In vitro performance of two common valved holding chambers with a chlorofluorocarbon-free beclomethasone metered-dose inhaler

STUDY OBJECTIVE

To compare in vitro aerosol deposition from a beclomethasone dipropionate metered-dose inhaler (MDI) containing hydrofluoroalkane propellant with that of the MDI in combination with two common valved holding chambers (VHCs) to evaluate how these VHCs affect the respirable dose of beclomethasone dipropionate.

DESIGN

In vitro aerosol deposition study.

SETTING

University research center.

DEVICES

Beclomethasone dipropionate hydrofluoroalkane MDI alone, the MDI with OptiChamber VHC, and the MDI with AeroChamber-Plus VHC.

INTERVENTION

The respirable dose (1-5-microm aerosol particles) of beclomethasone dipropionate was determined by sampling 10 80-microg actuations from five runs with each configuration (MDI alone, MDI with OptiChamber, and MDI with AeroChamber-Plus), using a well-established in vitro cascade impactor method.

MEASUREMENTS AND MAIN RESULTS

Beclomethasone dipropionate aerosol was washed from the impactor with 50% methanol and quantified by means of high-performance liquid chromatography. Differences among outcomes were determined by using analysis of variance. Mean beclomethasone dipropionate respirable dose from AeroChamber-Plus (27.2 +/- 10.0 microg/actuation) was not significantly different (p>0.05) from that of the MDI alone (29.0 +/- 7.0 microg/actuation). OptiChamber respirable dose (12.8 +/- 6.0 microg/actuation) was less than half that produced by either the AeroChamber-Plus or the MDI alone (p=0.013).

CONCLUSIONS

The OptiChamber and AeroChamber-Plus VHCs do not demonstrate equivalent in vitro performance when used with a beclomethasone dipropionate MDI that contains hydrofluoroalkane propellant. The respirable dose of beclomethasone dipropionate aerosol from the hydrofluoroalkane MDI was decreased by only 6% when the MDI was mated to an AeroChamber-Plus VHC and by 56% when used with an OptiChamber VHC.

Fenoterol delivery by Respimat soft mist inhaler versus CFC metered dose inhaler: cumulative dose-response study in asthma patients

OBJECTIVES

Respimat (RMT) soft mist inhaler (SMI) is a novel, propellant-free alternative to chlorofluorocarbon metered-dose inhalers (CFC-MDIs). The aim of this study was to evaluate the safety and establish the equipotent dose of fenoterol delivered by RMT SMI vs. a conventional MDI.

DESIGN

Double-blind, randomized, crossover, comparative study between fenoterol inhaled via RMT (either 50 microg/actuation, RMT50; or 100 microg/actuation. RMT100) and MDI (100 microg/actuation; MDI100).

PATIENTS AND INTERVENTIONS

A total of 41 asthma patients received cumulative doses of fenoterol 600 microg (RMT50) or 1200 microg (RMT100 and MDI100) on 3 test days.

MEASUREMENTS AND RESULTS

The bronchodilator response (forced expiratory volume in 1 second [FEV1]) was considered therapeutically equivalent (i.e., noninferior) if the 95% confidence intervals for the difference in their mean changes from baseline were within limits of +/- 0.15L. Systemic exposure was evaluated from plasma fenoterol levels. Adverse events (AEs) were recorded. RMT50 and RMT100 produced noninferior bronchodilatation to MDI100 from 30minutes after the first dose. RMT50 showed equivalent safety and tolerability to MDI100, whereas RMT100 produced a higher incidence of AEs, a significantly greater plasma potassium reduction and a significant increase in pulse rate. Fenoterol plasma levels were twice as high with RMT100 as with RMT50 or MDI100. CONCLUSIONS; The nominal dose of fenoterol administered via RMT SMI can be at least halved to achieve equivalent efficacy, safety, and tolerability to a MDI.

The delivery of chlorofluorocarbon-propelled versus hydrofluoroalkane-propelled beclomethasone dipropionate aerosol to the mechanically ventilated patient: a laboratory study

We describe a laboratory investigation comparing the delivery of chlorofluorocarbon (CFC)- and hydrofluoroalkane (HFA)-formulated beclomethasone dipropionate (BDP) by metered-dose inhaler and holding chamber (AeroChamber HC MV) in a simulation of a mechanically ventilated adult patient.

METHODS

We equipped each HC MV (n = 5) with an 8.0 mm diameter endotracheal tube (ETT), locating the HC MV in the inspiratory limb of a breathing circuit linked to a mechanical ventilator set to simulate tidal breathing at tidal volume = 830 mL, respiratory rate = 15 breaths/min, inspiratory-expiratory ratio of 1:2.1, peak inspiratory pressure = 20 cm H(2)O. Temperature and humidity settings were 35+/-1 degrees C and 100% relative humidity (close to body conditions). We compared delivery of 5-actuations of CFC- and HFA-BDP (both 50 microg/actuation), measuring total emitted mass captured by a filter at the distal end of the ETT. In a separate study, we inserted the distal end of the ETT within the entry cone of a cascade impactor so that the aerosol particle size distribution could be determined with the circuit at similar environmental conditions as described previously. We made benchmark measurements with circuit temperature and humidity at room ambient conditions (21+/-1 degrees C and 54+/-5% RH respectively).

RESULTS

Total emitted mass (5 measurements/device) was significantly greater for HFA-BDP (14.1+/-1.1 microg/actuation) compared with CFC-BDP (2.4+/-0.8 microg/actuation) (paired t test, p < 0.001). More HFA-BDP (2.7 +/- 0.2 microg/actuation) was lost from the delivery system during exhalation (0.9 +/- 0.4 microg/actuation for CFC-BDP) (p < 0.001). The mass median aerodynamic diameter (MMAD) increased from 1.2 microm (room ambient) to 2.8 microm (higher temperature and humidity conditions) for HFA-BDP. In contrast, MMAD for CFC-BDP remained close to 4.6 microm under either condition, but particles finer than about 4.0 microm increased in size when the circuit was saturated.

CONCLUSIONS

Total emitted mass for HFA-BDP was increased by a factor of 5.8 compared with CFC-BDP, due largely to the finer particle size distribution of the HFA-based solution formulation. Additional water vapor required to operate the breathing circuit at close to body conditions resulted in fine particle growth with both formulations.

A functional on-chip pressure generator using solid chemical propellant for disposable lab-on-a-chip

This paper presents a functional on-chip pressure generator that utilizes chemical energy from a solid chemical propellant to perform fluidic delivery in applications of plastic-based disposable biochips or lab-on-a-chip systems. In this functional on-chip pressure generator, azobis-isobutyronitrile (AIBN) as the solid chemical propellant is deposited on a microheater using a screen-printing technique, which can heat the AIBN at 70 degrees C to produce nitrogen gas. The output pressure of nitrogen gas, generated from the solid chemical propellant, is adjustable to a desired pressure by controlling the input power of the heater. Using this chemical energy source, the generated pressure depends on the deposited amount of the solid chemical propellant and the temperature of the microheater. Experimental measurements show that this functional on-chip pressure generator can achieve around 3 000 Pa pressure when 189 mJ of energy is applied to heat the 100 microg of AIBN. This pressure can drive 50 nl of water through a microfluidic channel of 70 mm and cross-sectional area of 100 microm x 50 microm. Due to its compact size, ease of fabrication and integration, high reliability (no moving parts), biologically inert gas output along with functionality of gas generation, this pressure generator will be an excellent pressure source for handling the fluids of disposable lab-on-a-chip, biochemical analysis systems or drug delivery systems.

Albuterol aerosol delivered via metered-dose inhaler to intubated pediatric models of 3 ages, with 4 spacer designs

OBJECTIVE

To determine the amount of albuterol, in various particle size ranges, delivered from a hydrofluoroalkane-propelled metered-dose inhaler (Airomir) in 3 models of pediatric intubation (ages 8 months, 4 years, and 16 years) using 4 types of aerosol reservoir: 3 spacers (ACE, AeroChamber HC MV, metal NebuChamber without 1-way valve) and 1 holding chamber (metal NebuChamber with 1-way valve).

METHODS

Five reservoirs of each type were tested with albuterol sulfate delivered via metered-dose inhaler that delivers 100 microg of albuterol per actuation. Each reservoir was connected to an endotracheal tube (ETT) that corresponded to the given patient age (8 months = 4 French; 4 years = 5 French; 16 years = 7.5 French) and to a valved system that allowed connection of the ETT to a cascade impactor. Simulated tidal volumes representative of children of the given ages were passed through the reservoir. Both the cascade impactor and the ETT were enclosed within a 100% humidity, 37 degrees C environment.

RESULTS

For the total amount of albuterol inhaled onto the impactor, and both the 1.1-4.7 microm and 1.1-3.3 microm inhaled fine-particle fractions, the NebuChamber-with-valve showed significantly greater drug delivery than the NebuChamber-without-valve, the AeroChamber HC MV, or the ACE (p < 0.001). Among the reservoirs without valves the NebuChamber showed significantly greater delivery than the AeroChamber HC MV or ACE (p < 0.001) for total drug deposition and for both the 1.1-4.7 microm and 1.1-3.3 microm fine-particle fractions. These results were consistent over all age groups. The AeroChamber HC MV had significantly greater delivery (total deposition) than the ACE (p < 0.001), except in the 4-year-old model. There were no significant differences between the AeroChamber HC MV and the ACE for either the 1.1-4.7 microm or the 1.1-3.3 microm fine-particle fraction.

CONCLUSION

An aerosol reservoir with 1-way valve positioned between the spacer and the ETT improved the amount of inhaled albuterol 300-900%, compared to the other reservoirs.

Balancing ethanol cosolvent concentration with product performance in 134a-based pressurized metered dose inhalers

The effects of formulation parameters on the product performance characteristics of solution metered dose inhalers (MDIs) were determined using ethanol as the cosolvent and HFA 134a as the propellant. Solubility of beclomethasone dipropionate (BDP) was determined in various blends of 134a and ethanol and was shown to increase with ethanol concentration. Product performance was assessed using the APS Model 3306 Impactor Inlet in conjunction with APS Model 3320 Aerodynamic Particle Sizer (APS). Nine solution formulations containing various BDP and ethanol concentrations were studied. Chemical analysis of the Impactor Inlet was performed in order to determine the "respirable" deposition of the MDI system. With increased ethanol concentration, the throat deposition and plate deposition increased and the respirable deposition decreased. The mass median aerodynamic diameter (MMAD) increased with the increasing drug concentration, but did not show a significant increase with an increase in ethanol concentration. This indicates that the efficiency of solution MDIs decreases with increased ethanol concentration. A Maximum Respirable Mass (MRM) was calculated based on the drug solubility at a particular ethanol concentration and the respirable deposition for a 50mcl valve and QVAR actuator for that ethanol concentration. The MRM represents the maximum amount of a given drug that can be delivered to the lungs theoretically and is very sensitive to the solubility profile of the drug. The MRM increased with the increasing ethanol concentration in the formulation until a plateau was reached at an ethanol concentration of 10-15% w/w. The MRM initially increases with increase in ethanol concentration due to the increase in drug solubility. However, at higher ethanol concentrations the increase in drug solubility was negated by a decrease in the respirable deposition. This study illustrates the importance of considering both formulation properties and product performance characteristics when optimizing a metered dose inhaler drug delivery system.

The influence of formulation variables on the performance of alternative propellant-driven metered dose inhalers

There are a multitude of formulation factors to consider when developing a pMDI. Evaluation of each of these variables has been performed over the years, but there has been an abundance of different approaches in the determination of the effects on device performance. Thus, although much is known about pMDI on the empirical level, a systematic approach has clearly been missing. With the ratification of the Montreal Protocol and the introduction of alternative propellant systems, the opportunity to establish relationships between different levels of testing, such as in vitro measurements and in vivo outcomes, and in vivo assessments and clinical outcomes, has arrived. This review outlines research efforts that have focused on the formulation of propellant-driven metered dose inhalers using alternative propellants. These formulation factors, including device characteristics, are reviewed with respect to the performance of MDIs.

Effect of propellant on the pharmacokinetics and pharmacodynamics of inhaled albuterol in asthmatic subjects

Hydrofluoroalkane (HFA) propellants have largely replaced chlorofluorocarbon (CFC) propellants in metered dose inhalers (MDI). It is important to document the pharmacokinetics (PK) and pharmacodynamics (PD) of medications delivered using HFA propellants compared to CFC propellants. Six adult asthmatics with mild to moderate asthma were selected for the study. Each subject inhaled 180 microg of albuterol from an MDI with holding chamber. Venous blood was collected for measuring albuterol levels at intervals over 12 h, and spirometric measurements of airflow were measured over the same time period. Plasma samples were analyzed using a GC/MS assay developed in our laboratory. PK and PD parameters were calculated by nonlinear regression using WinNonlin. There were no statistically significant differences between PD parameters for HFA versus CFC propellants. The area under the plasma albuterol concentration versus time curve (AUC) was 72% greater for the HFA formulation, indicating a greater lung bioavailability (p = 0.015). This difference in bioavailability did not result in a statistically significant difference in FEV(1) values between the two propellants.

Effects of inhaled corticosteroids with different lung deposition on exhaled hydrogen peroxide in stable COPD patients

BACKGROUND

The effects of inhaled corticosteroids (ICS) on markers of oxidative stress in patients with stable COPD are unclear.

OBJECTIVES

The aim was to investigate the effect of ICS on exhaled H(2)O(2) in stable COPD patients and to compare ICS with different lung deposition.

METHODS

Forty-one stable patients with moderate COPD (FEV(1) approximately 60% predicted) were randomized to sequence 1; first HFA-134a beclomethasone dipropionate (HFA-BDP, an ICS with more peripheral deposition) 400 microg b.i.d., then fluticasone propionate (FP, an ICS with more central deposition) 375 microg b.i.d. (n = 20) or sequence 2; first FP, then HFA-BDP (n = 21). Both 4-week treatment periods were preceded by a 4-week washout period. After each period, the concentration of H(2)O(2) in exhaled breath condensate was measured.

RESULTS

The H(2)O(2) concentration decreased significantly after the first treatment period in both sequence 1 and 2 (p < 0.05, p = 0.01, respectively). In neither sequence was there a return to baseline values after the second washout, indicating a carry-over effect. The concentrations remained low in both sequences during the second treatment period.

CONCLUSIONS

Both ICS appeared to reduce exhaled H(2)O(2) in stable COPD patients. However, this study showed no difference between ICS with different deposition patterns, which in part may be due to the carry-over effect.

Lecithin microemulsions in dimethyl ether and propane for the generation of pharmaceutical aerosols containing polar solutes

Water soluble compounds have been incorporated into solution phase metered dose inhalers (MDIs) utilizing lecithin inverse microemulsions in dimethyl ether (DME) and propane. DME and propane acted as both solvent and propellant. Experiments utilizing model propellants (dimethylethyleneglycol (DMEG) and hexane) were used to investigate microemulsion physicochemical phenomena, and the results were used to design and interpret the technically more challenging MDI experiments. NMR and viscosity experiments with model propellants were consistent with a "sphere-to-string" micellar shape change as the solvent was varied from pure DMEG to pure hexane. Water soluble solutes, including selected peptides and fluorescently labeled poly-alpha, beta-[N-(2-hydroxyethyl) D,L-aspartamide] (fPHEAs), dissolved in DME/propane dependent on lecithin and water content. MDIs containing microemulsions generated aerosols with mass median aerodynamic values ranging from 2.7 to 3.1 microns, within the range of commercially available formulations. Fine particle fraction values (50-70%) exceeded those of commercial formulations. fPHEA up to 18 kDa did not adversely affect the aerosol characteristics. Deposition of the aerosol onto a water surface resulted in the formation of liposomes with partially entrapped solute.

Effects on lung function, symptoms, and bronchial hyperreactivity of low-dose inhaled beclomethasone dipropionate given with HFA-134a or CFC propellant

The aim of this study was to compare the efficacy of BDP 200 microg bid via metered dose inhaler, using HFA-134a (Chiesi Farmaceutici S.p.A., Parma, Italy) versus CFC (Becotide, Allen & Hanburys, U.K.) as a propellant. 172 adult patients (86 in each group) with stable mild persistent asthma who completed a 7-day run-in period were randomized to receive a 6-week treatment in a double-blind, double dummy, parallel-group design; 164 patients completed the study. Morning and evening PEFR, use of rescue salbutamol, number of day-time and night-time asthma attacks, number of night-time awakenings and clinical symptoms were recorded daily on a diary card. Pulmonary function tests (FEV(1), FVC, PEFR, and MEF(50)) were measured at the clinic before and after the 1-week run-in period, and after 3 and 6 weeks of treatment. A challenge test with inhaled methacholine was completed at baseline and at the end of the treatment period to assess potential bronchial hyper-reactivity in a subgroup of subjects (n = 65; 34 HFA, 31 CFC). In accordance with asthma of mild severity (FEV(1) predicted over 90% in both groups), a small improvement in lung function compared to baseline was seen for both treatments, significantly for FEV(1) in BDP HFA and MEF(50) in both groups. The two formulations of BDP had similar efficacy for the primary outcome variable morning PEFR (ITT population mean difference 5.8 L/min; C.I. -4.9 to +16.5) as well as for the secondary outcomes of evening PEFR and clinic FEV(1). There were small improvements in methacholine PD(20) and PC20 in both groups, with no significant difference between treatments. A total of 22 and 19 drug-related adverse events were reported in the BDP HFA and CFC groups, respectively; most events were of seasonal nature or were local effects due to the use of inhaled corticosteroids. It can be concluded that the newly developed formulation of BDP given via HFA-134a seems to provide similar asthma control, compared with the same low daily dose of the active drug delivered via CFC. Further studies are needed using higher doses in moderate to severe asthma to confirm these preliminary findings.

Local versus total systemic bioavailability of beclomethasone dipropionate CFC and HFA metered dose inhaler formulations

For inhaled formulations, the balance between desired local effects and undesired systemic activity can be expressed by L/T, where L represents bioavailability of drug from the lungs and T represents total systemic bioavailability. L/T is most useful when comparing formulations of the same inhaled substance. A high L/T is desirable as this implies efficient drug delivery to the target site, and minimization of unwanted activity from non-targeted drug delivery. The objective of this publication is to compare L/T for CFC and HFA inhaler formulations of beclomethasone dipropionate (BDP). Predictions of the L/T comparison were tested with clinical trials. From five deposition and pharmacokinetic studies, L/T ratios for CFC-BDP and HFA-BDP were calculated as 0.21 and 0.92, respectively. These ratios predicted two differences for the therapeutic use of these products: (1) a smaller dose of HFA-BDP than CFC-BDP may be required for efficacy; and (2) a smaller number of adverse events may be observed for the HFA-BDP product, when delivered at the equivalent dose, compared to the CFC comparitor. A dose-response study confirmed that less than half the dose of HFA-BDP is needed to give the same efficacy as CFC-BDP. Two safety studies that measured adrenal suppression demonstrated less suppression with HFA-BDP than with a comparable efficacious dose of CFC-BDP. It is concluded that L/T is a useful parameter that incorporates the systemic contributions of lung deposition and pharmacokinetics. It is recommended that this parameter be considered whenever deposition and pharmacokinetic data for two formulations of the same inhaled substance are compared.

Improved control of asthma symptoms with a reduced dose of HFA-BDP extrafine aerosol: an open-label, randomised study

BACKGROUND

Extrafine aerosols may improve asthma symptom control through increased lung deposition of medication to inflamed peripheral airways.

METHODS

The effect of switching patients with asthma maintained on up to 2000 microg/day chlorofluorocarbon-beclomethasone dipropionate (CFC-BDP), 1600 microg/day budesonide, 1000 microg/day fluticasone, or 2000 microg/day flunisolide, to a reduced dose of hydrofluoroalkane-134a BDP (HFA-BDP) extrafine aerosol (maximum 800 microg/day) was investigated during an open-label multicentre study. Following a 7-14-day run-in on previous medication, 716 patients were randomised to 24 weeks' treatment with an appropriate reduced dose of HFA-BDP.

RESULTS

Morning peak expiratory flow (AM PEF) measurements showed that, after 24 weeks, the reduced dose of HFA-BDP maintained equivalent lung function compared with all previous medications. Furthermore, asthma symptom scores revealed improvements across all groups and the proportion of symptom free days and nights and beta-agonist free days increased significantly (p < 0.05) in all but one group. Quality of life improved with 80% of patients reporting goo/very good overall asthma control compared with 70% previously. Treatment-associated adverse events were generally infrequent, mild and transient.

CONCLUSIONS

Patients on conventional inhaled corticosteroids may reduce their daily steroid dose to 800 microg or less whilst maintaining lung function and improving asthma symptom control by using the extrafine aerosol of HFA-BDP.

Evaluation of efficacy and safety of flunisolide hydrofluoroalkane for the treatment of asthma

BACKGROUND

Inhaled corticosteroids are currently recommended as first-line therapy for the long-term control and management of persistent asthma. Flunisolide hydrofluoroalkane (HFA) is a new formulation of the corticosteroid flunisolide that is delivered by a metered-dose inhaler containing an HFA propellant. HFA replaces the chlorofluorocarbon (CFC) propellant of the previous formulation, producing aerosols of smaller average particle size.

OBJECTIVE

This article reviews the physical and pharmacologic properties, deposition profile, and potential clinical benefits of flunisolide HFA for the treatment of asthma.

METHODS

Data included in this review were found via MEDLINE (search term, flunisolide HFA).

RESULTS

Flunisolide HFA has a mass median aerodynamic diameter (MMAD) of 1.2 microm, smaller than the 3.8 microm MMAD of the CFC formulation. Compared with flunisolide CFC, more of each flunisolide HFA dose reaches the lungs and less is deposited in the oropharynx. In addition, scintigraphic studies have found that the extra-fine particle size of flunisolide HFA gives it better access to small airways. In short- and long-term clinical studies, flunisolide HFA has been found to significantly increase pulmonary function relative to placebo. Although not statistically superior to the previous CFC formulation, flunisolide HFA exhibited small improvements in secondary efficacy measures, such as as-needed albuterol use and asthma symptoms, relative to flunisolide CFC. Furthermore, research suggests that the new HFA formulation has a low risk of systemic corticosteroid effects (eg, hypothalamic-pituitary-adrenal axis suppression, growth inhibition in children). Also, lower levels of oropharyngeal deposition, such as those seen with flunisolide HFA, are associated with lower incidence of local effects (eg, candidiasis).

CONCLUSION

Flunisolide HFA offers effective asthma control with a high level of tolerability in an extra-fine particle formulation that distributes corticosteroid to all areas of the lung, including small airways.

New liquid aerosol generation devices: systems that force pressurized liquids through nozzles

Over the past few decades, aerosol delivery devices have been relatively inefficient, wasteful, and difficult for patients to use. These drawbacks have been tolerated because the drugs available for inhalation have wide therapeutic margins and steep dose-response curves at low doses. Recently several forces have converged to drive innovation in the aerosol device industry: the ban on chlorofluorocarbon propellants in metered-dose inhalers, the need for more user-friendly devices, and the invention of expensive inhalable therapies for topical and systemic lung delivery. Numerous devices are in development to improve the efficiency, ease of use, and reproducibility of aerosol delivery to the lung, including systems that force liquid through a nozzle to form the aerosol cloud. The Respimat is a novel, compact, propellant-free, multi-dose inhaler that employs a spring to push drug solution through a nozzle, which generates a slow-moving aerosol. Deposition studies show that the Respimat can deliver 39-44% of a dose to the lungs. Clinical asthma and chronic obstructive pulmonary disease trials with bronchodilators show that the Respimat is 2-8 times as effective as a metered-dose inhaler. Respimat has been tested with bronchodilators and inhaled corticosteroids. The AERx device uses sophisticated electronics to deliver aerosol from a single-dose blister, using an integral, disposable nozzle array. The electronics control dose expression and titration, timing of aerosol generation with the breath, and provide feedback for proper inhalation technique. Lung deposition ranges from 50 to 80% of the loaded dose, with remarkable reproducibility. AERx has been tested with a variety of drugs, for both topical and systemic delivery, including rhDNase (dornase alfa), insulin, and opioids. These novel devices face competition from other technologies as well as financial and regulatory hurdles, but they both offer a marked improvement in the efficiency of pulmonary drug delivery.

Inhalation delivery of anticancer agents via HFA-based metered dose inhaler using methotrexate as a model drug

In the present study, the feasibility of delivering anticancer drugs via metered dose inhaler (MDI) was demonstrated using methotrexate (MTX) as a model anticancer drug. MDI formulations of MTX were prepared using hydrofluoroalkane-134a containing 0.67% MTX and 10% ethyl alcohol. The particle size of MTX was reduced by cryo milling with or without a surfactant (Pluronic F77) and the milled drug was employed for MDI formulations, which were subsequently evaluated for their medication delivery, mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD). Further, the efficacy of aerosolized MTX was evaluated by determining the in-vitro cytotoxicity of MTX against HL-60 cells using a six-stage viable impactor and the induction of apoptosis in HL-60 cells by acridine orange staining. Our results indicate that MTX aerosols having an MMAD varying between 2.2 and 3.2 microm (GSD 2.6-3.7) with a respirable fraction varying between 14.2 and 17.1% could be obtained by using MTX, which was cryo milled either alone or in combination with Pluronic F77. Exposure of HL-60 cells plated in third, fourth, fifth, and sixth stages of viable impactor to two actuations of MDI showed a cell kill of greater than 50%. Further, aerosolized MTX was found to induce apoptosis in HL-60 cells, as assessed by the morphological examination of the cells with fluorescent and confocal microscopy. Our results demonstrate that it is possible to deliver cytotoxic concentrations of MTX in an in vitro system simulating the lower respiratory tract (by using a six-stage viable impactor) via MDI and the cytotoxicity of the aerosolized MTX could be further improved by the optimization of the aerodynamic size.

Moving from CFC aerosol to HFA aerosol or dry powder inhalers: what do patients think?

BACKGROUND/OBJECTIVES

Environmentally friendly hydrofluoroalkane (HFA) pressurised metered-dose inhalers are currently being marketed to replace chlorofluorocarbon (CFC)-driven devices. It is uncertain whether these new formulations with different properties are acceptable to patients. Similarly, switching a patient to a dry powder inhaler (DPI) carries the risk of non-acceptance.

METHODS

One hundred patients with obstructive airway disease on regular CFC aerosol inhaler medication underwent a standardised, structured interview. During the interview patients were asked to use a new HFA aerosol inhaler and three DPIs in random order. Patients' notions were recorded.

RESULTS

Most patients (96) agreed to change from their CFC to the HFA inhaler, of those, only 12 did so with some reservation. Properties (taste, user-friendliness, design) of the HFA inhaler were rated favourably. DPIs represented an acceptable alternative to aerosol inhalers. In fact, 57 patients preferred a DPI over the HFA inhaler. Not all powder devices were equally acceptable. Replacing the CFC inhaler with patients' preferred alternative devices resulted in a more than 3-fold increase in costs.

CONCLUSION

Concerns about the acceptability of reformulated CFC-free aerosol inhalers are ill founded. However, if given the choice, many patients prefer a DPI over the HFA inhaler. The transition offers an opportunity to review patients' current treatment and the proficiency of their inhaling technique. Moving to CFC-free inhalers will have revenue implications.

A new HFA-134a propellant in the administration of inhaled BDP via the Jet spacer: controlled clinical trial vs the conventional CFC

This study was carried out with the aim of demonstrating the efficacy and tolerability of beclomethasone dipropionate (BDP) aerosol spray 500 microg b.i.d. via a spacer device (Jet, Chiesi Farmaceutici S.p.A.) using a new HFA-134a formulation or chlorofluorocarbon (CFC) propellant. After having completed a 2-week run-in period, 154 adult patients (77 in each group) with mild-to-moderate persistent asthma were randomised into two groups to receive the study treatment for a duration of 12 weeks in a double-blind, multinational, multicentre, parallel-group design. Morning and evening peak expiratory flow rate (PEFR), use of rescue salbutamol, number of day- and night-time asthma attacks, number of night-time awakenings due to asthma and clinical symptoms were recorded daily by patients on diary cards. Pulmonary function tests (FEV1, FVC, PEFR, FEF25-75%, MEF50 and FEF25) and vital signs were measured at the clinic at study entry, at the start of treatment and every 2 weeks thereafter. Morning serum cortisol (8.00-10.00 a.m.) was measured at the start and at the end of the treatment period. Adverse events were recorded throughout the total study period. Significant improvements over baseline were reported in both groups in terms of lung function, symptoms and use of rescue inhaled salbutamol. Equivalence between groups was demonstrated for the primary end-point morning PEFR, as well as for evening PEFR and FEV1. No statistically significant differences in the comparisons between groups, except for FEF25 (P=0.044), were observed in any of the other efficacy variables. Adverse events were reported in 31% of patients in the BDP-HFA group and in 32% in the CFC group. Adverse drug reactions were 4 and 2 in the two groups, respectively. No drug-related serious adverse events were reported in either of the groups. No signs of relevant adrenal suppression were observed in both groups: 2 patients in each group had final values below the normal range. In conclusion, the BDP-HFA-134a formulation proved to be equivalent in efficacy and comparable in safety to the standard BDP-CFC product over 12 weeks in adult patients with mild-to-moderate persistent asthma.

Fluticasone propionate via the Diskhaler or hydrofluoroalkane-134a metered-dose inhaler on methacholine-induced airway hyperresponsiveness

STUDY OBJECTIVE

s: To compare the effect of 4 weeks of treatment with fluticasone propionate (FP), 100 micro g bid, delivered either via the Diskhaler (GlaxoSmithKline; Middlesex, UK) or a hydrofluoroalkane (HFA)-134a pressurized metered-dose inhaler (pMDI) on airway responsiveness.

DESIGN

A single-center, randomized, double-blind, double-dummy, placebo-controlled crossover study.

SETTING

Outpatients.

PATIENTS

Patients with mild asthma who had not received corticosteroids for 4 weeks prior to the study.

INTERVENTIONS

FP, 100 micro g bid, via the Diskhaler, HFA-134a pMDI, or placebo for periods of 4 weeks.

MEASUREMENTS AND RESULTS

The primary efficacy variable was the provocative dose of methacholine causing a 20% fall in FEV(1) (PD(20)) at the end of each 4-week treatment period. The FP formulations were defined as equivalent if the treatment difference was within +/- 1 doubling dose of methacholine. Forty-seven patients were included in the per-protocol population. The baseline PD(20) geometric mean was 0.21 mg, which increased to 0.55 mg with FP via the HFA-134a pMDI and to 0.68 mg with FP via the Diskhaler. The treatment difference between adjusted means was - 0.16 doubling doses (95% confidence interval, - 0.62 to 0.31 doubling doses; p = 0.503). Both significantly decreased airway responsiveness compared to placebo (p < 0.001), and also significantly increased lung function with no difference between the two active groups. FP was well tolerated with few adverse events and no effect on serum cortisol levels.

CONCLUSIONS

FP delivered via the HFA-134a pMDI is equivalent to FP via the Diskhaler in reducing airway responsiveness.

Therapeutic ratio of hydrofluoroalkane and chlorofluorocarbon formulations of fluticasone propionate

OBJECTIVES

To compare the therapeutic ratio of chlorofluorocarbon (CFC) and hydrofluoroalkane-134a (HFA) formulations of fluticasone propionate (FP).

METHODS

We performed a randomized, placebo-controlled, crossover study comparing 6 weeks of treatment with FP using 500 micro g/d and 1,000 microg/d formulations of CFC and HFA. The primary end points were provocative dose of methacholine causing a 20% fall in FEV1 (PD20) and overnight urinary cortisol/creatinine excretion.

RESULTS

Eighteen patients with mild-to-moderate asthma and geometric mean (SEM) PD20 of 82.3 micro g (19.2 micro g) completed the study. All treatments significantly improved PD20 values and morning peak expiratory flow vs placebo, while 1,000 microg/d was significantly better than 500 microg/d for the CFC formulation of FP (CFC-FP) but not the HFA formulation of FP (HFA-FP). Only 1,000 microg/d of CFC-FP caused significant suppression of overnight urinary cortisol/creatinine compared to placebo. There were no differences between formulations at either dose.

CONCLUSIONS

The increased airway benefit with CFC-FP > 500 microg/d was offset by greater systemic effects. Although HFA-FP had fewer systemic effects than CFC-FP at 1,000 microg/d, there was no benefit to increasing HFA-FP to > 500 microg/d.