2012

Thin, Absorbent Skin Adhesive

New technology offers improved fluid-handling capacity and strong, skin-friendly adhesion for direct-contact wound treatment, stoma care, and other applications.

An aging population and accompanying demand for wound dressing and stoma care technologies that provide better treatment than conventional techniques have prompted the medical adhesives industry to produce a new generation of product solutions. One recently proven technology is a highly breathable formulation with superior fluid-handling capacity called Avery Dennison® Thin Absorbent Skin Adhesive, which is poised to shift current market expectations of conventional acrylic adhesives.

altThe patent-pending technology, which consists of a transparent polyurethane film coated with an advanced acrylic adhesive, represents a breakthrough in acrylic adhesive functionality. Although conventional acrylic adhesives have a high moisture vapor transmission rate (MVTR) and are widely used for securement of dressings, they display no absorbency. In contrast, Thin Absorbent Skin Adhesive technology offers high MVTR and absorbs wound exudates.

The new technology enables medical device manufacturers to offer skinfriendly adhesive solutions in diverse applications including direct-contact wound care, postoperative dressings, multilayer dressings, stoma flanges, and electrode backings.

Fluid Management

The advanced performance characteristics of Thin Absorbent Skin Adhesive technology were demonstrated in a two-part study conducted at the Avery Dennison Medical Solutions inhouse test facilities. It evaluated fluid management and in vivo properties of Thin Absorbent Skin Adhesive technology compared with conventional acrylicbased film dressings and commercial hydrocolloid dressings.

Five commercial acrylic-based film dressings and two commercial hydrocolloid dressings were included in the first phase of the study, which tested Fluid Handling Capacity (FHC) following the European standard EN13726.

According to the test results, the Thin Absorbent Skin Adhesive recorded an MVTR of 1480 g/m²/24h — three times higher than the MTVR of the hydrocolloid dressings tested. The MTVR measurement was comparable to that of the commercial film dressings tested.

The overall FHC was obtained by combining the MVTR and static absorption values. The Thin Absorbent Skin Adhesive had a static absorption measurement of 930 g/m²/24h, giving it a total FHC of 2410 g/m²/24h. This value far exceeded the FHC of both the acrylic-based film dressings and the hydrocolloid dressings.

In Vivo Testing

altThe study’s second objective was to evaluate the adhesive properties and effect on skin condition of the Thin Absorbent Skin Adhesive compared with two commercial film dressings. To perform effectively, medical adhesives must provide the right amount of adhesion to secure dressings for the desired period. Too little adhesion can result in adhesive failure, while excessive adhesion can lead to skin stripping and damage on removal.

The in vivo testing involved six human subjects, who were aged 21 to 50 and in good health. The study was overseen by the Avery Dennison Medical Research Review Committee per approved protocol. The dressings under evaluation were applied to adjacent sites on the subjects’ volar forearms. They were worn for three days and removed with a peel tester. A series of measurements and observations were then made, including peel force, adhesion, pain on removal, and adhesive residue.

Dermal average peel force and dermal maximum peel force were both measured using the peel tester. Here, the Thin Absorbent Skin Adhesive performed comparably with the two commercial film dressings tested. Moreover, there was less variation between the Thin Absorbent Skin Adhesive’s average peel value and maximum peel value, an indicator of smooth dressing removal.

In addition, the Thin Absorbent Skin Adhesive demonstrated adhesion comparable to the commercial dressings. It scored approximately 6 on a 0–7 adhesion scale, with 7 being perfect adhesion. It also scored within the acceptable pain range on removal, as rated by the test subjects, and did not leave residue on the skin. The Thin Absorbent Skin Adhesive also displayed clean edges and minimal edge lift compared with the other dressings.

Transepidermal water loss and skin hydration were measured one hour after dressing removal and compared against a baseline measurement. The Thin Absorbent Skin Adhesive’s score on the two tests was nearly 100 percent, showing that the three-day application of the dressing did not disrupt the skin barrier function.