Light and moisture, which the closure does not solve
Updated
On this page8
Light
Many actives are light sensitive and a dispensing container often sits on a counter or a windowsill rather than in a cupboard. Forty-eight of the 94 containers on this shelf block light, which is why amber is the traditional color for this category rather than a styling convention.
Moisture, which is the harder one
Tablets and capsules take up water from the air, which affects both stability and how they behave. The container, the liner and sometimes a desiccant are the system, and a closure chosen purely for child resistance may seal poorly against humidity.
A CR closure is not automatically a good seal
The mechanism is about resisting a child, not about excluding water vapor, and those are different jobs. If moisture matters, the liner is a separate specification to ask about rather than something the CR feature implies.
Desiccants are a product decision, not an afterthought
A canister or sachet occupies volume, must not be swallowed, and has to be matched to the headspace and the moisture load. Adding one late means rechecking the fill and arguably the package.
Opened daily is the worst case
Every opening admits room air, so a container opened once a day for a month has been exposed thirty times. That is the real exposure profile for this category and it argues for a container sized to the dispensing period rather than a larger one.
Which is why these are small
Fifteen to 325 ml covers a dispensing quantity rather than bulk storage. Buying a larger container because it costs less per unit works against both the moisture problem and the light one.
Amber is not automatic protection
Color reduces transmitted light by an amount that varies with the material and the depth of tint, so amber PET and amber glass are not equivalent. If light protection is a real requirement rather than a convention, it is worth asking what the material actually blocks.