Delivery of antibacterial triclosan by PAMAM dendrimers

• Main Author: Gardiner, Jonathan P. D.
• Published: University of Manchester 2009
• Subjects: 617.601
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505414

Dental plaque can build up to levels which predispose the oral cavity to dental caries or periodontal disease. Therefore many dental products contain antimicrobial compounds to help control plaque formation. Triclosan (TeN) has been used as an antimicrobial in oral care for over 30 years. It has a broad spectrum of antimicrobial activity with high activity against Gram-negative bacteria (those associated with oral disease states). Strategies to increase the delivery efficiency of antibacterials using formulation aids such as polyamidoamine (P AMAM) dendrimers are of interest. P AMAM dendrimers can potentially act as a mucoadhesive delivery system due to electrostatic interactions between the cationic dendrimer and an ionic mulch in oral buccal mucus. Solubilisation studies demonstrated an increase in the level of triclosan solubilised with increasing dendrimer concentration over the range 1mM-5mM. However, solubilisation studies over the pH range 5-12 showed that the dendrimer was unable to enhance triclosan solubility at lower pH values. The solubilising effect observed was attributed to the ionization of triclosan (pKa 7.9) resulting from dendrimer induced pH changes. T\ IH NMR telaxation studies on a solution of 3 mM G3 PAMAM dendrimer and triclosan in pH 12 aqueous solution showed a reduction in T\ for proton resonances corresponding to triclosan, compared to triclosan without dendrimer. However, no significant chemical shift or line broadening effects were observed inferring the interaction between dendrimer and triclosan is relatively weak.