Oromucosal multilayer films for tailor-made, controlled drug delivery

ABSTRACT

Introduction: The oral mucosa has recently become increasingly important as an alternative administration route for tailor-made, controlled drug delivery. Oromucosal multilayer films, assigned to the monograph oromucosal preparations in the Ph.Eur. may be a promising dosage form to overcome the requirements related to this drug delivery site.

Areas covered: We provide an overview of multilayer films as drug delivery tools, and discuss manufacturing processes and characterization methods. We focus on the suitability of characterization methods for particular requirements of multilayer films. A classification was performed covering indication areas and APIs incorporated in multilayer film systems for oromucosal use in order to provide a summary of data published in this field.

Expert opinion: The shift in drug development to high molecular weight drugs will influence the field of pharmaceutical development and delivery technologies. For a high number of indication areas, such as hormonal disorders, cardiovascular diseases or local treatment of infections, the flexible layer design of oromucosal multilayer films provides a promising option for tailor-made, controlled delivery of APIs to or through defined surfaces in the oral cavity. However, there is a lack of discriminating or standardized testing methods to assess the quality of multilayer films in a reliable way.

KEYWORDS:

• Mucoadhesive films
• oromucosal permeation
• multilayer films
• buccal formulations
• sublingual formulations
• bilayer films

Article highlights

• The oral mucosa as drug application side is gaining importance for local and systemic drug delivery.

• Due to their flexible layer design including insoluble backing layers and mucoadhesive layers, oromucosal multilayer films are suitable dosage forms for tailor-made and site-specific drug delivery.

• Oromucosal multilayer films have featured improved pharmacokinetic profiles of various drug candidates compared to conventional dosage forms and have been assessed as promising dosage form to overcome some negative issues associated with other oral dosage forms like lozenges, tablets or ointments.

• There is a lack of critical requirements and definitions for oromucosal films in general, but in particular for multilayer films, which might be a key reason for their limited market presence so far.

• Different manufacturing processes for multilayer films are feasible in small lab scale (double casting, casting and pasting or other assembling methods), while upscaling to production scale might be challenging and demands further investigations by academia and pharmaceutical industry to increase the number of approved multilayer dosage forms on the international market.

Declaration of interest

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.

Additional information

Funding

This paper was supported by Heinrich-Heine-Universität Düsseldorf.