Standard high-performance liquid chromatography testing for potency and content uniformity apply to thin-film oral dosage
forms. Analytical methods for testing films are similar to other solid dosage forms, but the potential interference of the
film-forming polymers during methods development must not be overlooked. Taste-masking analysis is conducted through qualified
human panels and/or in vitro testing using electronic techniques (7).
Testing methods used to characterize dissolvable films include USP tests for disintegration and dissolution. Additional test
methods may be developed to simulate environmental influences such as pH and temperature.
Standard physical testing will ensure that the films demonstrate the appropriate strength required to withstand the rigors
of processing and packaging without breakage. Film strength is evaluated through tensile and burst tests that measure the
force required to break the film.
Finally, stability of OTFs has been demonstrated by the various commercial products claiming 2- to 3-year expiration date
periods. Although these products tend to be sensitive to environmental moisture, the primary packaging is critical and sufficient
for meeting the International Conference on Harmonization stability requirements for extended expiration dating (11).
Beyond immediate-release applications
While the prospects for increased acceptance and product extensions of more over-the-counter OTFs and the eventual launch
of prescription drug OTFs is an exciting time for growth, formulators have only begun to explore and develop the next generation
of dissolvable film technology for pharmaceutical and medical device applications (see Figure 3). Emerging areas for immediate
- Multilayer drug construction: two or more layers of API-loaded films could be combined into one format, providing the benefit
of layering APIs that would otherwise be incompatible. The layers may be formulated to have the same or various dissolution
- Topical applications: the use of dissolvable films may be feasible in the delivery of active agents such as analgesics or
antimicrobial ingredients for wound care and other applications.
- Binding agents: dissolvable films could potentially be used to encapsulate a compressed tablet or enclose a multilayer or
combination system to enable controlled release of the dose.
- Buccal, sublingual, and mucosal delivery systems: dissolvable films may be layered or combined with bioadhesives for these
types of oral delivery systems. The benefits of multilayer constructions discussed previously could apply in these systems
and dissolution rates could be designed to range from minutes to hours.
- Gastroretentive dosage systems: dissolvable films are being considered in dosage forms for which water-soluble and poorly
soluble molecules of various molecular weights are contained in a film format (4). Dissolution of the films could be triggered
by the pH or enzyme secretions of the gastrointestinal tract, and could potentially be used to treat gastrointestinal disorders.
- Diagnostic devices: dissolvable films may be loaded with sensitive reagents to allow controlled release when exposed to a
biological fluid or to create isolation barriers for separating multiple reagents to enable a timed reaction within a diagnostic
The true potential for oral thin-film technology is only beginning to be recognized. Additional immediate release over-the-counter
OTFs, and eventually prescription drug OTFs will be commercially launched. Future dissolvable films will likely evolve beyond
immediate-release oral delivery of drug compounds; exploration into the use of film formats to deliver nano-scale to large
molecules is already underway. In addition, the chemistry and processing of the dissolvable-film platform technology broadens
the application potential into implantable, topical, sublingual, dermal and gastro-retentive applications. Ultimately, dissolvable-film
technology is only limited by the imagination and capabilities of the formulator.
Beth Vondrak is vice-president and general manager at ARx, LLC, a wholly owned subsidiary of Adhesives Research, Inc., and Scott Barnhart is technical director at ARx, LLC, PO Box 100, 100 Seaks Run Road, Glen Rock, PA 17327, tel. 717.227.3260/3206, fax 717.235.0172,
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2. P. Frey, "Film Strips and Pharmaceuticals," Pharma. Mfg. & Packag. Sourcer, Winter, 92–93 (2006).
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Falls Church, VA, 2006), 18–31.
4. S.D. Barnhart and M.S. Sloboda, "The Future of Dissolvable Films," Drug Delivery Technol. 7 (8), 34–37 (2007).
5. I. Muir, "Growing Sales and New Opportunities for Oral Fast Dissolve," ONDrugDelivery—Oral Drug Delivery: When You Find
the Holy Grail (East Sussex, UK),
http://www.ondrugdelivery.com/publications/Oral_Drug_Delivery_07.pdf, accessed Feb. 20, 2008.
6. P. Van Arnum, "Outsourcing Solid Dosage Manufacturing," Pharmaceutical Technol.
30 (6), 44–52 (2006).
7. S.D. Barnhart, "Thin Film Oral Dosage Forms," in Modified Release Drug Delivery Technology, 2nd ed., Vol. 1, in press (Informa Healthcare; New York, NY, 2008) 209-216.
8. Novartis Pharmaceuticals Annual Report (2005), p. 43.
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10 (10), 11–13 (2006).
10. B. Meathrel and C. Moritz, "Dissolvable Films and Their Potential in IVDs," IVD Technol.
13 (9), 53–58 (2007).
11. ICH, "ICH Q1C Stability Testing for New Dosage Forms," Federal Register
62 (90), 25634–25635 (1997).