Understanding the Importance of Capsules in Dry Powder Inhalers.

Francesca Buttini,Chiara Allegrini,Eride Quarta,Federico Lavorini

doi:10.3390/pharmaceutics13111936

Francesca Buttini, Chiara Allegrini + Show 2 more

Open Access

https://doi.org/10.3390/pharmaceutics13111936

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Journal: Pharmaceutics	Publication Date: Nov 16, 2021
Citations: 16	License type: CC BY 4.0

Affiliation: University of Parma, University of Florence

Abstract

Pulmonary drug delivery is currently the focus of research and development because of its potential to produce maximum therapeutic benefit to patients by directing the drug straight to the lung disease site. Among all the available delivery options, one popular, proven and convenient inhaler device is the capsule-based dry powder inhaler (cDPI) for the treatment of an increasingly diverse range of diseases. cDPIs use a hard capsule that contains a powder formulation which consists of a mixture of a micronized drug and a carrier usually the lactose, known for its good lung tolerance. The capsule is either inserted into the device during manufacturer or by the patient prior to use. After perforating, opening or cut the capsule in the device, patients take a deep and rapid breath to inhale the powder, using air as the vector of drug displacement. The system is simple, relatively cheap and characterized by a lower carbon footprint than that of pressurized metered dose inhalers. This article reviews cDPI technology, focusing particularly on the importance of capsule characteristics and their function as a drug reservoir in cDPIs.

Highlights

Pressurized metered-dose inhalers, dry powder inhalers (DPIs) and nebulizers are the main categories of inhaled drug delivery systems, each class with its unique strengths and weaknesses [1]
Asthma and COPD patients [20,21] displayed no or fewer errors when using multiple-dose DPIs, such as the Ellipta, which require three steps to take the medication compared to the capsule-based DPI Handihaler or Breezhaler, which require eight steps to inhale the medication. These findings suggest that a DPI with a more intuitive design and requiring fewer steps to take the medication could be suitable for most patients
The therapeutic application of capsule-based dry powder inhaler (cDPI) began at the end of the 1960s, when the Spinhaler was introduced as the first DPI containing a powder formulation of broncho-active drugs in a gelatin capsule, which the patient loaded into the device prior to use

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Around the 1980s, the Italian company ISF was the first to patent an inhalation device that caused the capsule to rotate around its minor axis [5] To date, this spinning mechanism is still the most efficient in releasing and deaggregating the powder that leaves the capsule driven by centrifugal force [6]. DPIs have several advantages over pMDIs: they simplify the inhalation technique and reduce the necessity for the patient’s cooperation They enable the administration and deposition of high drug doses within the lungs, thereby limiting the incidence of both local and systemic side effects.

Types of Dry Powder Inhalers

Formulation Aspects of DPI

Effect of Moisture on Product Stability and Mechanical Performance

Findings

Conclusions