The Influence of Cyclodextrin and pH on the Solubility of Ketoprofen

2012 ◽  
Vol 506 ◽  
pp. 433-436 ◽  
Author(s):  
W. Samprasit ◽  
Theerasak Rojanarata ◽  
Prasert Akkaramongkolporn ◽  
Tanasait Ngawhirunpat ◽  
Praneet Opanasopit
Keyword(s):  
Aqueous Solution ◽  
Stability Constant ◽  
Zeta Potential ◽  
Solubility Diagram ◽  
Phase Solubility ◽  
Combined Approach ◽  
Cyclodextrin Complexation ◽  
Cyclodextrin Cavity ◽  
Phase Solubility Diagram ◽  
Apparent Stability

Cyclodextrin complexation and pH adjustments have been reported as useful tools to increase the solubility of drug. The aim of this study was to investigate the influence of both cyclodextrin and pH on the overall solubility of ketoprofen. β-cyclodextrin (β-CD) and hydroxypropyl β-cyclodextrin (HP-β-CD) were used for the preparation of inclusion complex by shaking method in aqueous solution at pH 2, 5, 7 and 10. It was found that the solubility of ketoprofen significantly increased with increasing pH and cyclodextrin concentration, showing AL type phase solubility diagram. However, the apparent stability constant of complex (KC) was found to decrease with increasing pH due to the decreased affinity of ionized drug to cyclodextrin cavity. The ionization of ketoprofen increased when the pH was raised, corresponding with its higher zeta potential. The result indicated that the solubility of ketoprofen could be improved by using a combined approach of pH adjustments and complexation with cyclodextrin. Moreover, the unionized drug that was formed by pH adjustments interacted with cyclodextrin more strongly than the ionized drug.

scholarly journals Soluble 1:1 complexes and insoluble 3:2 complexes – Understanding the phase-solubility diagram of hydrocortisone and γ-cyclodextrin

2017 ◽  
Vol 531 (2) ◽  
pp. 504-511 ◽  
Author(s):  
Christian Schönbeck ◽  
Tobias L. Madsen ◽  
Günther H. Peters ◽  
René Holm ◽  
Thorsteinn Loftsson
Keyword(s):  
Solubility Diagram ◽  
Phase Solubility ◽  
Phase Solubility Diagram

Elucidation of the complexation mechanism between (+)-usnic acid and cyclodextrins studied by isothermal titration calorimetry and phase-solubility diagram experiments

2009 ◽  
Vol 22 (3) ◽  
pp. 232-241 ◽  
Author(s):  
Freimar Segura-Sanchez ◽  
Kawthar Bouchemal ◽  
Geneviève Lebas ◽  
Christine Vauthier ◽  
Néréide S. Santos-Magalhaes ◽  
...  
Keyword(s):  
Isothermal Titration Calorimetry ◽  
Usnic Acid ◽  
Solubility Diagram ◽  
Titration Calorimetry ◽  
Phase Solubility ◽  
Complexation Mechanism ◽  
Phase Solubility Diagram

scholarly journals Molecular solubilization of fullerene C60 in water by γ-cyclodextrin thioethers

2012 ◽  
Vol 8 ◽  
pp. 1644-1651 ◽  
Author(s):  
Hai Ming Wang ◽  
Gerhard Wenz
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Equilibrium State ◽  
Solubility Diagram ◽  
Fullerene C60 ◽  
Phase Solubility ◽  
Particle Sizes ◽  
Organic Cosolvents ◽  
Phase Solubility Diagram

Various hydrophilic γ-cyclodextrin (CD) thioethers, containing neutral or ionic side arms were found to form molecular disperse solutions of C60 in water reaching concentrations of 15 mg/L. Equilibrium state was approached after seven days without the use of organic cosolvents. The 1:2 stoichiometry of the C60/γ-CD thioether complexes was demonstrated by a parabolic phase-solubility diagram. In contrast, native γ-CD forms nanoparticles with C60. Particle sizes of C60 were determined by dynamic light scattering.

Oral Bioavailability Enhancement of Amisulpride: Complexation and its Pharmacokinetics and Pharmacodynamics Evaluations

2020 ◽  
Vol 13 (2) ◽  
pp. 132-144
Author(s):  
Prajapati Jagruti B. ◽  
Sawant Krutika K. ◽  
Bhramanand Dubey
Keyword(s):  
Complex Formation ◽  
Inclusion Complex ◽  
Oral Bioavailability ◽  
Water Solubility ◽  
Solubility Diagram ◽  
Phase Solubility ◽  
Linear Type ◽  
Market Product ◽  
Pure Drug ◽  
Phase Solubility Diagram

Background: Many CNS drugs have low bioavailability due to their poor water solubility of extensive first-pass metabolism and hence have less effectiveness. Objective: The present study aims to enhance the solubility and oral bioavailability of poorly watersoluble antipsychotic drug Amisulpride (AMS) through complexation with 2-hydroxypropyl β- cyclodextrin (HPβCD). It has slow and erratic absorption after oral administration. Methods: This report describes the study of the phase solubility diagram, preparation of the inclusion complex and tablet of prepared inclusion complex, characterization of the physico-chemical properties of the inclusion complex and tablet. Results: In-vitro study (100 % drug release in 15 minutes), and in-vivo study of an AL-type (linear type) phase solubility diagram indicated a complex of AMS-HP-β-CD with the constant complex formation of 13245 M−1 at 37°C. The complex formation was confirmed by DSC, IR, and X-ray diffraction. The extent of absorption of the complex was determined in rats and was compared with that of pure drug and the market product. The peak plasma concentration of pure drug was 30.05 ± 1.3 ng/ml (Cmax) at 60 ± 3 min, whereas with the market product the value was 54.85 ± 1.2 ng/ml at 40 ± 1 min and with AMS-HPβCD inclusion complex the value was 79.01 ± 1.5 ng/ml. The AUCtot of the pure drug was 2980.34±3.6, the market product was 7238.73±2.9 and of the inclusion complex was 11871.1±2.8. Conclusion: Pharmacodynamic studies in mice showed improved effectiveness of drug compared to pure drug. The oral bioavailability of AMS was improved from 48% to 78%.

scholarly journals Preparation and in vitro Evaluation of Inclusion Complexes of Nelfinavir with Chemically Modified ?-cyclodextrins

2013 ◽  
Vol 11 (2) ◽  
pp. 107-116 ◽  
Author(s):  
Shivanand Hiremath ◽  
Ganesh Godge
Keyword(s):  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Solubility Diagram ◽  
Aqueous Solubility ◽  
Water Soluble ◽  
Phase Solubility ◽  
Ir Study ◽  
Order Complexes ◽  
Phase Solubility Diagram

Nelfinavir is a poorly water-soluble antiretroviral drug with relatively low bioavailability. In the present study, the practically insoluble drug, nelfinavir (NFV) and its inclusion complexes with hydroxypropyl-?-cyclodextrin (HP-?-CD) were investigated to improve the aqueous solubility and the dissolution rate of the drug, thus enhancing its bioavailability. The phase solubility diagram with HP-?-CD was classified as AL-type at all temperatures investigated, indicating the formation of higher order complexes. The apparent complexation constants (K1:1) calculated from phase solubility diagram were 145.49, 188.45 and 255.54 M-1 at 25, 37 and 45 ± 0.5°C, respectively. Aqueous solubility and dissolution studies indicated that the dissolution rates were remarkably increased; this could be mainly attributed to the improved solubility and dissolution associated with inclusion complex between drug and HP- ? -CD. Absence of endothermic and characteristic diffraction peaks corresponding to NFV was observed for the inclusion complex in DSC and PXRD. FT-IR study indicated that the presence of intermolecular hydrogen bonds between NFV and HP-?-CD in inclusion complex, resulting in the formation of amorphous form. DOI: http://dx.doi.org/10.3329/dujps.v11i2.14558 Dhaka Univ. J. Pharm. Sci. 11(2): 107-116, 2012 (December)

Influence of β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin on Enhancement of Solubility and Dissolution of Isradipine

2017 ◽  
Vol 10 (3) ◽  
pp. 3752-3757
Author(s):  
Narendar D ◽  
Ettireddy S
Keyword(s):  
Inclusion Complex ◽  
Dissolution Rate ◽  
Solid Dispersions ◽  
Physical Stability ◽  
Molecular Complexes ◽  
In Vitro Dissolution ◽  
Molar Ratio ◽  
Phase Solubility ◽  
Cyclodextrin Complexation

The content of this investigation was to study the influence of β-cyclodextrin and hydroxy propyl-β-cyclodextrin complexation on enhancement of solubility and dissolution rate of isradipine. Based on preliminary phase solubility studies, solid complexes prepared by freeze drying method in 1:1 molar ratio were selected and characterized by DSC for confirmation of complex formation. Prepared solid dispersions were evaluated for drug content, solubility and in vitro dissolution. The physical stability of optimized formulation was studied at refrigerated and room temperature for 2 months. Solid state characterization of optimized complex performed by DSC and XRD studies.  Dissolution rate of isradipine was increased compared with pure drug and more with HP-β-CD inclusion complex than β-CD. DSC and XRD analyzes that drug was in amorphous form, when the drug was incorporated as isradipine β-CD and HP-β-CD inclusion complex. Stability studies resulted in low or no variations in the percentage of complexation efficiency suggesting good stability of molecular complexes. The results conclusively demonstrated that the enhancement of solubility and dissolution rate of isradipine by drug-cyclodextrin complexation was achieved.   

scholarly journals Evaluation of N-Alkyl-bis-o-aminobenzamide Receptors for the Determination and Separation of Metal Ions by Fluorescence, UV-Visible Spectrometry and Zeta Potential

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1737 ◽  
Author(s):  
Marisela Martinez-Quiroz ◽  
Xiomara E. Aguilar-Martinez ◽  
Mercedes T. Oropeza-Guzman ◽  
Ricardo Valdez ◽  
Eduardo A. Lopez-Maldonado
Keyword(s):  
Aqueous Solution ◽  
Zeta Potential ◽  
Metal Ions ◽  
Environmental Concern ◽  
Separation Of Metal Ions ◽  
Complexing Capacity ◽  
Alkyl Groups ◽  
Molecular Fluorescence ◽  
Uv Visible ◽  
Phase Sensor

This paper presents the synthesis and evaluation of physicochemical behavior of a new series of N-alkyl-bis-o-aminobenzamides (BOABs) in aqueous solution. The study was targeted to the complexing capacity of five metal ions (Fe2+, Cu2+, Cd2+, Hg2+ and Pb2+) of environmental concern as the medullar principle of a liquid phase sensor for its application in the determination of these metal ions due to its versatility of use. Molecular fluorescence, UV-visible and Zeta potential were measured for five BOABs and the effect of alkyl groups with different central chain length (n = 3, 4, 6, 8 and 10) on physicochemical performance determined. The results have shown that these derivatives present higher sensibility and selectivity for Cu2+ even in the presence of the other metal ions. An additional application test was done adding a pectin (0.1 wt %) solution to the BOAB-Cu+2 complex to obtain a precipitate (flocs) as a potential selective separation process of Cu from aqueous solution. The solid was then lyophilized and analyzed by SEM-EDS, the images showed spheric forms containing Cu+2 with diameter of approximately of 8 μm and 30 wt %.

N-ACYL SUBSTITUTED PHENYLHYDROXYLAMINES: THE EFFECT OF RADICAL CHANGE ON ANALYTICAL BEHAVIOR

1957 ◽  
Vol 35 (12) ◽  
pp. 1454-1460 ◽  
Author(s):  
C. A. Armour ◽  
D. E. Ryan
Keyword(s):  
Aqueous Solution ◽  
Stability Constant ◽  
Radical Change ◽  
Spectrophotometric Study ◽  
Iron Complex ◽  
Membered Ring ◽  
Analytical Reagents ◽  
Colorimetric Reagent ◽  
Analytical Behavior

The synthesis of a number of N-acyl substituted phenylhydroxylamines is outlined and the effect of the change in the nature of the acyl group on their usefulness as analytical reagents is described. Stability constant measurements in alcohol show an increase in stability with an increase in basicity of reagent regardless of the nature of the attached group; their ability to precipitate complexes from aqueous solution, however, is markedly dependent on the nature of the attached radical. A spectrophotometric study shows the existence of both a 1:1 and a 1:3 iron complex. A more sensitive colorimetric reagent results with an unsaturated five-membered ring as the attached grouping.

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