AUGUST 2011

Chew and deliver

Medicated chewing gum, launched in 1928, is becoming increasingly popular as a method for drug delivery. Aliasgar Shahiwala of the Dubai Pharmacy College explains the benefits for the pharmaceutical industry.

Faced with soaring R&D costs, an impending onslaught of patent expirations, mega-merger mania and increasing consumer demands for improved medications, pharmaceutical companies are relying heavily on advanced drug-delivery technology to help sustain the high growth and profit margins they have enjoyed since the 1990s. Against this background, pharma companies are recognising that drug-delivery technology is a powerful strategic marketing tool to differentiate products and extend product lifecycles, thereby overcoming marketplace challenges.

Drug-delivery applications are a valuable, cost-effective lifecycle-management resource. By infusing drugs with innovative new therapeutic benefits, drug-delivery systems extend products' profitable lifecycle, giving pharmaceutical companies competitive and financial advantages, and providing patients with improved medications. Formulation development is being used in the creation of new dosage formats for existing products, which not only reduces the cost and time of new drug development, but also helps with patent protection and bypassing existing patents.

Drug-delivery gum

Medicated chewing gum (MCG) is a drug-delivery system that consists in an active ingredient incorporated into a chewing gum that is released through the mechanical action of chewing. The first MCG product, 'Aspergum', which contained acetylsalicylic acid for headaches, was launched in 1928. The success story of nicotine chewing gum in the 1980s led to a more widespread acceptance of chewing gum as a drug-delivery system.

MCG is a good vehicle for administering active ingredients in pharmaceuticals and nutraceutics. It offers a highly convenient, patient-compliant way of dosing medications, particularly for people with swallowing difficulties such as children and the elderly.

It is also an ideal dosage format for drugs that help cure or relieve oral diseases, including toothache, periodontal disease, bacterial and fungal infections, and aphthous and dental stomatitis. MCG containing chlorhexidine is used to treat inflammatory conditions such as gingivitis.

Medicated challenges

The potential of medicated chewing gums has not yet been fully exploited because the manufacturing process requires technology that is different from that used in pharmaceutical production. This consists of equipment and facilities involving hot-melt processes, which are rare in the pharmaceutical industry.

The recent availability of directly compressible chewing-gum excipients has enabled fast, safe, low-cost development of MCG as a drug-delivery option. The launch of the Health in Gum® (directly compressible powdered gum) range of products in 2009 by leading gum-base supplier CAFOSA sparked a growing interest in the pharmaceutical world. Health in Gum® is a co-processed powdered chewing-gum excipient containing a mixture of gum base, polyols, plasticisers and anticaking agents. It complies with food chemical specifications and is 'generally regarded as safe', as regulated by FDA title 21 C.F.R. Section 172.615. Chewing gum made with this material can be directly compressed on an in-house pharmaceutical tablet-compression machine, which enables fast, low-cost development of MCGs.

As it does not require a high temperature, thermo-sensitive APIs can also be processed. This method is also ideal for water-sensitive drugs. Formulations made with Health in Gum® are similar to a tablet in appearance, but incorporate chewability, as in standard gum.

MCG potential

MCG is gaining new support. In 2012 the European Pharmacopoeia included the only commercially available device for in vitro release testing of medicated gums: a mechanical masticator that is being used by medicated gum manufacturers. Further in the future, the concept of chewing gum as a drug-delivery system may be used in preference to other oral mucosal drug-delivery systems for local and systemic delivery of most prescribed drugs as a result of higher patient acceptance and compliance.

Using the MCG formulation, the revitalisation of old products and the reformulation of newly patented products will differentiate them from upcoming generics competition. Thus, the potential of MCG for direct systemic delivery with higher patient compliance, its fast onset of action and the opportunity for product-line extension make it a likely drug-delivery system.

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