Copyright © 2008 John Wiley & Sons, Ltd. Phytother. Res. 23, 246–250 (2009) DOI: 10.1002/ptr 246 A. A. MOGHADAMNIA ET AL. Copyright © 2008 John Wiley & Sons, Ltd. PHYTOTHERAPY RESEARCH Phytother. Res. 23, 246–250 (2009) Published online 13 October 2008 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/ptr.2601 The Efficacy of the Bioadhesive Patches Containing Licorice Extract in the Management of Recurrent Aphthous Stomatitis A. A. Moghadamnia 1 *, M. Motallebnejad 2 and M. Khanian 3 1 Department of Pharmacology, Babol University of Medical Sciences, Babol, Iran 2 Department of Oral Medicine, Babol University of Medical Sciences, Babol, Iran 3 Faculty of Dentistry, Babol University of Medical Sciences, Babol, Iran This study evaluated the efficacy of licorice bioadhesive hydrogel patches to control the pain and reduce the healing time of recurrent aphthous ulcer. This study was carried out in three episodes of ulcers: in the first episode of ulcer, all 15 patients were asked to record their baseline individual pain level by a visual analog scale. In the second and third episodes, comparative and consecutive subjective and objective evaluations of the bioadhesive were done. The effects of the following variables were investigated: (1) VAS pain score for 5 consecutive days, (2) profile of aphthous ulcers on days 3 and 5, (3) time to complete relief of pain and healing of the ulcers, (4) diameter of the lesions and necrotic zone. A significant reduction in VAS was recorded following application of the licorice patches on days 2, 3, 4 and 5 compared with the no-treatment group ( p < 0.001). Licorice patches caused a significant reduction in the diameter of the inflammatory halo and necrotic center compared with the placebo group ( p = 0.03). According to the results of this study, licorice bioadhesive can be effective in the reduction of pain and of the inflammatory halo and necrotic center of aphthous ulcers. Copyright © 2008 John Wiley & Sons, Ltd. Keywords: recurrent aphthous stomatitis; licorice; mucoadhesive; biopatch; topical therapy. Received 5 May 2007 Revised 26 April 2008 Accepted 14 May 2008 * Correspondence to: A. A. Moghadamnia, Department of Pharmacology, Babol University of Medical Sciences, post code 4717641367, Babol, Iran. E-mail: moghadamnia@yahoo.com INTRODUCTION Recurrent aphthous stomatitis (RAS) is a common condition in which recurring ovoid or round ulcers affect the oral mucosa. It is one of the most painful oral inflammatory ulcerative conditions which cause pain during eating, swallowing and speaking (Miller and Ship, 1977; Sircus et al., 1967). Recurrent aphthous stomatitis is the most common oral condition diagnosed by dentists and physicians (Rogers, III, 1977; Woo and Sonis, 1996). The prevalence of the disease varies in different stud- ies according to the investigated populations (Harries et al., 1987; Scully et al., 2003). An overall prevalence of 10–20% has been reported for the general popula- tion (Rennie et al., 1985; Scully et al., 2003), with a higher prevalence of RAS (56%) in selected groups, such as university students (Donatsky, 1973). Although hereditary (Ship, 1965; Shohat-Zabarski et al., 1992), dietary (Eversole, 1994), hematologic (Burgan et al., 2006), infectious (Barile et al., 1963; Sun et al., 1996), allergic (Boulinguez et al., 2003) and immunologic (Natah et al., 2000) factors have been implicated, their role as the main etiological factors in the pathogenesis remains to be elucidated. Furthermore, with the dramatic world- wide increase in patients with immuno-suppression caused by medical treatments, systemic diseases, or both, the prevalence of these conditions may be increasing. Pain is a common symptom of RAS (Mahdi et al., 1996). There is no specific management for RAS, and there- fore analgesic, antimicrobial and immuno-modulatory drugs have been used individually or simultaneously (Porter et al., 1998). Topical treatment is used to pro- mote healing and pain relief (Scully et al., 2003) mean- while, systemic treatment is reserved for severe cases and is not applicable in most situations (Katz et al., 1994). Antiinflammatory, antibiotic and some immuno- modulatory agents have been used as topical and systemic treatments in RAS (Jurge et al., 2006) so far topical medications with mucosal adherence properties have been used with some success, including Orabase (Scully et al., 2003), Zirlactin (Rodu and Russell, 1988) and Cianoacrylate (Jasmin et al., 1993). In Chinese traditional medicine, licorice remains one of the most commonly prescribed herbs and has been used in the treatment of various ailments ranging from tuberculosis to peptic ulcers (Huang, 1993). Since licorice has been shown to have antiinflammatory properties in herbal medicine (Shibata, 2000), the present study undertook to assess the efficacy of the application of licorice bioadhesive hydrogel patches formulated from tragacant gum in the pain control of RAS. As dental practitioners and researchers become better trained in oral medi- cine, it is anticipated that the physiopathology, preven- tion and treatment of RAS will improve in the future. MATERIAL AND METHODS Patients. A total of 15 patients, 5 women and 10 men (age 22–35 years, mean ± SD, 26.27 ± 4.28 years) with