Inhalation devices: from basic science to practical use, innovative vs generic products

ABSTRACT

Introduction: Inhalation therapy is a convenient method of treating respiratory diseases. The key factors required for inhalation are the preparation of drug carriers (aerosol particles) allowing reproducible dosing during administration. These technical challenges are accomplished with a variety of inhalation devices (inhalers) and medicinal formulations, which are optimized to be easily converted into inhalable aerosols.

Areas covered: This review is focused on the most important, but often overlooked, effects, which are required for the reliable and reproducible inhalable drug administration. The effects of patient-related issues that influence inhalation therapy, such as proper selection of inhalers for specific cases is discussed. We also discuss factors that are the most essential if generic inhalation product should be considered equivalent to the drugs with the clinically confirmed efficacy.

Expert opinion: Proper device selection is crucial in clinical results of inhalation therapy. The patients’ ability to coordinate inhalation with actuation, generation of optimal flow through the device, use of optimal inspiratory volume, all produces crucial effects on disease control. Also the severity of the disease process effects proper use of inhalers. Interchanging of inhalers can produce potentially conflicting problem regarding efficacy and safety of inhalation therapy.

KEYWORDS:

• Drug administration
• inhalation
• aerosol
• bioequivalence
• drug approval
• drug delivery systems
• inhalers
• generic drugs
• lung deposition
• nebulizers and vaporizers

Article highlights

• Knowledge of basic mechanisms governing the successful deposition of inhaled particles is crucial in planning inhalation therapy

• Proper selection of inhalers for individual subjects is a key factor in a successful and reproducible inhalatory therapy

• The influence of the patients ability to use an inhaler and the effect of disease process on the ability of inhaling doses of medicinal aerosols is crucial in use of innovative and generic products, affecting the possibility of switching inhalers

• In generic OIP quality of the assembly of the inhaler components is crucial in determining the comparability of inhalers in the licensing process, also affecting the interchangeability of inhalers by the patient

• Interchangeability of inhalers, use of generic products can produce potentially conflicting problems in efficacy and safety of inhalation therapy

This box summarizes key points contained in the article.

Declaration of interest

TR Sosnowski was supported by project no. 2014/13/B/ST8/00808 of the National Centre for Science (Poland). M Pirozynski received lecture fees from AstraZeneca, Berlin Chemie, Chiesi, GlaxoSmith Kline, Hasco Lek, Meda, Novartis, Olympus Europe, TEVA. TR Sosnowski received lecture fees from Adamed, AstraZeneca, GlaxoSmithKline, TEVA and participated in research grants funded by Adamed, TEVA, Hasco Lek, Lek-AM, GlaxoSmithKline. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.