Q. What are the main challenges facing tabletting manufacturers?

Prideaux: In anticipation of future patent losses, we are seeing tablet manufacturers trying to boost the productivity of their blockbusters to ensure a robust supply chain as a counter to new generic entrants. The challenge here is to increase capacity and reduce costs, without a massive investment. There are a number of solutions on the market that can help achieve this, including multi-tip tooling, die segment turrets and coatings; all of which can facilitate the speed or output of an existing tablet press. Paying greater attention to the fine detail of tooling design and the effective maintenance of both the tooling and press can also help reduce tablet press down time and increase productivity.

Globalisation and the relocation of products to alternative plants worldwide can also create problems. For instance, subtle changes in environmental conditions and material supply can hinder process replication at a new site, and there is also the challenge of training new operatives. The knowledge and support of key suppliers with global experience can be vital in supporting this process, and the speed and effectiveness of the supplier's response can be critical.

Natoli: One of the major challenges for the tabletting industry is the competition that is now coming from developing, low-labour index countries. However, competition also has its benefits because it encourages innovation and process improvements. The need for reduced costs and manufacturing times has also led a number of manufacturers to use direct compression, which offers reduced costs and processing times. However, caution is required because some blends using this method result in unfavourable powders that are not suitable for tabletting.

Looking more in-depth at the tabletting manufacturing process, there are a number of common challenges that must be faced such as capping, sticking and tool binding. To overcome these issues, many tablet manufacturers have their punch or die configurations modified to be better suited for the product being compressed. This isn't a new trend as such, but is becoming more prevalent as tablet manufacturers attempt to reduce costs by minimising powder processing.

Chesnoy: The manufacturing processes for tablets can be divided into three techniques: wet granulation, dry granulation and direct compression.

With wet and dry granulation techniques, the challenges relate to the complexity of the many steps involved in obtaining a powder blend exhibiting required flowability and compressibility parameters. For the simpler process of direct compression, the main challenges are to guarantee excipient properties and control any variables.

According to a survey conducted in 2010, poor formulation design accounts for 34% of common problems encountered during tablet manufacturing, while problems in blend uniformity account for 15%.¹ This means that around 50% of the problems encountered by tabletting manufacturers could be solved by adjusting the mechanical properties of powders, such as flowability, dilution potential and compressibility.

The remaining problems are linked to tabletting equipment. As the excipient's performances should be tested on different tablet presses, the development of a tablet press simulator could help gain a better understanding of the physical behaviour of excipients, and blends thereof, under compression. Conventional presses equipped with data acquisition systems could also provide information on compression cycles, ejection force and heckle plot analysis.