What type of desiccant is generally used in effervescent tablet bottles?

Desiccant is a common thing in our daily life and is widely used in all aspects of life such as food, medicine, packaging, etc. The effervescent tablet bottle is a highly functional pharmaceutical packaging. When choosing, in addition to paying attention to the material and sealing of the bottle itself, the selection of the desiccant in the bottle is also very important, which is related to the shelf life of the drug. And the stability of drug efficacy, then, which type of desiccant is more suitable for effervescent tablet bottle?
In general, the water removal methods of desiccants include chemical adsorption and physical adsorption. Physical adsorption is the direct absorption of water content in the air by physical means. Chemisorption is a chemical reaction between water in the air and a desiccant to form a hydrate. Below we briefly describe the moisture absorption rate and performance comparison of several desiccants.

Silica gel desiccant
The inside of the silica gel desiccant is a network of extremely fine pores, which can absorb water and retain it through its physical attraction. The moisture absorption rate of high-quality silica gel is about 20% under constant temperature and humidity conditions, but this desiccant is expensive and is often used in seafood with high moisture content, high-end canned food and medicine. Silica gel desiccant is the only one that has passed the US FDA certification and can be used directly in contact with food and medicine.
Molecular Sieve Desiccant
In general, the moisture absorption rate is about 25%, but the price is relatively high. Under the condition of ultra-low humidity, molecular sieve can still absorb a large amount of water vapor in the environment, effectively control the environmental humidity, withstand high temperature, and can also adsorb other gases. It absorbs moisture very fast and can absorb a lot of water vapor in a very short time.
Based on the hygroscopic effect and various properties of the above desiccants, the type of desiccant used in the effervescent tablet bottle depends on the performance of the effervescent tablet and the relevant testing values, and then depends on the packaging requirements of the manufacturer. Generally, the bottle of effervescent tablets is usually matched with silica gel desiccant and molecular sieve to achieve good drying effect.