The reflection of the texture of swollen polymer matrix on the release of incorporated substance

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Matej Pavli ◽  
Julijana Kristl ◽  
Andrej Dolenc ◽  
Alenka Zvonar ◽  
Franc Vrečer ◽  
...  
Keyword(s):  
Drug Release ◽  
Texture Analysis ◽  
Polymer Matrix ◽  
Free Water ◽  
Drug Dissolution ◽  
Water Molecules ◽  
Prolonged Release ◽  
Cellulose Ethers ◽  
Gel Structure ◽  
Gel Layer

AbstractOur aim was to investigate the texture of hydrated biopolymer matrices that are now being considered in the design of pharmaceutical controlled-release dosage forms, in order to determine their influence on the release of an active compound. Prolonged release of pentoxifylline, a highly soluble drug, is needed for once-daily administration to achieve its therapeutic effect. For this purpose, pentoxifylline was incorporated in a polymer matrix made of a combination of xanthan and locust bean gum (XLBG), both of which are of biotechnological origin. Different methods were used to investigate the interplay of the XLBG gel structure characteristics in the absence and presence of 200 mM CaCl2 on pentoxifylline release: drug-release studies, determination of swelling, erosion, and viscoelasticity of the gel, as well as its texture analysis and microscopic imaging. From the results obtained, the following conclusions can be drawn: the pentoxifylline release from XLBG matrices in water was prolonged for 24 h whereas from the control lactose formulation was completed within 30 min. The presence of Ca2+ ions in water resulted in faster pentoxifylline release, in spite of less swelling and erosion. However, the rheology, texture analysis and scanning electron microscopy revealed that in the presence of the Ca2+ ions the gel layer of the XLBG was more cohesive and thinner, as the attraction for water molecules was lower due to the condensation of counter-ions on the xanthan carboxylic-moieties, and consequently greater interpolymer interactions. Therefore, relatively larger amounts of free water molecules were available within the XLBG hydrogel in the presence of Ca2+, allowing faster drug dissolution and diffusion. Here, the presence of Ca2+ ions had a completely opposite effect on XLBG gel structure and drug release in comparison with other more investigated matrix polymers like alginate or non-ionic cellulose ethers. A firm matrix structure that is accompanied by low swelling and erosion cannot guarantee a more prolonged drug release.

scholarly journals The Correlation between Physical Crosslinking and Water-Soluble Drug Release from Chitosan-Based Microparticles

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 455
Author(s):  
Emilia Szymańska ◽  
Katarzyna Woś-Latosi ◽  
Julia Jacyna ◽  
Magdalena Dąbrowska ◽  
Joanna Potaś ◽  
...  
Keyword(s):  
Drug Release ◽  
Polymer Matrix ◽  
Drug Loading ◽  
Water Soluble ◽  
Dissolution Behavior ◽  
Complex Nature ◽  
Prolonged Release ◽  
Scanning Calorimetry ◽  
Burst Effect ◽  
The Impact

Microparticles containing water-soluble zidovudine were prepared by spray-drying using chitosan glutamate and beta-glycerophosphate as an ion crosslinker (CF). The Box–Behnken design was applied to optimize the microparticles in terms of their drug loading and release behavior. Physicochemical studies were undertaken to support the results from dissolution tests and to evaluate the impact of the crosslinking ratio on the microparticles’ characteristics. The zidovudine dissolution behavior had a complex nature which comprised two phases: an initial burst effect followed with a prolonged release stage. The initial drug release, which can be modulated by the crosslinking degree, was primarily governed by the dissolution of the drug crystals located on the microparticles’ surfaces. In turn, the further dissolution stage was related to the drug diffusion from the swollen polymer matrix and was found to correlate with the drug loading. Differential Scanning Calorimetry (DSC) studies revealed the partial incorporation of a non-crystallized drug within the polymer matrix, which correlated with the amount of CF. Although CF influenced the swelling capacity of chitosan glutamate microparticles, surprisingly a higher amount of CF did not impact the time required for 80% of the drug to be released markedly. The formulation with the lowest polymer:CF ratio, 3:1, was selected as optimal, providing satisfactory drug loading and displaying a moderate burst effect within the first 30 min of the study, followed with a prolonged drug release of up to 210 min.

Colon targeting oral matrix tablets of mesalamine: Design, development and invitro evaluation

2020 ◽  
Vol 10 (1) ◽  
pp. 18-27
Author(s):  
Audinarayana N ◽  
Anala Srinivasulu ◽  
Vellore Sruthikumari ◽  
Likitha ◽  
Ananda Deepak V
Keyword(s):  
Drug Release ◽  
Guar Gum ◽  
Stability Study ◽  
Matrix Tablets ◽  
Drug Dissolution ◽  
Matrix Tablet ◽  
Cellulose Acetate Phthalate ◽  
Design Development ◽  
Release Pattern ◽  
The Matrix

The principle in this present research is to formulate Mesalamine containing colon targeted tablets by using different polymers and evaluate the effect of different polymers in drug release pattern. The matrix tablets of Mesalamine are formulated by polysaccharides based polymers like Cellulose acetate phthalate (CAP), Ethyl cellulose (EC), Guar gum (GG) and Xanthan gum (XG) which protects the drug to release in Stomach and Small Intestine. The invitro drug dissolution investigation of F2 (GG and XG) Matrix tablet was controlled by swelling into a viscous gel in colonic pH, which have been accomplished as the best tablet. The optimized tablet F2 was found to be stable in stability study (short term) with reproducible evaluation data, which also shows the highest swelling index, increased viscosity in colonic pH. The drug release pattern from the F2 formulation follows swelling and erosion behavior. From the data it show that F2 tablets suitable for providing colon targeted drug delivery.

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.

Formulation and Evaluation of Nelfinavir Extended Release Trilayer Matrix Tablets by Design of Experiment

2018 ◽  
Vol 11 (5) ◽  
pp. 4259-4268
Author(s):  
Nirmala Rangu ◽  
Gande Suresh
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Hydroxypropyl Methylcellulose ◽  
Magnesium Stearate ◽  
Zero Order ◽  
Matrix Tablets ◽  
Drug Dissolution ◽  
Crystalline Cellulose ◽  
Dissolution Profile ◽  
Release Formulation

The present study was aimed to develop once-daily controlled release trilayer matrix tablets of nelfinavir to achieve zero-order drug release for sustained plasma concentration. Nelfinavir trilayer matrix tablets were prepared by direct compression method and consisted of middle active layer with different grades of hydroxypropyl methylcellulose (HPMC), PVP (Polyvinyl Pyrrolidine) K-30 and MCC (Micro Crystalline Cellulose). Barrier layers were prepared with Polyox WSR-303, Xanthan gum, microcrystalline cellulose and magnesium stearate. Based on the evaluation parameters, drug dissolution profile and release drug kinetics DF8 were found to be optimized formulation. The developed drug delivery system provided prolonged drug release rates over a period of 24 h. The release profile of the optimized formulation (DF8) was described by the zero-order and best fitted to Higuchi model. FT-IR studies confirmed that there were no chemical interactions between drug and excipients used in the formulation. These results indicate that the approach used could lead to a successful development of a controlled release formulation of nelfinavir in the management of AIDS.

Mesoporous Silica Molecular Sieve based Nanocarriers: Transpiring Drug Dissolution Research

2017 ◽  
Vol 23 (3) ◽  
pp. 467-480 ◽  
Author(s):  
Satyanarayan Pattnaik ◽  
Kamla Pathak
Keyword(s):  
Drug Release ◽  
Mesoporous Silica ◽  
Molecular Sieves ◽  
Release Kinetics ◽  
Drug Loading ◽  
Scale Up ◽  
Water Soluble ◽  
Drug Dissolution ◽  
Water Soluble Drugs ◽  
Loading Methods

Background: Improvement of oral bioavailability through enhancement of dissolution for poorly soluble drugs has been a very promising approach. Recently, mesoporous silica based molecular sieves have demonstrated excellent properties to enhance the dissolution velocity of poorly water-soluble drugs. Description: Current research in this area is focused on investigating the factors influencing the drug release from these carriers, the kinetics of drug release and manufacturing approaches to scale-up production for commercial manufacture. Conclusion: This comprehensive review provides an overview of different methods adopted for synthesis of mesoporous materials, influence of processing factors on properties of these materials and drug loading methods. The drug release kinetics from mesoporous silica systems, the manufacturability and stability of these formulations are reviewed. Finally, the safety and biocompatibility issues related to these silica based materials are discussed.

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.

Temperature and concentration dependence of equivalent conductivity in Ca(NO3)2-CaI2-H2O system

1980 ◽  
Vol 45 (6) ◽  
pp. 1639-1645 ◽  
Author(s):  
Jindřich Novák ◽  
Ivo Sláma
Keyword(s):  
Linear Function ◽  
Concentration Dependence ◽  
Mole Fraction ◽  
Constant Temperature ◽  
Salt Concentration ◽  
Free Water ◽  
Water Molecules ◽  
Equivalent Conductivity ◽  
Calcium Salts ◽  
Fraction I

The dependence of the equivalent conductivity on the temperature and composition of the Ca(NO3)2-CaI2-H2O system was studied. The ionic fraction [I-]/([I-] + [NO-3]) was changed from 0.1 to 0.5, the mole fraction of calcium salts (assumed in anhydrous form in the presence of free water molecules) was 0.075-0.200. The equivalent conductivity was found to be a linear function of the ionic fraction at constant temperature and salt concentration.

scholarly journals 3D Printed Microfluidic Devices for Drug Release Assays

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 13
Author(s):  
Benzion Amoyav ◽  
Yoel Goldstein ◽  
Eliana Steinberg ◽  
Ofra Benny
Keyword(s):  
3D Printing ◽  
Drug Release ◽  
Particle Production ◽  
Cost Effective ◽  
Drug Dissolution ◽  
Cytotoxicity Test ◽  
High Durability ◽  
One Step ◽  
Cost Effective Alternative ◽  
Multiple Recycling

Microfluidics research for various applications, including drug delivery, cell-based assays and biomedical research has grown exponentially. Despite this technology’s enormous potential, drawbacks include the need for multistep fabrication, typically with lithography. We present a one-step fabrication process of a microfluidic chip for drug dissolution assays based on a 3D printing technology. Doxorubicin porous and non-porous microspheres, with a mean diameter of 250µm, were fabricated using a conventional “batch” or microfluidic method, based on an optimized solid-in-oil-in-water protocol. Microspheres fabricated with microfluidics system exhibited higher encapsulation efficiency and drug content as compared with batch formulations. We determined drug release profiles of microspheres in varying pH conditions using two distinct dissolution devices that differed in their mechanical barrier structures. The release profile of the “V” shape barrier was similar to that of the dialysis sac test and differed from the “basket” barrier design. Importantly, a cytotoxicity test confirmed biocompatibility of the printed resin. Finally, the chip exhibited high durability and stability, enabling multiple recycling sessions. We show how the combination of microfluidics and 3D printing can reduce costs and time, providing an efficient platform for particle production while offering a feasible cost-effective alternative to clean-room facility polydimethylsiloxane-based chip microfabrication.

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