Endoscopic photographic comparison of drug delivery by ear-drops and by aerosol spray

The Otomize (Stafford-Miller Ltd) aerosol spray is a new device for delivering topical ear medication in otitis externa. Both the manufacturers and a recent study have claimed that the spray produces better coverage of the external ear canal than do traditional ear-drops. We performed an endoscopic photographic comparison study to investigate this claim. The area of tympanic membrane and ear canal covered with medication was greater in those ears treated with the aerosol (P < 0.001, paired t-test). The ability of the aerosol to deliver drug to the level of the tympanic membrane suggests a possible role for this device in the treatment of chronic otitis media. The technique of endoscopic photography provides an objective and reproducible means of investigating drug delivery systems for otological conditions.     

Demonstration of dilatation of peripheral airways

Summary. To investigate the ability of various lung-function tests to demonstrate dilatation of peripheral airways, ten asthmatics inhaled increasing doses of a f2-agonist by two different and controlled techniques. Low inspiratory flow with a long post-inspi-ratory pause favoured peripheral deposition, and a high inspiratory flow with a short post-inspiratory pause favoured central deposition of drug in the airways. Ordinary spirometry, maximum expiratory flow rates after breathing air as well as a helium-oxygen mixture, a single breath N₂-test and resistance of the respiratory system were obtained before and after each of five terbutaline doses with both inhalation techniques. By using a double-dummy technique, the study could be performed double blinded. Effects were compared at doses giving equal effects on PEF, assumed to represent equal deposition of bronchodilator and effects on central airways. At such ‘iso A PEF doses’, particularly FVC and the slope of phase III of the N₂-test improved more following the slow inhalation technique. It is concluded that changes in those tests reflect dilatation in peripheral airways in asthmatics.,     

舒喘灵气雾剂治疗毛细支气管炎临床观察

目的 探讨舒喘灵气雾剂对毛细支气管炎的治疗效果。方法 选择106例住院毛细支气管炎患儿随机分为两组,对照组给予常规治疗,治疗组在常规治疗的基础上给予舒喘灵气雾剂,每天3次吸入。疗程结束后,观察毛细支气管炎改善情况。结果 治疗组有效率90％,对照组有效率17.4％,两组对比P<0.01,差异显著。结论 舒喘灵气雾剂对毛细支气管炎治疗效果佳,副作用小,值得推广。     

雾化吸入对新生儿肺炎患儿血氧饱和度的影响

采用动脉血氧饱和度仪对５２例新生儿肺炎患儿，在雾化吸入治疗过程中的动脉血氧饱和度（ＳａＯ２）进行了监测，对比了吸氧与否对ＳａＯ２改变的影响。结查表明：与基础值比较，雾化吸入时患儿的ＳａＯ２显著下降（Ｐ＜０．０１），而雾化吸入同时吸氧者ＳａＯ２无明显变化（Ｐ＞０．０５），但两者比较具有显著性差异（Ｐ＜０．０１）。结果提示雾化吸入可使新生儿肺炎患儿ＳａＯ２下降；同时吸氧，对防止ＳａＯ２的下降有一定作用。     

Comparison of Output Particle Size Distributions from Pressurized Aerosols Formulated as Solutions or Suspensions

The delivery of particles as small as possible (preferably <5 µm) to the respiratory tract should be the aim of those formulating metered dose inhalers (MDIs). This may be facilitated by the formulation of solution, rather than suspension-type, pressurized aerosol units. Two series of MDIs were compared; one contained suspended micronized disodium fluorescein (0.1%, w/v), while the other contained the same concentration of dissolved salicylic acid. Either oleic acid, L--phosphatidylcholine, or sorbitan trioleate was incorporated at 0.15% (w/v) as suspending agent (disodium fluorescein) or solubilizing agent (salicylic acid). The propellant blend was 70% (w/w) Freon 12 and 30% (w/w) Freon 11 in all cases. This exhibited a vapor pressure of 50.6 psig (444.7 kPa) at 21°C. The output particle size distribution of the aerosol reaching the cascade impactor showed a mass median aerodynamic diameter (MMAD) of approximately 4 and 2 µm for the suspension and solution formulations respectively, regardless of the surfactant used. Larger MMADs were observed for solution aerosols formulated with oleic acid (2.32 µm) compared to those containing L--phosphatidylcholine (1.93 µm) or sorbitan trioleate (2.07 µm). Possible reasons for these observations are discussed.     

Evaluation of quantitative aerosol techniques for use in bronchoprovocation studies

To investigate airway physiology by use of inhaled aerosols, it is frequently necessary to measure the actual amount of material deposited on the airway wall as well as the site of particle deposition. To satisfy these needs, radiolabeled aerosols and gamma camera techniques have been used to measure regional deposition of inhaled particles. To make quantitative measurements of the amount deposited, previous investigators have used a "phantom" technique to indirectly calibrate the gamma camera for the attenuation of gamma rays through the lungs and chest wall. For this calibration, the phantom is a simulated lung containing a known amount of radioactivity. Radioactive counts emitted from the phantom are assumed to be attenuated in the same manner as the intact human lung. The present article describes a technique to determine directly the amount of inhaled aerosol deposited in the lung and simultaneously to calibrate the gamma camera for each individual subject. We used right angle light scattering and a gamma camera to measure individual values of the deposition fraction (DF) of inhaled aerosol deposited in the lung and the coefficient of attenuation (AC) of gamma rays in normal and obstructed lungs of human subjects. Radiolabeled monodisperse aerosols 1 and 2 microns in diameter were used. Knowledge of the activity of the inhaled aerosol (microcurie per liter), the volume inhaled, and the measured DF determined each subject's AC (counts per minute per microcurie). DF varied by an order of magnitude in normal (0.04 to 0.48) and obstructed (0.16 to 0.75) of subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

SARS-CoV-2 Aerosol Exhaled by Experimentally Infected Cynomolgus Monkeys

We analyzed size of severe acute respiratory coronavirus 2 (SARS-CoV-2) aerosol particles shed by experimentally infected cynomolgus monkeys. Most exhaled particles were small, and virus was mainly released early during infection. By postinfection day 6, no virus was detected in breath, but air in the isolator contained large quantities of aerosolized virus.     

Dose-response comparison of broxaterol and salbutamol pressurized aerosols

Summary The bronchodilating activity and tolerability of broxaterol and salbutamol administered by pressurized metered dose inhalers have been compared in 9 adult patients with bronchial asthma and clinically stable and reversible bronchospasm. Placebo was used as a control. On 3 different days broxaterol and salbutamol in cumulative doses of 100, 200 and 400 g and placebo were administered every 30 min according to a double-blind, Latin-square design.After each dose of broxaterol and salbutamol the increases in FVC and FEV₁ were always significantly larger than after placebo. Broxaterol at the doses tested induced a bronchodilator response which depended on the dose according to a relation not significantly different from a straight line, and with a potency at least comparable to that of salbutamol. The tolerability of the two drugs was good: only in 1 patient were slight tremors observed after the highest dose of each drug.The bronchodilating activity and the tolerability of broxaterol were not significantly different from those of salbutamol at the same doses.     

Solute Absorption from the Airways of the Isolated Rat Lung. II. Effect of Surfactants on Absorption of Fluorescein

To determine the effects on the pulmonary barrier of several surface active agents, a series of metered dose inhalers (MDIs) was prepared and used to dose aerosolized surfactant to the airways of isolated perfused rat lungs. The MDIs contained a range of concentrations, from 0.1 to 5.0% (w/w), of either oleic acid, oleyl alcohol, or Span 85, which released 45 µg (0.1%, w/w) to 1660 µg (5.0%, w/w) of surfactant per actuation. The permeability of the pulmonary barrier was assessed by the rate of transfer of disodium fluorescein dosed as 100 µl of aqueous solution (1 mg/ml) after administering the surfactants. Some 12.1 ± 4.7% of the recovered surfactant, per dose, was assessed to reach the pulmonary regions of the lung. All surfactants tested caused an increase in fluorescein transfer rates. A single actuation from the MDI containing 5% (w/w) oleic acid produced gross edema in all lungs tested within 40 min and the first-order half-lives of absorption were reduced almost threefold, from 12.9 ± 2.5 min for controls to 4.5 ± 0.8 min. Differences in absorption were noted between the acid and the alcohol, which is consistent with the hypothesis that both the hydrocarbon chain and the polar head group have roles in the altered permeability to fluorescein. The absorption of fluorescein when dosed from the MDI containing 5% (w/w) Span 85 was increased but all surfactants dosed from the lowest concentration MDI of 0.1% (w/w) did not alter absorption rates of the dye relative to those of controls. Results are discussed in light of current interest in absorption enhancement and the presence of surfactants in currently marketed MDIs.