Novel Oral Dosage Forms : Fast-Disintegrating Tablets

FAST-DISINTEGRATING TABLETS

Coming up with novel ways to deliver drugs is key to maintaining profitability.
One approach is to use technologies such as mouth-dissolving tablets or wafers, also known as fast melt, fast dissolving or orodispersible. 

The demand for solid dosage forms that can be dissolved/suspended in water, chewed or rapidly dissolved in the mouth is particularly strong in the paediatric and geriatric markets, with further application to other patients who prefer the convenience of a readily administered dosage form. 

Orally disintegrating, or orodispersible, tablets (ODTs) are designed to disappear rapidly in the mouth before swallowing and disintegrate in less than 3 minutes. The primary advantage of ODTs is that no external source of liquid is needed for consumption. For patients with dysphagia or children too young to swallow tablets or capsules, ODTs provide a useful alternative.

When placed in the oral cavity, orodispersible tablets release the drug instantaneously, with rapid onset of action. Drugs delivered via the oramucosal route are able to avoid first-pass metabolism and enzymatic degradation to which conventional oral dosage forms are subject, resulting in increased bioavailability. The majority of commercially available products in this class utilise their rapid disintegration to facilitate swallowing of the active compound rather than to deliver drug directly into systemic circulation. 

Three general technologies are commonly applied for the production of fast-disintegrating systems: Freeze-drying, Moulding (compression- or heat-moulding) and Direct Compression. 

The production method involves a careful choice of compromises that may result, such as loss of physical resistance/mechanical strength, retardation of disintegration time and high cost of production. The choice of a suitable type and an optimal amount of disintegrants is paramount for ensuring a high disintegration rate. 

The demand for fast-melting tablets (FMTs) has initiated the rapid development of a lucrative platform and of much interest in this type of formulation. The advantage of this convenient administration method has encouraged both academia and industry to generate new fast-disintegrating formulations and technological approaches in this field.

However popular, these tablets must be strong enough to survive manufacturing and shipping, yet friable enough to instantly release their pharmaceutical ingredients once they are placed in the mouth or ingested. Many orodispersible tablets are fragile and brittle, which usually warrants special packaging for protection during storage or transportation to ensure that the tablet remains in one piece until the point of ingestion. 

The key properties of FMTs are fast absorption of water into the core of the tablets and disintegration of associated particles into individual components for fast dissolution. Traditional (or standard compendial) tests have limitations in discriminating between the disintegration times of the different fast-dissolve formulations  with their very short disintegration times, and they also may not always reflect the real in vivo disintegration of tablets.

Measuring Tablet Disintegration

The Tablet Disintegration Rig fitted
to the TA.XTplus Texture Analyser

A thorough analysis of disintegration behaviour is vital for the formulation of new dissolving tablets to ensure reliable breakdown. 

The tablet has to be resilient enough to endure manufacturing and shipping yet release a sufficient amount of disintegrants to deliver an optimum dissolution rate.

When attached to a TA.XTplus Texture Analyser, the Tablet Disintegration Rig facilitates the assessment of the mechanical properties of fast-melting tablets. The rig closely replicates the in vivo conditions of the human mouth, enabling manufacturers to examine water absorption and the disintegration of associated particles. This allows the determination of tablet disintegration time and behaviour, giving a valuable insight into performance and efficacy.

Assessment of disintegration
profile of a fast-melt tablet

The unique geometry of the rig allows the disintegration medium to access the tablet from all areas. The dry tablet sample is secured to a probe by a thin strip of double sided adhesive tape along its diameter. The probe’s surface has a ‘channelled’ design, allowing fluid to flow freely around the tablet while ensuring contact is maintained with the probe. 

Once the probe is lowered into the medium, the tablet is positioned on a perforated platform, and the texture analyser applies a constant force onto it. The perforated surface enables free ingress of water beneath the sample and dispersion of the disintegrant.

A summary of how to perform texture analysis on the alternatives to traditional tablet-form medications using a TA.XTplus Texture Analyser can be viewed in this video...

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We can design and manufacture probes or fixtures for the TA.XTplus texture analyser that are bespoke to your sample and its specific measurement.

Once your measurement is performed, our expertise in its graphical interpretation is unparalleled. Not only can we develop the most suitable and accurate method for the testing of your sample, but we can also prepare analysis procedures that obtain the desired parameters from your curve and drop them into a spreadsheet or report designed around your requirements.

For more information on how to measure texture, please visit the Texture Analysis Properties section on our website.

The TA.XTplus texture analyser is part of a family of texture analysis instruments and equipment from Stable Micro Systems. An extensive portfolio of specialist attachments is available to measure and analyse the textural properties of a huge range of food products. Our technical experts can also custom design instrument fixtures according to individual specifications.

No-one understands texture analysis like we do!

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