The most popular form of pharmaceutical drugs is solid dosage, and this has been the case for many years. Demand for tablet form medication is on the rise as the ageing global population increases and interest from developing markets escalates.

The mass appeal of tablets and rising competition from emerging markets is pushing manufacturers to find quick, efficient and cost-effective methods of producing high-quality tablets. In a bid to find an answer to up-scaling production easily, manufacturers are turning to multi tip tooling which is seeing a huge revival thanks to its ease and efficiency.

Solid dose on the rise
The figures quoted on the growth of the oral solid dosage market are impressive. The Future Market Insights report projects that the global oral solid dosage pharmaceutical formulation market will register 6.5% CAGR during the forecast period 2017 to 2027. The market is forecast to grow from $493.2 billion in 2017 to $926.3 billion by 2027 end. By dosage form, tablets will continue to remain preferred in the market, with sales anticipated to exhibit the highest CAGR in the market.

Mass production of tablets is key to the success of pharmaceutical companies, therefore, finding and implementing production methods to meet demand is important. There are several techniques used to increase production from ensuring the tablet design is correct, through to employing efficient monitoring processes and management systems which allow manufacturers to undertake in-depth analysis of tablet production. One technique that is increasingly assisting in high-volume manufacture is multi tip tooling. Multi tip tooling continues to transform the way tablets are produced and it is now seen as the most productive form of tablet manufacture without the investment in new machinery or man-hours.

Design tip
Multi tip tooling offers many benefits over a standard punch. The greatest advantage by far is its capacity to produce more tablets per cycle. Multi tip punches allow the number of tablets per turret rotation to be multiplied by the number of tips on the punch. This can range from just two tips, to over 40 tips per punch face. The number of tips is dependent on the design of the tablet and this is an important consideration when using multi tipped tooling. Although most tablet designs can be applied, it is influenced by the press and tool type capabilities.

The tablet’s design can affect so many factors when producing an oral solid dose. It has an impact upon anti-counterfeiting, tooling strength, coating of tablets, durability, functionality and producibility. The tablet design must factor in the use of multi tip tooling. Without this important element, manufacturing problems can occur which will negatively affect not only the tooling itself but also the final tablet.

When using multi tips a popular design shape is one which is round as this can be configured in an efficient group on a single tool. Capsules, ovals and polygons can be more challenging to arrange on the tool to allow smooth operation. The tablet design in relation to its size will also dictate the number of tips that can be accommodated per punch, with other limiting factors including the barrel size and the addition of certain types of seal groove.

A design that is being explored by manufacturers where appropriate is the micro or miniature tablet. This is a tablet of just 1–4mm in size. As well as the obvious benefits like ease of swallowing, improved transportation and the reduced use of ingredients and surface coating; a huge advantage is the ability to produce many micro tablets from just one punch. Although its small dimensions present benefits to increased output, is can present a challenge to the tooling design.
One potential design consideration when selecting micro-tooling is the use of reinforced punch tips to prevent these fine tips from bending under load during compression. The fitting of restricted fill cams also needs some thought, these control and limit the movement of the lower punch to limit the depth of fill. This prevents the punch tip from dropping too low in the die bore. Recessed dies must also be incorporated into the design to accommodate the reinforced tip, preventing the reinforced stem from contacting the die. To ensure the most effective design is deployed, liaison with an expert tooling designer is important.

Cost-effective manufacturing
Applying multi tipped tooling to an existing press will eliminate the need to invest in expensive new capital equipment. The number of tool set-ups required per production batch is reduced and product batches are completed quickly, decreasing the overall time required to produce the required number of tablets. This in turn reduces energy consumption with decreased press running time and a reduction in the labour required per press. Machine maintenance is also reduced, whilst overall press availability will be improved making time for additional production runs. This combination has impressive cost-saving implications, which are enhanced further with the increased output of tablets.

Before multi tip tooling can be successfully installed in a press, there are several checks that need to be completed in order to ensure fault-free production. Some presses are simply not compatible. The press must be in good working order with no significant wear in the turret area, punch guides, keyways and die pockets. The cams should also be replaced if there are any signs of excessive wear.

It is important that the upper turret has a keyway in the guide to ensure alignment with the tooling. A keyway is not necessary on the lower turret guide as the tip will remain captive in the die, however, when using a higher number of tips, a keyway on the lower turret will help with the setting process preventing damage to the lower tips.

When installing multi tips use a die alignment tool to ensure correct setting and prevent damage to the production punches. If the die is not set accurately, misalignment of the upper and lower punch can result in punch tightness. Any unwanted contact between the punch tip and the die wall can transfer to problems through barrel and head wear during compression. This in turn will cause friction and heating damaging the fill and ejection cams and resulting in premature tool wear.

The condition of die pockets can also determine if multi tip tooling can be used. The die table needs to be in good working order. If this is not the case, it may have to be replaced, or if the pockets are oversize, a revised tolerance to the diameter of the die specification may have to be applied. It is also important to check that the die pockets are clear of burrs and any foreign objects. Also examine the die fixing bullets to establish they are in good condition. This will ensure the multi tips work smoothly and to their full capacity, therefore providing return on investment.

Fulfilling Productivity
Pharmaceutical manufacturing is an ever-changing environment, which requires improvements and alterations in order to react to this evolvement. To produce tablets cost-effectively, investment in new technologies and processes must be developed. Multi tip tooling is one method which is helping to significantly increase production, in many cases by over 200%. It is transforming the way tablets are produced and is now seen as the most productive and cost-effective forms of solid dose manufacture.

Alex Bunting is marketing manager at I Holland