betadex and paeonol

Polyphenol oxidase (PPO) was extracted from Hass avocados and its physicochemical properties were analyzed. The optimum pH and temperature of the enzyme were pH 7.5 and 20°C. This PPO showed a high thermal stability, since 26% of the initial activity was retained by the enzyme after heating at 60°C for 40 min. Inhibition studies were performed using different chemical reagents, and the order in the inhibition efficiency was paeonol > 4-hydroxybenzaldehyde > β-cyclodextrin (β-CD). The first two inhibitors presented a non-competitive mechanism while the inhibition by β-CD results from a mixed type mechanism. Since the aqueous solubility of paeonol (a natural compound) is very low, the inclusion complex between this drug and β-CD was obtained in solution and solid state. The stoichiometry of the paeonol:β-CD complex was 1:1 and its ΔG° of formation was -26 kJ/mol. The complexation of paeonol by β-CD not only enhances the aqueous solubility and thermal stability of the drug, but also improves the in vitro inhibition efficiency against PPO. Colorimetric analysis on avocados pulp (in vivo) showed that the inclusion complex does not increase the inhibitory effect of paeonol, remaining practically unchanged. However, the formulation of paeonol:β-CD inclusion complex allows employing this compound as PPO inhibitor in aqueous solutions.

Topics: Acetophenones; beta-Cyclodextrins; Biocatalysis; Catechol Oxidase; Maillard Reaction; Persea; Solubility; Temperature; Water

To prepare paeonol-beta-cyclodextrin inclusion complex (Pae-beta-CYD) loaded colon-specific release tablets.. The core tablets were prepared with the mixture of Pae-beta-CYD inclusion complex, peotin and calcium acetate, and coated with ethanolic solution of Eudragit S100. The effects of coating weight, amount of plasticizer, curing time and temperature on the release of drug from tablets were investigated in vitro.. About 5-6 h retarded release of paeonol in the dissolution media of pectinase or rats colon contents were obtained by 12% coating weight gain and 20% Dibutyl phthalate (DBP) was used as plasticizer, and subsequently curing the tablets at 45 degrees C for 12 h.. Pae-beta-CYD loaded colon-specific release tablets showed pH environment and enzyme dependant release properties.

Topics: Acetophenones; Animals; beta-Cyclodextrins; Colitis, Ulcerative; Colon; Drug Delivery Systems; Excipients; Humans; Hydrogen-Ion Concentration; Rats; Rats, Sprague-Dawley; Tablets, Enteric-Coated

By preparing an inclusion complex of paeonol (PAE) with β-cyclodextrin (β-CD), this study investigated its release behavior from thermo-sensitive poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The PAE-β-CD complex was prepared via coprecipitation. According to differential scanning calorimeter (DSC) and X-ray diffraction (XRD) results, the solid PAE-β-CD complex was found in the amorphous state, indicating that each PAE molecule was encapsulated by a β-CD molecule. The change of chemical shifts of H3 and H5 in proton nuclear magnetic resonance (H NMR) spectra indicated that PAE was inside the CD cavity. PNIPAAm hydrogels containing different cross-linker contents were then synthesized and had a similar lowest critical solution temperature (LCST) of around 33°C. Experimental results of swelling and deswelling indicated that increasing the cross-linker content of the hydrogel decreased the swelling ratio and increased the water retention. According to experimental results of PAE-β-CD complex release, the release rate at 45°C (>LCST) was higher than at 25°C (

Topics: Acetophenones; Acrylic Resins; beta-Cyclodextrins; Calorimetry, Differential Scanning; Chemical Precipitation; Cross-Linking Reagents; Drug Carriers; Hydrogels; Temperature; X-Ray Diffraction

In the present study, using paeonol as model drug, a new sealed-control temperature method of preparing inclusion complex was developed, the effects of heating temperature, heating time, and crystallinity of beta-cyclodextrin (beta-CD) on formation of inclusion complex and release of the drug were investigated.. A physical mixture of paeonol and beta-CD was sealed in a container, and heated at the desired temperature for the specified time. The inclusion complex of paeonol and beta-CD was confirmed by IR spectrum and powder X-ray diffraction.. The results indicated that the inclusion complex formation of paeonol beta-CD by sealed-control temperature method was affected by heating temperature, heating time, and crystallinity of beta-CD. The inclusion complex was able to inhibit sublimation of paeonol, and dissolution rate of paeonol was increased when the paeonol was included by beta-CD.. Preparation of inclusion complex was simple and quick by sealed-control temperature method.

Topics: Acetophenones; beta-Cyclodextrins; Crystallization; Drug Compounding; Hot Temperature; Solubility; Spectrophotometry, Infrared; Temperature; X-Ray Diffraction

Thermodynamic parameters of inclusion complex of beta-cyclodextrin (beta-CD) with paeonol and two of its isomers in aqueous solution have been determined with nano-watt-order isothermal titration calorimetry (ITC) and the host-guest inclusion structure has been investigated by using 1H NMR spectra at 298.2 K. The analysis of thermodynamic data reveals that stoichiometry of beta-CD complex with paeonol (Pae) or acetovanillone (Ace) is 1:1 whereas the inclusion complex of beta-CD with 2-hydroxyl-5-methoxyacetophone (Hma) is in 1:1 coexistence with 2:1 stoichiometry. Further analysis indicates that formation of all the complexes is simultaneously driven by enthalpy and entropy, the inclusion complexation of Pae.beta-CD, Ace.beta-CD and Ham.beta-CD2 is predominantly driven by entropy while Ham.beta-CD by enthalpy. The 1H NMR spectra data provide clear evidence of the inclusion phenomena, which shows that the aromatic ring of the guest molecule insert itself into the torus from the narrow side of the cavity.

Topics: Acetophenones; beta-Cyclodextrins; Calorimetry; Drug Compounding; Isomerism; Magnetic Resonance Spectroscopy; Models, Chemical; Molecular Structure; Solubility; Solvents; Thermodynamics; Titrimetry; Water

Measure the thermal stability and the forming constant of inclusion complex for paeonol with beta-CD, and investigate interaction between beta-CD and paeonol,. The thermal stability investigated by using different thermal analysis. The forming constant was determined by using phase method.. Comparing with melt temperature of paeonol, that of its inclusion complex increase about 220 degrees C. The solubility of paeonol increases with the increased concentration of beta-CD, the composing ratio and the inclusion constant of beta-CD-paeonol is respectively 1/1 and 27.42 mL x mg(-1).. Inclusion constant is applied to research the stability of included drug in physiological condition.

Topics: Acetophenones; beta-Cyclodextrins; Drug Carriers; Drug Interactions; Drug Stability; Hot Temperature; Paeonia; Plant Bark; Plants, Medicinal; Solubility

To study the solubilization effect of 2-hydroxypropyl-beta-cyclodextrin(HPCD) on paeonolum at various pH value.. Phase-solubility method was adopted to study the solubilization effect at 25 degrees C and UV spectrohotometer was used to determine paeonolum content.. The apparent solubility of paeonolum was significantly enhanced by increased HPCD concentration. The apparent stability constant of paeonolum compounds was calculated up to 1 425 in which pH was 3 and HPCD concentration was 133.33 mmol x L(-1). The solubility of paeonolum came up to 10 mg x mL(-1).. HPCD is an ideal solubilizer for paeonolum.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Acetophenones; beta-Cyclodextrins; Drug Stability; Excipients; Hydrogen-Ion Concentration; Paeonia; Plants, Medicinal; Solubility