PHARMACEUTICAL FORMULATION AND CHARACTERIZATION OF EUCALYPTUS OIL LOADED FAST DISSOLVING ORAL FILMS EMPLOYING DIVERSE POLYMERIC BASES

Background: Fast-dissolving oral films (FDFs) represent a modern drug delivery system designed to disintegrate rapidly in the mouth without water, making them highly suitable for pediatric and geriatric populations. Eucalyptus oil, rich in 1,8-cineole, is utilized for its antimicrobial, anti-inflammatory, and soothing effects on oral and respiratory conditions. Integrating this essential oil into an FDF platform ensures a rapid onset of action and improves patient compliance for managing respiratory relief. Objective: The primary goal of this study was to formulate and characterize eucalyptus oil-loaded FDFs and evaluate the impact of different hydrophilic polymer types and their concentrations on the films’ physicomechanical properties. Methods: Twelve formulations (F1 to F12) were prepared using the solvent casting technique. The study utilized four polymers at varying concentrations: HPMC E5, PVA, NaCMC, and PVP K30. Eucalyptus oil loading (5% w/w), PEG 400 as a plasticizer (15% w/w), and Tween 80 as a surfactant were maintained across formulations. The films were characterized for appearance, thickness, folding endurance, surface pH, moisture content, tensile strength, and disintegration time. Key Results: All films were smooth and flexible, with surface pH values (6.5–6.9) compatible with oral mucosa. Increasing polymer concentration led to a proportional rise in thickness (0.060 to 0.115 mm) and tensile strength (1.23 to 3.61 MPa). HPMC-based films exhibited superior folding endurance (up to 300 ± 12), while NaCMC films showed the fastest disintegration (minimum 20 ± 3s). Formulation F2 (HPMC E5 2.5%) was identified as optimal, featuring uniform thickness (0.076 mm), high folding endurance (265 ± 10), and rapid disintegration (26 ± 3s). Conclusion: The study concludes that polymer selection and concentration significantly influence FDF performance. HPMC E5 at 2.5% provides the ideal balance of mechanical integrity and rapid drug release. These films offer a stable and patient-compliant delivery platform for eucalyptus oil in treating mild respiratory infections.