Development Of Throat Nano-Spray Formulation For The Treatment Of Streptococcus Pyogenes Tonsillitis

Abstract

Background:
Tonsillitis is an inflammatory condition of the tonsillar tissues, commonly caused by Streptococcus pyogenes, leading to pain and difficulty in eating. Conventional treatments such as gargles and ointments often suffer from poor patient compliance due to inconvenience. In contrast, nano oral sprays offer a more convenient and patient-friendly alternative by enhancing drug delivery and retention on the oral mucosa.

Materials & Methods:

Allicin, an active constituent of Allium sativum (garlic), was selected due to its potent antimicrobial properties. It has a molecular weight of 162.28 g/mol and limited water solubility (0.8%). A nanoemulsion-based oral spray was developed using the water titration method and pseudo-ternary phase diagrams. Oleic acid was selected as the oil phase due to its high solubility (200 mg/ml). Various surfactant ratios (1:1, 2:1, 3:1) were optimized. Mucoadhesive potential was evaluated using Gum Ghatti (GG) at different concentrations.

Results:
The optimized nanoemulsion showed a pH of 6.95 ± 0.58, viscosity of ~71 mPas, and refractive index of 1.463 ± 0.35. The particle size was 227.5 nm with a PDI of 0.270, indicating good uniformity. The spray exhibited a discharge rate of 60 ± 1.5 µL per actuation. GG (5% and 10% w/v) demonstrated superior mucoadhesion compared to CMC-Na. Drug release followed the Higuchi model. The nano spray showed a significantly higher antibacterial activity (zone of inhibition: 25.0 ± 1.00 mm) compared to marketed formulations. Stability studies confirmed good physical and thermodynamic stability, with a calculated shelf life of approximately 13.99 months.

Conclusion:
The developed allicin nano oral spray demonstrated enhanced antibacterial efficacy, improved bioavailability, and strong mucoadhesive properties. It provides prolonged residence time, better patient compliance, and reduced side effects, making it a promising alternative for effective tonsillitis management.