Desiccants and Silica Gel

Desiccants are always considering as a perfect partner to keep along with for moisture-sensitive products. In the pharmaceutical industry, the most commonly used desiccating materials are silica gel, molecular sieves, and clay minerals. They can be incorporated into sachets, canisters, cards, or maybe into bottle closures.

Like excipients, these desiccants show humidity-dependent sorption/desorption behavior. However, their sorption capacity is far above typical excipients. This allows them to perform effectively in a much lower amount relative to drug products.

The overall moisture absorption capability of the desiccants are often calculated from the weighted sum of the moisture sorption isotherms of the active pharmaceutical ingredient (API), excipients, and desiccant. Use of desiccant isn't advised in cases where high levels of unbound water should be maintained for product performance (e.g., gelatin capsule shells).

We all are familiar with small silica gel packets. In our daily life, we are meeting those tiny packets from many places such as along with our new pair of shoes, inside our laptop bag, in a tablet container, along with the pregnancy kit, ...etc.

Usually, we will not keep these tiny silica gel packets once we opened the shoebox or laptop bags. But once we are familiar with the advantages of silica gel, we will never throw it. It has a good capability to absorb moisture from the surroundings. That is why the manufacturers are keeping it with their new products to avoid damages due to excess moisture.

We can use silica gel packets along with our food items also. There is a specific product named oxy-guard, which can keep along with the food products. Oxy-guard is an oxygen absorber. It can absorb oxygen from the food items such as bread, coffee beans, dried nuts, ...etc and keep them fresh for a long time.