Study design: A single-blinded placebo-controlled trial was performed, dividing 50 RAS subjects into group A and group B with 25 subjects in each group. Patients in group A received topical application of crushed doxycycline hyclate tablet with denture adhesive (Fixon) and few drops of saline solution just once at the first visit. Group B received placebo similarly. Treatment response was assessed by measuring pain reduction, ulcer duration, and adhesive retention time. Data were analyzed using the Student’s t-test.

Results: Participants who received doxycycline hyclate had significantly less pain by day 1 (P<.001) and the lesion healed faster (P< 001) compared with placebo.

Conclusion: Doxycycline hyclate as a single application decreased pain and speeded recovery.