The fixation of a water-soluble drug in calcium-induced alginate gel beads and the release profiles from the vehicle.

1997 ◽  
Vol 12 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Yoshifumi Murata ◽  
Norie Katayana ◽  
Takashi Kajita ◽  
Etsuko Miyamoto ◽  
Susumu Kawashima
Keyword(s):  
Water Soluble ◽  
Alginate Gel ◽  
Gel Beads ◽  
Water Soluble Drug ◽  
Release Profiles

Preparation of Zinc Phthalocyanine-Calcium Alginate Gel Beads and its Use for Photocatalytic Oxidation Decolorization of Methyl Orange

2014 ◽  
Vol 809-810 ◽  
pp. 252-257
Author(s):  
Min Hong Xu ◽  
Hai Feng Chen ◽  
Guo Xiang Pan ◽  
Pei Song Tang
Keyword(s):  
Methyl Orange ◽  
Hydroxyl Radicals ◽  
Calcium Alginate ◽  
Photocatalytic Oxidation ◽  
Water Soluble ◽  
Zinc Phthalocyanine ◽  
Alginate Gel ◽  
Gel Beads ◽  
Calcium Alginate Gel ◽  
Free Hydroxyl

A supported photocatalyst zinc phthalocyanine-calcium alginate gel beads (Zn-MPc-SA) was prepared through the mixture of water-soluble zinc phthalocyanine (Zn-MPc) and sodium alginate was drip into 5% (w/v) CaCl2 solution. The Zn-MPc-SA was characterized by IR. Methyl orange was selected as a substrate to investigate the photocatalytic activity of Zn-MPc-SA. The results shown that: the surplus of methyl orange was 22.05% at the condition of pH 3, methyl orange 10mg/L 25mL, H2O2 50μL, Zn-MPc-SA 0.1460g and visible light irradiation for 3h. Zn-MPc-SA remains efficient in repetitive test cycles with no obvious degradation of catalytic activity. The reaction mechanism was likely to involve free hydroxyl radicals.

Behavior of alginate gel beads containing chitosan salt prepared with water-soluble vitamins

2002 ◽  
Vol 53 (2) ◽  
pp. 249-251 ◽  
Author(s):  
Yoshifumi Murata ◽  
Yukari Kontani ◽  
Hiroko Ohmae ◽  
Susumu Kawashima
Keyword(s):  
Water Soluble ◽  
Alginate Gel ◽  
Gel Beads ◽  
Chitosan Salt

scholarly journals Drug Release Profile from Calcium-Induced Alginate-Phosphate Composite Gel Beads

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Yoshifumi Murata ◽  
Youko Kodama ◽  
Takashi Isobe ◽  
Kyoko Kofuji ◽  
Susumu Kawashima
Keyword(s):  
Calcium Phosphate ◽  
Drug Release ◽  
Release Profile ◽  
Water Soluble ◽  
Drug Release Profile ◽  
Alginate Gel ◽  
Gel Beads ◽  
Composite Gel ◽  
The Matrix

Calcium-induced alginate-phosphate composite gel beads were prepared, and model drug release profiles were investigated in vitro. The formation of calcium phosphate in the alginate gel matrix was observed and did not affect the rheological properties of the hydrogel beads. X-ray diffraction patterns showed that the calcium phosphate does not exist in crystalline form in the matrix. The initial release amount and release rate of a water-soluble drug, diclofenac, from the alginate gel beads could be controlled by modifying the composition of the matrix with calcium phosphate. In contrast, the release profile was not affected by the modification for hydrocortisone, a drug only slightly soluble in water.

NANO-SIZED SOLID DISPERSION OF A POORLY WATER-SOLUBLE DRUG

2012 ◽  
pp. 31-35
Author(s):  
Truong Dinh Thao Tran ◽  
Ha Lien Phuong Tran ◽  
Nghia Khanh Tran ◽  
Van Toi Vo
Keyword(s):  
Drug Release ◽  
Droplet Size ◽  
Solid Dispersion ◽  
Water Soluble ◽  
Drug Dissolution ◽  
Dissolution Enhancement ◽  
Particle Size Reduction ◽  
Water Soluble Drug ◽  
Poorly Water Soluble ◽  
Poorly Water Soluble Drug

Purposes: Aims of this study are dissolution enhancement of a poorly water-soluble drug by nano-sized solid dispersion and investigation of machenism of drug release from the solid dispersion. A drug for osteoporosis treatment was used as the model drug in the study. Methods: melting method was used to prepare the solid dispersion. Drug dissolution rate was investigated at pH 1.2 and pH 6.8. Drug crystallinity was studied using differential scanning calorimetric and powder X-ray diffraction. In addition, droplet size and contact angle of drug were determined to elucidate mechanism of drug release. Results: Drug dissolution from the solid dispersion was significantly increased at pH 1.2 and pH 6.8 as compared to pure drug. Drug crystallinity was changed to partially amorphous. Also dissolution enhancement of drug was due to the improved wettability. The droplet size of drug was in the scale of nano-size when solid dispersion was dispersed in dissolution media. Conclusions: nano-sized solid dispersion in this research was a successful preparation to enhance bioavailability of a poorly water-soluble drug by mechanisms of crystal changes, particle size reduction and increase of wet property.

Enhancement of Solubility and Dissolution Rate of Poorly Water Soluble Drug using Cosolvency and Solid Dispersion Techniques

1970 ◽  
Vol 1 (4) ◽  
pp. 349-356
Author(s):  
Meka Lingam ◽  
Vobalaboina Venkateswarlu
Keyword(s):  
Dissolution Rate ◽  
Solid Dispersions ◽  
Physicochemical Characterization ◽  
Aqueous Solubility ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
Peg 400 ◽  
Water Soluble Drug ◽  
Poorly Water Soluble ◽  
Poorly Water Soluble Drug

The low aqueous solubility of celecoxib (CB) and thus its low bioavailability is a problem.    Thus, it is suggested to improve the solubility using cosolvency and solid dispersions techniques. Pure CB has solubility of 6.26±0.23µg/ml in water but increased solubility of CB was observed with increasing concentration of cosolvents like PEG 400, ethanol and propylene glycol. Highest solubility (791.06±15.57mg/ml) was observed with cosolvency technique containing the mixture of composition 10:80:10%v/v of water: PEG 400: ethanol. SDs with different polymers like PVP, PEG were prepared and subjected to physicochemical characterization using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), solubility and dissolution studies. These studies reveals that CB exists mainly in amorphous form in prepared solid dispersions of PVP, PEG4000 and PEG6000 further it can also be confirmed by solubility and dissolution rate studies. Solid dispersions of PV5 and PV9 have shown highest saturation solubility and dissolution rate

Improved Dissolution Properties of Ketoconazole through Application of Liquisolid Techniques

2015 ◽  
Vol 8 (4) ◽  
pp. 3053-3059
Author(s):  
Sudarshan Singh ◽  
S S Shyale ◽  
H G Sandip
Keyword(s):  
Drug Release ◽  
Immediate Release ◽  
Water Soluble ◽  
Wet Granulation ◽  
Wetting Properties ◽  
Enhanced Dissolution ◽  
Water Soluble Drug ◽  
Drug Concentrations ◽  
Water Soluble Drugs ◽  
Liquisolid Compacts

In present investigation liquisolid compact technique is investigated as a tool for enhanced dissolution of poorly water-soluble drug Ketoconazole. The liquisolid tablets were formulated with liquid medications, namely Propylene Glycol (PG) drug concentrations, 60% w/w, 70% w/w and 80% w/w. Avicel pH102 was used as a carrier material, Aerosil 200 as a coating material and Sodium starch glycollate as a super-disintegrant. Quality control tests, such as uniformity of tablet weight, uniformity of drug content, tablet hardness, friability test, disintegration and dissolution tests were performed to evaluate prepared tablets. For further confirmation of results the liquisolid compacts were evaluated by XRD and FTIR studies to prove that, solubility of Ketoconazole has been increased by liquisolid compact technique. From the results obtained, it was be speculated that such systems exhibit enhanced drug release profiles due to increased wetting properties and surface of drug available for dissolution. As liquisolid compacts demonstrated significantly higher drug release rates, in PG as compared to directly compressible tablets and conventional wet granulation, we lead to conclusion that it could be a promising strategy in improving the dissolution of poor water soluble drugs and formulating immediate release solid dosage forms.  

Nitrification and Autotrophic Denitrification in Calcium Alginate Beads

1987 ◽  
Vol 19 (1-2) ◽  
pp. 175-182 ◽  
Author(s):  
Z. Lewandowski ◽  
R. Bakke ◽  
W. G. Characklis
Keyword(s):  
Calcium Carbonate ◽  
Calcium Ions ◽  
Continuous Flow ◽  
Calcium Alginate ◽  
Microbial Respiration ◽  
Flow System ◽  
Alginate Beads ◽  
Alginate Gel ◽  
Gel Beads ◽  
Calcium Alginate Gel

Immobilization of nitrifiers and autotrophic denitrifiers (Thiobacillus denitrificans) within calcium alginate gel was demonstrated. Calcium carbonate reagent was immobilized along with bacteria as the stabilizing agent. Protons released as a result of microbial respiration reacted with calcium carbonate producing calcium ions which internally stabilized the calcium alginate gel. The microbially active gel beads were mechanically stable and active for three months in a continuous flow system without addition of calcium.

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