The purpose of this study was to develop pluronic-based in situ gelling formulations of metronidazole (MTZ) for treatment of bacterial vaginosis, aimed at prolonging the residence time, controlling drug release, enhancing efficacy, decreasing recurrence, and increasing patient compliance. The in situ gel formulations were prepared using different concentrations of pluronic F-127 (PF-127) alone and in combination with pluronic F-68 (PF-68). The prepared formulations were evaluated for their gelation temperature (Tgel), in vitro drug release, rheological properties, mucoadhesion properties and tolerability by vaginal mucosa in tissue levels. The Tgel decreased with increasing PF-127 concentration. The Tgel was modulated by addition of PF-68 to be within the acceptable range of 25-37°C. With increasing pluronic concentration, the in-vitro drug release decreased, viscosity and mucoadhesive force increased. Histopathological examination of rabbit vaginas from the control and treated groups revealed normal histology of the vagina and cervix. Based on the in-vitro evaluation of prepared formulations, the in situ gelling liquid formulated with PF-127/PF-68 (20/10 %, m/m) was selected for further clinical evaluation.

The purpose of this study was to develop pluronic-based in situ gelling formulations of metronidazole (MTZ) for treatment of bacterial vaginosis, aimed at prolonging the residence time, controlling drug release, enhancing efficacy, decreasing recurrence, and increasing patient compliance. The in situ gel formulations were prepared using different concentrations of pluronic F-127 (PF-127) alone and in combination with pluronic F-68 (PF-68). The prepared formulations were evaluated for their gelation temperature (Tgel), in vitro drug release, rheological properties, mucoadhesion properties and tolerability by vaginal mucosa in tissue levels. The Tgel decreased with increasing PF-127 concentration. The Tgel was modulated by addition of PF-68 to be within the acceptable range of 25-37°C. With increasing pluronic concentration, the in-vitro drug release decreased, viscosity and mucoadhesive force increased. Histopathological examination of rabbit vaginas from the control and treated groups revealed normal histology of the vagina and cervix. Based on the in-vitro evaluation of prepared formulations, the in situ gelling liquid formulated with PF-127/PF-68 (20/10 %, m/m) was selected for further clinical evaluation.

The purpose of this study was to develop pluronic-based in situ gelling formulations of metronidazole (MTZ) for treatment of bacterial vaginosis, aimed at prolonging the residence time, controlling drug release, enhancing efficacy, decreasing recurrence, and increasing patient compliance. The in situ gel formulations were prepared using different concentrations of pluronic F-127 (PF-127) alone and in combination with pluronic F-68 (PF-68). The prepared formulations were evaluated for their gelation temperature (Tgel), in vitro drug release, rheological properties, mucoadhesion properties and tolerability by vaginal mucosa in tissue levels. The Tgel decreased with increasing PF-127 concentration. The Tgel was modulated by addition of PF-68 to be within the acceptable range of 25-37°C. With increasing pluronic concentration, the in-vitro drug release decreased, viscosity and mucoadhesive force increased. Histopathological examination of rabbit vaginas from the control and treated groups revealed normal histology of the vagina and cervix. Based on the in-vitro evaluation of prepared formulations, the in situ gelling liquid formulated with PF-127/PF-68 (20/10 %, m/m) was selected for further clinical evaluation.

The purpose of this study was to develop pluronic-based in situ gelling formulations of metronidazole (MTZ) for treatment of bacterial vaginosis, aimed at prolonging the residence time, controlling drug release, enhancing efficacy, decreasing recurrence, and increasing patient compliance. The in situ gel formulations were prepared using different concentrations of pluronic F-127 (PF-127) alone and in combination with pluronic F-68 (PF-68). The prepared formulations were evaluated for their gelation temperature (Tgel), in vitro drug release, rheological properties, mucoadhesion properties and tolerability by vaginal mucosa in tissue levels. The Tgel decreased with increasing PF-127 concentration. The Tgel was modulated by addition of PF-68 to be within the acceptable range of 25-37°C. With increasing pluronic concentration, the in-vitro drug release decreased, viscosity and mucoadhesive force increased. Histopathological examination of rabbit vaginas from the control and treated groups revealed normal histology of the vagina and cervix. Based on the in-vitro evaluation of prepared formulations, the in situ gelling liquid formulated with PF-127/PF-68 (20/10 %, m/m) was selected for further clinical evaluation.

To enhance the activity of amantadine against HCV, its amide prodrugs with thiazolidine-4-carboxylic acid derivatives (6-9) and bile acids (10 and 11) were designed and synthesized. In vitro kinetic stability of amide prodrugs 8 and 10 were investigated in aqueous buffer solution with variable pH values (1.2, 4.5. 6.8, 7.4. 8.0) and in biological fluids of 90% human plasma and rat liver homogenate at 37°C. In vivo release of the parent drug from these prodrug was investigated in mice with the thioazolidine-4-carboxylic acid amide 8 as representative of these delivery systems. Results from the in vivo distribution study indicated that the level of amantadine increased significantly in liver from 8 when compared to amantadine itself. The study suggested the synthesized delivery systems is promising carrier to enhance the hepatic bioavailability of amantadine.

To enhance the activity of amantadine against HCV, its amide prodrugs with thiazolidine-4-carboxylic acid derivatives (6-9) and bile acids (10 and 11) were designed and synthesized. In vitro kinetic stability of amide prodrugs 8 and 10 were investigated in aqueous buffer solution with variable pH values (1.2, 4.5. 6.8, 7.4. 8.0) and in biological fluids of 90% human plasma and rat liver homogenate at 37°C. In vivo release of the parent drug from these prodrug was investigated in mice with the thioazolidine-4-carboxylic acid amide 8 as representative of these delivery systems. Results from the in vivo distribution study indicated that the level of amantadine increased significantly in liver from 8 when compared to amantadine itself. The study suggested the synthesized delivery systems is promising carrier to enhance the hepatic bioavailability of amantadine.

A new xanthone glycoside, 8-hydroxy-3,5-dimethoxy-1-O-[α-L-arabinofuranosyl-(1 → 6)-β-D-glucopyranosyl]-xanthone (1) in addition to two known xanthones named 8-hydroxy-3,5-dimethoxy-1-O-β-Dglucopyranosyl-xanthone (2) and 1,8-dihydroxy-3,5-dimethoxyxanthone (methylbellidifolin) (3) were isolated from the methanol extract of aerial part of Centaurium spicatum, and tested for their cytotoxic activities against three different types of cell lines HeLa, THP-1and HL-60 cell lines. All compounds showed cytotoxicities to all cell lines, whereas showed a moderate activity against human monocytic cell line HL-60. Among three tested xanthones, the cytotoxic activity of compound 1 was stronger than those of other xanthones and the IC50 values for compound 1 were 3.22 (against THP-1), 8.67 (against HeLa) and 74.6 (against HL-60) μM, respectively.

A new xanthone glycoside, 8-hydroxy-3,5-dimethoxy-1-O-[α-L-arabinofuranosyl-(1 → 6)-β-D-glucopyranosyl]-xanthone (1) in addition to two known xanthones named 8-hydroxy-3,5-dimethoxy-1-O-β-Dglucopyranosyl-xanthone (2) and 1,8-dihydroxy-3,5-dimethoxyxanthone (methylbellidifolin) (3) were isolated from the methanol extract of aerial part of Centaurium spicatum, and tested for their cytotoxic activities against three different types of cell lines HeLa, THP-1and HL-60 cell lines. All compounds showed cytotoxicities to all cell lines, whereas showed a moderate activity against human monocytic cell line HL-60. Among three tested xanthones, the cytotoxic activity of compound 1 was stronger than those of other xanthones and the IC50 values for compound 1 were 3.22 (against THP-1), 8.67 (against HeLa) and 74.6 (against HL-60) μM, respectively.

A sensitive high-performance liquid chromatographic method with fluorescence detection was developed to determine memantine (MT) in rat plasma. The method consists of pre-column labeling of MT with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) and a clean-up step with solid-phase extraction. A good separation of DIB-MT was achieved within 12 min on an octadecylsilica (ODS) column (150x4.6 mm i.d.; 5 µm) with a mobile phase of acetonitrile–water (70:30, v/v). The calibration curve prepared with fluoxetine as an internal standard showed good linearity in the range of 10–400 ng/mL (r= 0.999). The limits of detection and quantitation at signal-to-noise ratios of 3 and 10 were 2.0 and 6.6 ng/mL, respectively. The method was shown to be reliable with precisions of 5% for intra-day and 9% for inter-day as relative standard deviation. The fluorescence property and reaction yield of authentic DIB-MT were also examined. The proposed method was successfully applied to study the pharmacokinetic interaction between MT and methazolamide.

A sensitive high-performance liquid chromatographic method with fluorescence detection was developed to determine memantine (MT) in rat plasma. The method consists of pre-column labeling of MT with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) and a clean-up step with solid-phase extraction. A good separation of DIB-MT was achieved within 12 min on an octadecylsilica (ODS) column (150x4.6 mm i.d.; 5 µm) with a mobile phase of acetonitrile–water (70:30, v/v). The calibration curve prepared with fluoxetine as an internal standard showed good linearity in the range of 10–400 ng/mL (r= 0.999). The limits of detection and quantitation at signal-to-noise ratios of 3 and 10 were 2.0 and 6.6 ng/mL, respectively. The method was shown to be reliable with precisions of 5% for intra-day and 9% for inter-day as relative standard deviation. The fluorescence property and reaction yield of authentic DIB-MT were also examined. The proposed method was successfully applied to study the pharmacokinetic interaction between MT and methazolamide.