The technique of liquisolid compress is a new technique developed in 1990s, which was considered to be the most promising technique to improve the dissolution of water-insoluble drugs. In this article, tanshinone II(A) and the extracts of the ester-solubility fractions were chosen as the model drugs to evaluate the effects of the liquisolid technique for enhancement of dissolution properties of tanshinone II(A). Several liquisolid tablets (LS) formulations containing different dosage of drugs and various liquid vehicle were pre-pared and for all the formulations, microcrystalline cellulose and silica were chosen as the carrier and coating materials to evaluate their flow properties, such as angle of repose, Carr's compressibility index and Hausner's ratio. The interaction between drug and excipients in prepared LS compacts were studied by differential scanning calorimetry(DSC) and X-ray powder diffraction (XRPD). The dissolution curves of tanshinone II(A) from liquisolid compacts were investigated to determine the technique's effect in improving the dissolution of tanshinone II(A) and its impacting factors. According to the results, the dissolution increased with the rise in the dissolution of the liquid-phase solvent. The R-value and drug dosage can significantly affect the drug release, but with less impact on active fractions. This indicated that liquisolid technique is a promising alternative for improvement of dissolution property of water-soluble drugs, and can make a synergistic effect with other ester-soluble constituents and bettern improve the release of tanshinone II(A). Therefore, the technique of liquisolid compress will have a better development prospect in traditional Chinese medicines.
Calorimetry, Differential Scanning ; Diterpenes, Abietane ; chemistry ; Solubility ; X-Ray Diffraction

STATEMENT OF PROBLEMS: The heat produced during polymerization of polymer-based provisional materials may cause thermal damage to the vital pulp. PURPOSE: This study was performed to evaluate the exotherm reaction of the polymerbased provisional materials during polymerization by differential scanning calorimetry and to compare the temperature changes of different types of resins. MATERIAL AND METHODS: Three dimethacrylate-based materials (Protemp 3 Garant, Luxatemp Plus, Luxatemp Fluorescence) and five monomethacrylate-based material (Snap, Alike, Unifast TRAD, Duralay, Jet) were selected. Temperature changes of polymer-based provisional materials during polymerization in this study were evaluated by D.S.C Q-1000 (TA Instrument, Wilmington, DE, USA). The following three measurements were determined from the temperature versus time plot: (1) peak temperature, (2) time to reach peak temperature, (3) heat capacity. The data were statistically analyzed using one-way ANOVA and multiple comparison Bonferroni test at the significance level of 0.05. RESULTS: The mean peak temperature was 39.5 degrees C (+/- 1.0). The peak temperature of the polymer-based provisional materials decreased in the following order: Duralay > Unifast TRAD, Alike > Jet > Luxatemp Plus, Protemp 3 Garant, Snap, Luxatemp Fluorescence. The mean time to reach peak temperature was 95.95 sec (+/- 64.0). The mean time to reach peak temperature of the polymer-based provisional materials decreased in the following order: Snap, Jet > Duralay > Alike > Unifast TRAD > Luxatemp Plus, Protemp 3 Garant, Luxatemp Fluorescence. The mean heat capacity was 287.2 J/g (+/- 107.68). The heat capacity of the polymer-based provisional materials decreased in the following order: Duralay > TRAD, Jet, Alike > Snap, Luxatemp Fluorescence, Protemp 3 Garant, Luxatemp Plus. CONCLUSION: The heat capacity of materials, determined by D.S.C., is a factor in determining the thermal insulating properties of restorative materials. The peak temperature of PMMA was significantly higher than others (PEMA, dimethacrylate). No significant differences were found among PEMA (Snap) and dimethacrylate (P > 0.05). The time to reach peak temperature was greatest with PEMA, followed by PMMA and dimethacrylate. The heat capacity of PMMA was significantly higher than others (PEMA, dimethacrylate). No significant differences were found among PEMA and dimethacrylate (P>0.05).
Calorimetry, Differential Scanning* ; Crowns* ; Denture, Partial, Fixed* ; Fluorescence ; Hot Temperature ; Polymerization ; Polymers ; Polymethyl Methacrylate

OBJECTIVES: The purpose of the present study was to evaluate the effects of proanthocyanidin (PAC), a crosslinking agent, on the physical properties of a collagen hydrogel and the behavior of human periodontal ligament cells (hPDLCs) cultured in the scaffold. MATERIALS AND METHODS: Viability of hPDLCs treated with PAC was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The physical properties of PAC treated collagen hydrogel scaffold were evaluated by the measurement of setting time, surface roughness, and differential scanning calorimetry (DSC). The behavior of the hPDLCs in the collagen scaffold was evaluated by cell morphology observation and cell numbers counting. RESULTS: The setting time of the collagen scaffold was shortened in the presence of PAC (p < 0.05). The surface roughness of the PAC-treated collagen was higher compared to the untreated control group (p < 0.05). The thermogram of the crosslinked collagen exhibited a higher endothermic peak compared to the uncrosslinked one. Cells in the PAC-treated collagen were observed to attach in closer proximity to one another with more cytoplasmic extensions compared to cells in the untreated control group. The number of cells cultured in the PAC-treated collagen scaffolds was significantly increased compared to the untreated control (p < 0.05). CONCLUSIONS: Our results showed that PAC enhanced the physical properties of the collagen scaffold. Furthermore, the proliferation of hPDLCs cultured in the collagen scaffold crosslinked with PAC was facilitated. Conclusively, the application of PAC to the collagen scaffold may be beneficial for engineering-based periodontal ligament regeneration in delayed replantation.
Calorimetry, Differential Scanning ; Cell Count ; Collagen* ; Cytoplasm ; Humans ; Hydrogel* ; Periodontal Ligament ; Regeneration ; Replantation

BACKGROUNDThe shape memory effect of nickel-titanium (NiTi) archwires is largely determined by the phase transition temperature. It is associated with a reversible transformation from martensite to austenite. The aim of this study was to characterize austenite, martensite and R phase temperatures as well as transition temperature ranges of the commonly used clinical NiTi orthodontic arch wires selected from several manufacturers.

METHODSDifferential scanning calorimetry (DSC) method was used to study the phase transformation temperatures and the phase transition processes of 9 commonly used clinical NiTi alloys (types: 0.40 mm (0.016 inch), 0.40 mm x 0.56 mm (0.016 inch x 0.022 inch)).

RESULTSThe austenite finish temperatures (Af) of 0.40 mm Smart, Ormco and 3M NiTi wires were lower than the room temperature, and no phase transformation was detected during oral temperature. Therefore, we predicted that these types of NiTi did not possess shape memory property. For 0.40 mm and 0.40 mm x 0.56 mm Youyan I NiTi wires, no phase transformation was detected during the scanning temperature range, suggesting that these two types of wires did not possess shape memory either. The Af of 0.40 mm x 0.56 mm Smart, L&H, Youyan II Ni-Ti wires were close to the oral temperature and presented as martensitic-austenitic structures at room temperature, suggesting the NiTi wires listed above have good shape memory effect. Although the 0.40 mm x 0.56 mm Damon CuNiTi wire showed martensitic-austenitic structures at oral temperature, its Af was much higher than the oral temperature. It means that transformation from martensite to austenite for this type of NiTi only finishes when oral temperature is above normal.

CONCLUSIONThe phase transformation temperatures and transformation behavior varied among different commonly used NiTi orthodontic arch wires, leading to variability in shape memory effect.

The paper is aimed to establish a methods for identication of pearl powder and conch powder from different origins. Hermetic aluminum pan was used to encapsulate samples. The optimal testing conditions were: heating rate 10 degrees C x min(-1), sample weight 3 mg and nitrogen gas flow rate 40 mL x min(-1). The enthalpy values of pearl powder and conch powder was obvious different. Identication of pearl powder and conch powder by DSC is a practical method for its accuracy, convenience and practificality.
Animal Shells ; chemistry ; Animals ; Calorimetry, Differential Scanning ; methods ; China ; Discriminant Analysis ; Pinctada ; chemistry ; classification ; Powders ; chemistry

Poly lactic acid (PLA)/Poly (butyleneadipate-co-terephthalate)(PBAT) and glyceryl triacetate (GTA) blend were prepared by torque rheometer, and the effect of GTA on thermodynamical performance, mechanical properties and microstructure of PLA/PBAT composites were studied using differential scanning calorimeter(DSC), dynamic mechanical analysis(DMA), universal testing machine, impact testing machine and scanning electron microscope(SEM). After adding GTA, Tg values of the two phases gradually became closer, blends cold crystallization temperature and melting temperature decreased. When with 3 phr GTA, the dispersed phase particle size of PLA/PBAT blend decreased. Mechanics performance test showed that the elongation at break and impact strength of the PLA/PBAT blend was greatly increased with 3 phr GTA, and the elongation at break increased 2.6 times, improved from 17.7% to 64.1%.
Acetates ; chemistry ; Calorimetry, Differential Scanning ; Crystallization ; Lactic Acid ; Polyesters ; chemistry ; Polymers ; Temperature

This study sought to clarify the molecular location and the interaction between mitoxantrone and mitoxantrone transforsomes. The anthraquinone of mitoxantrone, a heterocyclic ring that intercalates in the lipid of bilayer, was determined by UV-spectrophotometry and electron probes scan microscopy. Two aminoethylamino side-chains of the drugs fit to the phosphates of lecithin were determined by 8-value, thus the interaction with lecithin was substantiated. Differential scanning calorimetry confirmed that mitoxantrone has remarkable stabilizing effect on the mitoxantrone transforsomes membrane. The mitoxantrone binds tightly to lecithin. So a high degree of encapsulation efficiency and the sustained-release character of mitoxantrone transforsomes are verified.
Anthraquinones ; chemistry ; Calorimetry, Differential Scanning ; Delayed-Action Preparations ; chemistry ; Lecithins ; chemistry ; Mitoxantrone ; chemistry ; Spectrophotometry

AIMTo establish the differential scanning calorimetric (DSC) methodology for controlling the crystal-type B form of nateglinide.

METHODSAccurately weighed pure dried (P2O5 as desiccant for 4 h at 80 degrees C in vacuum) fine powder of crystal-type B and H of nateglinide were measured dQ/dT by DSC at heating rate of 10 degrees C. min-1 and temperature between 100 degrees C and 200 degrees C to calculate the enthalpy delta HB and delta HH. Accurately weight a series of uniform mixtures of crystal-type B and H of dried fine powder of nateglinide in different proportions. The enthalpy of the mixtures is measured by DSC as above to calculate the enthalpy (sigma delta H). Using B% as X, sigma delta H as Y, the regression equation was obtained. According to this equation, the unknown composition of mixed crystal was evaluated by the sigma delta H values. The method was used to control the limitation of crystal-type B of nateglinide by the sigma delta H value of mixture of known composition as reference.

RESULTSThe results measured from different laboratories showed that the repeatability was 0.61% and the recoveries were 86.2%-127% when the amounts of crystal-type B were between 0-15%.

CONCLUSIONThis method can be used to evaluate the crystal-type B composition of nateglinide.

OBJECTIVETo characterize austenite, martensite and R phase temperatures as well as transition temperature ranges of the commonly used nickel-titanium (NiTi) orthodontic arch wires selected from several manufacturers.

METHODSDifferential scanning calorimetry (DSC) method was used to study the phase transformation temperatures and the phase transition processes of 9 commonly used NiTi alloys (types: 0.406 mm, 0.406 mm x 0.559 mm).

RESULTSThe austenite finish temperatures of A, B, D NiTi wires were 22.4 CT, 21.9 degrees C, 22.5 degrees C, respectively. No phase transformation was detected during oral temperature. It indicated that these types of NiTi wires did not possess shape memory property. For C and H NiTi wires, no phase transformation was detected during the scanning temperature range, suggesting that these two types of wires did not possess shape memory either. The austenite finish temperatures of E, G and I NiTi wires were 34.3 degrees C, 36.6 degrees C, 38.5 degrees C, respectively, which were close to the oral temperature and presented as martensitic-austenitic structures at room temperature, suggesting that the NiTi wires listed above had good shape memory effect. Although F NiTi wire also showed martensitic-austenitic structures at room temperature, its austenite finish temperature (61.5 degrees C) was much higher than oral temperature.

CONCLUSIONSThe transformation phase temperatures and transformation behavior were varied among different NiTi alloys, leading to variability in shape memory effect.

Porous silica was used as a carrier to prepare tanshinone solid dispersions (SDs). sThe effect of the spray drying method or the solvent method on the drug dissolution of SD was studied. The structure characteristics of SDs was analyzed by SEM, DSC,XPRD and FTIR. And in vitro dissolution was also investigated. The results showed that drugs were highly dispersed into SDs prepared by spray drying method and the solvent method in amorphous form. In addition, the results of the dissolution tested in vitro exhibited that the tanshinone I and tanshinone II A, accumulated dissolutions of SDs prepared using solvent achieved 80. 9% ,84. 6% and 86. 2% ,88. 7% within 45,60 min, respectively. And SDs prepared using spray-drying method were 92.7% ,95. 3% and 95. 8%, 97. 1% within 45,60 min, respectively. The tanshinone SDs were prepared successfully by spray drying method and solvent method. The SDs prepared by spray drying method was more conducive to improving the dissolution.
Calorimetry, Differential Scanning ; Diterpenes, Abietane ; chemistry ; isolation & purification ; Porosity ; Silicon Dioxide ; chemistry ; Spectroscopy, Fourier Transform Infrared