Development and Evaluation of a Herbal Oral Gel for the Management of Mouth Ulcers

Abstract

The present study aimed to formulate and evaluate a polyherbal oral gel containing extracts of Curcuma longa, Glycyrrhiza glabra, and eugenol for the management of oral ulcers The gel was prepared using Carbopol 934 as the gelling agent and incorporated in mouth oral pH with suitable excipients including glycerine, propylene glycol, methyl paraben, peppermint oil, triethanolamine, and purified water to enhance stability, consistency, and patient acceptability. The formulated gel was evaluated for various physical parameters such as appearance, color, odor, pH, viscosity, spreadability, extrudability, drug content uniformity, and stability. The optimized formulation exhibited a smooth and homogeneous appearance, acceptable pH (6.6–6.8), good spreadability, pseudoplastic viscosity, excellent extrudability, and satisfactory stability during storage. The gel demonstrated promising activity against common oral pathogens, and other microorganisms associated with oral infections. The study concludes that the developed herbal oral gel is a safe, effective, and economical alternative for the management of mouth ulcers and maintenance of oral health.

Introduction

The text describes the development and evaluation of a herbal oral gel containing Curcuma longa, Glycyrrhiza glabra, and eugenol for the management of oral diseases such as gingivitis, periodontitis, dental caries, mouth ulcers, and oral mucosal inflammation.

Background

Oral diseases are common health problems caused largely by microbial biofilms and pathogenic organisms. Conventional antimicrobial and antiseptic treatments can cause problems such as mucosal irritation, altered taste, and antimicrobial resistance when used for long periods. Therefore, herbal medicines are being explored as safer alternatives because of their potential antimicrobial, antioxidant, anti-inflammatory, analgesic, and wound-healing properties.

The three main herbal ingredients have complementary functions:

• Curcuma longa (turmeric): Provides antimicrobial, antioxidant, and wound-healing effects. Curcumin may help control oral pathogens and reduce tissue damage.
• Glycyrrhiza glabra (licorice): Contains glycyrrhizin and flavonoids that may provide antimicrobial, soothing, and anti-inflammatory effects and help against cariogenic bacteria.
• Eugenol: A major component of clove oil, widely used in dentistry for its analgesic and antiseptic properties and its ability to relieve dental pain.

Combining these ingredients may produce a synergistic effect by targeting several mechanisms involved in oral disease.

Materials and Methods

The study used authenticated plant materials and pharmaceutical excipients. Carbopol 934 was used as the gelling agent, while propylene glycol functioned as a solvent and humectant. Methyl paraben was used as a preservative, triethanolamine for pH adjustment, and peppermint oil as a flavoring agent.

Preparation of Extracts

Three extraction methods were used:

• Curcuma longa rhizomes were powdered and extracted with ethanol using Soxhlet extraction for approximately 6–8 hours.
• Glycyrrhiza glabra roots were extracted using a 70:30 ethanol-water mixture through maceration for 24–48 hours.
• Eugenol-rich clove oil was obtained from powdered clove buds through hydro-distillation using a Clevenger apparatus for approximately 3–4 hours.

The resulting extracts were filtered, concentrated, and stored for formulation.

Herbal Oral Gel Formulation

The gel was prepared using the dispersion method. Carbopol 934 was hydrated in water, while the herbal extracts were dissolved or mixed with propylene glycol. Eugenol was incorporated into the mixture, followed by preservatives and peppermint oil. Triethanolamine was then added to neutralize the Carbopol and adjust the formulation to an oral-compatible pH of approximately 6.0–7.5.

Three formulations were prepared:

• F1: Lower concentration of herbal extracts and gelling agent.
• F2: Intermediate/optimized formulation.
• F3: Higher concentration of herbal extracts and gelling agent.

F2 contained approximately 1.5% each of Curcuma longa and Glycyrrhiza glabra extract, 0.3% eugenol, and 1.2% Carbopol 934.

Evaluation of the Formulation

The prepared gel was evaluated through several tests to determine its quality, stability, uniformity, and suitability for oral application.

Main evaluation parameters

1. Organoleptic properties: Color, odor, taste, appearance, texture, homogeneity, and consistency were examined.
2. Phytochemical tests: Chemical identification tests were performed to confirm characteristic constituents of turmeric, licorice, and eugenol.
3. pH: Measured using a calibrated digital pH meter, with the desired oral-gel range maintained at 6.0–7.5.
4. Viscosity: Measured using a Brookfield viscometer to determine the gel's flow behavior. The formulation showed pseudoplastic behavior, which is suitable for oral topical application.
5. Spreadability: Determined using the glass-slide method. Good spreadability indicates that the gel can be easily and uniformly applied to oral tissues.
6. Extrudability: Evaluated to determine how easily the gel could be removed from its tube under pressure.
7. Drug content uniformity: UV-visible spectrophotometry was used to determine whether the active ingredients were uniformly distributed throughout the gel.
8. Stability studies: The formulations were evaluated under different temperature and humidity conditions following ICH stability-testing principles.

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Copyright

Copyright © 2026 Shraddha Nitin Wagh, Prathmesh Umesh Kumbhakarna, Varad Vijay Gosavi, Mr. Swapnil Harishchandre, Miss. Rasika Bhalke, Mr. Mahendra Giri . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.