex aerosolized to the lungs of a human patient. This dose should be sufficient to test the clinical efficacy of cationic lipid-mediated gene delivery for the treatment of cystic fibrosis.

Aerosols↗

Clinical efficacy of nebulized drugs.

There is a mandatory need for effortless drug administration to young children since the prevalence among them of recurrent wheezing is a 15-20%. It is becoming increasingly evident that many of these children respond dramatically well to beta2-agonists and topical steroids; accordingly this sub-group of children should be treated as asthmatics. The dose of topical steroids is critical as opposed to that of beta2-agonists which are often administered in doses well above the minimal effective dose. Budesonide suspension has proven its efficacy in adults in a study of 21 patients with asthma treated with budesonide suspension delivered from a nebulizer activated during inspiration versus metered dose inhalation (MDI) via a large-volume spacer. Nebulized in this manner the suspension exhibited a dose-dependent effect, apparently equipotent to the MDI administration as evaluated from daily peak expiratory flow measurements and symptom scoring. Continuous nebulization of budesonide in 18 schoolchildren with bronchial asthma similarly showed a dose-dependent improvement of lung function and symptom score, though in a 1:2 potency ratio as compared to MDI administration, probably due to loss of nebulized aerosol during expiration. In a subsequent study of 23 young children unresponsive to beta2-agonist therapy, nebulized budesonide was without demonstrable effect. Recently, a study of 31 young children with steroid-dependent asthma demonstrated a significant improvement from continuous nebulization of budesonide 1mg twice daily. In conclusion, the efficacy of nebulized budesonide has been convincingly demonstrated in patients with reversible symptoms of asthma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Characterization of heparin aerosols generated in jet and ultrasonic nebulizers.

Inhaled heparin has been used for asthma treatment, but results have been inconsistent, probably due to highly varying lung doses. We determined the output per unit time and the particle size distributions of sodium heparin, calcium heparin, and low molecular weight (LMW) heparin formulations in five concentrations from Sidestream jet nebulizers (Medic-Aid, Bognor Regis, England) and an Ultraneb 2000 ultrasonic nebulizer (DeVilbiss, Langen, Germany). We also determined the inhaled mass and the estimated respirable mass for some combinations. For the jet nebulizer, output per minute increased with increasing concentration and flow rate, and particle size decreased from 3.64 to 2.01 microns (mass median diameter [MMD]). The percentage of particles less than 3 microns ranged from 41% to 74%. For the ultrasonic nebulizer, maximum output per minute was achieved at a concentration of 7000 i.u./mL; this maximum depended upon the viscosity and temperature of the solution. MMD was independent of formulation, temperature, or concentration and ranged from 5.61 to 7.03 microns. Sodium heparin/calcium heparin in a concentration of 20,000 i.u./mL in the jet nebulizer driven at 10 L/min produced the highest dose of heparin capable of reaching the lower respiratory tract. Mass balance was determined for these combinations with the jet nebulizer run until visible aerosol generation ceased. Of a loading dose of 80,000 i.u. of heparin, 45,000 i.u. remained in the dead space of the nebulizer, 20,000 i.u. was deposited on the exhalation filter, and 15,000 i.u. was captured on the inhalation filter (inhaled mass). This corresponds to a respirable mass of 10,000 i.u. of heparin with a high probability of reaching the lower respiratory tract in normal healthy adults.

Adult↗

Basis for nebulized antibiotics: droplet characterization and in vitro antimicrobial activity versus Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

The aims of this study were to (1) quantify the particle size characteristics of several antibiotics considered suitable for aerosol therapy after aerosolization with the PARI IS/2 nebulizer (Pari GmbH, Sarnberg, Germany) and (2) determine the degree to which in vitro antimicrobial activity of these antibiotics is maintained after nebulization. The aerosolized drugs were tobramycin sulfate, streptomycin, and imipenem, with saline solution as the control. Mean mass aerodynamic diameter of the nebulized drugs was 3.25 microns for tobramycin, 2.26 microns for imipenem, and 2.38 microns for streptomycin. In vitro tests showed that tobramycin and imipenem were unaltered in their bacteriostatic activity against strains of Escherichia coli (American Type Culture Collection [ATCC] 25922) and Staphylococcus aureus (ATCC 29213) as well as against Pseudomonas aeruginosa (ATCC 27853) with minimal inhibitory concentration (MIC) values less than 0.3 microgram/mL. Nebulized streptomycin showed significantly higher MIC values against P. aeruginosa (ATCC 27853). These results suggest that tobramycin and imipenem may be prescribed as an aerosol generated by jet nebulization (PARI IS/2) to treat S. aureus, E. coli, and P. aeruginosa infections without any risk of altering the drugs minimum bacteriostatic activity by the nebulization process. Aerosolization of streptomycin with this nebulizer may not be as effective against P. aeruginosa because it seems to alter the bacteriostatic activity.

Aerosols↗

Evaluation of nebulizer performance under various humidity conditions.

Jet nebulizers are a drug delivery tool commonly used for treating respiratory diseases. When a nebulizer generates aerosols, the rate at which droplets evaporate depends on humidity conditions around the nebulizer outlet. Because the relative humidity (RH) of the air affects the evaporation rate, the aerosol distribution and drug delivery dose is also affected by RH. Four nebulizers were chosen for comparison in this study: PARI LC Plus (PARI Respiratory Equipment, Inc., Midlothian, VA), SideStream (Medic-Aid Ltd., UK), VixOne (Westmed, Inc., Tucson, AZ), and Micromist (Hudson Respiratory Care Inc., Temecula, CA). Two different formulations were used: albuterol (liquid solution) and budesonide (suspension). Particle distribution (mass median aerodynamic diameter [MMAD] and geometric standard deviation [GSD]), nebulizer efficiency (total efficiency and respirable fraction [RF] efficiency for particles less than 4.7 microm), and dead volume (the amount of solution remaining after nebulization) were compared at the RH of 5%, 50%, and 80%. Our results showed that the MMAD increased (p value varied from <0.001 to 0.016) with the increase in RH, except for with the VixOne unit with albuterol (p = 0.24). The MMAD from the budesonide always appeared higher than from the albuterol. The RF (and thus, the inhalation dose) was lower with a higher RH. Except for the PARI LC Plus with budesonide, the RF decreased approximately 15-27% when the RH rose from 5% to 50%. For the PARI LC Plus nebulizer, the lower dead volume (0.22 mL) with higher residual drugs (62.3% of total drug) was obtained at an RH of 5% comparing the RH of 50% and 80% because of the unit's unique design.

Aerosols↗

In vitro evaluation of aerosol bronchodilator delivery during noninvasive positive pressure ventilation: effect of ventilator settings and nebulizer position.

OBJECTIVE: Respiratory failure due to exacerbation of obstructive lung disease has been successfully treated with noninvasive positive pressure ventilation (NPPV). However, there have been no reports of factors affecting aerosol delivery during NPPV. Our objective was to determine the effect of ventilator settings and nebulizer position on albuterol delivery during NPPV. DESIGN: Bench model study. SETTING: University laboratory. SUBJECTS: None. INTERVENTIONS: A Respironics BiPAP S/T-D30 with a standard circuit was attached to a lung model simulating spontaneous breathing. Inspiratory/expiratory pressures of 10/5, 15/5, 20/5, 15/10, 20/10, and 25/10 cm H2O were tested at respiratory rates of 10 and 20/min. A nebulizer was filled with 5 mg of albuterol in 4 mL of solution, driven with 8 L/min oxygen, and placed at either a proximal (ventilator outlet) or distal (between leak port and lung model connection) position. Albuterol delivery was estimated by measuring the amount of the albuterol collected on a filter placed at the inlet of the lung model. MEASUREMENT AND MAIN RESULTS: Albuterol delivery varied from 5.2 +/- 0.4% to 24.5 +/- 1.3% of the nominal dose and was significantly affected by the position of the nebulizer, respiratory rate, and BiPAP settings (p <.001 in each case). The greatest albuterol delivery was observed with the nebulizer operating at the distal position and a respiratory rate of 20/min. At this respiratory rate and nebulizer placement, albuterol delivery increased with increasing inspiratory pressure levels and decreased as expiratory pressure levels were increased. Nebulizer flow did not affect function of the ventilator. CONCLUSIONS: At optimum nebulizer position (between the leak port and patient connection) and ventilator settings (high inspiratory pressure and low expiratory pressure), as much as 25% of the nominal albuterol dose may be delivered during NPPV.

Aerosols↗

Pharmacoscintigraphic comparison of HMR 1031, a VLA-4 antagonist, in healthy volunteers following delivery via a nebulizer and a dry powder inhaler.

A pharmacoscintigraphic study was conducted to compare the dose deposition of HMR 1031 from the existing nebulizer formulation and the new Ultrahaler device to help determine the doses for future phase 2 trials. This was a single-dose, open-label, randomized, two-way crossover study in which HMR 1031 (3 mg) was delivered by the Ultrahaler and the Pari LC Star nebulizer to 12 healthy male subjects. For both treatments, the formulations were radiolabeled with technetium-99m pertechnetate such that a maximum of 10 MBq was delivered on each study day. Scintigraphic images were acquired immediately after dosing to estimate the percentage of the dose delivered to the lungs and oropharynx. Serial plasma samples were collected up to 12 hours post-dose on each occasion and analyzed for HMR 1031 by a LC/MS/MS method with a lower limit of quantitation of 10 pg/mL (0.01 ng/mL). Pharmacokinetic parameters were calculated for HMR 1031 using noncompartmental methods. No serious adverse events were reported. The systemic absorption of HMR 1031 following inhalation administration was relatively rapid, with median T(max) values of 0.5 hours and 1.0 hours post-dose after administration via Ultrahaler and nebulizer, respectively. The mean plasma AUC(0-12) (Ultrahaler, 15.8 ng*h/mL; nebulizer, 11.1 ng*h/mL) and C(max) (Ultrahaler, 4.96 ng/mL; nebulizer, 2.28 ng/mL) values were approximately 42% and 118% higher for the Ultrahaler compared with the nebulizer. The mean terminal half-life of HMR 1031 was similar after administration from both devices (2.91 and 3.18 hours). Based on the scintigraphic data, the lung deposition of HMR 1031 after administration by Ultrahaler (24.6% of the administered dose) was approximately 37% higher compared with the lung deposition from the nebulizer (18.0% of the administered dose). This observation was in agreement with the relative difference in the plasma AUC values achieved after administration of the two formulations. The in vivo results based on the scintigraphic data were also comparable with those from in vitro studies for the Ultrahaler. Based on the ratio of the dose delivered by both the formulations, the required doses for the future Ultrahaler formulation can be predicted.

Administration, Inhalation↗