How to Calculate the Correct Amount of Desiccant for Pharmaceutical applications?

A lot of manufacturers provide desiccant materials in various forms and to a variety of specifications. These materials range from cat litter to hazardous industrial materials. You must consult desiccant suppliers about the most economical and effective drying solution for any application. In this article, we’ll learn about desiccants and explore different types of pharmaceutical desiccants. We’ll also help you figure out the correct amount of desiccant for storing pharmaceuticals.

What are Desiccants?

Desiccants are drying agents that perform the function of extracting water from a wide range of materials. They can be either soluble or insoluble substances that adsorb water as a result of their chemical properties. Examples of desiccants include silica gel, activated carbon, montmorillonite clay, and more (more on this later). Soluble agents include calcium chloride and glycerol. Molecular sieves and alumina are also great desiccants.

Desiccants help prevent the contents of sealed packages from getting damaged due to humidity. This explains why so many products include small packages of silica gel and similar materials. Desiccants can hold a large percentage of their weight in moisture. They can adsorb most of the humidity within the package. Desiccants are also used extensively in industrial and pharmaceutical applications. They’re used for humidity detection, waste removal, cleaning, and regenerative drying.

Calculating the correct amount of Desiccant for Pharmaceuticals

Desiccants protect pharmaceuticals from damage due to humidity. A barrier layer is needed with the desiccant to limit the exchange of air. Desiccants come in various forms depending on their use-case scenario. They’ve found an irreplaceable place in the packaging of various pharmaceuticals.

Apart from selecting the correct type of desiccant, calculating the correct amount of desiccant is also important. By using the appropriate amount of desiccant, you can maintain the efficacy of the product. But, the appropriate amount of desiccant depends on the following parameters:

• The amount of desiccant required also depends on the type of container. It differs for flexible (foil or polybag) and rigid type (drum or pail) of containers.
• The surface area of the container walls in ft2 or in2 for flexible containers; or the volume of the container in gallons, ft3 or in3 for rigid containers.
• Adsorption capacity and adsorption rate of the desiccants used.

Let’s learn more about all the major types of pharmaceutical desiccants.

Types of Pharmaceutical Desiccants

Silica Gel Packets

Silica gel packets contain silica gel made from amorphous sodium silicate that is highly absorptive in nature. It is capable of absorbing 40% of its own weight, unlike others on the market. Silica gel is a hard, translucent material with an extremely high capacity for moisture at temperatures below 75°F and humidity levels above 40%. It is quite stable, non-toxic, has excellent moisture absorption performance, and doesn’t affect any product it comes in contact with. It is highly suited for the moisture-proof packaging in pharmaceuticals.

Activated Carbon Packet

Activated carbon helps control unwanted odors and gases through the process of adsorption. It finds its application extensively as an adsorbent of odors and toxic gases. There’s no other substance that performs like it when it comes to the adsorption of odors.

Molecular Sieve Packet

A molecular sieve is a very aggressive desiccant. It quickly absorbs moisture and odor. Molecular sieves are aluminosilicates, a crystalline porous solid. They have a three-dimensional structure with different pore sizes (3–5 Å). You need to activate molecular sieve packets before you can use them. You can also regenerate them at higher temperatures (180°C — 260°C). It is available in the form of beads that have specific pore sizes.

Clay Desiccant Packet

Montmorillonite clay is a type of naturally occurring adsorbent. It is created by the controlled drying of magnesium aluminum silicate. Montmorillonite clay is a free-flowing granular material with high moisture adsorbing ability. Its adsorbing ability lies from 20% to 80% relative humidity under normal packaging and storage conditions.

Cover stock is an important factor that improves the efficiency of any desiccant. Cover stock is the material used for packaging the desiccant. It must let the desiccant perform its functions efficiently without harming the product in any way. It allows the desiccant to maintain an acceptable adsorption rate. Tyvek is a spun-bonded, high-density, polyethylene material that is commonly used as cover stock for desiccant packets.

Final Words

In the packaging of pharmaceuticals, you must be mindful of the characteristics of the desiccants and material used in its packaging. All these parameters are specific to the desiccants under consideration. They must be taken into consideration if you want to get the desired results. We hope that this article helped you understand the correct amount of desiccant to be used in pharmaceutical applications.

Got any questions? Let us know in the comments below or write to us and we’ll get back to you at the earliest.