Pulmonary drug delivery. Part II: The role of inhalant delivery devices and drug formulations in therapeutic effectiveness of aerosolized medications

Abstract

Research in the area of pulmonary drug delivery has gathered momentum in the last several years, with increased interest in using the lung as a means of delivering drugs systemically. Advances in device technology have led to the development of more efficient delivery systems capable of delivering larger doses and finer particles into the lung. As more efficient pulmonary delivery devices and sophisticated formulations become available, physicians and health professionals will have a choice of a wide variety of device and formulation combinations that will target specific cells or regions of the lung, avoid the lung's clearance mechanisms and be retained within the lung for longer periods. It is now recognized that it is not enough just to have inhalation therapy available for prescribing; physicians and other healthcare providers need a basic understanding of aerosol science, inhaled formulations, delivery devices, and bioequivalence of products to prescribe these therapies optimally.

Inhalasjonsmedisiner må brukes riktig

“…Når ventilen åpnes, presses legemiddelet ut i aerosolform ved hjelp av drivgassen. Av opprinnelig utløst dose, vil kun 10-20 prosent avsettes i lungene (1). Denne lave prosentvise effektiviteten skyldes at apparatet avgir en stor andel partikler som er større enn 5 µm, i tillegg til at den gassdrevne spraydosen har stor hastighet ut fra munnstykket (1).…”

“…Dette kan medføre flere bivirkninger både lokalt og systemisk, fordi pasienten risikerer å svelge virkestoffet og dermed i større grad blir eksponert systemisk (1). Det ideelle inhalasjonsapparatet genererer derfor flest mulig partikler med optimal størrelse og hastighet.…”

“…Pasienten skal derfor holde pusten i fire til ti sekunder etter inhalasjonen. Hvis det pustes ut umiddelbart, vil legemiddelet bli med ut igjen uten å gi den ønskete effekten (1).…”

Managing diabetes with inhaled insulin

“…However, it was not until the development of devices capable of delivering drugs to the appropriate lung surface that the advancement of inhaled insulin could become a reality. In addition, research has focused on technologies to produce dry-powder formulations of insulin that meet the biophysical parameters facilitating deposition in the alveolar space and maximizing glucose-lowering activity [11,12]. There are a number of factors that influence the successful delivery of insulin to the deep lung space.…”

Loco-regional administration of nanomedicines for the treatment of lung cancer

“…Additionally, it is common for DPI devices to be misused leading to reduced efficacy (Dolovich et al, 2005). While methods to overcome such drawbacks have been explored such as modifying devices to accommodate different inspiratory flow rates, such as the Turbohaler (Labiris & Dolovich, 2003), dry powder platforms are in this moment not ready for the administration of chemotherapy to treat lung cancer as demonstrated by the lack of clinical trials using this approach. However, once this threshold will be crossed, the technology appears to have great potential for an anticancer treatment administration in the outpatient setting.…”