Tunability of Pore Diameter and Particle Size of Amorphous Microporous Silica for Diffusive Controlled Release of Drug Compounds

2007 ◽  
Vol 111 (36) ◽  
pp. 13404-13409 ◽  
Author(s):  
Caroline A. Aerts ◽  
Els Verraedt ◽  
Randy Mellaerts ◽  
Anouschka Depla ◽  
Patrick Augustijns ◽  
...  
Keyword(s):  
Particle Size ◽  
Controlled Release ◽  
Pore Diameter ◽  
Microporous Silica ◽  
Drug Compounds

Study of 5-Fluorouracil Loaded Chitosan Nanoparticles for Treatment of Skin Cancer

2020 ◽  
Vol 14 (3) ◽  
pp. 210-224
Author(s):  
Gayatri Patel ◽  
Bindu K.N. Yadav
Keyword(s):  
Particle Size ◽  
Controlled Release ◽  
Skin Cancer ◽  
Basal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Basal Cell ◽  
Chitosan Nanoparticles ◽  
Entrapment Efficiency ◽  
Fractional Factorial ◽  
Spherical Particles

Background: The purpose of this study was to formulate, characterize and in-vitro cytotoxicity of 5-Fluorouracil loaded controlled release nanoparticles for the treatment of skin cancer. The patents on nanoparticles (US8414926B1), (US61654404A), (WO2007150075A3) etc. helped in the selection polymers and method for the preparation of nanoparticles. Methods: In the present study nanoparticles were prepared by simple ionic gelation method using various concentrations of chitosan and sodium tripolyphosphate (TPP). Several process and formulation parameters were screened and optimized using 25-2 fractional factorial design. The prepared nanoparticles were evaluated for particle size, shape, charge, entrapment efficiency, crosslinking mechanism and drug release study. Results: The optimized 5-Fluorouracil loaded nanoparticle were found with particle size of of 320±2.1 nm, entrapment efficiency of 85.12%± 1.1% and Zeta potential of 29mv±1mv. Scanning electron microscopy and dynamic light scattering technique revealed spherical particles with uniform size. The invitro release profile showed controlled release up to 24 hr. Further study was carried using A375 basal cell carcinoma cell-line to elucidate the mechanism of its cytotoxicity by MTT assay. Conclusion: These results demonstrate that the possibility of delivering 5-Fluorouracil to skin with enhanced encapsulation efficiency indicating effectiveness of the formulation for treatment of basal cell carcinoma type of skin cancer.

Controlled Release Behaviors of Ketoprofen from Matrix Polymer of Chitosan and poly(ethylene glycol)

2013 ◽  
Vol 813 ◽  
pp. 399-402
Author(s):  
Chimsook Thitipha ◽  
Thitiphan Chimsook
Keyword(s):  
Particle Size ◽  
Controlled Release ◽  
Drug Release ◽  
Ethylene Glycol ◽  
Diffusion Method ◽  
Poly Ethylene Glycol ◽  
Matrix Polymer ◽  
Percentage Yield ◽  
Poly Ethylene ◽  
Composition Ratios

The aim of present work was to prepare floating microsphere of ketoprofen using matrix polymer of chitosan and poly (ethylene glycol) by solvent diffusion method. The floating microsphere of ketoprofen was prepared from matrix polymer of chitosan and poly (ethylene glycol) with various composition ratios and evaluated such as particle size, drug compatibility and drug release of microspheres. The scanning electron microscopy of microspheres confirmed their hollow structures with smooth surface. Formulation CPK 4 to CPK 6 exhibited the best controlled release pattern in ketoprofen. The concentration and size of poly (ethylene-glycol) affected the particle size, percentage yield and drug release of microspheres.

Controlled release of chlorhexidine from amorphous microporous silica

2010 ◽  
Vol 142 (1) ◽  
pp. 47-52 ◽  
Author(s):  
E. Verraedt ◽  
M. Pendela ◽  
E. Adams ◽  
J. Hoogmartens ◽  
J.A. Martens
Keyword(s):  
Controlled Release ◽  
Microporous Silica

scholarly journals PREPARATION AND EVALUATION OF CHITOSAN SODIUM ALGINATE CARBAMAZEPINE MICROSPHERES

2017 ◽  
Vol 10 (3) ◽  
pp. 271 ◽  
Author(s):  
Sreeja C Nair ◽  
Karthika Ramesh ◽  
Krishnapriya M ◽  
Asha Paul
Keyword(s):  
Drug Delivery ◽  
Particle Size ◽  
Controlled Release ◽  
Sodium Alginate ◽  
Physical Parameters ◽  
Effective Management ◽  
Release Drug ◽  
Conventional Drug ◽  
Preparation And Evaluation ◽  
Evaluation Parameters

ABSTRACTObjective: The objective behind our study is that a mucoadhesive rectal hydrogel chitosan sodium alginate carbamazepine (CBZ) microspheres forthe purpose of controlled release for the treatment of epilepsy to avoid the possible side effects.Methods: The study was conducted to formulate controlled release chitosan sodium alginate CBZ microspheres with the dispersion of CBZ into thenatural polymers chitosan and sodium alginate forming microspheres conducting along with their evaluation studies.Results: The formulated microspheres were subjected to various evaluation parameters, and all the physical parameters examined are within theacceptable limits. Further, the optimized microsphere formulation (CM5) was characterized. Hence, the developed optimized microsphere formulation(CM5) seems to be a viable substitute to conventional drug delivery system for the effective management of epilepsy.Conclusion: The prepared formulation also provides a desired CBZ loaded sodium alginate microspheres with the controlled release drug delivery.Keywords: Carbamazepine, Sodium alginate microspheres, Particle size.

scholarly journals PREPARATION, CHARACTERIZATION AND EVALUATION OF POLY (LACTIDE –CO –GLYCOLIDE) MICROSPHERES FOR THE CONTROLLED RELEASE OF ZIDOVUDINE

2017 ◽  
Vol 9 (12) ◽  
pp. 70 ◽  
Author(s):  
Seema Kohli ◽  
Abhisek Pal ◽  
Suchit Jain
Keyword(s):  
Particle Size ◽  
Controlled Release ◽  
Double Emulsion ◽  
Entrapment Efficiency ◽  
Diffusion Method ◽  
Average Particle ◽  
Plga Microspheres ◽  
Good Reproducibility ◽  
Solvent Diffusion ◽  
Emulsion Solvent Diffusion Method

Objective: The purpose of this research work was to develop and evaluate microspheres appropriate for controlled release of zidovudine (AZT).Methods: The AZT loaded polylactide-co-glycolide (PLGA) microspheres were prepared by W/O/O double emulsion solvent diffusion method. Compatibility of drug and polymer was studied by Fourier-transform infrared spectroscopy (FTIR). The influence of formulation factors (drug: polymer ratio, stirring speed, the concentration of surfactant) on particle size encapsulation efficiency and in vitro release characteristics of the microspheres was investigated. Release kinetics was studied and stability study was performed as per ICH guidelines.Results: Scanning electron microscopy (SEM) images show good reproducibility of microspheres from different batches. The average particle size was in the range of 216-306 μm. The drug-loaded microspheres showed 74.42±5.08% entrapment efficiency. The cumulative percentage released in phosphate Buffer solution (PBS) buffer was found to be 55.32±5.89 to 74.42±5.08 %. The highest regressions (0.981) were obtained for zero order kinetics followed by Higuchi (0.968) and first order (0.803).Conclusion: Microsphere prepared by double emulsion solvent diffusion method was investigated and the results revealed that 216-306 μm microsphere was successfully encapsulated in a polymer. FT-IR analysis, entrapment efficiency and SEM Studies revealed the good reproducibility from batch to batch. The microspheres were of an appropriate size and suitable for oral administration. Thus the current investigation show promising results of PLGA microspheres as a matrix for drug delivery and merit for In vivo studies for scale up the technology.

Novel amorphous microporous silica spheres for controlled release applications

2011 ◽  
Vol 100 (10) ◽  
pp. 4295-4301 ◽  
Author(s):  
Els Verraedt ◽  
Guy Van den Mooter ◽  
Johan A. Martens
Keyword(s):  
Controlled Release ◽  
Silica Spheres ◽  
Microporous Silica

Investigation into the Controlled-Release Kinetic Models of Rose Perfume in SBA-15 and KIT-6

2014 ◽  
Vol 955-959 ◽  
pp. 399-402
Author(s):  
Yi Feng Yu ◽  
Ai Bing Chen ◽  
Ting Ting Xing ◽  
Yun Hong Yu ◽  
Hai Jun Lv
Keyword(s):  
Controlled Release ◽  
Pore Diameter ◽  
Slow Release ◽  
Release Kinetic ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Release Agent ◽  
Release Data ◽  
Release Kinetic Models ◽  
New System

A new system for the controlled release of rose perfume is presented. Mesoporous SBA-15 and KIT-6 materials as controlled-release agent are synthesized via hydrothermal method. Rose perfume was introduced into the pores of SBA-15 and KIT-6 via the incipient wetness impregnation method. This silica reservoir maintained a slow release of rose perfume over more than 10h. Rose perfume release was controlled by configurational diffusion in the SBA-15 and KIT-6 pores having free diameters of less than 12 nm. The release of rose perfume was tuned by adapting pore diameter and temperature. By fitting the release data, the results show that the release actions of rose perfume in SBA-15 and KIT-6 are consistent with Korsmeyer-Peppas model and First-order’model respectively.

Fine-Grained Concrete with Nanodispersed Silica Additive

2020 ◽  
Vol 992 ◽  
pp. 156-161
Author(s):  
N.P. Lukuttsova ◽  
E.G. Borovik ◽  
D.A. Pehenko
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Pore Diameter ◽  
Fine Grained ◽  
Silica Concentration ◽  
Calcium Hydrosilicates ◽  
Additive Particle ◽  
Nanodispersed Silica ◽  
Silica Additive ◽  
Number Of Particles

The effect of the modifying nanodispersed silica (NS) additive, obtained by the polycondensation method, on the properties of fine-grained concrete (FGC) is studied. It is revealed that the dependence of the NS-additive particle size on its age is extreme. The maximum number of particles of up to 100 nm in the additive is observed at the age of 10 days, and then their number decreases. However, it affects the FGC strength little even after 30 days of the additive storage. It is established that the NS-additive could be most effectively used with 0.23% of an active silica concentration and pH 4.1 in combination with S-3. At that, the porosity declines from 17.5 to 12.9% and the pore diameter diminishes from 3.171 to 0.689 μm. It leads to an increase in the compressive strength by 2 times and a decrease in water absorption by 1.6 times as compared to the control composition without additives. An increase in the frost resistance of the modified fine-grained concrete to F250 is recorded; it occurs due to a decrease in porosity at portlandite binding with amorphous silica additives into low-basic calcium hydrosilicates.

scholarly journals Nanoporous smartPearls for dermal application – Identification of optimal silica types and a scalable production process as prerequisites for marketed products

2019 ◽  
Vol 10 ◽  
pp. 1666-1678 ◽  
Author(s):  
David Hespeler ◽  
Sanaa El Nomeiri ◽  
Jonas Kaltenbach ◽  
Rainer H Müller
Keyword(s):  
Particle Size ◽  
Production Process ◽  
Pore Diameter ◽  
Active Agent ◽  
Amorphous State ◽  
Silica Particles ◽  
Batch Size ◽  
Maximum Loading ◽  
Rotary Evaporator ◽  
Scalable Production

smartPearls are a dermal delivery system for poorly soluble active agents, consisting of nanoporous silica particles loaded with a long-term stable, amorphous active agent in its mesopores (2–50 nm). The amorphous state of the active agent is known to increase dermal bioavailability. For use in marketed products, optimal silica types were identified from commercially available, regulatory accepted silica. In addition, a scalable production process was demonstrated. The loading of the particles was performed by applying the immersion–evaporation method. The antioxidant rutin was used as a model active agent and ethanol was applied as the solvent. Various silica particles (Syloid®, Davisil®) differing in particle size (7–50 µm), pore diameter (3–25 nm) and pore volume (0.4–1.75 mL/g) were investigated regarding their ease of processing. The evaporation from the silica–ethanol suspensions was performed in a rotary evaporator. The finest powders were obtained with larger-sized silica. The maximum loading staying amorphous was achieved between 10% and 25% (w/w), depending on the silica type. A loading mechanism was also proposed. The most suitable processing occurred with the large-sized Syloid® XDP 3050 silica with a 50 µm particle size and a pore diameter of 25 nm, resulting in 18% (w/w) maximum loading. Based on a 10% (w/w) loading and the amorphous solubility of the active agent, for a 100 kg dermal formulation, about 500 g of loaded particles were required. This corresponds to production of 5 kg of loaded smartPearls for a formulation batch size of a ton. The production of 5 kg (i.e., about 25 L of solvent removal) can be industrially realized in a commercial 50 L rotary evaporator.

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