Coating systems are typically mixtures of polymers, plasticisers, colouring agents and other excipients, which can be stirred into water or an organic solvent to produce a dispersion for the film coating of solid oral dosage forms such as tablets.
The two new products - introduced at the Conference on Pharmaceutical Ingredients (CPhI) in Brussels last week - are an extension of BASF's Kollicoat range, which encompasses a number of immediate- and sustained-release polymer systems. Last year, BASF launched Kollicoat IR, the first of a new generation of excipients based on polyvinyl alcohol-polyethylene glycol copolymer.
The new lines are: Kollicoat IR White, which has been created using the firm's proprietary X-fast technology and ensures extremely fast dispersibilty in water; and Kollicoat Protect, which provides moisture protection for sensitive drugs as well as taste masking.
Kollicoat IR White is the first ready-to-use coating system developed by BASF, and like its parent overcomes one of the primary problems with using polymers for coating immediate-release tablets.
Only a few polymers, such as hydroxypropyl methylcellulose, hydroxypropylcellulose and Eudragit E can be used for instant-release coatings on pharmaceuticals. The drawbacks of these polmers are mainly high viscosityin solution, which limits the polymer concentration in spray solutions to a maximum of 10 per cent, and limited flexibility which can make the films prone to cracking.
In contrast, Kollicoat IER White is a highly flexible film-former with low viscosity. It can also be combined with colourants such as iron oxides or lakes to give coloured coatings, and readily accepts printing, according to BASF. It protects against unpleasant taste and odour, improves appearance, makes tablet easier to swallow, gives distinctive colouring and protects the active ingredients.
Meanwhile, Kollicoat Protect also has Kollicoat IT at its core (with the chemical name polyvinyl alcohol-polyethylene glycol copolymer and polyvinyl alcohol). This gives it the same low viscosity and high flexibility, but the addition of PVA improves its taste-masking and barrier properties.
It can also be used as a subcoating, a peroxide-free wet granulation binder or as a pore former in sustained release coatings, according to BASF.