# Design of a Foam-Actuated Nano-Emulgel for Perioceutic Drug Delivery: Formulation, Characterization, and Antimicrobial Efficacy

## TL;DR

A foam-based drug delivery system using azithromycin and xanthan gum gel was developed to treat periodontitis with localized delivery and reduced side effects.

## Contribution

A novel foam-actuated nano-emulgel formulation for localized periodontal drug delivery was developed and characterized.

## Key findings

- Azithromycin showed optimal solubility in olive oil (0.347 mg/mL) for nano-emulgel formulation.
- The nano-emulgel exhibited high encapsulation efficiency (98–100%) and rapid drug release (2–8 h).
- The formulation demonstrated potent antimicrobial activity against oral pathogens with minimum inhibitory concentrations ranging from 0.390 to 1.56 µg/mL.

## Abstract

Periodontitis is a prevalent oral condition worldwide. Azithromycin, a conventional lipophilic drug for periodontal treatment, often causes systemic side effects when administered orally. To address this, azithromycin-loaded nano-emulgels were developed using olive oil as a carrier within a xanthan gum aqueous gel phase. This oil-in-aqueous gel emulsion was actuated into a foam for localized drug delivery in gingival and periodontal disease. The solubility of azithromycin in various vehicles was tested, with olive oil showing the best solubility (0.347 mg/mL). Thermodynamic stability testing identified viable nano-formulations, with encapsulation efficiencies ranging from 98 to 100%. These formulations exhibited rapid drug release within 2–8 h. Muco-adhesion studies and ex vivo permeability tests on porcine buccal mucosa highlighted the beneficial properties of xanthan gum for local drug retention within the oral cavity. Antimicrobial efficiency was assessed using minimum inhibitory concentrations against various oral pathogens, where the formulation with equal surfactant and co-surfactant ratios showed the most potent antibacterial activity, ranging from 0.390 to 1.56 µg/mL. This was supported by the shear-thinning, muco-adhesive, and drug-retentive properties of the xanthan gel base. The study also examined the influence of the oil phase with xanthan gum gel on foam texture, rheology, and stability, demonstrating a promising prototype for periodontitis treatment.