Ionotropically Gelled Bicontinuous Cubic Phase as a Matrix for Controlled Release

1993 ◽  
Vol 331 ◽  
Author(s):  
S. Puvvada ◽  
J. Naciri ◽  
B. R. Ratna
Keyword(s):  
Release Rate ◽  
Release Profile ◽  
Water Soluble ◽  
Cubic Phase ◽  
First Order ◽  
On Demand ◽  
Release Studies ◽  
Order Release ◽  
Bicontinuous Cubic ◽  
Soluble Polysaccharide

AbstractRelease studies from a lipid-based matrix, known as the bicontinuous cubic phase, are presented. This matrix consists of nano-sized pores within which various proteins and drugs can be dispersed and subsequently released to the exterior. To control the release rate, the aqueous pores of the cubic phase were gelled using sodium alginate, a water soluble polysaccharide. Studies show that the release rate is significantly lowered upon gelation and the first order release profile exhibited by the ungelled cubic phase is converted to a zeroorder linear profile. Further, it has been shown that the release trends can be reversed by degelation. This opens up the possibility of releasing large quantities of the protein when required (drugs on demand concept) by degelling the gelled samples.

Predicting the release profile of small molecules from within the ordered nanostructured lipidic bicontinuous cubic phase using translational diffusion coefficients determined by PFG-NMR

Nanoscale ◽  
2017 ◽  
Vol 9 (7) ◽  
pp. 2471-2478 ◽  
Author(s):  
Thomas G. Meikle ◽  
Shenggen Yao ◽  
Alexandru Zabara ◽  
Charlotte E. Conn ◽  
Calum J. Drummond ◽  
...  
Keyword(s):  
Small Molecules ◽  
Diffusion Coefficients ◽  
Translational Diffusion ◽  
Release Profile ◽  
Cubic Phase ◽  
Bicontinuous Cubic ◽  
Pfg Nmr

Encapsulation and Diffusion of Water-Soluble Dendrimers in a Bicontinuous Cubic Phase

Langmuir ◽  
2002 ◽  
Vol 18 (4) ◽  
pp. 1073-1076 ◽  
Author(s):  
Sang Won Jeong ◽  
Greger Orädd ◽  
Göran Lindblom
Keyword(s):  
Water Soluble ◽  
Cubic Phase ◽  
Bicontinuous Cubic ◽  
And Diffusion

Enhanced loading of water-soluble actives into bicontinuous cubic phase liquid crystals using cationic surfactants

2003 ◽  
Vol 260 (2) ◽  
pp. 404-413 ◽  
Author(s):  
Matthew L. Lynch ◽  
Akua Ofori-Boateng ◽  
Amanda Hippe ◽  
Kelly Kochvar ◽  
Patrick T. Spicer
Keyword(s):  
Liquid Crystals ◽  
Cationic Surfactants ◽  
Water Soluble ◽  
Cubic Phase ◽  
Bicontinuous Cubic ◽  
Phase Liquid

scholarly journals DEVELOPMENT OF NATURAL AND MODIFIED GUM BASED SUSTAINED-RELEASE FILM-COATED TABLETS CONTAINING POORLY WATER-SOLUBLE DRUG

2019 ◽  
pp. 266-271
Author(s):  
AJAY KUMAR SHUKLA ◽  
RAM SINGH BISHNOI ◽  
MANISH KUMAR ◽  
C.P. JAIN
Keyword(s):  
Sustained Release ◽  
Release Rate ◽  
In Vitro Release ◽  
Release Profile ◽  
Water Soluble ◽  
The Core ◽  
Water Soluble Drug ◽  
Poorly Water Soluble ◽  
Seed Gum ◽  
Poorly Water Soluble Drug

Objective: The objective of this work was to the development of natural and modified gum based sustained-release film-coated tablets containing poorly water-soluble drug. Methods: Tamarind seed gum (TSG), fenugreek seed gum (FSG), sodium trimetaphosphate, hydroxypropyl methylcellulose (HPMC), sodium alginate (SA), and nifedipine (NFD) were used. The core tablets of nifedipine were prepared and evaluated for weight, diameters, thickness, hardness, and disintegration time. The core tablets were coated using 2% w/v solution of TSG, MTSG, FSG, and MFSG. The in vitro release rate of drug from these coated tablets was compared with the release rate of drug from the tablets coated with 2% w/v of HPMC. Results: The tablets coated with natural and modified TSG sustained the release of the drug up to 11 h and 14 h, respectively, and natural and modified FSG sustained release the drug up to 9 h and 11 h, respectively. The tablets coated with HPMC sustained released the drug up to 15 h. The drug release profile of tablets coated with modified TSG was comparable to the release profile of tablets coated with HPMC. Conclusion: On the basis of the release profile, it is concluded that unmodified and modified TSG can be used as release rate-controlling membrane.

Triply-periodic nanostructures in surfactant, block copolymer, and biomembrane systems, and simulation of TEMs

1993 ◽  
Vol 51 ◽  
pp. 884-885
Author(s):  
David M. Anderson ◽  
Tomas Landh
Keyword(s):  
Liquid Crystalline ◽  
Diblock Copolymers ◽  
Cubic Phase ◽  
List Type ◽  
Interpenetrating Networks ◽  
Triply Periodic ◽  
Wide Range ◽  
Bicontinuous Cubic ◽  
Phase Liquid ◽  
Dividing Surface

First discovered in surfactant-water liquid crystalline systems, so-called ‘bicontinuous cubic phases’ have the property that hydropnilic and lipophilic microdomains form interpenetrating networks conforming to cubic lattices on the scale of nanometers. Later these same structures were found in star diblock copolymers, where the simultaneous continuity of elastomeric and glassy domains gives rise to unique physical properties. Today it is well-established that the symmetry and topology of such a morphology are accurately described by one of several triply-periodic minimal surfaces, and that the interface between hydrophilic and hydrophobic, or immiscible polymer, domains is described by a triply-periodic surface of constant, nonzero mean curvature. One example of such a dividing surface is shown in figure 5.The study of these structures has become of increasing importance in the past five years for two reasons:1)Bicontinuous cubic phase liquid crystals are now being polymerized to create microporous materials with monodispersed pores and readily functionalizable porewalls; figure 3 shows a TEM from a polymerized surfactant / methylmethacrylate / water cubic phase; and2)Compelling evidence has been found that these same morphologies describe biomembrane systems in a wide range of cells.

Molecular, rheological and physicochemical characterisation of puka gum, an arabinogalactan-protein extracted from the Meryta sinclairii tree

2020 ◽  
Author(s):  
MSM Wee ◽  
Ian Sims ◽  
KKT Goh ◽  
L Matia-Merino
Keyword(s):  
Hydrodynamic Radius ◽  
Average Molecular Weight ◽  
Gum Arabic ◽  
Water Soluble ◽  
Arabinogalactan Protein ◽  
Type Ii ◽  
Weight Average Molecular Weight ◽  
Soluble Polysaccharide ◽  
Physicochemical Characterisation ◽  
Increasing Temperature

© 2019 Elsevier Ltd A water-soluble polysaccharide (type II arabinogalactan-protein) extracted from the gum exudate of the native New Zealand puka tree (Meryta sinclairii), was characterised for its molecular, rheological and physicochemical properties. In 0.1 M NaCl, the weight average molecular weight (Mw) of puka gum is 5.9 × 106 Da with an RMS radius of 56 nm and z-average hydrodynamic radius of 79 nm. The intrinsic viscosity of the polysaccharide is 57 ml/g with a coil overlap concentration 15% w/w. Together, the shape factor, p, of 0.70 (exponent of RMS radius vs. hydrodynamic radius), Smidsrød-Haug's stiffness parameter B of 0.031 and Mark-Houwink exponent α of 0.375 indicate that the polysaccharide adopts a spherical conformation in solution, similar to gum arabic. The pKa is 1.8. The polysaccharide exhibits a Newtonian to shear-thinning behaviour from 0.2 to 25% w/w. Viscosity of the polysaccharide (1 s−1) decreases with decreasing concentration, increasing temperature, ionic strength, and at acidic pH.

Formulation Development and Characterization of controlled release core in cup matrix tablets of venlafaxine HCl

2020 ◽  
Vol 15 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Vikas Jhawat ◽  
Gandhi Sivaraman ◽  
Om Prakash Sunnapu ◽  
Ramya Krishna Nakkala ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Zero Order ◽  
Water Soluble ◽  
Matrix Tablets ◽  
Drug Dissolution ◽  
Crystalline Cellulose ◽  
Hydrophobic Polymers

Background: Venlafaxine HCl is a selective serotonin reuptake inhibitor which is given in the treatment of depression. The delivery of the drug at a controlled rate can be of great importance for prolonged effect. Objective: The objective was to prepare and optimize the controlled release core in cup matrix tablet of venlafaxine HCl using the combination of hydrophilic and hydrophobic polymers to prolong the effect with rate controlled drug release. Methods: The controlled release core in cup matrix tablets of venlafaxine HCl were prepared using HPMC K5, K4, K15, HCO, IPA, aerosol, magnesium sterate, hydrogenated castor oil and micro crystalline cellulose PVOK-900 using wet granulation technique. Total ten formulations with varying concentrations of polymers were prepared and evaluated for different physicochemical parameters such FTIR analysis for drug identification, In-vitro drug dissolution study was performed to evaluate the amount of drug release in 24 hrs, drug release kinetics study was performed to fit the data in zero order, first order, Hixson–crowell and Higuchi equation to determine the mechanism of drug release and stability studies for 3 months as observed. Results: The results of hardness, thickness, weight variation, friability and drug content study were in acceptable range for all formulations. Based on the In vitro dissolution profile, formulation F-9 was considered to be the optimized extending the release of 98.32% of drug up to 24 hrs. The data fitting study showed that the optimized formulation followed the zero order release rate kinetics and also compared with innovator product (flavix XR) showed better drug release profile. Conclusion: The core-in-cup technology has a potential to control the release rate of freely water soluble drugs for single administration per day by optimization with combined use of hydrophilic and hydrophobic polymers.

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