Dissolvable Films: Dissolvable Films for Flexible Product Format in Drug Delivery - Pharmaceutical Technology

Latest Issue

Latest Issue
PharmTech Europe

Dissolvable Films: Dissolvable Films for Flexible Product Format in Drug Delivery
For pediatric and geriatric patients, fast-dissolving drug-delivery systems provide an easier way to take medications and vitamins. Oral thin films have evolved to provide systemic delivery of active pharmaceutical ingredients for over-the-counter and soon, prescription drugs. The authors review the practical benefits of dissolvable films, their manufacture, and their market potential.

Pharmaceutical Technology

Taste-masking options . Similar to other oral immediate- release drug delivery forms in which the dosage form contacts the tongue, taste-masking plays a critical role in the success of a product's acceptance and is an equally critical component of the film's formulation. Many of the same taste-masking techniques used to formulate syrups and soft-chew oral dosage medications can be used in OTFs. Traditional flavor and sweetener combinations, encapsulation or particle coating of the API, and complexation with ion-exchange resins are some of the techniques that may be successfully applied for masking bitter-tasting or objectionable materials in OTFs. When possible, taste-masking techniques resulting in discrete particles larger than 250 m should be avoided, as these could potentially present uniformity challenges in the finished dosage form (7).

Manufacturing oral thin films

Figure 2
Because OTFs may incorporate APIs with a narrow therapeutic index, tight manufacturing tolerances must be held to deliver a uniform pharmaceutical product. The manufacturing techniques used for OTFs are built upon the proven liquid-casting techniques used for decades in the commercial manufacturing of advanced polymers and coatings found in transdermal drug-delivery systems (4), in vitro diagnostic devices, and other medical devices (see Figure 2).

Casting and drying. Liquid casting is the preferred manufacturing method over 100% solids extrusion because it avoids exposing APIs to elevated temperatures that may cause drugs to degrade. Liquid casting also allows for film uniformity and low variability with regard to mass. A typical relative standard deviation (RSD) for uniformity testing of an oral thin-film batch prepared by liquid casting is on the order of 1–2% RSD (7).

The casting station transfers a bulk solution from the mixing vessel into a thin film on the surface of a release liner (2) in widths of typically 30–120 cm. The preferred finished film thickness is typically 12–100 m, although various thicknesses are possible to meet API loading and dissolution needs. Multiple casting techniques may be selected on the basis of the fluid rheology, desired applied mass, and required dosage uniformity. These coating techniques include knife-over-roll, reverse roll, slot-die, gravure cylinder, and Meyer rod coating.

Drying of the cast bulk liquid is accomplished by passing the coating through an oven or series of ovens to evaporate any solvent(s) used to prepare the liquid. The dried film is wound into a roll and wrapped in foil packaging to ensure environmental protection during handling and storage, before being processed into single, pre-measured unit doses (10).

Packaging and converting . The converting and packaging stage also provides product flexibility to drug manufacturers. The rolled film can be die-cut into any shape or size or slit into narrower rolls as required for the application. For branding purposes and to meet industry regulations, converters may choose to print information directly onto the film unit doses before packaging.

Currently, most drug-containing films are packaged by unit in primary packaging. The specific number of unit doses is then organized within a secondary shelf carton. To provide product stability during the expiration dating period, several packaging suppliers offer multilayer flexible-film and foil-laminated products with high moisture barriers. Industry packaging standards vary by product and market, and requirements should be discussed for each product during the design phase. Criteria that may be taken into consideration include the need for unit-dose packaging, barcode labeling, and the content in instructions for use, child-resistant seals, and senior-friendly packaging (2).


blog comments powered by Disqus
LCGC E-mail Newsletters

Subscribe: Click to learn more about the newsletter
| Weekly
| Monthly
| Weekly

What role should the US government play in the current Ebola outbreak?
Finance development of drugs to treat/prevent disease.
Oversee medical treatment of patients in the US.
Provide treatment for patients globally.
All of the above.
No government involvement in patient treatment or drug development.
Finance development of drugs to treat/prevent disease.
Oversee medical treatment of patients in the US.
Provide treatment for patients globally.
All of the above.
No government involvement in patient treatment or drug development.
Jim Miller Outsourcing Outlook Jim MillerOutside Looking In
Cynthia Challener, PhD Ingredients Insider Cynthia ChallenerAdvances in Large-Scale Heterocyclic Synthesis
Jill Wechsler Regulatory Watch Jill Wechsler New Era for Generic Drugs
Sean Milmo European Regulatory WatchSean MilmoTackling Drug Shortages
New Congress to Tackle Health Reform, Biomedical Innovation, Tax Policy
Combination Products Challenge Biopharma Manufacturers
Seven Steps to Solving Tabletting and Tooling ProblemsStep 1: Clean
Legislators Urge Added Incentives for Ebola Drug Development
FDA Reorganization to Promote Drug Quality
Source: Pharmaceutical Technology,
Click here