Antimicrobial Adhesives - Methods, Challenges and Advancements

Posted on 6/15/2017 7:10:44 AM By Deb Bhattacharjee
  

In earlier blogs, we discussed broadly how novel and differentiated adhesives could be developed by incorporating additional functionalities.  In particular, we concentrated on barrier adhesives.  In this blog, we would discuss about antimicrobial adhesives.

Typically, a broad spectrum antimicrobial agent like chlorhexidine or polyvinylpyrrolidone-iodine complex is homogeneously dispersed in a storage stable, dermatologically acceptable, room temperature tacky pressure-sensitive adhesive.  When the composition is placed in contact with the skin, it uniformly and controllably releases the broad-spectrum antimicrobial agent with substantially unaltered activity.1

Adhesive manufacturers incorporate antimicrobial compounds like sodium salt of o-phenylphenateinto adhesives based on starch, protein, natural and synthetic gums, and latexes to protect the adhesives against attack by bacteria and mold during manufacture and storage, and throughout their service life.

One of the challenges in developing antimicrobial adhesive is to achieve the right balance of antimicrobial concentration in the adhesive to get the right antimicrobial efficacy as well as maintain the right adhesive properties.  It is, therefore, highly desirable for antimicrobial adhesives to generate high log reduction of microbial activity throughout a 7 day period without generating cytotoxic side effects and negatively impacting moisture transmission rates and adhesive strength.An antimicrobial adhesive composition comprising chlorhexidine which inhibits microbial growth by more than 2 log throughout a 7 day contact time period, while exhibiting a grade 0 cytotoxicity has been reported.2

Acrylic adhesives containing chlorhexidine gluconate has been designed to address needs associated with applications like transparent film dressing that require longer time wear with sustained antimicrobial efficacy (up to 7 days), but can be modified to address multiple applications each with their unique set of performance requirements.

A critical technological advance in the field of antimicrobial medical adhesive tape has been reported by incorporating a powerful antimicrobial to control microbiological contamination by neutralizing harmful pathogens on contact.3

When cetylpyridinium chloride was incorporated (about 2.5 wt. %) into a commercially available, filled, photo-activated dental adhesive, antimicrobial activity could be incorporated without altering diametral tensile strength.4

The concept of active packaging by incorporating antimicrobials like sorbic acid, benzoic acid, silver-substituted zeolite, triclosan, etc.in various structures of packaging films to control the growth of microorganisms in food could have a significant impact on shelf-life extension and food safety.5-7

References:

  1. “Pressure-sensitive adhesive having a broad spectrum antimicrobial therein”, US 4310509, 01/12/1982
  2. “Antimicrobial adhesives having improved properties”, WO2014124231A2, 08/14/2014
  3. “TrioMed Innovations Europe SA”, Belgium
  4. “Antimicrobial properties of an orthodontic adhesive combined with cetylpyridinium chloride”, Al-Musallam TA1, Evans CA, Drummond JL, Matasa C, Wu CD; Am J OrthodDentofacialOrthop. 2006 Feb; 129(2):245-51.
  5. “Antimicrobial food packaging in meat industry”, Stefania Quintavalla and LoredanaVicini, Meat Science 62 (2002) 373–380
  6. “Effect of active packaging incorporated with triclosan on bacteria adhesion”, Camilloto GP1, Pires AC, SoaresNde F, Araújo EA, Andrade NJ, Ferreira SO., J Food Sci. 2010 Oct;75(8):E557-64
  7. “Antimicrobial food packaging”, edited by Jorge Barros-Velazquez, Academic Press, 27-Dec; 676 pages