How A Simple Innovation Changes The Tablet’s Future
The shape of a tablet is often used to promote a new drug and therefore its physical features are the major concern of marketing departments. While this may be appropriate for some pharmaceuticals, there are many factors other than shape that will ensure that a new product is successful. In fact, small changes in the shape of a tablet can impact not only the public’s acceptance, but also the tablet’s efficiency, and ease of manufacture. Unfortunately it is sometimes the case that attention is given to the shape of a tablet only when it is promoted to the public.
It is essential that the design, including shape of a tablet is fully considered at the earliest possible stage. A faulty design can cost the company many millions in lost revenue, and even affect the successful launch of the tablet. And although many companies do pay careful attention to the design, some do not comprehend how the shape of a tablet can affect its production and effectiveness in use.
Experienced manufacturers know the right questions to ask when it comes to tablet tooling, and they are keen to engage with tooling manufacturers. They realise that a faulty design can create tabletting issues, and that even small changes to the shape or design of a tablet that may be almost invisible to the naked eye can often produce dramatic improvements.
Why It is Important
It cannot be overemphasised how important it is to consider all aspects of a tablet design from the outset The marketing department often strongly influences the design process and some companies hope to hold to their customer’s loyalty by offering unique designs that will promote a certain level of brand recognition. Tablets are also designed based on needs of the end user. A simple round shape provides for straightforward production as well as a product that is efficient in use. A ‘break-easy’ design also offers versatility as well as functionality if the dosage is flexible. To achieve these properties the manufacturing process should not be unnecessarily complex, to ensure that the design remains effective in use.
Unfortunately it is often that ease of production is overlooked when a company is designing their tablets. There are certain shapes that create problems not only with tooling but also in terms of packaging. An incorrect design can clog, chip and even create dust within packages, especially in the bottom of the package. All of these issues have a detrimental impact on the product, and it is why the shape of the tablet should be checked meticulously at the start of the design process, to avoid any added costs later on.
Ease of Use
The FDA has provided a standard set of guidelines that should be used when considering the attributes such as shape and size of tablets in order to encourage acceptance by the consumer. Paediatric and elderly patients may have more difficulty than others in swallowing some tablets. It is therefore necessary to consider the demographic when contemplating tablet use. The shape should be considered in terms of ease of use – for example some patients may find it difficult to swallow a size 8 diameter tablet, whereas one of similar size but of oval cross-section may be easier to swallow. Oval tablets in general are easy to swallow, and are less likely to cause accidents than tablets that have a spherical shape.
The safety and comfort of the patient should also be considered as these factors determine the compliance with medication. Oval shaped tablets are generally easier to swallow and have faster transit times than other tablet shapes that are available. In developing drugs, the FDA encourages applicants to consider the design of the tablet and develop accordingly.
Compliance is also important when referring to the production of generic reference-listed drugs or “branded products”. By ensuring that the shape of a generic tablet closely matches the original branded products, so its acceptance by the patient will increase and help reduce the likelihood of any medication errors or non-compliance that may occur. Even so, the FDA recommends a change in the generic design when it is proven that the shape makes it easier to swallow the product.
As well as the issues mentioned above, other considerations that should be given to ensure a successful product include the friability of the material, weight, transit time as well as dissolution of the tablet. The production as well as the packaging department should be encouraged to be involved with tablet design to prevent sticking, picking and even chipping. A simple thing like friability is important as the FDA has received some reports of products that are too friable which makes it difficult for the tablet to be pushed through blister packs.
Branded or smaller tablets can improve the patient’s experience and offer a huge savings for manufacturers. An example would be a multivitamin manufacturer that has some problems with their tablet. The oval shaped tablet was marketed for females and was easy to swallow and follows the guidelines. However, during the production stage, the manufacturer experienced costly issues concerning the tablet presses. The design was found to cause high ejection forces that created excessive punch head wear resulting in premature wear to the equipment. By redesigning the tablets the manufacturer was rewarded with an increased production efficiency, lower expenses and a tablet shape that was more appealing to male and female patients.
Changes in tablet design can reduce the production cost, and adjusting the shape can also reduce problems in the tablet press caused by issues such as friction and heat. Reducing these can help reduce operating costs, and it is surprising how such effects can quickly add up to big benefits to the manufacturer.
What Design change Can Help Increase Efficiency?
An example of a simple change to the design of a tablet that has led to improved efficiency is the switch from a bevel edge to a radius edge design especially in the case of uncoated flat bevelled tablets. This improvement does not affect the overall shape but can markedly increase production capacity. It is understandable that companies will want to limit the cost of the entire manufacturing process but care should be taken in simply copying an existing design. If the design is fundamentally flawed it can lead to unexpected costs being incurred further down the production process.
The flat-face design is the oldest design used in tablet production. As technology for tablet production has improved, so manufacturers found a way to modify the design to reduce edge attrition of the tablets. This attrition happens when the flat face punch tool enters the compression cycle in a tablet press and pushes the powder to the outside area of the punch tip and through the die wall. The powder can then extrude through the small clearance between the punch and die wall. In the flat-face tip, there is no cup or depth which can spread the compression force and for simple flat-face designs, the pressure limit determines the punch tip size.
The flat face bevel edge (FFBE) design was developed to overcome the edge attrition that occurs with a simple flat face design. It is the oldest and now the most common tablet design in production. It limits the soft edges of the tablet by guiding the loose powder back into the tablet. Unfortunately with the bevel edge design the compression force has to be limited so as to avoid bending or distortion of the punch tip. Although the bevel edge design modifies edge attrition, it does introduce another problem – it limits the compression force, which can make it difficult to achieve the desired hardness of the tablet.
To combat this problem, another design was created – the flat face radius edge (FFRE). This design allows higher compression force to be applied without causing damage to the punch tip when producing flat faced tablets. The design should be considered when creating flat face bevelled edge tablets as it improves manufacture, the quality of the product and therefore increases patient acceptance.
By eliminating the bevel edge and using the radius edge (FFRE), the compression force can be increased, thereby preventing issues such as sticking of the powder to the corner junction of the bevel and the flat. The FFRE also provides a more uniform hardness within the tablet, which is especially desirable when a uniform dissolution is required. With the FFRE design, the powder has a natural flow inside the radius which helps reduce the formation of hot spots or discoloration at the top of the tablet. This shape has advantages in production and also helps eliminate problems when a higher compression force is needed.
Using the FFRE instead of the FFBE is a simple change to make but the impact can be massive. Changing the tool can reduce machine downtime by reducing the chance of punches becoming deformed or damaged. The design can also increase acceptance by consumers – tablets that have a softer look and better mouth feel are often highly desirable. Although the change from FFBE to FFRE design is barely noticeable, an appealing tablet will increase acceptance and compliance. The FFRE design simply has many advantages and should be considered for all new designs that are applied to non-coated tablets. With increasing uptake of the FFRE design, the FFBE design could become obsolete in the future.
Another variation on the simple flat face tabled design is the concave bevel edge (CCBE). Thos is the same as the FFBE, with its design commonly used for round shaped tablets, reducing edge attrition during the coating process. The design can also benefit from the addition of radius edges. Such a change would give a more robust design, which would also permit an increase in the compression force. By replacing the bevel with radius leads to a compound cup design that would be more desirable than the CCBE.
The subtle move from a bevelled edge to a radius edge design is an example of a design change the may be completely unnoticed by the marketing department, but which can have a profound effect on the commercial viability of the tablet. A small change such as this can definitely influence production as well as consumer experience.
Many such considerations come into mind whenever a tablet is designed. To ensure that the tablet is successful, it is necessary that all departments be involved in the process. From the marketing department to production and packaging, it is important that each department is given the opportunity to comment on the design to ensure the product’s success. Involving the tooling supplier is also important as they have the experience to provide guidance and help prevent manufacturing issues. Keeping all parties involved will ensure a timely and successful product launch. It is in everyone’s interest to make certain that the product will succeed in the market and provide an excellent experience for patients.