After having announced the development collaboration eight months ago, Italian firm Eurand yesterday declared that it managed to successfully formulate an orally disintegrating tablet (ODT) form of the GSK drug, winning itself the million Euro milestone payment in the process. The new formulation is based on Eurand's taste masking and microencapsulation dosage form technologies, AdvaTab and Microcaps. Although the specific compound being reformulated is being kept strictly under wraps, GSK is aiming to file for marketing authorisation in the US by the end of this year. The orally disintegrating tablet formulation is currently being evaluated in a bioequivalence study, the start of which triggered the milestone payment by GSK to Eurand. Eurand's Microcaps technology has already been applied to several branded products (such as Benadryl Fastmelt (diphenhydramine citrate) and Tylenol (acetaminophen) in the US) and allows any bas odours or tastes in a product to be masked. This is essentially achieved by encapsulating each particle of the drug substance in a continuous membrane which forms an inert barrier between the drug and the taste buds. The Microcaps technology coats each particle with polymeric membranes with varying degrees of thickness and porosity using phase separation and/or spray coating processes. The particular membranes used can be modified for each product according to specific requirements such as gastrointestinal release rate or final dosage form. GSK has selected an orally disintegrating tablet, but the technology can also be applied to chewable tablets or sprinkles for example, and can also be used to convert liquid formulations to solid ones. This perhaps particularly noteworthy as, despite refusing to name the product under development, GSK's pipeline reveals that it is planning an oral formulation of its topo-isomerase 1 inhibitor Hycamtin (topotecan) used as a second line therapy in the treatment of small cell lung cancer in injectable form. Coincidentally, this new formulation is also due to for submission for marketing authorisation sometime this year. AdvaTab., the other dosing technology being applied to the GSK compound, brings the orally disintegrating feature to the product. According to the companies, applying this technology means that the new formulation of the GSK drug dissolves in the mouth in around 30 seconds without water, whilst also leaving no bad taste thanks to the Microcaps system. As well as the speedy disintegration time, AdvaTab purportedly offers a cost efficient production process, high drug dosages per drug unit and robust tablets. With conventional production methods lubricant is incorporated throughout a tablet to provide lubrication between the tablet press and the tablet itself, however this can result in the tablet becoming hydrophobic and requiring higher compression forces for a given tablet hardness. According to Eurand, its patented production process for AdvaTab tablets offers distinct advantages over this method. The tablets are compressed using an external lubrication system (i.e. lubricant on the tablet surface alone), which the company says results in a hard, durable tablets which do not require high compression forces during production and do not repel liquids when ingested. By combining the Microcaps and AdvaTab dosage form technologies, Eurand claims that products take the patient-preferred dosage form as well as providing a better taste and feel. These features can make all the difference in patient compliance, where poor-tasting or awkward dosage forms can reduce the chances that patients stick to a course of medication. As such, the ODT market is blossoming as manufacturers try to differentiate their products and push them to the top of the popularity list. Eurand has already reported an enthusiastic response from the industry for the AdvaTab/Microcaps combination, and has been in "advanced negotiations" with firms in Japan, Europe and the US for a variety of products. As manufacturers seek out new ways to extend product lifecycles and try and ward off costs associated with patent expiries and new drug development projects, the ODT market is growing quickly as a popular choice for pharma firms. Already worth billions, the ODT market continues to grow at around 20 per cent each year according to industry analysts.