The cost-effectiveness of strategies to reduce mortality from an intentional release of aerosolized anthrax spores

BACKGROUND

Intentional exposures to aerosolized Bacillus anthracis spores have caused fatalities.

OBJECTIVE

To evaluate the cost-effectiveness of strategies to reduce mortality from future inhalational anthrax exposures.

METHODS

Computer cohort simulation of a 100,000-person single-site exposure (worst-case scenario) and a 100-person multiple-site exposure (resembling the recent US attack). For each scenario, universal vaccination and an emergency surveillance and response (ESR) system were compared with a default strategy that assumed eventual discovery of the exposure.

RESULTS

If an exposure was unlikely to occur or was small in scale, neither vaccination nor an ESR system was cost-effective. If an exposure was certain and large in scale, an ESR system was more cost-effective than vaccination ($73 v. $29,600 per life-year saved), and a rapid response saved more lives than improved surveillance.

CONCLUSIONS

Strategies to reduce deaths from anthrax attacks are cost-effective only if large exposures are certain. A faster response is more beneficial than enhanced surveillance.

Lung deposition of HFA beclomethasone dipropionate in an animal model of bronchopulmonary dysplasia

The best delivery of a drug in ventilated neonates is obtained when using a small particle diameter solution administered via a spacer. Lung deposition of hydrofluoroalkane beclomethasone dipropionate (QVAR, 1.3 microm particles), delivered via an Aerochamber-MV15, was measured in piglets under conditions mimicking ventilated severely ill neonates (uncuffed 2.5 mm endotracheal tube; peak pressure 16 cm H2O; respiratory rate 40/min). After determining the mass and particle size distribution of the 99mTc-labeled and unlabeled drug, three lung deposition studies were performed: after 1 h of ventilation (controls, n = 18), after 48 h aggressive ventilation inducing an acute lung injury (nine piglets out of the controls), and after increasing the pressure to 24 cm H2O during drug delivery (five piglets out of the nine with acute lung injury). All piglets were then killed for lung histology. Results (median, range), expressed as a percentage of the delivered dose, were compared using an inferential or the Friedman test. While lung deposition was low, it was greater (p = 0.003) in controls (2.66%, 0.50-7.70) than in piglets with histologically confirmed acute lung injury (0.26%, 0.06-1.28) or under a high-pressure ventilation (1.01%, 0.30-2.15). Lung deposition of QVAR in an animal model of ventilated neonates is low, variable, and dramatically affected by lung injury.

In vitro investigation of drug particulates interactions and aerosol performance of pressurised metered dose inhalers

PURPOSE

To determine a relationship between adhesive and cohesive inter-particulate forces of interactions and in vitro performance in pressurised metered dose inhalers (pMDIs) suspension formulations.

METHODS

Interparticulate forces of salbutamol sulphate (SS), budesonide (BUD) and formoterol fumarate dihydrate (FFD) were investigated by in situ atomic force microscopy (AFM) in a model propellant 2H, 3H perfluoropentane (HPFP). Experimental data were analysed using the recently developed cohesive/adhesive analysis method (CAB) and compared with in vitro deposition performances in pMDIs systems using Andersen cascade impactor (ACI).

RESULTS

The in vitro investigation suggested that the micronised drug materials had significantly different aerosolisation profiles when manufactured as single or combination formulations. In general, the greatest significant differences were observed between SS single drug and SS-BUD and SS-FFD combinations. Analysis of the in vitro performance for the SS only formulation suggested that the cohesive nature of SS (as predicted by the CAB and observed with AFM) led to tightly bound flocs that did not fully deaggregate upon aerosolisation.

CONCLUSIONS

It is suggested that the relationship between interparticulate interactions and in vitro performance of pMDIs suspension systems, when compared to direct measurement of the adhesion/cohesion forces, indicated good correlation. This approach may be useful in expediting the development of pMDI formulation and predicting performance.

Usefulness of HFA-BDP for adult patients with bronchial asthma: randomized crossover study with fluticasone

In this randomized crossover study, 22 adult patients with moderate-to-severe persistent bronchial asthma were assigned to one of two groups. Patients in group 1 were administered fluticasone dry powder inhaler (DPI) for 8 weeks followed by a 2-week washout period, then hydrofluoroalkane-beclometasone dipropionate (HFA-BDP) for 8 weeks. After a further 2-week washout, they were again administered fluticasone DPI for 8 weeks. Patients in group 2 were assigned HFA-BDP followed by fluticasone PII and finally HFA-BDP over the same time periods. In both groups, no significant difference was observed in use of beta2-agonists and symptom score between the treatment periods; however, markers of pulmonary function were significantly higher when on HFA-BDP versus fluticasone DPI. Significant increases of morning peak expiratory flow (PEF) (p < 0.01), forced expiratory volume in 1 second (FEV1.0) (p < 0.01), V50 (p < 0.05), and V25 (p < 0.01) were observed at 18 weeks in group 1, whereas there were significant decreases of V50 (p < 0.05) at 18 weeks in group 2. No significant difference was noted in circulating eosinophil count and serum ECP between the 2 treatments; however, ECP in induced sputum and nitric oxide in expired gas were significantly lower (p < 0.05 and < 0.01, respectively) when on HFA-BDP versus fluticasone DPI. HFA-BDP might be delivered to small airways more effectively than fluticasone DPI.

Pharmacokinetics of beclomethasone dipropionate in an hydrofluoroalkane-134a propellant system in Japanese children with bronchial asthma

BACKGROUND

Hydrofluoroalkane-134a (HFA) has been shown to be a safe replacement for chlorofluorocarbons (CFCs) as a pharmaceutical propellant, with the advantage that it has no ozone-depleting potential. This is the first report of the pharmacokinetics of beclomethasone dipropionate (BDP) delivered from a pressurized solution formulation using an HFA propellant system (HFA-BDP) in Japanese children with bronchial asthma.

METHODS

Plasma concentrations of beclomethasone 17-monopropionate (17-BMP),a major metabolite of BDP, following an inhaled dose of HFA-BDP (200 microg as four inhalations from 50 microg/actuation) in five Japanese children with bronchial asthma were quantified and analyzed by a non-compartmental analysis to obtain pharmacokinetic parameters.

RESULTS

The area under the concentration-time curve from time zero to the last quantifiable time (AUC(0-t)) was 1659 +/- 850 pg x h/mL (arithmetic mean +/- standard deviation (SD)), the maximum concentration observed (C(max)) was 825 +/- 453 pg/mL and the apparent elimination half-life (t(1/2)) was 2.1 +/- 0.7 hours. The time to reach Cmax Tmax was 0.5 hours in all patients. No special relationship was observed between these parameters and age or body weight. These parameters were compared with the previously reported parameters of American children with bronchial asthma. The Japanese/American ratio of the geometric means of each parameter was 1.36 for AUC(0-t), 1.04 for Cmax and 1.4 for t(1/2). The median of Tmax was 0.5 hours in American patients as well as Japanese patients.

CONCLUSIONS

The pharmacokinetics of HFA-BDP in Japanese children with bronchial asthma are reported for the first time and a similarity to those in American children is suggested.

In VitroValidation of99mTc-HFA-FP Delivered via pMDI-Spacer

The purpose of the study was to label Flixotide (fluticasone propionate [FP] with HFA propellant), with technetium-99m and validate that (99m)Tc acts as a suitable marker for FP when delivered via pMDI-spacer. Sodium pertechnetate was mixed with 5 mL of butanone. (99m)Tc was extracted into butanone and transferred into an empty canister. The (99m)Tc lined canister was heated, and the butanone evaporated to dryness. A supercooled commercial Flixotide canister was decrimped, and the contents transferred to the (99m)Tc lined canister and recrimped. The particle size distribution of FP and (99m)Tc from 10 radiolabeled canisters was measured using an Anderson cascade impactor calibrated to 28.3 L/min, and compared to commercial FP. The drug (FP) content of each particle size fraction was measured using ultraviolet spectrophotometry and the (99m)Tc level in each fraction was measured using an ionization chamber. The percentage of particles in the fine particle fraction (<;4.7 microm) and the percentage of (99m)Tc from commercial and radiolabeled canisters were compared. The mean (SD) % FP in the fine particle fraction, before and after label was 43.2 (1.8) % and 43.9 (2.6) %, respectively. The mean (SD) % (99m)Tc in the fine particle fraction was 42.1 (5.1) %. The mean %FP exiting spacer at (<4.7 microm) before labeling was not significantly different from the mean % FP exiting spacer at (<4.7 microm) after labeling (p > 0.05). The mean % (99m)Tc attached to particles at (<4.7 microm) after radiolabeling was not significantly different from the mean % FP levels (p > 0.05). The validation in this study indicates that (99m)Tc can act as a suitable marker for HFAFP, delivered via pMDI-spacer.

Generating Monodisperse Pharmacological Aerosols Using the Spinning-top Aerosol Generator

Pharmacological aerosols of precisely controlled particle size and narrow dispersity can be generated using the spinning-top aerosol generator (STAG). The ability of the STAG to generate monodisperse aerosols from solutions of raw drug compounds makes it a valuable research instrument. In this paper, the versatility of this instrument has been further demonstrated by aerosolizing a range of commercially available nebulized pulmonary therapy preparations. Nebules of Flixotide (fluticasone propionate), Pulmicort (budesonide), Combivent (salbutamol sulphate and ipratropium bromide), Bricanyl (terbutaline sulphate), Atrovent(ipratropium bromide), and Salamol (salbutamol sulphate) were each mixed with ethanol and delivered to the STAG. Monodisperse drug aerosol distributions were generated with MMADs of 0.95-6.7 microm. To achieve larger particle sizes from the nebulizer drug suspensions, the STAG formed compound particle agglomerates derived from the smaller insoluble drug particles. These compound agglomerates behaved aerodynamically as a single particle, and this was verified using an aerodynamic particle sizer and an Andersen Cascade Impactor. Scanning electron microscope images demonstrated their physical structure. On the other hand using the nebulizer drug solutions, spherical particles proportional to the original droplet diameter were generated. The aerosols generated by the STAG can allow investigators to study the scientific principles of inhaled drug deposition and lung physiology for a range of therapeutic agents.

Two-dimensional and three-dimensional imaging show ciclesonide has high lung deposition and peripheral distribution: a nonrandomized study in healthy volunteers

Drug deposition is an important factor that contributes to safety and efficacy outcomes of inhaled steroid therapy. Ciclesonide is a nonhalogenated, inhaled corticosteroid under investigation for the treatment of asthma. Therefore, this study was performed to assess lung deposition of ciclesonide. Technetium-99m (99mTc)-labeled ciclesonide (where the 99mTc-label is physically dissolved in the ciclesonide-hydrofluoroalkane [HFA] solution aerosol) inhaled by healthy volunteers was analyzed by two-dimensional (2-D) and three-dimensional (3-D) imaging to determine lung deposition. Six healthy volunteers inhaled one puff of 40 microg (exactuator, equivalent to 50 microg ex-valve) ciclesonide for 2-D imaging, and two healthy volunteers inhaled 10 puffs of 40 microg ciclesonide for 2-D and 3-D imaging. The ciclesonide aerosol was administered via metered-dose inhaler (MDI) containing HFA-134a as propellant. The ex-actuator mean (+/- standard deviation) deposition of ciclesonide in the lungs was higher (52% +/- 11%) than in the mouth/pharynx (38% +/- 14%). Two-dimensional and 3-D imaging showed that ciclesonide reached all regions of the lung. Mean percent deposition in peripheral regions (47% and 34%) was higher than in lower central regions (17% and 30%), as revealed by 3-D and 2-D imaging, respectively. Inhalation of up to 400 microg of ciclesonide produced no drug-related side effects. In conclusion, ciclesonide administered via metered-dose inhaler using HFA-134a as a propellant provided high lung deposition (>50%), greater distribution throughout peripheral regions of the lungs, and relatively low oropharyngeal deposition.

Manipulation of beclomethasone-hydrofluoroalkane interactions using biocompatible macromolecules

The aim of this work was to physically stabilise beclomethasone dipropionate (BDP) microparticles within a hydrofluoroalkane (HFA) propellant using biocompatible polymers in order to allow the efficient delivery of the steroid to the airways from a pressurised metered dose inhaler (pMDI). BDP microparticles were coated with a number of different "amphiphilic" macromolecular excipients by spray-drying an aqueous BDP suspension in which the excipients were dissolved. The physical stability of the coated BDP microparticles was assessed both indirectly using a twin-stage impinger (TSI) and directly using "in-situ" laser diffraction particle size analysis in a range of nonpolar solvents. The solubility of the formulation excipients within a number of the nonpolar vehicles was determined using an internally manufactured filtration rig and the influence of zeta potential within the microparticle suspensions measured in a series surrogate nonpolar systems. The size of the pure BDP microparticles increased significantly (p < 0.05, ANOVA) from 3.13 +/- 0.15 microm to 9.86 +/- 0.50 microm upon suspension within a nonpolar HFA solvent. However, the addition of poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) to the BDP microparticles dramatically reduce this aggregation leading to the production of physically stable suspensions with excellent aerosolisation properties (Stage 2 deposition >40% in the twin-stage impinger). It is postulated that the enhanced physical stability observed when PVA and PVP are coated onto BDP microparticles is partially as a result of steric stabilisation in HFA solvents. However, the large zeta potential associated with the nonpolar microparticle suspensions suggest that charge stabilisation may also influence the physical stability within these systems.

The functional benefit of anti-inflammatory aerosols in the lung periphery

BACKGROUND

The target of anti-inflammatory therapy in asthma is thought to be situated, at least partly, in the lung periphery, and inhaled steroid aerosols are being engineered to reach it. However, the potential effect of such aerosols cannot be fully evaluated by conventional lung function tests because these are insensitive to peripheral lung structure.

OBJECTIVE

A prospective cohort study was conducted to investigate whether ultrafine steroid aerosols can elicit a response in the lung periphery, using a validated multibreath washout technique that can distinguish acinar from conductive lung zone function.

METHODS

In 30 stable patients with asthma with a wide range of disease severity (FEV(1) 27% to 108% predicted), we assessed conductive and acinar airway function abnormality at baseline, with patients on a standard dry powder steroid aerosol and after switching them to an ultrafine steroid aerosol.

RESULTS

Only in those patients with abnormal acinar airway function at baseline (n = 16) did acinar heterogeneity show a consistent improvement after switching to an ultrafine steroid aerosol; the improvement was also correlated with baseline acinar heterogeneity (r = -0.67; P = .007). Although all patients with asthma also presented conductive airway abnormality at baseline, no changes were observed in this lung zone with the switch to the ultrafine aerosol (P > .1).

CONCLUSION

Among stable patients with asthma, those with acinar lung zone abnormality at baseline have the potential to receive functional benefit from an ultrafine steroid aerosol. Clinical studies comparing the efficacy of steroid aerosols targeted to the deep lung should at least include a measurement of peripheral lung zone function.

CLINICAL IMPLICATIONS

A new noninvasive measure of small airways function reveals why, and for which particular patients with asthma, small steroid aerosol particles can be of therapeutic use.

Spray Pattern Analysis for Metered Dose Inhalers: Effect of Actuator Design

PURPOSE

This study was conducted to identify the device factors influencing spray pattern and particle size to gain a more complete understanding of spray plume measurements.

METHODS

A statistically designed experiment was used to investigate the influence of three actuator features (orifice diameter, expansion chamber depth, and orifice length) on spray pattern and particle size profiles. Custom-built actuators were manufactured and analyzed with laser light sheet illumination methods for spray patterns and laser diffraction for particle size analysis.

RESULTS

In addition to orifice size, spray patterns were significantly influenced by the actuator orifice length and sump depth. Particle size analysis of the plumes generated from actuators used in these studies showed that all actuator features (orifice size, length, and sump depth) were significant factors influencing particle size.

CONCLUSIONS

The performance of propellant-based metered dose inhaler aerosols seems to be significantly related to sump depth and orifice length, in addition to orifice size. Rational design of propellant-based metered dose inhalers should therefore consider these variables in addition to formulation strategies and simply modifying orifice diameter.

Clinical comparability between the CFC and HFA budesonide pressurised metered-dose inhalers in paediatric patients with asthma: a randomised controlled trial

OBJECTIVE

To evaluate the efficacy and tolerability of a novel hydrofluoroalkane (HFA) pressurised metered dose inhaler (pMDI) formulation of budesonide (Pulmicort) versus the conventional chlorofluorocarbon (CFC) pMDI formulation in paediatric patients with asthma.

METHODS

This was a Phase III, multicentre, 12-week, double-blind, randomised, parallel-group study involving children (6-12 years of age) with mild to moderate asthma. Patients received either budesonide HFA pMDI or budesonide CFC pMDI 200 mug twice daily, with or without a spacer (NebuChamber/Nebunette). Primary efficacy endpoint: mean percentage change in forced expiratory volume in 1 second (FEV(1)) from baseline to week 12. Secondary efficacy endpoints included changes in FEV(1) per cent of predicted normal, forced vital capacity, morning and evening peak expiratory flow rate, asthma symptoms and use of rescue medication.

RESULTS

A total of 159 patients received treatment (HFA 77, CFC 82). For mean percentage change in FEV(1) from baseline to week 12, the difference between the treatments (CFC pMDI - HFA pMDI) was -3.1% (95% confidence interval [CI] -8.0% to 1.8%) for the full analysis set and was not affected by spacer use. The upper CI was < 10% (the predefined non-inferiority margin), so non-inferiority was demonstrated. Improvements in the secondary efficacy endpoints with both budesonide formulations were not significantly different. In both groups there were similar numbers of adverse events and no evidence of oral candidiasis at week 12.

CONCLUSIONS

Treatment with budesonide HFA pMDI is effective and well tolerated in children with asthma and is clinically comparable to budesonide CFC pMDI.

Heliox-driven albuterol nebulization for asthma exacerbations: an overview

Our understanding of albuterol nebulization driven by helium-oxygen mixture (heliox) has matured with recent advances in clinical therapy, delivery systems, and understanding of dosing; this has led to substantial improvements in delivery as well as refinements of research protocols for asthma exacerbations. This review begins with heliox inhalation therapy and then addresses heliox as a driving gas for nebulization. Technical considerations are reviewed, including optimal gas mixtures, flow-rate adjustment factors, and nebulizer setup.

A comparison of 2 extrafine hydrofluoroalkane-134a-beclomethasone formulations on methacholine hyperresponsiveness

BACKGROUND

Small airways inflammation is a recognized pathologic component of asthma, and it is postulated that the observed airway-wall remodeling in small airways could be due to uncontrolled inflammation in airways that are not penetrated by conventional inhaled corticosteroids. Thus, extrafine particle formulations of inhaled corticosteroids are of clinical interest.

OBJECTIVE

To compare 2 extrafine solution hydrofluoroalkane-134a formulations of beclomethasone dipropionate (Beclate and Qvar).

METHODS

Fifteen asthmatic patients (mean +/- SEM forced expiratory volume in 1 second [FEV1], 2.62 +/- 0.21 L; provocative concentration of methacholine causing a 20% decrease in FEV1 [PC20], 1.06 +/- 0.58) were randomized to completion in a placebo-controlled, double-blind, crossover manner to receive Beclate or Qvar at doses of 100 or 400 microg/d for 2 weeks, with a 1-week washout period before each randomized treatment. Methacholine hyperresponsiveness was the primary outcome measure.

RESULTS

The 2 formulations were equivalent in terms of predefined equivalence limits of +/- 1 doubling dilution for PC20 at both doses: -0.25 (95% confidence interval [CI], -0.77 to 0.27) doubling dilution difference between the 100-microg doses and a 0.26 (95% CI, -0.29 to 0.82) doubling dilution difference between the 400-microg doses for the difference between Beclate and Qvar, respectively. Both formulations, at either dose, produced a statistically significant (P < .05) reduction in mean exhaled nitric oxide levels: 400 microg/d of Beclate, 14.1 ppb (95% CI, 5.6 to 22.6 ppb); and 400 microg/d of Qvar, 14.2 ppb (95% CI, 6.0 to 22.4 ppb). The higher doses produced a statistically significant (P < .05) reduction in early morning urinary cortisol-creatinine ratio (geometric mean fold suppression: Beclate, 1.48 [95% CI, 1.16 to 1.89]; and Qvar, 1.42 [95% CI, 1.12 to 1.79]). Both formulations significantly improved peak expiratory flow, FEV1, and forced expiratory flow between 25% and 75% of forced vital capacity at the higher doses (P < .05).

CONCLUSIONS

Beclate and Qvar were equivalent for all primary and secondary outcome measures.

Safety and clinical relief over 1 year with triamcinolone acetonide hydrofluoroalkane-134a nasal aerosol in patients with perennial allergic rhinitis

The intranasal corticosteroid triamcinolone acetonide (TAA) is an effective treatment for allergic rhinitis (AR). A new hydrofluoroalkane-134a (HFA)-propelled formulation (TAA-HFA) has been approved recently. This study assessed the safety and efficacy of TAA-HFA in patients with perennial AR over 1 year. A total of 396 patients aged 12-69 years with perennial AR (PAR) enrolled in this 1-year, open-label study. Patients received TAA-HFA, 220 microg, once daily for 2 weeks before adjusting their dose to 440 or 110 microg once daily as needed to control symptoms. Doses were standardized to 440 microg across all patients at approximately 4 months. Physical examinations, vital signs, and laboratory measurements were conducted at baseline, 6 months, and study end. Patient and physician global symptom evaluations were performed at visits 3-10. Patients recorded any adverse events (AEs) on daily diary cards. Of the 396 patients enrolled, 349 (88.1%) reported AEs. The most frequently reported AEs were pharyngitis, rhinitis, local reactions, headache, epistaxis, and sinusitis. Most AEs were mild to moderate in intensity; 34 patients discontinued because of AEs. There were no clinically relevant changes in physical examinations, vital signs, or laboratory measurements. A total of four serious AEs were reported; all were recorded as not related to study drug. Mean patient and physician scores of symptom relief showed significant relief from week 2 (visit 3) through the final visit. Long-term administration of TAA-HFA, 440 microg, exhibited a good safety and tolerability profile, while providing moderate-to-complete symptom relief as rated by patients and physicians.

Deposition pattern of heliox-driven bronchodilator aerosol in the airways of stable asthmatics

To compare the deposition patterns of heliox-driven and air-driven radiolabeled bronchodilator aerosol, a prospective randomized study was undertaken at the Ben Taub Hospital in Houston, Texas. The working hypothesis was that nebulization with heliox would improve the peripheral deposition of a bronchodilator aerosol. Twelve mild-moderate known asthmatics were recruited for the study. They were asked to withhold medications for 8-24 hours prior to reporting for the study. Each subject was randomized to receive either heliox or oxygen for delivery of albuterol labeled with Tc-99m DTPA. Prior to the nebulization, baseline spirometry was performed. Following nebulization, the subjects were scanned for 1,000,000 counts on the ADAC Genesis Scanner. A postbronchodilator spirometry was then performed. Subjects returned about a week later, this time to have the same process repeated with the other gas. The normalized pixel counts were obtained, and the frequency distribution histograms were constructed for each of the deposition images. Skew and kurtosis were calculated. A lower skew and kurtosis value suggests a more peripheral distribution of the bronchodilator, whereas a higher pixel count corresponds with an increased area and uniformity of deposition. There were no statistically significant differences in baseline PFTs on the 2 days of the study. The pixel count was statistically higher after the heliox-driven nebulization than the air-driven nebulization. The skew and kurtosis values were lower after the heliox-driven nebulization than after the air-driven nebulization of radiolabeled aerosol. All patients had a good bronchodilator response with either driving gas. However, the degree of improvement was more with heliox-driven nebulization than with air-driven nebulization. We conclude that aerosol delivery with heliox results in more uniform and peripheral deposition. Thus, this mode of delivery can be used when uniform, peripheral deposition is desired as with drug delivery during an exacerbation or with aerosolized gene therapy.

Application of USP inlet extensions to the TSI impactor system 3306/3320 using HFA 227 based solution metered dose inhalers

The objective of this study was to further evaluate the need for a vertical inlet extension when testing solution metered dose inhalers using the TSI Model 3306 Impactor Inlet in conjunction with the TSI Model 3320 Aerodynamic Particle Sizer (APS). The configurations tested using the TSI system were compared to baseline measurements that were performed using the Andersen Mark II 8-stage cascade impactor (ACI). Seven pressurized solution metered dose inhalers were tested using varied concentrations of beclomethasone dipropionate (BDP), ethanol, and HFA 227 propellant. The inhalers were tested with the cascade impactor, and with the TSI system. The TSI system had three different configurations as the manufacturer provided (0 cm) or with inlet extensions of 20 and 40 cm. The extensions were located between the USP inlet and the Model 3306 Impactor Inlet. There were no practical differences between each system for the stem, actuator, or USP inlet. The fine particle mass (aerodynamic mass < 4.7 microm) was affected by extension length and correlated well with the ACI when an extension was present. APS particle size measurements were unaffected by the extension lengths and correlated well to particle size determined from the ACI analysis. It has been confirmed that an inlet extension may be necessary for the TSI system in order to give mass results that correlate to the ACI, especially for formulations having significant concentrations of low volatility excipients. Additionally, the results generated from this study were used to evaluate the product performance of HFA 227 based solution formulations that contain varying concentrations of ethanol as a cosolvent.

Pharmacokinetic and pharmacodynamic properties of inhaled beclometasone dipropionate delivered via hydrofluoroalkane-containing devices

Inhaled corticosteroids have a key role in the treatment of asthma and chronic obstructive pulmonary disease. In recent times, beclometasone dipropionate has been reformulated in pressurised metered dose inhalers (pMDIs), using hydrofluoroalkanes (HFAs) as a propellant. Extensive toxicological testing has shown that HFA-propellants are well tolerated. Among the reformulated beclometasone dipropionate-containing pMDIs, only the characteristics of the two Qvar formulations have been thoroughly explored. Compared to the reference beclometasone dipropionate formulation, the mass median aerodynamic diameter of the Qvar formulations are substantially smaller (1.1 vs 4.0 microm), whereas that of Modulite averages 2.6 microm. Scintigraphic and pharmacokinetic studies indicate a higher lung deposition for both the Qvar and the Beclazone formulations, compared with reference beclometasone dipropionate formulation. Since the 2- to 3-fold increase in pulmonary deposition results in a 2.6- to 3-fold difference in relative efficacy for Qvar, half the dose of the reference beclometasone dipropionate formulation has been currently recommended in adult patients with asthma, a recommendation that is supported by a large number of clinical trials. Conversely, the design of the studies conducted to compare the efficacy of Qvar with fluticasone propionate and budesonide does not allow establishing their equivalence on a milligram per milligram basis. Good studies on the bioequivalence between the reference beclometasone dipropionate formulation and the Modulite or Beclazone formulations are not available.

Neurobehavioral effects and hormones profile among spray painters

A cross-sectional study was conducted in 25 spray painters and 35 control subjects to evaluate neurobehavioral function, and thyroid and reproductive hormones profile. This study indicated higher prevalence of psychological and neurological symptoms, and clinical findings among spray painters when compared with controls. Levels of TSH were significantly (p<0.01) elevated in spray painters over the control group (3.04 +/- 1.53 vs 1.88 +/- 1.07 microIU/ml, mean +/- SD), respectively. Two of the 25 spray painters acquired sub-clinical hypothyroidism, and one subject was detected with overt hypothyroidism. T4 levels were significantly (p<0.05) suppressed in spray painters while T3 was not changed significantly in both the groups. Reproductive hormones (LH, FSH, and testosterone) showed no significant changes in control and spray-painting group. However, two spray painters had abnormally high level of LH (26.43 and 12.22 IU/l; normal range 0.5-10 IU/l). These subjects were also found to have abnormally higher level of FSH (38.63 and 14.11 IU/l; normal range 1.3-11.5 IU/l). An isolated higher level of FSH (39.94 IU/l) was also observed in one spray painter. No abnormality in the level of LH was observed in control group while 3 subjects from this group had abnormally high level of FSH. Testosterone levels were under the normal range (3-12 ng/ ml) in both the groups. This study might suggest that spray painters are at risk of developing neurobehavioral, thyroid and reproductive problems.

Effect of ambient humidity on light transmittance through skin phantoms during cryogen spray cooling

Cryogen spray cooling (CSC) is a technique employed to reduce the risk of epidermal damage during dermatologic laser surgery. However, while CSC protects the epidermis from non-specific thermal damage, it might reduce the effective fluence reaching the target chromophore due to scattering of light by the spray droplets and subsequent water condensation/freezing on the skin surface. The objective of this work was to study the effect of ambient humidity (omega) on light transmittance during CSC. An integrating sphere was employed to measure the dynamics of light transmittance through a deformable agar phantom during CSC. The study included two representative CSC spurt patterns studied using four omega: 57, 40, 20 and 12%. Results show that during CSC, as omega increased, light transmittance decreased. For the highest humidity level (57%) studied, light transmittance reached a minimum of 55% approximately 30 ms after spurt termination. In a controlled environment with omega = 12%, light transmittance reached a minimum of 87% approximately 30 ms after spurt termination. The reduced light transmittance immediately after spurt termination was most likely because of scattering of light caused by condensation of water vapour due to aggressive cooling of ambient air in the wake of the cryogen spurt.

Bronchoprotection with formoterol via dry powder and metered-dose inhalers in patients with asthma

BACKGROUND

Determination of device comparability for new inhaled medications is essential.

OBJECTIVE

To evaluate the methacholine bronchoprotection afforded by formoterol, 12 microg, delivered via Clickhaler and Aerolizer dry powder inhalers and a pressurized metered-dose inhaler (pMDI) in mild-to-moderate asthmatic patients.

METHODS

Two separate randomized, double-blind, double-dummy, crossover studies were performed. Peak bronchoprotection (30 minutes) was measured after administration of a single dose in a placebo-controlled study (n = 16). First-dose (8 hours) and trough (12 hours) protection were evaluated after 2 weeks (n = 28). Doubling dilution differences (DDD) in the methacholine provocation concentration that caused a decrease in forced expiratory volume in 1 second of 20% from baseline were compared, with equivalence defined if the 95% confidence interval was within the predefined equivalence limits of +/- 1.5 DDD (peak) and +/- 1.0 DDD (trough).

RESULTS

For peak single-dose effects, DDD (95% confidence interval) data showed significant protection vs placebo for all devices but no significant differences among active inhalers. For trough first-dose effects, there was significant protection vs baseline for all devices and equivalence for Clickhaler vs Aerolizer (-0.41; -0.85 to 0.04) and Aerolizer vs pMDI (-0.27; -0.66 to 0.13) but not for Clickhaler vs pMDI (-0.68; -1.12 to -0.23). For trough effects after 2 weeks, there was significant residual protection from baseline and equivalence for Clickhaler vs Aerolizer (-0.32; -0.94 to 0.30), Clickhaler vs pMDI (0.34; -0.96 to 0.27), and Aerolizer vs pMDI (-0.02; -0.57 to 0.52).

CONCLUSIONS

Formoterol delivered by 3 different inhalers exhibited a significant degree of peak and trough bronchoprotection after single and repeated dosing, with most comparisons being within predefined equivalence limits.

The CFC to HFA transition and its impact on pulmonary drug development

The terms of the Montreal Protocol have eliminated chlorofluorocarbons (CFCs) and other ozone-depleting agents from commercial use, with the exemption of their use as propellants in metered-dose inhalers. Two new propellants have been approved for CFC substitutes: hydrofluoroalkane (HFA)-134a and HFA-227. An extensive safety program was conducted by the International Pharmaceutical Aerosol Consortium for Toxicity Testing (IPACT studies I and II), which found that the HFAs were as safe as or safer than the CFCs. The change from CFCs to HFAs in metered-dose inhalers was not a straightforward exchange. Indeed, substantial new technology had to be developed to make the HFAs suitable for use in metered-dose inhalers. Fortunately, with new understandings of respiratory diseases and the areas of the lungs that need to be targeted by medications, the new HFAs provided the opportunity to improve the performance of the beta-agonist products and created some entirely new ability for inhaled steroids to reach all the airways, both large and small, where asthma pathology resides. The transition from CFCs also spurred novel new drug-delivery technologies, improved dry powder inhalers, and highly dispersible engineered powders.