Effect of electrostatic charge, flow, delay and multiple actuations on the in vitro delivery of salbutamol from different small volume spacers for infants.

Abstract

Background -A study was undertaken to determine the influences of electrostatic charge, flow, delay, and multiple actuations on the in vitro delivery of salbutamol generated by a pressurised metered dose inhaler (pMDI) from small volume spacers used in infants. Methods -Ten actuations from a salbutamol pMDI were drawn at different flow rates after either single or multiple actuations, with or without delay, through either static or reduced static spacers. An ionic detergent was used to reduce the charge of plastic spacers (Babyhaler, Babyspacer, Aerochamber, Nebuhaler). Electrostatic charge was measured using an electrometer. A multistage liquid impinger was used to determine the particle size distribution of the output of the pMDI through the spacers. Results -Electrostatic charge on the surface of plastic spacers had the greatest influence on delivery, causing a decrease in drug delivery. Reducing charge by coating the surface with ionic detergent resulted in an increase of 46.5-71.1% (p<0.001) in small (<6.8 pm) particle delivery from small volume plastic spacers. Lower flow, delay, and multiple actuations resulted in decreased delivery from static spacers. Lower flow resulted in a decrease of 15% in small (<9.6 gm) particle delivery. Delay and multiple actuations resulted in a decrease of 40.7% and 76.0%, respectively, in small (<6.8 tm) particle delivery. The influences of lower flow, delay, and multiple actuations were greatly reduced or even eliminated by reducing charge. However, multiple actuations still resulted in a significant decreased delivery (p<0.05). The reduced static Nebuhaler had a higher delivery than all small volume spacers. Conclusions -Electrostatic charge has a major influence on the delivery of salbutamol from small volume spacers. Using a metal spacer or ionic detergent coating ofplastic spacers resulted in no or reduced charge and hence in improved delivery. Lower flow, delay, and multiple actuations played a major part only in static spacers. (Thorax 1996;51:985-988)

Washing plastic spacers in household detergent reduces electrostatic charge and greatly improves delivery

“…The in vitro studies confirm and extend the authors' previous work [8,10]. Coating a plastic spacer with an ionic detergent is a simple method of reducing electrostatic charge, thereby increasing the in vitro drug delivery.…”

“…However, the authors' previous in vitro work [8,10] has demonstrated that detergent coating improves the delivery of salbutamol through different plastic spacers (Aerochamber1, Babyhaler1, Babyspacer1, Nebuhaler1, and Volumatic), confirming that electrostatic charge plays a major role. A low-volume metal spacer [21] has been developed to eliminate the problem of static charge, but in view of the present results and the issues of cost and availability, a simple plastic spacer may remain the device of choice worldwide.…”

“…min -1 ), which could have increased the influence of static by prolonging the contact time between the aerosol cloud and the walls of the spacer. Effects of various inhalation modes on the deposition of radioactive aerosols are well known [20], but previous in vitro studies have demonstrated that the influence of lower flow rates and delay was greatly reduced or even eliminated by reducing the charge on the spacer, and that the use of non-electrostatically charged spacers leads to a higher and more predictable dose delivery [10,21].…”

The National Consensus Project* «cystic Fibrosis: Definition, Diagnostic Criteria, and Therapy». Section «inhalation Therapy» (Abridged)

“…Проблема синхронизации вдоха с моментом посту-пления лекарственного препарата -одна из самых важных при использовании дозированных аэрозольных ингаляторов. Не все дети оказываются в состоянии пра-вильно освоить этот дыхательный маневр, поэтому для оптимизации осаждения медикамента применяют рас-пределяющее устройство -спейсер [35].…”

Salbutamol in asthma treatment: with nebulizer or inhaler?

“…Fakat basit ve pratik bir yöntem olan aracı tüpün yüzeyini gün-de bir iyonik deterjan ile kaplamanın akciğere ulaşan ilaç miktarını %50-70 oranında artırdığı ve akciğere giden ilaç miktarının belirlenmesinde elektrostatik yükü ortadan kaldırmanın ilaç akım hızından daha önemli olduğu ortaya konmuştur. Ayrıca, yeni kullanılmaya baş-lanan tüplerin daha fazla elektrostatik yük içermesin-den dolayı kullanımda olan eski aracı tüplere göre hastaya ulaşan ilaç miktarında anlamlı bir azalmaya neden olduğu, aracı tüpü kullandıktan sonra sadece su ile yı-kamanın elektrostatik yükü azaltmadığı ve dolayısıyla hastaya ulaşan ilaç miktarını azalttığı, aracı tüpün iç yüzeyini alüminyum folyo ile kaplamanın iyonik deterjanla maruziyete benzer şekilde elektrostatik yükü anlamlı oranda azalttığı gösterilmiştir (12,13).…”