scholarly journals A Study on Solubilization of Poorly Soluble Drugs by Cyclodextrins and Micelles: Complexation and Binding Characteristics of Sulfamethoxazole and Trimethoprim

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Sinem Göktürk ◽  
Elif Çalışkan ◽  
R. Yeşim Talman ◽  
Umran Var
Keyword(s):  
Surface Tension ◽  
Complex Formation ◽  
Sodium Dodecyl ◽  
Binding Constants ◽  
Phase Solubility ◽  
Poorly Soluble Drugs ◽  
Binding Characteristics ◽  
Sds Micelles ◽  
Poorly Soluble ◽  
Triton X

The present study is focused on the characterization of solubilization of poorly soluble drugs, that is, sulfamethoxazole (SMX) and trimethoprim (TMP) by cyclodextrins (α-, β-, and γ-CDs) and anionic surfactant sodium dodecyl sulfate (SDS). The phase solubility diagrams drawn from UV spectral measurements are of theALtype and indicate an enhancement of SMX and TMP solubility in the presence of CDs. Complex formation tendency of TMP with CDs followed the order: γ-CD > β-CD > α-C. However, the complex formation constant values, for SMX-CD system yielded the different affinity and follow the order: β-CD > γ-CD > α-CD. With taking into consideration of solubilization capacity of SDS micelles, it has been found that the solubility enhancement of TMP is much higher than that of SMX in the presence of SDS micelles. The binding constants of SMX and TMP obtained from the Benesi-Hildebrand equation are also confirmed by the estimated surface properties of SDS, employing the surface tension measurements. In order to elucidate the solubilization characteristics the surface tension measurements were also performed for nonionic surfactant Triton X-100. Polarity of the microenvironment and probable location of SMX and TMP were also discussed in the presence of various organic solvents.

scholarly journals Co-solvation effect on the binding mode of the α-mangostin/β-cyclodextrin inclusion complex

2015 ◽  
Vol 11 ◽  
pp. 2306-2317 ◽  
Author(s):  
Chompoonut Rungnim ◽  
Sarunya Phunpee ◽  
Manaschai Kunaseth ◽  
Supawadee Namuangruk ◽  
Kanin Rungsardthong ◽  
...  
Keyword(s):  
Complex Formation ◽  
Inclusion Complex ◽  
Binding Mode ◽  
Phase Solubility ◽  
Binary Complex ◽  
Experimental Phase ◽  
Drug Molecules ◽  
Poorly Soluble ◽  
Experimental And Theoretical Studies ◽  
Solvent Complex

Cyclodextrins (CDs) have been extensively utilized as host molecules to enhance the solubility, stability and bioavailability of hydrophobic drug molecules through the formation of inclusion complexes. It was previously reported that the use of co-solvents in such studies may result in ternary (host:guest:co-solvent) complex formation. The objective of this work was to investigate the effect of ethanol as a co-solvent on the inclusion complex formation between α-mangostin (α-MGS) and β-CD, using both experimental and theoretical studies. Experimental phase-solubility studies were carried out in order to assess complex formation, with the mechanism of association being probed using a mathematical model. It was found that α-MGS was poorly soluble at low ethanol concentrations (0–10% v/v), but higher concentrations (10–40% v/v) resulted in better α-MGS solubility at all β-CD concentrations studied (0–10 mM). From the equilibrium constant calculation, the inclusion complex is still a binary complex (1:1), even in the presence of ethanol. The results from our theoretical study confirm that the binding mode is binary complex and the presence of ethanol as co-solvent enhances the solubility of α-MGS with some effects on the binding affinity with β-CD, depending on the concentration employed.

Surface tension studies of lauryl sulfobetaine - β-cyclodextrin and dodecyltrimethylammonium bromide - β-cyclodextrin inclusion complexes in aqueous solution

1999 ◽  
Vol 77 (7) ◽  
pp. 1208-1213 ◽  
Author(s):  
S Göktürk ◽  
M Mahramanlloglu ◽  
M Tunçay
Keyword(s):  
Surface Tension ◽  
Complex Formation ◽  
Inorganic Compounds ◽  
Binding Constants ◽  
Polar Group ◽  
Dodecyltrimethylammonium Bromide ◽  
Adsorption Model ◽  
Langmuir Adsorption ◽  
Polar Groups ◽  
Concentration Curves

β-Cyclodextrin (β-CD) is a cyclic oligosaccaride with an apolar cavity that shows a certain degree of selectivity in binding organic and inorganic compounds. Lauryl sulfobetaine (LSB) and dodecyltrimethylammonium bromide (DTAB), having the same hydrophobic and different polar groups are used in order to compare the influence of the polar group on complex formation with β-CD. The surface tension increased as β-CD is added to premicellar region of amphoteric (LSB) and cationic surfactant (DTAB) solutions. The relation between the surface tension and surfactant concentration can be expressed by the Szyszkowski equation, which combines the Langmuir adsorption model and the Gibbs equation. Binding constants were determined from the effect of added β-CD on the surface tension vs. concentration curves for LSB and DTAB aqueous solutions.Key words: β-cyclodextrin, surfactant, surface tension method, complex formation, binding constant.

scholarly journals Incorporation of Ag Nanoparticles Into Micelles. Stability Studies of Self-Organized Nanoparticlesmicelles Structures

2016 ◽  
Vol 39 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Przemysław Siejak ◽  
Krzysztof Polewski
Keyword(s):  
Ag Nanoparticles ◽  
Biological Membrane ◽  
Sodium Dodecyl ◽  
Ammonium Bromide ◽  
Physical Parameters ◽  
Aqueous Environment ◽  
Self Organized ◽  
Sds Micelles ◽  
Triton X ◽  
Kinetics Of

Abstract In this paper we present the results of measured physical parameters of self-organized structures consisting of hydrophobic functionalized silver nanoparticles and amphiphilic molecules capable of micelles formation. Those systems may be considered as simple models for transfer of nanoparticles through the biological membrane. Three different surfactants were used: negatively charged sodium dodecyl sulphite, SDS, neutral Triton X-100 and positively charged tetredodecyltrimethyl ammonium bromide, TTABr. We have found that hydrophobic functionalized Ag nanoparticles are encapsulated in neutral Triton X-100 micelles with a diameter of 10 nm without significant change in the size of the micelles. The efficiency of encapsulation of Ag by SDS micelles is lower compared to Triron X-100 and no incorporation of Ag nanoparticles into TTABr occurs. Obtained results indicate that in aqueous environment ionic properties of molecules creating micelles and concentration ratios between components determine the efficiency and kinetics of two competitive processes association or aggregation of nanoparticles and encapsulation of Ag nanoparticles within micelles.

Fluorescence Probe Studies of Anthracene and 9-Methylanthracene in Detergent Micelles

1987 ◽  
Vol 40 (5) ◽  
pp. 851 ◽  
Author(s):  
E Blatt
Keyword(s):  
Steady State ◽  
Fluorescence Probe ◽  
Photophysical Properties ◽  
Equilibrium Constants ◽  
Sodium Dodecyl ◽  
Site Occupancy ◽  
Time Resolved ◽  
Aromatic Molecules ◽  
Sds Micelles ◽  
Triton X

The photophysical properties of anthracene and 9-methylanthracene have been investigated in a variety of solvents and the resulting information used to interpret data after incorporation of the two fluorophores into aqueous solutions comprising Triton X-100, cetyltrimethylammonium bromide (ctab) or sodium dodecyl sulfate (sds) micelles. The fluorescence probe methods used to elucidate micellar properties such as microviscosity , micropolarity, and the permeability of the micelle/water interface to aromatic molecules and ions, included steady-state polarization, time-resolved anisotropy and steady-state and lifetime quenching techniques. NN- Dimethylaniline (dma) and I-ions were shown to partition into Triton X-100 micelles with partition coefficients, Kp, of about 70 and 51, respectively. Excimer formation between dma and the two probes was not observed in Triton X-100 micelles, these results indicating high micropolarities (E ≈30) and microviscosities ; from polarization and anisotropy measurements the microviscosity was in the range 60-156 cP . In contrast, excited-state complexation was observed in ctab and sds. For anthracene in ctab, triplex formation occurred with an equilibrium constant, Kc, of 137 dm3 mol-l. Weak ground-state complexation between I- and the two probes was also observed in Triton X-100 and ctab micelles with equilibrium constants, Kc, in the range 0.36-9.6 dm3 mol-l. The importance of probe characterization is highlighted by the results in sds where multiple-site occupancy occurred.

SOLUBILIZATION AND PARTIAL CHARACTERIZATION OF HUMAN AND PORCINE THYROTROPHIN RECEPTORS

1978 ◽  
Vol 78 (1) ◽  
pp. 89-102 ◽  
Author(s):  
P. J. D. DAWES ◽  
V. B. PETERSEN ◽  
B. REES SMITH ◽  
R. HALL
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Binding Activity ◽  
Human Thyroid ◽  
Scatchard Analysis ◽  
Binding Characteristics ◽  
Approximate Molecular Weight ◽  
Membrane Bound ◽  
Triton X

Thyrotrophin (TSH) receptors have been extracted from human and porcine thyroid membranes by treatment with Triton X-100.125I-Labelled bovine TSH was used to monitor receptor activity. Analysis by gel filtration and electrophoresis on acrylamide gels containing sodium dodecyl sulphate suggested that Triton extracts of human thyroid membranes contained TSH receptors with a molecular weight in the region of 50 000 closely associated with Triton micelles of approximate molecular weight 300 000. Isoelectric focusing studies indicated that the Triton-solubilized TSH binding activity had an isoelectric point of pH 4–4·5. The soluble TSH receptors were heat-labile, showed optimum TSH binding at pH 7·4 and reduced hormone binding at high ionic strength. The TSH binding characteristics of membrane-bound and solubilized human TSH receptors were similar and both preparations gave curved Scatchard plots. Solubilized porcine TSH receptors appeared to have a similar molecular weight to the human receptors and were also closely associated with Triton micelles of approximate molecular weight 300 000. Scatchard analysis of TSH binding to membrane-bound or solubilized porcine TSH receptors gave approximately linear plots with association constants of 2·8 ± 0·95 (s.e.m.) × 109 and 1·7 ± 0·27 × 1091/mol respectively. Comparison of the binding capacities of the solubilized and membrane-bound porcine receptors indicated that the 0·5% Triton extracts contained 40% of the original TSH binding activity and that this was present at a concentration of 25 ng/ml.

Technological Advancements in Oral Films

2019 ◽  
Vol 9 (01) ◽  
pp. 15-20
Author(s):  
B Pandey ◽  
A B Khan
Keyword(s):  
3D Printing ◽  
Historical Background ◽  
Poorly Soluble Drugs ◽  
Modern Approach ◽  
Poorly Soluble ◽  
Critical Process Parameters ◽  
Biopharmaceutical Properties ◽  
Oral Films ◽  
Hot Melt ◽  
Modern Technologies

The aim of the review was to explore the necessity, advantages and different techniques of oral films for enhancing solubility of poorly soluble drugs with an emphasis on the newer, state-of the art technologies, such as 3D printing and hot-melt extrusion (HME). The historical background of oral films is presented along with the regularly used techniques. The modern approach of quality-by-design (QbD) is unravelled, identifying appropriate critical process parameters (CPP) and applied to oral films. A section is devoted modern technologies such as 3D printing and HME of oral films. Oral films are innovative formulations by which poorly soluble drugs have been founds to give positive results in enhancing their solubility and dissolution characteristics. With modern sophisticated techniques, precise mass production of oral films has been given a thrust. Oral films have better patient compliance, improved biopharmaceutical properties, improved efficacy, and better safety. By applying QbD and implementation of modern technologies the newer generation of oral films are yielding promising results

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

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