• Journal of Pharmaceutical Investigation
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• v.16 no.2
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• pp.55-67
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• 1986

Inclusion complexation of tiaprofenic acid (TPA) with cyclodextrins $({\alpha}-,\;{\beta}-,\;{\gamma}-CyDs)$ in aqueous solution and in solid phase was investigated by solubility method, measurement of partition coefficient, ultra-violet, circular dichroism, infrared spectroscopies, powder X-ray diffractometry and differential scanning calorimetry. Investigations were made to prepare inclusion complexes of TPA with ${\beta}-CyD$ in solid powdered form by coprecipitation, freeze-drying, spray-drying and co-pulverization methods. The coprecipitation, freeze-drying and spray-drying methods were successful in obtaining inclusion complexes. The results showed that the latter two methods might be originally superior to the former in obtaining powdered inclusion completes. Especially, it was shown by powder X-ray diffractometry that spray-dried ${\beta}-CyD$ alone, TPA-spray-dried ${\beta}-CyD$ physical mixture, and spray-dried $TPA-{\beta}-CyD$ complex were amorphous. The dissolution behaviours of $TPA-{\beta}-CyD$ systems prepared by above four methods were compared with those of TPA alone and $TPA-{\beta}-CyD$ physical mixture, and the rates of dissolution of TPA in pH 1.2 buffer were greatly enhanced by inclusion complexation and copulverization.

• Journal of Photoscience
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• v.9 no.3
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• pp.75-79
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• 2002

Solubility of carbon tetrachloride ($CCl_4$) in water increases appreciably in presence of $\beta$-cyclodextrin ($\beta$CD). $CCl_4$ is a very good quencher of 1-naphthol (1ROH) fluorescence. By studying the quenching of fluorescence of 1ROH included in $\beta$CD cavity, it was found that there is an increase in the availability of $CCl_4$ around $\beta$CD in the aqueous medium. This could help to rationalize the enhanced solubility of $CCl_4$.

• Journal of the Korean Society of Food Culture
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• v.16 no.4
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• pp.316-322
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• 2001

This study was performed to investigate flavor modification effects of ${\beta}-cyclodextrin$ $({\beta}-CD)$ inclusion complex on the flavor of Doenjang (Korean traditional fermented soy paste) with various substitution levels of 10, 20, and 30%. Water and protein contents of the substituted samples showed significantly lower values compared to those of control(p<0.05). Results of DSC(Differential Scanning Calorimetry) showed that significantly higher ${\Delta}H$ values (386.03 and 304.23) in the 20 and 30% substituted samples represented the stabilized internal cell structures(p<0.05). Internal structures observed with the scanning electronic microscope tended to be less rough and organized making even and ordered internal cell structures as the substitution levels were increased. Results of sensory evaluation showed significantly higher savory flavor and significantly lower bitter and astringent flavors with the substituted samples compared to those of control(p<0.05). Results from this study showed the substitutions of ${\beta}-CD$ could possibly modify unfavored flavors of Doenjang while keeping the unique, nutritional and functional properties when ${\beta}-CD$ was used as a flavor modifier.

• Archives of Pharmacal Research
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• v.18 no.1
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• pp.22-26
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• 1995

The solubility and dissolution rate of naproxen (NPX) complexed with 2-hydroxypropyl-.betha.-cyc-lodextrin (2-HP.betha.CD) using coprecipitation, evaporation, freeze-drying and kneading method were investigated. Solubility of NPX linearly increased (correlation cefficient, 0.995) as $2-HP\betaCD$ concentraction increased, resutling in $A_l$ type phase solubility curve. Inclusion complexes prepared by four different methods were compared by different methods were compared by dfferential scanning calorimetry(DSC). The NPX showed sharp endothemic peak around $156^{\circ}C$ but inclusion complexes by evaporation, freeze-drying and kneading method showed very broad peak without distinct phase transtion temperature. In contrast, inclusion complex prepared by coprecipitation method resulted in detectable peak around $156^{\circ}C$ which is similar to NPX, suggesting incoplete formation of indusion co plex. Dissolution rate of inclusion complexes prepared by evaporation, frezz-drying and kneding except coprecipitation method was largely enhanced in the simultaed gastric and intestinal fluid when compared to NPX powder and commercial $NA-XEN^\registered$tablet. However, about 65% of NPX in gstric fluid. in case of inclusion complex prepared by coprecipitation method, formation of inclusion complex appeared to be incoplete, resulting in no marked enhancement of dissolution rate. From these findings, inclusion complexes of poorly water-soluble NPX with $2-HP\betaCD$ were useful to increase soubility and dissolution rate, resting in enhancement of bioavailability and minimization of gastrointestinal toxicity of drug upon oral administration of inclusion complex.

• Archives of Pharmacal Research
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• v.10 no.2
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• pp.69-74
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• 1987

The characteristics of zipeprol-$\beta$-cyclodextrin system were studied by circular dichroism, competitive UV method and dialysis method. In this experiment, binding constants by competitive UV method, circular dichroism and dialysis method were 155 M$^{-1}$ 187 M$\^{-1}$/($\pm$ 5%) and 315 $^{-1}$, repectively. It shows that zipeprol forms 1:1 compelx with $\beta$-cyclodextrin by circular dichroism and 1:2 by dialysis method. pH profile shows that binding force seems to be a hydrophobic interaction. It is suggested that benzene ring be accomodated in the cavity of $\beta$-cyclodextrin.

• Journal of Photoscience
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• v.3 no.3
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• pp.153-158
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• 1996

The effects of $\alpha$- and $\beta$-cyclodextrins (CD) on the twisted intramolecular charge transfer (TICT) behavior of p-N,N'-dimethylaminobenzoic acid (DMABA) in buffered aqueous solution have been investigated by examining formation and decay behaviors of the TICT-typical dual fluorescence. The ratio of the TICT emission to the normal emission (I$_a$/I$_b$) increases linearly $\alpha$-CD concentration increases, while in the presence of $\beta$-CD it shows nonlinear dependences on the CD concentration. The analysis of the CD-dependent changes of the I$_a$/I$_b$ and absorption spectra demonstrates formation of 1:1 inclusion complexes between DMABA and CDs. The decay time of the normal emission (ca. 700 ps) is little affected by the formation of $\alpha$-CD inclusion complex, whereas it increases upto ca. 1.6 ns upon formation of $\beta$-CD inclusion complex. The TICT emission for the $\beta$-CD inclusion complex exhibits two decay components while it shows a single component for the $\alpha$-CD inclusion complex, indicating formation of one or two types of inclusion complex in the presence of $\alpha$-CD or $\beta$-CD, respectively. These results are attributed to the CD cavity size dependence on patterns of complexation between CDs and DMABA. The CD size dependences of the TICT fluorescence properties with the orientation of the guest molecule demonstrate that the specific hydrogen bonding between the carboxylic acid group and water plays an important role in the excited-state TICT.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.110-117
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• 2005

In this work, solid-state inclusion complex powders of itraconazole and $2-hydroxypropyl-{\beta}-cyclodextrin(HP-{\beta}-CD)$ were produced by a supercritical anti-solvent (SAS) process. In order to evaluate the degree of complexation, the thermal behavior of the microparticulate complexes was investigated using differential scanning calorimetry. The experimental results obtained for the solubility and dissolution rate of the microparticulate inclusion complexes in a buffer solution of pH 1.2 showed that the complexation of itraconazole with $HP-{\beta}-CD$ results in a significant increase in the solubility and dissolution rate of itraconazole. The particle size of the SAS-produced inclusion complexes was dramatically reduced ($<0.1-0.5{\mu}m$) compared with untreated itraconazole ($30-50{\mu}m$) and $HP-{\beta}-CD$ ($50-100{\mu}m$). The solubility of itraconazole was increased with the increase of pressure at a constant temperature to ca. $758.6{\mu}g/mL$ in an aqueous medium of pH 1.2. The dissolution rate of itraconazole was observed to be significantly improved and about 90% of itraconazole was found to be dissolved within 5-10 min.

• Clean Technology
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• v.19 no.3
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• pp.212-218
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• 2013

The microparticles of 2-hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta}$-CD) were prepared using aerosol solvent extraction system (ASES) by employing supercritical carbon dioxide as an antisolvent, The effects of various process parameters such as temperature, pressure, solution concentration and solution flow rate on the formation of HP-${\beta}$-CD microparticles were investigated. The HP-${\beta}$-CD microparticles prepared by the ASES process were observed to consist of agglomerates of nano-sized (50-200 nm) particles. When an aqueous solution of ethanol was used as a solvent for HP-${\beta}$-CD, the HP-${\beta}$-CD particles were found to be spherical in shape and to become larger as the water content increased. It was confirmed that the micronization of HP-${\beta}$-CD using the ASES process could enhance the inclusion efficiency of ibuprofen/HP-${\beta}$-CD complexes significantly.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.186-189
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• 1996

Neohesperidin dihydrochalcone(NHDC) is an intense sweetener with lingering aftertaste, which limits NHDC to use as a sweetener in food products. This study was conducted to examine the changes of teste quality of NHDC when using $\beta$-cyclodextrin($\beta$-CD) as a taste modifier. A series of $\beta$-CD(0.01%, 0.03%, 0.1%, 0.176%) was added to NHDC solution (100ppm) and the taste quality was evaluated by magnitude estimation. It was found that $\beta$-CD produced a significant effect in the reduction of aftertaste of NHDC(p<0.01) and sweetness as well.(p<0.001). Linear regression(log mean magnitude estimate versus $\beta$-CD concentration) analysis showed that the intensity of sweetness(n=-0.31) decreased more rapidly than that of aftertaste(m=-0.17). This result suggests the possibility that $\beta$-CD may form inclusion complex with NHDC, so that the hydrophobic portion is encapsulated in the cavity of $\beta$-CD and the carbohydrate moiety is oriented to the outside of the cavity. Or it may be that $\beta$-CD competes with the NHDC molecule for binding to the taste receptor, resulting in reduced perceived intensity.

• Journal of Pharmaceutical Investigation
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• v.20 no.3
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• pp.153-159
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• 1990

To increase the solubility of fentiazac which is used widely as a non-steroidal antiinflammatory drug, its inclusion complex and suppositories were prepared and studied. Inclusion complexes of fentiazac with ${\beta}-cyclodertin$ $({\beta}-CyD)$ were prepared by four diffrent methods; coprecipitation method, kneading method, solvent evaporation method, freeze drying method. Suppositories of $fentiazac/{\beta}-CyD$ with PEG 1500 and Witepsol H-15 were prepared by solvent evaporation method and freeze drying method. Inclusion complex formation of fentiazac with ${\beta}-CyD$ was ascertained by powder X-ray diffractometry, differential scanning calorimetry and IR spectroscopy. The dissolution rate of fentiazac from the inclusion complex increased in distilled water and KP 2nd disintegration test fluids (pH 6.8) but extemly decreased in KP 1st disintegration test fluid (pH 1.2). Inclusion complexes prepared by freeze drying method and solvent evaporation method were similar. Freeze drying method seemed to be suitable for preparation of complex with most higher dissolution rate but coprecipitation method seemed not to be suitable. The dissolution rate of fentiazac increased markedly by ${\beta}-CyD$ complexation. The release rates of suppositories increased in the following order. Complex prepared by freeze dying method in PEG 1500 > complex prepared by solvent evaporation method in PEG 1500 > fentiazac in PEG 1500 > complex prepared by freeze dying method in Witepsol H-15 > complex prepared by solvent evaporation method in Witepsol H-15 > fentiazac in Witepsol H-15.