Fast-dissolving drug-delivery systems were first developed in the late 1970s as an alternative to tablets, capsules, and syrups
for pediatric and geriatric patients who experience difficulties swallowing traditional oral solid-dosage forms (1). In response
to this need, a variety of orally disintegrating tablet (ODT) formats were commercialized. Most ODT products were formulated
to dissolve in less than one minute when exposed to saliva to form a solution that could then be more easily swallowed.
Dissolvable oral thin films (OTFs) evolved over the past few years from the confection and oral care markets in the form of
breath strips and became a novel and widely accepted form by consumers for delivering vitamins and personal care products.
Companies with experience in the formulation of polymer coatings containing active pharmaceutical ingredients (APIs) for transdermal
drug delivery capitalized on the opportunity to transition this technology to OTF formats. Today, OTFs are a proven and accepted
technology for the systemic delivery of APIs for over-the-counter (OTC) medications and are in the early- to mid-development
stages for prescription drugs.
This article provides insight into the functionality and benefits of dissolvable films and reviews the current product landscape
and market potential. The authors also explain how thin films are formulated and manufactured, and discuss potential future
Functionality and benefits
Pharmaceutical companies and consumers alike have embraced OTFs as a practical and accepted alternative to traditional OTC
medicine forms such as liquids, tablets, and capsules. OTFs offer fast, accurate dosing in a safe, efficacious format that
is convenient and portable, without the need for water or measuring devices (2). OTFs are typically the size of a postage
stamp and disintegrate on a patient's tongue in a matter of seconds for the rapid release of one or more APIs.
The formulation of dissolvable films is customarily facilitated through aqueous polymer matrices that span a wide molecular
weight (MW) range, thereby providing flexibility to achieve certain physical properties. With the selection of appropriate
polymer excipients, these properties can be tailored to meet specific API-loading needs and dissolution rates.
To date, the commercial launch of OTFs is primarily in OTC products addressing therapeutic categories such as cough/cold,
sore throat, and antacid/gas relief as well as a number of nutritional supplement applications (2) (see Table I). In compliance
with the appropriate monographs, current products deliver a specified API dose that is immediately released and ingested.
Some drug forms are more easily used in OTFs than others (soluble versus nonsoluble), but we can expect API concentrations
to increase as new OTF formulations are developed.
The capabilities of the base technology to create dissolvable films continue to evolve. For example, a common misconception
of the OTF format is that it is limited with regard to the loading capacity of APIs. Some researchers reference a limit of
30 mg of API content as the maximum concentration. A more accurate statement would be that OTFs have the capability to load
APIs up to 50% of the unit dose mass, as demonstrated by Novartis Consumer Health's Gas-X thin film, which contains 62.5 mg
of simethicone per dose (3).
Strategic therapeutic categories for oral thin films