Agreement between two methods for assessing bioequivalence of inhaled salbutamol

Effect of using acoustic flo-tone training device and its smartphone application on enhancing inhalation technique from metered-dose inhaler with spacer in asthmatic children

Aim of study: This research study aims to compare between two different counseling approaches; traditional verbal counseling vs. advanced counseling (in which we used the acoustic Flo-tone training device and its smartphone application combined with traditional verbal counseling) to determine the most beneficial counseling approach for asthmatic children who use metered-dose inhaler (MDI) with spacers concerning inhalation duration and inhalation technique mistakes. Methods: A total of 100 asthmatic children (8-18) years old were randomized into two groups (a control group, and an advanced group). Each group included 50 subjects. Every subject received 3 counseling meetings, one each month. Asthmatic children in the control group were trained on inhalation technique from MDI + spacer verbally (traditional counseling), while asthmatic children in advanced group were trained on inhalation technique from MDI + spacer verbally and by advanced counseling (whistling Flo-tone + smartphone application). At each visit mistakes in inhalation technique steps were; detected, corrected, and recorded and the inhalation duration was measured for every child in each group. Results: In both study groups, the total mean number of inhalation technique mistakes decreased significantly (p < 0.05) from visit 2, also the total mean inhalation durations in seconds showed a significant increase (p < 0.05) from visit 2. A significant (p < 0.05) reduction in the total mean number of mistakes and a significant (p < 0.05) increase in total mean inhalation durations were observed from visit 2 in advanced group compared to control group. Conclusion: Combination between traditional verbal and advanced counseling methods resulted in significant (P < 0.05) improvements in the number of inhalation technique mistakes and inhalation durations from MDI with spacer in children compared to using traditional verbal counseling alone.

Spacers and Valved Holding Chambers-The Risk of Switching to Different Chambers

Spacers are pressurized metered-dose inhaler (pMDI) accessory devices developed to reduce problems of poor inhaler technique with pMDIs. Spacers that feature a 1-way inspiratory valve are termed valved holding chambers (VHCs); they act as aerosol reservoirs, allowing the user to actuate the pMDI device and then inhale the medication in a 2-step process that helps users overcome challenges in coordinating pMDI actuation with inhalation. Both spacers and VHCs have been shown to increase fine particle delivery to the lungs, decrease oropharyngeal deposition, and reduce corticosteroid-related side effects such as throat irritation, dysphonia, and oral candidiasis commonly seen with the use of pMDIs alone. Spacers and VHCs are not all the same, and also are not interchangeable: the performance may vary according to their size, shape, material of manufacture and propensity to become electrostatically charged, their mode of interface with the patient, and the presence or otherwise of valves and feedback devices. Thus, pairing of a pMDI plus a spacer or a VHC should be considered as a unique delivery system. In this Rostrum we discuss the risk potential for a patient getting switched to a spacer or VHC that delivers a reduced dose medication.

Considerations in establishing bioequivalence of inhaled compounds

INTRODUCTION

Generic inhalers are often perceived as inferior to their branded counterparts; however, they are safe and effective if they can meet the regulatory requirements. The approach to assess bioequivalence (BE) in oral dosage form products is not sufficient to address the complexities of inhalational products (e.g., patient-device interface); hence, more considerations are needed and caution should be applied in determining BE of inhaled compounds.

AREAS COVERED

This review outlines the evaluation process for generic inhalers, explores the regulatory approaches in BE assessment, and highlights the considerations and challenges in the current in vitro and in vivo approaches (lung deposition, pharmacokinetic, pharmacodynamic/clinical studies, and patient-device interface) for establishing BE of inhaled compounds.

EXPERT OPINION

The ultimate goals in this field are to establish uniformity in the regulatory approaches to speed the drug submission process in different regions, clear physicians' misconception of generic inhalers, and have meaningful clinical endpoints such as improvement in patient quality of life when compared to placebo and brand name drugs. As inhalational drugs become more common for other indications such as antibiotics, the technologies developed for inhaled compounds in the treatment of chronic pulmonary diseases may be extrapolated to these other agents.

Regulatory Considerations for Approval of Generic Inhalation Drug Products in the US, EU, Brazil, China, and India

This article describes regulatory approaches for approval of "generic" orally inhaled drug products (OIDPs) in the United States, European Union, Brazil, China and India. While registration of a generic OIDP in any given market may require some documentation of the formulation and device similarity to the "original" product as well as comparative testing of in vitro characteristics and in vivo performance, the specific documentation approaches, tests and acceptance criteria vary by the country. This divergence is due to several factors, including unique cultural, historical, legal and economic circumstances of each region; the diverse healthcare and regulatory systems; the different definitions of key terms such as "generic" and "reference" drug; the acknowledged absence of in vitro in vivo correlations for OIDPs; and the scientific and statistical issues related to OIDP testing (such as how best to account for the batch-to-batch variability of the Reference product, whether to use average bioequivalence or population bioequivalence in the statistical analysis of results, whether to use healthy volunteers or patients for pharmacokinetic studies, and which pharmacodynamic or clinical end-points should be used). As a result of this discrepancy, there are ample opportunities for the regulatory and scientific communities around the world to collaborate in developing more consistent, better aligned, science-based approaches. Moving in that direction will require both further research and further open discussion of the pros and cons of various approaches.

The challenge of delivering therapeutic aerosols to asthma patients

The number of people with asthma continues to grow around the world, and asthma remains a poorly controlled disease despite the availability of management guidelines and highly effective medication. Patient noncompliance with therapy is a major reason for poor asthma control. Patients fail to comply with their asthma regimen for a wide variety of reasons, but incorrect use of inhaler devices is amongst the most common. The pressurised metered-dose inhaler (pMDI) is still the most frequently used device worldwide, but many patients fail to use it correctly, even after repeated tuition. Breath-actuated inhalers are easier to use than pMDIs. The rationale behind inhaler choice should be evidence based rather than empirical. When choosing an inhaler device, it is essential that it is easy to use correctly, dosing is consistent, adequate drug is deposited in both central and peripheral airways, and that drug deposition is independent of airflow. Regular checking of inhalation technique is crucial, as correct inhalation is one of the cornerstones of successful asthma management.

Targeting drugs to the airways: The role of spacer devices

AIM

Spacer devices are inhalation aids of varying dimension and complexity, specifically designed to overcome problems with the use of pressurised metered dose inhalers (pMDIs). The aim of this review is to examine the current understanding about these inhalation devices and discuss their advantages and disadvantages.

METHODS

The pertinent literature concerning the characteristics and effects of spacers on delivery and lung deposition of inhaled medications, as well as their clinical efficacy in patients with reversible airway obstruction, is examined.

RESULTS

Spacers minimise problems of poor inhalation technique with pMDI, reduce oropharyngeal deposition and increase lung deposition. Spacers improve the clinical effect of inhaled medications, especially in patients unable to use a pMDI properly. Compared to both pMDIs and dry-powder inhalers, spacers may increase the response to beta-adrenergic bronchodilators, even in patients with correct inhalation technique. A pMDI plus spacer has proven to be viable lower cost alternative to the use of a nebuliser for delivering large bronchodilator doses in patients with severe acute asthma or chronic obstructive pulmonary disease. The use of large-volume spacers is recommended for delivering high doses of inhaled corticosteroids, and may permit a lower maintenance dose to be used.

CONCLUSION

pMDIs may be routinely fitted with a spacer, especially in situations where correct pMDI use is unlikely.