ENHANCEMENT OF IN-VIVO ANTIINFLUENZA VIRUS ACTIVITY OF 5,7,4'-TRIHYDROXY-8-METHOXYFLAVONE BY DRUG-DELIVERY SYSTEM USING HYDROXYPROPYL CELLULOSE

Enhancement of in vivo antiviral activity of 5,7,4'-trihydroxy-8-metho xyflavone (F36) against H3N2 subtype of influenza A virus by drug deli very system (DDS) with hydroxypropyl cellulose (HPC) was studied. Alth ough in the absence of HPC F36 (0.5 mg/kg) showed no antiviral activit y against mouse-adapted influenza virus A/Guizhou/54/89 (H3N2) in mice , when F36 solution containing HPC was administered intranasally 5 min after the virus inoculation, proliferation of the virus in both nasal and broncho-alveolar cavities was inhibited significantly. The relati onship between concentration (0.2-0.5%) and deposition ratio of HPC wa s studied. When 10 mu l of fluorescein isothiocyanate (FITC)-conjugate d HPC solution was administered intranasally to BALB/c mice, depositio n ratio of HPC at 6h after inoculation in nasal cavity was dependent o n its concentration. The deposition ratio of HPC in broncho-alveolar c avity, however, was reversely-dependent on its concentration. Anti-inf luenza virus activity of F36 in nasal and broncho-alveolar cavities wa s dependent bath on the concentration and deposition ratio of HPC. HPC was most effective at 0.5% in nasal cavity and at 0.3% in broncho-alv eolar cavity. These results indicate that DDS with HPC enhances the an ti-influenza virus activity of F36 in vivo.