What Is a Desiccant? Types, Uses & Benefits in Pharmaceuticals

A desiccant is a substance that removes humidity—water—from the air in a contained environment (generally packaging) to protect the contents of the container from moisture damage. The English word “desiccant” emerged in the 17^th century from the original Latin word, “desiccare,” to make completely dry. At this time, chemists, scientists and physicians were in a period of discovery that led that also led to countless English neologisms derived from historic reliance on Latin across academia, medicine and science.

With that background, the term desiccant is familiar across many industries, i.e., food, apparel, appliances and technology, medical, pharmaceuticals, food and more to ensure the quality and safety of moisture-sensitive contents. The critical nature of pharmaceutical quality and safety calls for ongoing commitment to innovation in moisture protection solutions.

For some pharmaceutical products, desiccant solutions are critical to ensure patient safety and protect quality and efficacy of the medicine for its shelf life. Anyone who has opened bottles of capsules or tablets is familiar with desiccant packets and their many forms. Before discussing the variety of desiccant types available, it helps to understand how desiccants work.

How Do Desiccants Work?

Desiccants function in response to relative humidity (RH) within a container. They work by drawing water molecules from the air inside the container and holding them so that the drug product remains dry.

Relative humidity is the percentage of water vapor in the air vs. the maximum volume of moisture the air could hold. Think of the moisture as creating pressure and the desiccant reducing pressure by taking water vapor out of the air (where the drug can react with it) and pulling the moisture onto or into itself. Through these humidity-controlling agents, a dry interior environment can be established and maintained for packaged drug products.

Knowing what type of desiccant will perform best for the drug protects from costly risks and product degradations such as:

• Swelling or caking of the pharma or nutraceutical product
• Chemical decompositions
• Compromised drug potency/efficacy
• Color modification and oxidation

The Science of Absorption and Adsorption

Many industries use desiccants to protect medical goods, pharmaceuticals, consumables and technology or electronics from moisture-related damage. Packaging moisture control can be provided by two scientific processes, absorption and adsorption.

Absorption. The mechanism of absorption is familiar because daily life demonstrates many instances of absorption, for instance water being absorbed by a dry cloth or sponge. Desiccants demonstrate absorption takes moisture inside the absorbent material itself, often creating a chemical reaction to bind the water to form hydrates. This takes place until the volume of moisture exceeds the bonding capacity of the inner salts, to contain more moisture. Absorption is called a “bulk mechanism.”

Adsorption. Not as easily explained by routine example, adsorption gathers water vapor via molecular interactions with a desiccant having large internal surfaces. Instead of taking the moisture inside, adsorption causes moisture to accumulate on the exterior surfaces of the desiccant as surface layers without permeating the desiccant structure. Adsorption is called a “surface mechanism.”

Regardless of mechanism, if the desiccant’s saturation point is exceeded, RH increases and moisture will be released into the headspace, putting product quality at risk.

High temperatures can also lead to over-saturation of some desiccants, particularly the commonly used adsorption desiccant, silica gel. Heat will cause silica to achieve maximum saturation faster. This weakens the water-desiccant bond and again releases moisture into the headspace.

Common Types of Desiccants and Their Properties

For pharmaceutical and nutraceutical manufacturers, specifying the optimal desiccants to protect your packaged drug is a key decision. With many widely used desiccants from which to choose, knowing specific differentiators ensures the ideal selection.

Check out this article for a detailed look at the properties of pharmaceutical industry-preferred desiccants or browse the at-a-glance summary for a quick look.

Common Formats

Drop-in solutions include packets, canisters, capsules and bags offer clear advantages where flexibility, speed, and cost‑effectiveness are priorities. They are easy to implement on existing packaging lines without requiring container or closure redesign, making them ideal for legacy formats, short development timelines, or low‑to‑medium volume products.

Drop‑in desiccants allow manufacturers to tailor moisture protection by simply changing the size, type, or quantity of desiccant, providing formulation flexibility across multiple SKUs using the same packaging. They typically involve lower upfront investment than integrated solutions and can be sourced, qualified, and deployed quickly, which is beneficial during scale‑up, market testing, or lifecycle transitions.

For products with moderate moisture sensitivity or shorter shelf lives, drop‑in solutions deliver effective protection with minimal packaging change, offering a pragmatic and economical approach compared with more engineered desiccant systems.

Examples include DryGuard™ Desiccant Packets, Capsules, Canisters or Bags.

Integrated or embedded solutions offer advantages over traditional drop‑in solutions by providing more consistent and reliable moisture protection while improving safety, efficiency, and user experience. Because the desiccant is built into the container or closure, it delivers predictable moisture control without the risk of shifting, obstruction, or slower adsorption seen with loose components. Integrated designs cannot be removed or ingested, reducing choking and misuse risks and eliminating patient confusion.

From a manufacturing perspective, they simplify filling operations by removing an insertion step, improving line efficiency and reducing the risk of errors. They also help protect dose count accuracy, prevent product damage, and free up internal space for more compact packaging. Overall, integrated or embedded desiccants enhance product stability, patient safety, operational efficiency, and packaging design compared with traditional drop‑in desiccants.

Examples include OneLock®, Tubes and Stoppers and Desiccant Washers

Flat desiccants offer a slim, space‑efficient format. The desiccant can be compressed into tablets or fit neatly into a card, making them ideal for compact packaging without reducing product fill. Their fixed position delivers more consistent moisture protection while minimizing tablet damage, counting interference and loose components, resulting in cleaner pack presentation and better usability.

Advanced Desiccant Polymer (ADP) can be customized to your own format or fitting based on individual project requirements.

Examples include ADP® Plate, Dricard® and Desiccant Tablets

Summary of Different Types of Desiccants

Key Applications of Desiccants in Pharmaceuticals

• Protect tablets and capsules from humidity damage
• Protect bulk powder or tablets during manufacturing process
• Enhance product shelf life and integrity
• Ensure a variety of effective humidity control options for pharmaceutical packaging solutions (integrated solutions, canisters, capsules, packets)
  
  

Market Reliance on Effective Desiccants

The need for and incorporation of pharmaceutical desiccants is poised for growth in 2026-2032.  Overall, current estimates show:

• More than 60% of pharmaceutical packaging utilizes desiccants as part of quality and safety processes (source).

• Regulatory oversight and new drug types (i.e., biologics) present sensitivities that are conducive to benefitting from existing and novel desiccants to ensure compliance and safety.

• At least 65% of patients and prescribers favor products that integrate desiccants.

The Benefits of Using Desiccants

The advantages of approaching desiccants as cGMP in pharmaceutical packaging are many. Desiccants perform the following:

• Control humidity by drawing and holding moisture/water vapor away from product
• Reduce product degradation such as breakdown of active ingredients or solid form pills
• Improve transport and storage reliability for medications
• Reduce cost through lower product loss due to moisture damage

See how desiccants are used in medical device manufacturing here.

Safety and Handling of Desiccants

• Are desiccants toxic or hazardous?
  
  The healthcare sector operates on ethical and regulatory standards that call for safety and efficacy to be the priority of any product on the market. Color indicating desiccants are a clear example. Regulatory and environmental attention have increased prioritization of cobalt-dichloride-free indicating desiccants, prompting a growing preference for non-toxic solutions.
  
  
• Guidelines for pharmaceutical and food safe desiccant
  
  Research your product thoroughly to ensure selection of the optimal desiccant form and substance for the product specs. This includes not only chemical specifications, but real-life conditions, user demographics, solid dosage form, drug sensitivity, how administered, etc. These practices will lead to the level of sophistication (or simplicity) necessary to protect and promote the success of the product.
  
  
• What to do if the desiccant packet breaks?
  
  Under FDA cGMP guidance, an open or damaged desiccant is a major failure requiring FDA investigation. The FDA and European Commission requires that all desiccants include a visible “Do not eat,” or “Keep in Bottle” warning. Outer cartons and bottle are also required to indicate if a desiccant is present. Bottle and outer carton must include a poison control number in case of ingestion, and instruction to discard medication and report to manufacturer a damaged or open desiccant.
  
  
• What constitutes safe desiccant disposal and environmental considerations?
  
  Neither the European Environment Agency (EEA) or the US Environmental Protection Agency (EPA*) currently have specific language regarding handling or disposal of pharmaceutical desiccants. The US FDA considers desiccants as “packaging components.” Packaging components are under the governance of the EPA.

Final Thoughts

We have explored the important role played by the diverse functionality of modern desiccants. With a high (and growing) volume of solid oral dose products requiring effective moisture protection, desiccants are well positioned to meet a wide range of emerging needs. Colorcon continues to listen closely to customers, driving innovation that delivers reliable moisture protection while supporting sustainability goals.

The global nature of healthcare product distribution further reinforces the need for moisture-control solutions that are dependable, versatile, cost‑effective and environmentally responsible. Desiccants play a critical role across the entire pharmaceutical lifecycle—from development and manufacturing through distribution, storage and use by the end patient. Tomorrow’s packaging and product protection creativity can be put into motion today. Check out some current high achieving products to inspire along the way.

Frequently Asked Questions

• What are the benefits of desiccants for pharmaceuticals?
  
  Desiccants provide cost-effective quality assurance by preventing moisture damage (oxidation, hydrolysis), extending shelf life and preserving the integrity of active ingredients.
  
  
• Why are there desiccant packets in medication bottles? 
  
  Desiccants control moisture by keeping water vapor out of contact with the contents of the bottle. Without desiccants in the bottle, any water vapor present or introduced into the container through the process of distribution, storage and use would be in direct contact with the solid dose form of medicine, leaving it exposed to contamination, degradation of its physical form and therapeutic purpose.
  
  
• What happens if the desiccant gets wet?
  
  The purpose of desiccants is to take on and hold moisture to keep a dry environment. By that standard, every desiccant will “get wet.” While desiccant types vary in maximum adsorption or absorption, all will reach maximum saturation capacity at some point if moisture continues to be present. Once saturation is reached, any additional moisture will remain in the air space. Additionally, the desiccant may release moisture back into the headspace in response to more moisture present than it can hold.
  
  
• Is it safe to remove the desiccant from packaging?
  
  Technically, desiccants can be safely handled or removed from packaging. Their outer coverings are made from inert materials that are benign to touch. That said, while it is “safe” to remove a desiccant from the container, there is no beneficial reason for doing so and should be avoided. If medication remains in the container and the desiccant remains functional, it should be left for product protection. Additionally, desiccants present choking or potential ingestion hazards. Global regulators require desiccants display visual “Do Not Eat” warnings. Removing a desiccant from the container could increase exposure to that risk and thus should be left alone.