Appearance and user experience can quickly determine whether a consumer will purchase a tablet product again or continue to take the product as prescribed. The tablet is the most common solid dosage form and its design; various sizes, shapes, colours, and coatings, can drive the visual impact. Other important features—such as a smooth tablet shape—can improve the product's mouth appeal and influence consumer preferences.
It's important for tablet manufacturers to consider the consumer when designing a tablet and its associated compression tooling. During the tablet design phase, the limitations of the flat-face, bevel edge (FFBE) tablet design and the benefits of the flat-face, radius-edge (FFRE) design in encouraging consumer acceptance should be recognised.
Because a tablet's design can so strongly influence consumer acceptance, as design and coating decisions are being formed the manufacturer’s marketing department often provides significant input gleaned from consumer testing.
The management team should also include production personnel in the design decisions because they are responsible for delivering the final product. Their experience and expertise can greatly reduce production costs and minimise problems. Some tablet designs can result in difficult and unnecessary manufacturing challenges, higher tooling costs, and tablets with suboptimal physical properties.
The rise of the bevel edge
The FFBE tablet design became popular early in the development of rotary-tablet-press manufacturing, offering a significant improvement over the simple flat-face tablet design. Companies often developed FFBE tablets to improve tablet quality and reduce production costs. Due to powder leakage at the interface of the flat punch tip and the die wall, flat-face tablets suffered from weak edges that were prone to chipping and excessive friability.
Later the addition of the bevel edge to the tooling allowed the punch tip to push the formulation toward the die's center during compression, making stronger tablet edges than the flat-face tablet design allowed.
Over the decades, the FFBE design has become very popular in the tableting industry, but limitations exist on the amount of compression force that you can use with FFBE tooling without risking tip damage.
The Radius Edge Become Most Popular
Compared to the FFBE design, the FFRE tablet design offers smoother edges, providing greater consumer acceptance (Figure 1). Finite-element engineering analysis comparing FFBE and FFRE tablets of the same size indicates that the maximum compression force allowed for FFRE tablets is significantly higher than that for FFBE tablets. (Figure 2).
This offers manufacturers the option of using additional compression force to increase tablet breaking strength with no associated risk to the tooling or the tablet press, with the added benefit of no required formulation change. Tablets produced using high compression force are also less prone to edge erosion, sticking, and picking.
In the FFRE design the tablet edges are smoother and consumers have the impression that the tablet has a softer appearance and a more pleasant mouth feel. A comfortable mouth feel can help reduce the anxiety that elderly patients often experience with difficult-to-swallow tablets.
These observations are important to providing the first-impression appeal that is essential to establishing a successful product brand. A growing number of companies are manufacturing their uncoated flat-face tablets with FFRE rather than FFBE designs. This trend warrants consideration by companies seeking to produce quality tablets with greater consumer acceptance.
