Formulation and Characterization of Phytosomes as Drug Delivery System of Formononetin: An Effective Anti-Osteoporotic Agent

Background: Formononetin (FNT), a methoxy isoflavone, is a potential phytoconstituent utilized for refurbishing fractures in bone tissue. Conceding to its involvement in first-pass metabolism followed by glucuronidation, its absorption efficacy is limited. Hence, it belongs to the BCS class II classification. Objective: We designed the present work to enhance FNT oral bioavailability by using Phospholipids (PL) as a promising carrier. Formononetin Phospholipid Complex (FNT-PC) was prepared by the solvent evaporation method and characterized. Methods: FNT-PC was prepared by solvent evaporation method and characterization (FNT-PC) was performed using aqueous/n-octanol solubility and partition coefficient, FTIR, NMR, SEM, and in vivo pharmacokinetic study in female SD rats at 50 mg/kg. Results: Physicochemical properties like aqueous/n-octanol solubility and partition coefficient were enhanced in FNT-PC. The FTIR spectrum confirmed there was no involvement of functional groups in the preparation of FNT-PC. Whereas, the NMR study resulted in the attachment of carbon (C-8) position of FNT by replacing the quaternary amine of PL to form FNT-PC. When scrutinized for its surface morphology, the FNT-PC exhibited the amorphous geometry that remarkably enhanced the dissolution of FNT (p<0.05) from its pure form. This dissolution effect was also affirmed by the per-oral administration of FNT-PC in female Sprague Dawley (SD) rats at 50 mg/kg dose. The pharmacokinetic profile showed the free FNT levels were markedly increased, correspondingly decreasing the conjugated FNT levels in rat plasma. Conclusion: To summarize, FNT-PC could substantially reduce the first-pass metabolism with enhanced free concentration, improving oral bioavailability for therapeutic use.