Phytantriol (PT), ethanol (ET) and water were used to prepare in situ cubic liquid crystal (ISV2). The pseudo-ternary phase diagram of PT-ET-water was constructed and isotropic solution formulations were chosen for further optimization. The physicochemical properties of isotropic solution formulations were evaluated to optimize the composition of ISV2. In situ hexagonal liquid crystals (ISH2) were prepared based on the composition of ISV2 with the addition of vitamin E acetate (VitEA) and the amount of VitEA was optimized by in vitro release behavior. The phase structures of liquid crystalline gels formed by ISV2 and ISH2 in excess water were confirmed by crossed polarized light microscopy and small angle X-ray scattering, respectively. Rheological properties of ISV2 and ISH2 were studied by a DHR-2 rheometer. In vitro drug release studies were conducted by using a dialysis membrane diffusion method. Pharmacokinetics was investigated by determination of sinomenine hydrochloride (SMH) concentration in synovial membrane after intra-articular injection of SMH-loaded ISH2 in adjuvant-induced arthritis rats. The optimal ISV2 (PT/ET/water, 64 : 16 : 20, w/w/w) loaded with 6 mg x g(-1) of SMH showed a suitable pH, injectable and formed a cubic liquid crystalline gel in situ with minimum water absorption in the shortest time. The optimal ISV2 was able to sustain the drug release for 144 h. The optimal ISH2 system was prepared by addition of 5% VitEA into PT in the optimal ISV2 system. This ISH2 (PT/VitEA/ET/water, 60.8 : 3.2 : 16 : 20, w/w/w/w) was an injectable isotropic solution with suitable pH. The new ISH2 was able to sustain the drug release for more than 240 h. Local pharmacokinetics study indicated that the retention time and AUC(0-∞) of ISH2 group were increased significantly compared with that of SMH solution group and the AUC(0-∞) of ISH2 group was 6.01 times higher than that of SMH solution group. The developed ISH2 was suitable for intra-articular injection that may apply to patients in the treatment of rheumatoid arthritis.
Animals ; Chemistry, Pharmaceutical ; Diffusion ; Ethanol ; Fatty Alcohols ; Gels ; Injections, Intra-Articular ; Liquid Crystals ; Morphinans ; administration & dosage ; chemistry ; Rats ; Rheology ; Water ; alpha-Tocopherol

Hesperetin, an abundant bioactive component of citrus fruits, is poorly water-soluble, resulting in low oral bioavailability. We developed new formulations to improve the water solubility, antioxidant activity, and oral absorption of hesperetin. Two nano-based formulations were developed, namely hesperetin-TPGS (D-α-tocopheryl polyethylene glycol 1000 succinate) micelles and hesperetin-phosphatidylcholine (PC) complexes. These two formulations were prepared by a simple technique called solvent dispersion, using US Food and Drug Administration (FDA)-approved excipients for drugs. Differential scanning calorimetry (DSC) and dynamic light scattering (DLS) were used to characterize the formulations' physical properties. Cytotoxicity analysis, cellular antioxidant activity assay, and a pharmacokinetic study were performed to evaluate the biological properties of these two formulations. The final weight ratios of both hesperetin to TPGS and hesperetin to PC were 1:12 based on their water solubility, which increased to 21.5- and 20.7-fold, respectively. The hesperetin-TPGS micelles had a small particle size of 26.19 nm, whereas the hesperetin-PC complexes exhibited a larger particle size of 219.15 nm. In addition, the cellular antioxidant activity assay indicated that both hesperetin-TPGS micelles and hesperetin-PC complexes increased the antioxidant activity of hesperetin to 4.2- and 3.9-fold, respectively. Importantly, the in vivo oral absorption study on rats indicated that the micelles and complexes significantly increased the peak plasma concentration (C_max) from 2.64 μg/mL to 20.67 and 33.09 μg/mL and also increased the area under the concentration-time curve of hesperetin after oral administration to 16.2- and 18.0-fold, respectively. The micelles and complexes increased the solubility and remarkably improved the in vitro antioxidant activity and in vivo oral absorption of hesperetin, indicating these formulations' potential applications in drugs and healthcare products.
Administration, Oral ; Animals ; Antioxidants/chemistry* ; Biological Availability ; Calorimetry, Differential Scanning ; Dogs ; Dose-Response Relationship, Drug ; Drug Carriers ; Female ; Hep G2 Cells ; Hesperidin/chemistry* ; Humans ; Light ; Madin Darby Canine Kidney Cells ; Micelles ; Phosphatidylcholines/chemistry* ; Polyethylene Glycols/chemistry* ; Rats ; Rats, Sprague-Dawley ; Scattering, Radiation ; Solubility ; Solvents ; Vitamin E/chemistry* ; Water/chemistry* ; alpha-Tocopherol/chemistry*

BACKGROUND/AIMS: Ozone is an environmentally reactive oxidant, and pycnogenol is a mixture of flavonoid compounds extracted from pine tree bark that have antioxidant activity. We investigated the effects of pycnogenol on reactive nitrogen species, antioxidant responses, and airway responsiveness in BALB/c mice exposed to ozone. METHODS: Antioxidant levels were determined using high performance liquid chromatography with electrochemical detection. Nitric oxide (NO) metabolites in bronchoalveolar lavage (BAL) fluid from BALB/c mice in filtered air and 2 ppm ozone with pycnogenol pretreatment before ozone exposure (n = 6) were quantified colorimetrically using the Griess reaction. RESULTS: Uric acid and ascorbic acid concentrations were significantly higher in BAL fluid following pretreatment with pycnogenol, whereas gamma-tocopherol concentrations were higher in the ozone exposed group but were similar in the ozone and pycnogenol pretreatment groups. Retinol and gamma-tocopherol concentrations tended to increase in the ozone exposure group but were similar in the ozone and pycnogenol pretreatment groups following ozone exposure. Malonylaldehyde concentrations increased in the ozone exposure group but were similar in the ozone and pycnogenol plus ozone groups. The nitrite and total NO metabolite concentrations in BAL fluid, which parallel the in vivo generation of NO in the airways, were significantly greater in the ozone exposed group than the group exposed to filtered air, but decreased with pycnogenol pretreatment. CONCLUSIONS: Pycnogenol may increase levels of antioxidant enzymes and decrease levels of nitrogen species, suggesting that antioxidants minimize the effects of acute ozone exposure via a protective mechanism.
Animals ; Antioxidants/*pharmacology ; Ascorbic Acid/metabolism ; Bronchial Hyperreactivity/chemically induced/metabolism/*prevention & control ; Bronchoalveolar Lavage Fluid/chemistry ; Bronchoconstriction/drug effects ; Disease Models, Animal ; Female ; Flavonoids/*pharmacology ; Inhalation Exposure ; Lung/*drug effects/enzymology/physiopathology ; Malondialdehyde/metabolism ; Mice ; Mice, Inbred BALB C ; Nitric Oxide/metabolism ; Oxidative Stress/*drug effects ; *Ozone ; Uric Acid/metabolism ; Vitamin A/metabolism ; alpha-Tocopherol/metabolism