scholarly journals Fast Drug Release Using Rotational Motion of Magnetic Gel Beads

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Tetsu Mitsumata ◽  
Yusuke Kakiuchi ◽  
Jun-Ichi Takimoto
Keyword(s):  
Drug Release ◽  
Magnetic Fields ◽  
Rotational Motion ◽  
Phosphate Buffer Solution ◽  
Fickian Diffusion ◽  
Buffer Solution ◽  
Time Profiles ◽  
Gel Beads ◽  
High Elasticity ◽  
Fast Release

Accelerated drug release has been achieved by means of the fast rotation of magnetic gel beads. The magnetic gel bead consists of sodium alginate crosslinked by calcium chlorides, which contains barium ferrite of ferrimagnetic particles, and ketoprofen as a drug. The bead underwent rotational motion in response to rotational magnetic fields. In the case of bead without rotation, the amount of drug release into a phosphate buffer solution obeyed non-Fickian diffusion. The spontaneous drug release reached a saturation value of 0.90 mg at 25 minutes, which corresponds to 92% of the perfect release. The drug release was accelerated with increasing the rotation speed. The shortest time achieving the perfect release was approximately 3 minutes, which corresponds to 1/8 of the case without rotation. Simultaneous with the fast release, the bead collapsed probably due to the strong water flow surrounding the bead. The beads with high elasticity were hard to collapse and the fast release was not observed. Hence, the fast release of ketoprofen is triggered by the collapse of beads. Photographs of the collapse of beads, time profiles of the drug release, and a pulsatile release modulated by magnetic fields were presented.

scholarly journals EFFECTS OF VISCOELASTIC PROPERTIES AND HYDRATION KINETIC ON DRUG RELEASE FROM THE TABLET OF DICLOFENAC SODIUM BASED ON POLY (SODIUM ACRYLATE)-GRAFTED-GELLAN MATRIX

2019 ◽  
Vol 9 (4-A) ◽  
pp. 1-8
Author(s):  
Gouranga Nandi
Keyword(s):  
Drug Release ◽  
Phosphate Buffer ◽  
Diclofenac Sodium ◽  
Phosphate Buffer Solution ◽  
Fickian Diffusion ◽  
Sodium Acrylate ◽  
Release Mechanism ◽  
Drug Release Profile ◽  
Buffer Solution ◽  
Solution Ph

Investigation of the effects of viscoelasticity and hydration kinetic on the drug release behavior from the poly (sodium acrylate)-grafted-gellan matrix (PSAc-g-GG) was the main objective of this study. At first, poly (acrylic acid)-grafted-gellan was treated with 0.05M NaOH to obtain poly (sodium acrylate)-grafted-gellan followed by its purification and subsequent lyophilicity study and viscoelastic study on PSAc-g-GG with different degree of grafting. The study revealed that the degree of grafting greatly affects the viscoelastic and rheologic characteristics of the copolymer, which further affect the drug release profile from the polymeric matrix. The  copolymer with highest grafting (626.3%) exhibited much higher starting % strain (17.79%), stress (53.7 Pa) for structural breakdown at Gꞌ = Gꞌꞌ (214.4 Pa), higher storage modulus (G’), much greater values of complex viscosity (11.5 Pa.s) and cross-over point (Gꞌ = Gꞌꞌ =271.65 Pa) compared to that of the batch of copolymer with lower grafting. The water uptake index (%WE) was found to be directly proportional to the percentage grafting (%G), whereas the batches with higher grafting  revealed lower initial swelling rate representing its inversely proportional relation to %grafting in case of 0.1N HCl acid. Equilibrium swelling and hydration were also found to be proportional to % grafting.  The similar effect was observed in phosphate buffer solution (pH 6.8) with an exception that the degree of the swelling parameters obtained from phosphate buffer was very much greater compared to that found in 0.1N HCl. PSAc-g-GG exhibited extended drug release over a period of 10 hours with the drug release mechanism based on Case-1 Fickian diffusion or square root of time kinetic. The study also exhibited the usefulness of viscoelastic and swelling study in order to identify the effects of the degree of grafting on the drug release.

Drug Release Behaviors of a pH/Temperature Sensitive Hydrogel Bead with Core-Shelled Structure

2010 ◽  
Vol 148-149 ◽  
pp. 1427-1430 ◽  
Author(s):  
Kui Lin Deng ◽  
Li Rong Dong ◽  
Yu E Shi ◽  
Yu Bo Gou ◽  
Qian Li ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Phosphate Buffer Solution ◽  
Temperature Sensitive ◽  
Buffer Solution ◽  
Hydrogel Bead ◽  
The Core ◽  
Drug Delivery Carrier ◽  
Temperature Sensitive Hydrogel ◽  
Biomedical Fields

As a drug delivery carrier, a novel pH/temperature sensitive bead (pTSB) with core-shelled structure from poly(N-acryloylglycine) (PAG), copoly(N-acryloylglycine methyl este and N-acryloylglycine ethyl ester) was prepared by two steps. In pH=7.4 phosphate buffer solution (PBS), the cumulative release amount of indomethacin loaded in the pTSB was about 60.1 % within 500 mins, but this value only reached to 22.3 % in pH=2.1 PBS. The release behaviors of indomethacin from pTSB also exhibited a remarkable dependence on PAG content in the core. Additionally, the release rate of indomethacin was much faster at 18 oC than that at 37 oC due to the temperature sensitivity of poly(N-acryloylglycinates). The experimental results indicate that pTSB seems to have a potential application in the drug release system controlled via pH or temperature in the biomedical fields.

Drug-loaded ultrafine poly(vinyl alcohol) fibre mats prepared by electrospinning

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Chunxue Zhang ◽  
Xiaoyan Yuan ◽  
Lili Wu ◽  
Jing Sheng
Keyword(s):  
Drug Release ◽  
Photoelectron Spectroscopy ◽  
Vinyl Alcohol ◽  
Phosphate Buffer Solution ◽  
Poly Vinyl Alcohol ◽  
High Porosity ◽  
Buffer Solution ◽  
Drug Molecules ◽  
Alcohol Fibre

AbstractSubmicron poly(vinyl alcohol) (PVA) fibre mats embedded with Aspirin and bovine serum albumin (BSA) were prepared by electrospinning of their aqueous solutions. Fibre morphology was investigated by scanning electron microscopy. The composition of the fibre mats was characterized by Fourier transform IR spectroscopy and X-ray photoelectron spectroscopy. The in vitro drug release was investigated by immersing the fibre mats in phosphate buffer solution at 37°C. Results indicated that the morphology of fibre mats was influenced by the amount of drug, and more beaded and irregularly shaped fibres were found with increasing drug amounts. There were drug molecules distributed on the surface of the PVA fibres. Studies of in vitro drug release showed that both Aspirin and BSA were released more quickly from PVA fibre mats than from PVA films because of the large surface area and high porosity of the fibre mats.

scholarly journals Carbon-Based Magnetic Nanocarrier for Controlled Drug Release: A Green Synthesis Approach

2018 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Jessica Oliveira ◽  
Raquel Rodrigues ◽  
Lillian Barros ◽  
Isabel Ferreira ◽  
Luís Marchesi ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Magnetic Nanoparticles ◽  
Drug Release ◽  
Phosphate Buffer ◽  
Colloidal Stability ◽  
Ph Dependence ◽  
Phosphate Buffer Solution ◽  
Controlled Drug Release ◽  
Buffer Solution ◽  
Carbon Based

In this study, hydrophilic magnetic nanoparticles were synthesized by green routes using a methanolic extract of Rubus ulmifolius Schott flowers. The prepared magnetic nanoparticles were coated with carbon-based shell for drug delivery application. The nanocomposites were further chemically functionalized with nitric acid and, sequentially, with Pluronic® F68 (CMNPs-plur) to enhance their colloidal stability. The resulting material was dispersed in phosphate buffer solution at pH 7.4 to study the Doxorubicin loading. After shaking for 48 h, 99.13% of the drug was loaded by the nanocomposites. Subsequently, the drug release was studied in different working phosphate buffer solutions (i.e., PB pH 4.5, pH 6.0 and pH 7.4) to determine the efficiency of the synthesized material for drug delivery as pH-dependent drug nanocarrier. The results have shown a drug release quantity 18% higher in mimicking tumor environment than in the physiological one. Therefore, this study demonstrates the ability of CMNPs-plur to release a drug with pH dependence, which could be used in the future for the treatment of cancer "in situ" by means of controlled drug release.

Synthesis, Characterization and In Vitro Drug Release of Melphalan Magnetic Microspheres

2013 ◽  
Vol 22 ◽  
pp. 31-40
Author(s):  
Jin Qiao Xu ◽  
Hai Xing Xu ◽  
Zubad Newaz ◽  
Ran Li ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drug Release ◽  
Drug Loading ◽  
Phosphate Buffer Solution ◽  
Magnetic Microspheres ◽  
Targeted Chemotherapy ◽  
Buffer Solution ◽  
Magnetization Measurements ◽  
Co Precipitation

A new method of reversible association of melphalan (MEL) to magnetic Fe3O4 nanoparticles preparing MEL magnetic microspheres was developed for magnetically targeted chemotherapy. The efficacy of this approach was evaluated in terms of encapsulation efficiency (EE), drug loading content (DLC), delivery properties and cytotoxicity in vitro. Magnetic Fe3O4 nanoparticles were synthesized by co-precipitation methods and characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and magnetization measurements. The MEL magnetic microspheres were obtained through emulsion cross-linking method and characterized by FTIR, magnetization measurements and scan electron microscopy (SEM). The EE and DLC were determined using a Spectro Vision DB-18805 spectrophotometer. The MEL magnetic microspheres showed good EE values, between 60.6% and 75.6%, as well as good DLC values, between 16.7% and 32.2%, and the magnetic properties were not significantly affected by incorporation of the drug. The in vitro drug release study was carried out in phosphate buffer solution (PBS), simulating physiologic body fluid conditions at 37o C with pH = 7.4. The release profiles showed an initial fast release rate, which decreased as time progressed; about 60% of the drug was released in the first 4 h, and about 78.23 % had been released after 24 h. The results indicated that the prepared magnetic microspheres may be useful for potential applications of MEL for magnetically targeted chemotherapy.

scholarly journals Azobenzene functionalized mesoporous AlMCM-41-type support for drug release applications

2014 ◽  
Vol 12 (7) ◽  
pp. 788-795 ◽  
Author(s):  
Raul-Augustin Mitran ◽  
Daniela Berger ◽  
Laura Băjenaru ◽  
Silviu Năstase ◽  
Cristian Andronescu ◽  
...  
Keyword(s):  
Drug Release ◽  
Phosphate Buffer Solution ◽  
Fold Increase ◽  
Cytostatic Drug ◽  
Buffer Solution ◽  
Significant Toxicity ◽  
Murine Fibroblast ◽  
Mesoporous Support ◽  
Reduced Toxicity ◽  
Silane Precursor

AbstractA light-responsive material, aminoazobenzene functionalized AlMCM-41, was synthesized and characterized in order to be used as carrier for drug delivery devices. The light-induced hydrophobic-hydrophilic switching effect of azobenzene functionalized aluminosilicate was exploited in the release of irinotecan, a cytostatic drug. To obtain the functionalized mesoporous support, an azobenzene-silane precursor was synthesized by coupling 4-(4′-aminophenylazo) benzoic acid with 3-aminopropyl triethoxysilane and further grafted on AlMCM-41. The azobenzene functionalized mesoporous aluminosilicate exhibited no significant toxicity towards murine fibroblast healthy cells and a reduced toxicity towards murine melanocyte cells. The hybrid materials obtained by loading irinotecan on AlMCM-41 (wt. 35.4%) and aminoazobenzene modified AlMCM-41 (wt. 22%), respectively were characterized by FTIR, small and wide angle XRD, N2 adsorption-desorption isotherms and DSC analyses. A two-fold increase in the drug release rate from azobenzene functionalized aluminosilicate in phosphate buffer solution under UV irradiation was noticed, as compared with dark conditions. Moreover, the azobenzene functionalization of AlMCM-41 significantly increased the irinotecan delivery rate and total cumulative release in comparison with the pristine AlMCM-41 in similar conditions.

scholarly journals Calcium Alginate-Neusilin US2 Nanocomposite Microbeads for Oral Sustained Drug Delivery of Poor Water Soluble Drug Aceclofenac Sodium

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Manjanna Kolammanahalli Mallappa ◽  
Rajesh Kesarla ◽  
Shivakumar Banakar
Keyword(s):  
Drug Release ◽  
Calcium Alginate ◽  
Crosslinking Agent ◽  
Phosphate Buffer Solution ◽  
Water Soluble ◽  
Gelling Agent ◽  
Simulated Gastric Fluid ◽  
Buffer Solution ◽  
Simulated Intestinal Fluid ◽  
Neusilin Us2

The aim of the present study was to formulate and investigate the calcium alginate- (CA-) Neusilin US2 nanocomposite microbeads containing preconcentrate of aceclofenac sodium (ACF-Na) liquid microemulsion (L-ME) for enhancement of oral bioavailability. The preconcentrate L-ME is prepared by using Labrafac PG, Labrasol, and Span 80 as oil, surfactant, and cosurfactant, respectively. The solid CA nanocomposite microbeads of L-ME prepared by microemulsification internal gelation technique using sodium alginate (SA) gelling agent, Neusilin US2 as adsorbent, and calcium chloride as crosslinking agent. L-ME has good thermodynamic stability; globule size was found to be 32.4 nm with polydispersity index 0.219 and −6.32 mV zeta potential. No significant interactions of excipients, drug in the formulations observed by FT-IR, DSC and XPRD. The concentration of SA and Neusilin US2 influences the flow properties, mean particle size, mechanical strength, drug entrapment efficiency, and percentage of drug release. All the formulations show minimum drug release in simulated gastric fluid (SGF) pH 1.2 for initial 2 h, maximum drug release in pH 6.8 phosphate buffer solution (PBS) at 6 h, followed by sustaining in simulated intestinal fluid (SIF) of pH 7.4 up to 12 h. The interaction of SA with Neusilin US2 creates a thick thixotropic gel network structure which acts as barrier to control the release of drug in the alkaline pH environment. Neusilin US2 is a novel filler used to convert L-ME into solid nanocomposite microbeads to enhance dissolution rate of poor water soluble drugs sustaining the drug release for prolonged period of time.

Synthesis of N-Carboxymethyl Chitosan Beads for Controlled Drug Delivery Applications

2006 ◽  
Vol 514-516 ◽  
pp. 1015-1019 ◽  
Author(s):  
Rangasamy Jayakumar ◽  
Rui L. Reis ◽  
João F. Mano
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Phosphate Buffer Solution ◽  
Controlled Drug Delivery ◽  
Gastric Fluid ◽  
Carboxymethyl Chitosan ◽  
Water Soluble ◽  
Buffer Solution ◽  
Chitosan Beads

N-Carboxymethyl chitosan (NCMC) is a water soluble derivative of chitosan. The NCMC beads were prepared by using ionotropic gelation process with the counter polyanion tripolyphoshate at pH 4.0 and characterized by scanning electron microscopy. The swelling behavior of the beads at different time intervals was monitored at different pH conditions. The in vitro drug release behavior in various pH solutions was studied using indomethacin as a model drug with two different concentrations (0.3 and 0.6% w/w). The release percent of indomethacin from NCMC beads was found to increase with increasing of pH in phosphate buffer solution medium due to the ionization of carboxymethyl group and high solubility of indomethacin in alkaline medium. These results indicated that the NCMC beads are useful for controlled drug delivery systems through oral administration by avoiding the drug release in the highly acidic gastric fluid region of the stomach.

scholarly journals Olanzapine Loaded Nanostructured Lipid Carriers via High Shear Homogenization and Ultrasonication

2021 ◽  
Vol 89 (2) ◽  
pp. 25
Author(s):  
Adejumoke Lara Ajiboye ◽  
Uttom Nandi ◽  
Martin Galli ◽  
Vivek Trivedi
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Drug Loading ◽  
Particle Diameter ◽  
Phosphate Buffer Solution ◽  
Nanostructured Lipid Carriers ◽  
High Shear ◽  
Buffer Solution ◽  
High Shear Homogenization

The aim of this study was to understand the effect of high shear homogenization (HSH) and ultrasonication (US) on the physicochemical properties of blank and olanzapine loaded nanostructured lipid carriers (NLCs) along with their drug loading potential and drug release profiles from formulated particles. NLCs were prepared with different ratios of Compritol and Miglyol as the solid and liquid lipids, respectively, under changing HSH and US times between 0 to 15 minutes. The surfactants (Poloxamer 188 (P188) and tween 80) and the drug content was kept constant in all formulations. The prepared NLCs were evaluated for particle size, polydispersity index, zeta potential, drug crystallinity and chemical interactions between lipids and OLZ. The in-vitro drug release was performed using dialysis tube method in phosphate buffer solution (PBS) at pH 7.4. The formulated NLCs were negatively charged, spherically shaped and monodisperse, with particle sizes ranging from 112 to 191 nm. There was a significant influence of US time on the preparation of NLCs in comparison to HSH, where a significant reduction in the mean particle diameter was seen after 5 min of sonication. An increase of Miglyol content in NLCs led to an increase in particle size. In general, application of US led to decrease in particle size after HSH but an increase in particle diameter of low Miglyol containing preparation was also observed with longer sonication time. OLZ was successfully encapsulated in the NLCs and a total release of 89% was achieved in 24 hours in PBS at pH 7.4.

scholarly journals Determining the Optimal Conditions for the Production by Supercritical CO2 of Biodegradable PLGA Foams for the Controlled Release of Rutin as a Medical Treatment

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1645
Author(s):  
Diego Valor ◽  
Antonio Montes ◽  
Marilia Monteiro ◽  
Ignacio García-Casas ◽  
Clara Pereyra ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Mercury Intrusion Porosimetry ◽  
Phosphate Buffer Solution ◽  
Polymer Foam ◽  
Expansion Factor ◽  
Buffer Solution ◽  
Scanning Calorimetry ◽  
High Pressure And Temperature ◽  
Supercritical Foaming

Poly(D,L,-lactide-co-glycolide) (PLGA) foam samples impregnated with rutin were successfully produced by supercritical foaming processes. A number of parameters such as pressure (80–200 bar), temperature (35–55 °C), depressurization rate (5–100 bar/min), ratio lactide:glycolide of the poly(D,L,-lactide-co-glycolide) (50:50 and 75:25) were studied to determine their effect on the expansion factor and on the glass transition temperature of the polymer foams and their consequences on the release profile of the rutin entrapped in them. The impregnated foams were characterized by scanning electron microscopy, differential scanning calorimetry, and mercury intrusion porosimetry. A greater impregnation of rutin into the polymer foam pores was observed as pressure was increased. The release of rutin in a phosphate buffer solution was investigated. The controlled release tests confirmed that the modification of certain variables would result in considerable differences in the drug release profiles. Thus, five-day drug release periods were achieved under high pressure and temperature while the depressurization rate remained low.

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