Hydrocolloid dressings revolutionized wound care when they debuted in the late 1960s. Recent hydrocolloid innovations, especially integration of additives, continue to improve patient care. This article discusses the history of this game-changing medical material and the latest hydrocolloid developments and applications.
Hydrocolloids: Background and Brief History
What is a hydrocolloid? From a purely linguistic perspective, hydro refers to water, and a colloid is:
“a homogeneous noncrystalline substance consisting of large molecules or ultramicroscopic particles of one substance dispersed through a second substance.”
or more simply, “a substance of gelatinous consistency.”1
In the wound care realm, hydrocolloid typically refers to a category of pressure-sensitive adhesives (PSA). Hydrocolloids are used in wound dressings and other medical device components, such as the skin-facing portion of an ostomy flange. Hydrocolloid medical devices are usually made of a rubber-based PSA containing mixed particles that allow the medical device to absorb fluid. These particles might be pectin or another biocompatible, absorbent ingredient.
During absorption, the particles in the hydrocolloid form a soft, moist gel. By doing so, hydrocolloids help to create a moist wound healing environment. This soft, moist surface also means hydrocolloid dressings can be removed with minimal pain or wound bed disturbance. 2
Hydrocolloid material use in healthcare traces back to 1937. That year, Dental Digest published an article by American dentist Andy Sears about a new hydrocolloid impression technique.3 A former U.S. Army dentist, Dr. Sears used agar to make impressions for restorative dental applications, such as inlays and fixed bridges.4 For wound care, the initial hydrocolloid application came in the 1960s from Dr. James Chen of E.R. Squibb & Sons. Dr. Chen developed a hydrocolloid medical adhesive application for dental surgery.5 By the late 1960s, hydrocolloids found their way into stoma care applications for patients with ostomies.6 As wound care expert Liza G. Ovington, PhD, wrote:
A precursor to hydrocolloid dressings called Stomahesive® was marketed by E.R. Squibb to ostomy patients for protection of the skin around the stoma site. Stoma nurses started making subjective observations about the condition of the skin beneath the Stomahesive. In particular, they noted that irritated or excoriated peristomal skin appeared to heal beneath the Stomahesive product. In addition, ostomy patients began to write to Squibb to say what a difference this product was making in their lives. 7
Today, medical hydrocolloid adhesives remain the gold standard for stoma care, and they are also used in dressings to treat chronic wounds, skin tears, pressure ulcers, burns, acne blemishes, incisions, and scars.
Material Innovation and Processing Advances
Hydrocolloids with Beveled Edges: Next-generation extrusion technology is enabling hydrocolloid PSA manufacturers to offer dressings with longer wear times. Newer hydrocolloid extruders make materials more efficiently, with better quality and less waste. For example, they can create hydrocolloid materials with sleek beveled edges. Beveled edges help the dressing border to stay flat and smooth on the patient’s skin. Without a beveled edge, hydrocolloid dressings may have edge lift and can get caught on clothing. This limits dressing effectiveness and wear time. New extruder systems have better tension control and cooling capabilities, giving PSA manufacturers greater opportunities to work with temperature-sensitive materials.
Hybrid Hydrocolloids with Advanced Fluid-Handling Capabilities: Another innovation in the hydrocolloid family is the invention of hybrid materials that are both hydrocolloid and acrylic PSA. Avery Dennison Medical’s patented Thin Absorbent Skin Adhesive ™ (TASA™) is an example of one such development. This adhesive can be coated onto various carrier materials, including polyurethane films and nonwovens. Whereas traditional hydrocolloid adhesives typically are 0.3–1.0 mm thick, TASA is 0.1 mm thick. Also, it provides both breathability and absorption. This advanced fluid-handling capability enables wear times as long as seven days.
Hydrocolloid formulation and processing advances have enhanced the patient experience on multiple fronts, improving each of the following hydrocolloid types.
Traditional Nonintegrated: These hydrocolloids are similar to the original formulations of the 1970s. Primarily used for stoma care, they are capable of absorbing large amounts of fluid, swelling as they do. This swelling results in a strengthened, more secure seal of the stoma flange against the patient’s abdomen.
Advanced Integrated: These hydrocolloids contain a crosslinked PSA network, enabling the dressing to maintain its integrity and not break down in the wound. An advanced integrated hydrocolloid dressing maintains a stable weight before, during, and after it has absorbed moisture. The absorbed liquid, such as perspiration or wound exudate, quickly integrates into the dressing’s suspended particles, which form a gel-like substance. The dressing’s integrated framework holds everything together, completely intact, throughout the prescribed wear time.
Additive Containing: Hydrocolloids can be formulated to contain a wide variety of additives to encourage healing, moisturize skin, prevent odors, relieve pain, and block ultraviolet rays. For example, some hydrocolloid materials for stoma and wound care applications contain cyclodextrins to capture odor molecules when in contact with moisture. Others contain essential oils, antimicrobials, vitamins, glycerin, or topical pain relievers.
Moldable: These hydrocolloids have a consistency similar to a bendable, stretchable putty. They are designed so that the healthcare provider or patient can shape the hydrocolloid to suit their individual end use. For example, an ostomy appliance kit often includes hydrocolloid material pieces in the shape of small oval or circular rings. The patient or caregiver can stretch and mold the material, shaping it to fit precisely over the patient’s stoma. The hydrocolloid forms a seal around the stoma, and the ostomy bag flange is then placed over it. The moldability of this hydrocolloid component helps to prevent leakage of urine or feces onto the peristomal skin or clothing.
Hydrocolloids and Healing
Hydrocolloid dressing materials are formulated and processed so that they will adhere, absorb, and conform. Here is a look at how hydrocolloid wound care developments address the following healthcare challenges:
Patient pain and stress from chronic or acute wounds — Hydrocolloid dressings are soft and gentle against the wound bed. They absorb moisture without drying out, so that the wound bed maintains a healing level of moisture and does not stick to the dressing. Hydrocolloids facilitate autolytic debridement by providing a moist environment to support the body’s natural process for reducing and softening eschar. Additives in hydrocolloids also help lessen pain.
Wound odor — Additives such as cyclodextrins are natural, noncytotoxic odor-fighting components. When integrated into hydrocolloid dressings or stoma flanges, they prevent odors from forming from wound exudate or bacteria. This helps alleviate patient stress and ensure their confidence and sense of discretion regarding their wound and stoma care.
Ostomy care issues — The skin around a stoma can be vulnerable to irritation, especially if an ostomy appliance leaks. Hydrocolloid materials help create a secure seal around the stoma to prevent leakage. If a leak does occur, the hydrocolloid works to absorb excess moisture and keep the peristomal skin moist and healthy. Additives such as moisturizers can be integrated into hydrocolloids to enhance skin health.
Wound dressing disintegration — Advanced integrated hydrocolloids are designed to remain stable, secure, and intact while they absorb fluids and manage moisture. These hydrocolloid materials are engineered to prevent the risk for dressing breakdown into the wound.
Difficult-to-heal wounds — Hydrocolloid adhesives can be coated onto a variety of substrates and converted into different shapes for treatment of chronic wounds on different parts of the body. For example, there are bordered sacral hydrocolloid dressings that are specially designed for use on the sacral area, a common spot for pressure ulcers or incontinence-related skin damage.
Risks for skin tears and scarring — Thin hydrocolloids such as TASA are ideal for covering parts of the body vulnerable to skin tearing. Hydrocolloid dressings are also used to cover post-surgical wounds to help prevent scarring. Some of these dressings can be engineered with UV ray-blocking additives so that a patient’s wound is not impacted by sunlight exposure. They can be transparent so that they do not draw attention to the healing wound.
Acne and beauty care needs — There is growing, global demand for hydrocolloids to cover acne blemishes. Often in the shape of small dots, these dressings can be transparent or made in skin-tone colors. They also can be engineered with additives to encourage healing and relieve pain. Hydrocolloids also are trending into beauty care applications, such as for under-eye wrinkle alleviation and skincare uses.
Conclusion
From their origins in dentistry and ostomy care to their widespread use today for advanced wound care, hydrocolloid adhesive materials help healthcare providers and patients to manage challenging wounds and skin problems with optimal comfort. New extrusion technology has improved hydrocolloid PSA manufacturing efficiency and capabilities. The integration of additives into hydrocolloids has opened many new possibilities for an enhanced patient experience. Hydrocolloids, a long-time wound management solution, continue to deliver benefits and value.
References
- Google Definitions from Oxford Langauges. (n.d.). Colloid. Retrieved July 9, 2021.
- Avery Dennison Medical. (n.d.). Hydrocolloids. Retrieved July 9, 2021.
- Patton, C. (2018, May 21). One of Us: Sears family celebrates 100 years of Northeast Florida dentistry. The Florida Times-Union. Retrieved July 9, 2021.
- Onwubu, S., & Okonkwo, C. S. (2021, January 23). Hydrocolloids in Dentistry: A Review. Retrieved July 9, 2021.
- ConvaTec. (n.d.). Our History. Retrieved July 9, 2021.
- Science Direct. (n.d.). Hydrocolloids.
- Ovington, L. G. (1997, January 1). Hydrocolloid dressings give good adherence. Retrieved July 9, 2021.
This article was written by Nancy de Ceuster, Global Product Manager, and Davy van Bavel, Senior Research and Development Manager, Europe, Avery Dennison Medical, Turnhout, Belgium. They can be reached at