Preparation and Evaluation of Physicochemical Properties of the Doxepin Mucoadhesive Gel

Background: Oral mucositis is a common debilitating complication of cancer chemotherapy and radiotherapy that can reduce the quality of patient’s lives. Hence, treating this condition plays an important role in increasing the patient’s tolerance. Objectives: Doxepin mucoadhesive gel is useful for treating oral mucosa inflammation caused by long-term effects of chemotherapy, which has low adverse effects. Methods: Doxepin gel’s formulation was prepared with various concentrations of poloxamer 407 and hydroxypropyl methylcellulose in deionized water. The prepared gels were evaluated for pH, appearance, viscosity, spreadability, stability, and drug release. Results: After providing gels containing doxepin, formulations 1, 2, 8, and 9 had low quality and, thus, were removed from the study. Based on qualitative evaluations, formulations 3 and 4 did not meet the criteria for mucoadhesive gel and were removed from the study. The best formulation contained 17% w/w poloxamer 407, 10% w/w hydroxypropyl methylcellulose, and 5% w/w doxepin. Conclusions: Suitable physicochemical properties of prepared doxepin mucoadhesive gel enable it to well cover inflamed and damaged oral mucosa. On the other hand, doxepin’s slow release from formulation (8 hours) can increase therapeutic effects and reduce side effects, which can heal and soothe inflammations of the oral mucosa and be useful in cancer patient’s treatment.