Background: Ginkgo biloba is therapeutically important fossil species with extended benefits against CNS disorders as; it contains various potential constituents which are known for their specific actions. In spite of this fact its medicinal usage are limited due to the limited absorption, rapid elimination, vigorous biotransformation and low bioavailability of its therapeutic components. Objective: The present study is an attempt to develop a microemulsion system of standardized extract of Ginkgo biloba (EGB761) for intranasal application. Material and methods: It is developed by water titration method using Isopropyl Myristate (oil), Tween 80 (surfactant) and Ethanol (co surfactant). Results: EGB761 loaded microemulsions were developed and characterized. The optimized formulation showed particle size of 259.8 ± 6.3 nm, PDI score of 0.186 ± 0.092 and zeta potential as -9.87 ± 2.23 mv. Also, TEM images showed size range from 84 - 260 nm with smooth and spherical morphology. In vitro phyto-constituents release through isolated nasal mucosa showed release pattern of zero order kinetics with sustained release (up to 16 hours). Moreover, cytotoxicity evaluation (RPMI2650 cell lines) didnt show cytotoxicity for both GBME (99.3 % ± 2.28 % and 98.17 % ± 1.86%) and plain EGB761 extract (95.3 % ± 2.1 and 91.7 % ± 1.07) with different time periods (3 and 12 hours). Conclusion: Therefore, it has been concluded from the results that, EGB761 based microemulsion (GBME) is developed with particle size range between 84 260 nm, having zero order release kinetics. GBME is found to be safe on RPMI2650 cell line and can be further, investigated in in vivo system.
Key words: Phytochemicals; Bioavailability; Thermodynamic stability; Particle size analysis; Transmission Electron Microscopy (TEM); Central nervous system.