When The Blister Pack Works Too Well: What's A Customer To Do?Source: Brookfield Engineering Laboratories, Inc.
Maintaining capsule integrity is an important requirement for established pharmaceutical manufacturers who want happy customers. Ensuring delivery of capsules and tablets to the recipient in tact and good condition is a primary concern. Consumers, however, know from experience that some tablets and capsules can be difficult to extract from the blister pack. Is this a manufacturing problem? Or has R&D neglected to implement a fool proof test methodology for evaluating tablet and capsule removal from the blister pack? Chances are that protection during shipment was the overriding objective for the manufacturer’s engineering team. The challenge of extracting the tablet or capsule from the blister pack may have been overlooked.
How does a manufacturer test for extraction of a tablet or capsule from the blister pack? You can use human testers and base design decisions on their subjective judgment. However, you will need testers of different ages to assess the variety of tablets and capsules that pertain to children, teens, adults, senior citizens, etc. It may even make sense to consider male vs. female strength and the relative dexterity and agility of each sex.
Compression testing with a Texture Analyzer (see Figure 1), an axial load measurement instrument, provides a useful technical approach that can be used to simulate the extraction process. Using a probe shaped like the human finger, the Texture Analyzer can push the tablet or capsule out of its pack and quantify precisely the amount of force needed for extracting the item. Movement of the probe at different rates of travel can simulate end users who range from slow and deliberate in their extraction effort to those who are quick and like to punch out tablets and capsules as rapidly as possible.