Child-Resistant packing in Pharmaceuticals is kept aside, as most of the drugs packed in HDPE containers with CR Closure. But for few years many Innovator drug products are available in Child-Resistant design (Blister Pack) and most of them are patented or difficult to make generic due to various reasons such as Cost, Availability of supplier and manufacturing feasibility. There Packaging professional has to take a call on new design development or to use a certified pack design. But when coming to the level of protection (F Level) required for a specific drug is became a challenge, because getting Toxicology data is difficult to decide “F” Value.
A Weight of Evidence (bodyweight scaling) approach is usually applied for calculating “F” Value. “F” value is defined for children with below 25lb (11.4kg) weight. MTD (maximum tolerated dose) data can be used when paediatric and adult overdose data is not available, even preclinical data can be used. For combination products, each drug “F” value is calculated and the lower value is assigned to the combination.
Example: If a tablet is a combination of two APIs with non-additives hazards.
Drug A (500mg) – F3
Drug B (25mg) – F4
The package would be F3 based on Drug A.
“F” value (Failure value) is defined as the number of individual dose units of a drug that can be cause serious illness or injury in a 25lb (11.4kg) child. For Highly Toxic or Harmful drugs, the “F” value is usually set at F1, which indicates that the child’s access to a single unit is considered as a failure. Less Toxic or Less Harmful products, the “F” value is higher as F8. A default limit of F8 is usually adopted in the US when a child gains access to a 9th unit. Generally, the “F” value is calculated from F1 to F8.
The various complexities involved in child -resistant packaging is compiled in this booklet by Poornesh Pappala.