Concentration Of Ethyl Cellulose Research Articles

Formulation and Evaluation of Erythromycin Estolate Loaded Drug Balls

The purpose of research work was to develop and optimize drug balls of erythromycin estolate for oral mucosal delivery of drug for fast delivery of drug and better bio-availability with the aim to treatment of whooping cough with also additional advantages over the traditional dosage forms such as suspension and tablets which takes too much time for release of drug but drug balls release mucoadhesive liquid which shows fast drug release, better bioavailability, avoid hepatic first pass effect and fast action. Sodium alginate based drug balls containing erythromycin estolate were prepared by specific method. Sodium alginate, ethyl cellulose were selected on the basis of formulation of drug balls, mucoadhesive force, In-vitro drug release. A 32 factorial design was employed for preparation of drug balls wherein the concentration of sodium alginate, concentration of ethyl cellulose were selected as independent variables while in vitro drug release and percentage permeation were the dependent variables. Drug balls were evaluated with respect to the percentage mucoadhesion, drug content, invitro drug release and permeation studies. F4 formulation was optimized with mucoadhesive force, %permeation efficiency and In-vitro drug release. Drug balls were characterized by FTIR and DSC study. Stability study revealed that the formulation was found to be stable.

Microencapsulation and Its Characteristics and Applications and Manufacturing of Clarithromycin Microcapsules with Mixed Membrane

In this paper, the definition, characteristics, applications, wall materials and main preparation methods of microcapsules were described in details. At the same time, the mixed membrane microcapsules were prepared by solvent evaporation method with clarithromycin as model drug, ethyl cellulose and hydroxypropyl methyl cellulose as membrane materials. The optimal preparation conditions were explored, and the slow and controlled release properties of the mixed membrane microcapsules were investigated. The optimal preparation conditions of clarithromycin microcapsules were as following: the concentration of membrane material was 3%, the concentration of ethyl cellulose / hydroxypropyl methyl cellulose was 6:1-7:1, the dosage was 2:1-3:1, the concentration of SDS was 0.1%, the concentration of PVA was 1.0%, and the oil-water ratio was 1:8．

Rheological and rheo-birefringence features of semidilute ethyl cellulose dispersions under steady shear flow.

We have conducted comprehensive rheological and rheo-birefringence characterizations of a series of semidilute ethyl cellulose (EC)/α-terpineol dispersions under steady shear flow. The EC dispersions investigated have commonly been utilized as a binder agent in fabricating metal/metal-oxide pastes for a number of industrial applications, and were recently demonstrated to foster nearly monodisperse spherical aggregates under dilute conditions. Herein, semidilute EC dispersions are shown to exhibit rheological features practically no different from those known for standard entangled polymer solutions. The corresponding rheo-birefringence responses, however, reveal microstructural features that are reminiscent of general colloidal systems. The steady-state feature reveals a universal stress-birefringence relationship at various EC concentrations, along with a common critical stress (∼200 Pa) at which the EC network breaks into smaller clusters. The transient feature displays prominent and long-persisting periodic oscillations that have previously been observed only for nearly monodisperse rod-like colloids or liquid crystals. The overall findings shed new light on the role of EC serving as a commonplace polymer binder in industry and, from a scientific perspective, raise interesting questions related to the characteristic rheological and microstructural features of general polymer dispersions in overlapped regimes.

Stabilization of Ethyl‐Cellulose Oleogel Network Using Lauric Acid

AbstractThe use of oleogels in a wide range of applications requires a broad diversity of gel properties tailored for each purpose. The current research explores the combination of ethyl‐cellulose (EC) with lauric acid (LA), at different ratios with an emphasis to explore each component contribution and function in the gel structure and properties. The results suggest that oleogel physical properties strongly depend on the EC concentration. A transition from antagonistic to synergistic behavior between EC and LA with respect to the mechanical properties is observed above 4 wt% polymer. This behavior is seen in all LA concentrations, suggesting that the main effect arises from the EC while the LA acts as a stabilizer. In addition, LA reduces EC gelation temperature from approximately 140 °C to 79–101 °C, depending on the EC concentration, suggesting a ‘plasticizing’ effect. The recovery ability of EC oleogel after large amplitude deformation is improved from 16% to 34% due to the LA crystalline nature. LA crystal structure is not affected by EC concentration; however its crystallization temperature shifts to a lower temperature.Practical Applications: These results provide a broad overview of the composition‐function relation obtained while combining EC with LA.

Two-step process for synthesizing wheat-like silver nanoparticles by using facile wet-chemical method

Wheat-like silver nanoparticles (AgNPs) have been facilely synthesized by using two-step reduction method. The initial AgNPs are reduced from silver nitrate in the first step. Effects of ethyl cellulose concentration on the structure and morphology evolution of AgNPs are systematically investigated in the second step. With increasing the concentrations of ethyl cellulose, the AgNPs evolves from cauliflower-like particles to wheat-like species via a transitional shape of slender particles. The trade-off between oxidation of nitric acid and reduction of L-ascorbic acid under the induction of ethyl cellulose dispersant modifies the morphology of AgNPs, contributing to forming various shapes. The phase structure of synthesized AgNPs remains crystalline and independent of ethyl cellulose concentration. Our works indicate that such a wet-chemical method provides an easy-to-do approach for preparing AgNPs with specific shapes.

Development and in-vitro characterization of tiropramide tablets having immediate- and extended release layers

Purpose: The objective of this study was to explore the feasibility of developing of Tiropramide, bilayer tabletusing an immediate- and extended-release formulation. Method: After rheological performance of drug-excipientsmixture, Tiropramide HCl bilayer tablets were prepared by wet granulation method. FTIR analysis was performed toelucidate the compatibility behavior of drug and excipients. Effect of these varying concentrations of EthylCellulose (EC) and Hydroxy Propyl Methyl Cellulose (HPMC) were observed on the sustained release pattern of thematrices. Dissolution was performed by using 0.1N HCl and phosphate buffer pH 7.2 as medium at 37.0 ±0.5 ºC,while the stirring speed was set at 50RPM. The bilayer tablets were stored under conditions 40±2oC temperature and 75±5% humidity for stability testing. Results: It was observed that as the quantity of polymers (HPMC or EC)increases the sustained release effect also increases. It was obvious from these models that drug release form bilayer tablets followed the zero order model and Higuchi square root model and the drug release mechanism was diffusion and erosion. The polymers-drug combination was compatible in bilayer tablets before and during stability testing. Conclusion: Bilayer tablet of Tiropramide can be developed successfully in which one layer provides immediate release while the other prolongs the drug release.

DEVELOPMENT OF TAMOXIFEN CITRATE PELLETS BY HOT-MELT EXTRUSION FOR IMMEDIATE RELEASE: STUDY OF EFFECT OF VARIABLES

Objective: Objective of the study was to develop tamoxifen citrate immediate release pellets by hot-melt extrusion (HME) and to study the effect of various formulation and process variables.
 Methods: Pellets were prepared by HME technique. Effect of various parameters such as the concentration of ethylcellulose, PEG 6000, croscarmellose sodium, and spheronization speed were studied by using Central Composite Design. Pellets were evaluated for theoretical yield (%), mean pellet size (mm), sphericity (pellips), friability (%), porosity (%), mechanical crushing force (n), and dissolution efficiency. Optimized formulation was studied for compatibility study using IR, DSC, and XRD, SEM, In vitro drug release. In vitro Cell Cytotoxicity and Viability Assay were carried out using MCF-7 (human breast cancer cells) by MTT assay.
 Results: Results showed that a variable such as the amount of Methyl Cellulose, PEG 6000 and Spheronization speed showed positive correlation and amount of Croscarmellose sodium showed a negative correlation with dependent variables. Optimized formulation showed Korsmeyer Peppas model as a mechanism of drug release. Value of n was found to be in between 0.77+0.04, which reveals that, release mechanism of the drug as non-Fickian transport (0.45<n<0.89). MTT results of MCF-7 cells showed that optimized immediate release pellets have maximum cytotoxicity at 80 µg/ml.
 Conclusion: Study concluded that HME method and materials i.e. PEG 6000 and methylcellulose can effectively use to get immediate release of tamoxifen citrate so as to increase dissolution rate and cytotoxic effect.

Astaxanthin encapsulation in ethyl cellulose carriers by continuous supercritical emulsions extraction: A study on particle size, encapsulation efficiency, release profile and antioxidant activity

Supercritical emulsions extraction (SEE) technology was used to encapsulate astaxanthin (AXT) in ethyl cellulose (EC). The operating parameters were 8 MPa and 311 K with an L/G ratio of 0.1 (CO2 flow rate of 1.4 kg/h). Several emulsion formulations were tested, fixing the oil-water ratio at 20:80 (ethyl acetate/water) and varying EC concentration in the oily phase from 1.0–2.5% mass and the surfactant amount in the water phase from 0.1 to 0.6% mass. Both parameters influenced carriers morphology, size and distribution; a correlation between the EC amount in oily phase and its dynamic viscosity was proposed to explain the droplets/carriers size variation observed. Carriers aggregation was monitored at surfactant concentration higher than 0.3% mass. The best emulsion formulation was obtained using 1.0% mass of EC in the oily phase and 0.1% mass of surfactant in the water phase; in these conditions spherical nanocarriers with unwrinkled and smooth surface were obtained with a size of 242 nm and Poly Dispersity Index of 0.16. EC mass recovery was of 90%. Higher carrier mean size of 363 nm (Poly Disperity Index of 0.31) was measured when AXT was encapsulated in the same conditions, achieving an encapsulation efficiency of 84%. The carriers were loaded with 21 mg/g of AXT and showed an excellent antioxidant capacity, measured as Trolox equivalent (Trolox equivalent per kg of pure AXT), and equivalent to 3900 M Trolox. In vitro release profiles obtained in a simulated intestinal fluid (SIF) at pH 7.2 and 310 K, showed a release of 70% of the total encapsulated AXT after 10 h.

Engineering rheological properties of edible oleogels with ethylcellulose and lecithin

Addition of 1% (w/w) soy lecithin increased the shear moduli 10-fold and gel hardness 20-fold for 10% ethylcellulose (EC) oleogels. Higher lecithin addition levels or addition to gels with a higher EC concentration caused smaller increases. Similar trends were observed in the penetration force of the gels. Gels displayed thermal reversibility and a high temperature plateau at T≈120–130 °C. Large amplitude oscillatory shear rheology demonstrated similar solid-to-fluid transitions indicating that the polymer drives elastic softening and failure of the network. However, EC oleogels differed in their resistance to flow: the addition of unsaturated lecithin promoted a more gradual thickening response compared to gels containing saturated lecithin or only EC (the last two types of gels display strong intra-cycle thickening and thinning, more indicative of brittle failure). The thickening response of EC oleogels containing unsaturated lecithin, resembles more closely that of a model edible fat (lard).

FORMULATION AND IN VITRO EVALUATION OF SALBUTAMOL SULPHATE AND THEOPHYLLINE EXTENDED-RELEASE TABLETS USING MODIFIED POLYMERS

Objective: The main objective of this research work was to design, prepare and evaluate extended release (ER) tablets of anti-asthmatic drugs (salbutamol sulphate and theophylline) by direct compression method using diverse ratios of hydroxypropyl methylcellulose (HPMC K100M) and ethyl cellulose (EC) along with some other excipients.Methods: Extended-release matrix tablets of salbutamol sulphate and theophylline were successfully fabricated by direct compression method and coded the formulations as F1 to F7 depending on the ratios of modified polymers. The core tablets composed of hydrophilic polymers of various ratios that allow the discharge of drugs at a controlled rate after coming in contact with the aqueous medium. The designed tablets were subjected to various assessment parameters i.e. friability test, hardness test, drug content consistency and In vitro dissolution tests.Results: Prepared formulations were subjected to various assessment parameters and the findings obtained were within the prescribed limit. To perform the in vitro drug dissolution tests of fabricated tablets, the calibration plots of pure drugs using various solvents i.e. 0.1N HCl, phosphate buffer (pH 6.8) and distilled water were plotted. Dosage forms F1-F7 containing ethyl cellulose and HPMC K100M in various concentration demonstrates the prolonged medications discharge for up to 8 h, among these formulations, F6 shows 95.32±0.24 % for salbutamol sulphate and 94.19±0.39 % for theophylline release at the end of 8 h. This finding reveals that a particular window of concentrations of ethylcellulose and HPMC K100M was capable of providing prolonged drugs discharge.Conclusion: The results obtained in this research work clearly showed a promising potential of extended-release tablets containing a specific ratio of HPMC K100M and ethylcellulose as a release rate controlling polymers for effective treatment of asthma and chronic obstructive pulmonary diseases (COPD).

In vitro Permeation Study of Ketoprofen Patch with Combination of Ethylcellulose and Polyvynil Pyrrolidone as Matrix Polymers

Objective: Transdermal patch can release drug to provide systemic pharmacological effect. Matrix used in the patch formula influences the release of the drug. The aim of the study was to evaluate permeation of Ketoprofen patch containing combination of Ethyl Cellulose (EC) and Polyvynil Pyrrolidone (PVP) as matrix. EC is a hydrophobic polymer while PVP is a hydrophilic one. Transdermal formulation containing two polymers with different polarity will provide better permeation results than use only one type of polymer. Ketoprofen 1% was used as a model of active substance in the study. Methods: Ratio of EC and PVP concentration (1:1, 1:3 and 3:1) in patch formula was determined using Simplex Lattice Design (SLD) method. In vitro permeation study was done for 12 h using Franz diffusion cell and shed snake of Phyton reticulatus as a membrane. Amount of the drug released was analyzed using Spectrophotometer UV-Vis (λ = 262 nm). The drug release mechanism was known by determination the drug release kinetics order. Results: The study result showed that the higher PVP concentration was used in the formula, the higher percentage of Ketoprofen permeation was obtained. Patch formula containing EC:PVP in ratio 1:3 had the highest percentage of permeation (93.66%). The drug release kinetics of Ketoprofen from the patch followed zero order kinetics. Conclusion: Combination of EC and PVP in ratio 1:3 resulted the highest percentage of ketoprofen permeation for 12 h (93.66%). The drug release mechanism followed zero order kinetics. Key words: Ethylcellulose, Ketoprofen, Patch, Permeation, Polyvynil pyrrolidone, Simplex Lattice Design.

A Real‐Time Electrochemical Impedance Analysis for Water‐In‐Oil Emulsions of Bitumen Diluted with Naphtha

AbstractIn this paper, water‐in‐oil (W/O) emulsions of bitumen diluted with naphtha were characterized by a novel impedance technique in real time. Nyquist diagrams of electrochemical impedance spectra obtained for different systems present different spectra. For the system of bitumen in naphtha, only one semi‐circle is observed, and the resistance (RO) and capacitor (CO) are connected in parallel. Impedance measurement shows that the conductivity of bitumen results from the conductive components, asphaltenes. For the system containing W/O emulsions, Nyquist diagram is presented in two semicircles with different diameter, indicating different relaxation times corresponding to bitumen in naphtha and W/O emulsions respectively. The RO and CO are in parallel combination and then connect in series with the resistance (RW/O) and capacitor (CW/O) of W/O emulsions. The value of RW/O reduces with the decrease of volume fraction of W/O emulsions, which can be used to characterize the stability of emulsions. At the same time, the impedance spectra analysis plays an important role in the study of demulsification of W/O emulsions by comparing the RW/O after adding demulsifier ethylcellulose (EC). With the increase of EC concentration, the RW/O reduces and eventually disappears due to the decrease of volume fraction of emulsions. Further work needs to be studied to establish the relationship between dielectric constant and volume fraction of emulsions.

Formulation and Evaluation of Transdermal Patch of Diclofenac Sodium

Transdermal drug delivery has made an important contribution to medical practice. It is a medicated patch that delivers a specific amount of medication through the skin into the blood stream. An advantage of a transdermal drug delivery route over other types of medication delivery is that the patch provides a controlled release of the medication into the patient, usually through either a porous membrane covering a reservoir of medication or through body heat melting thin layers of medication embedded in the adhesive. The present investigation was aimed to formulate transdermal films of non steroidal anti-inflammatory drug, Diclofenac sodium using mercury substrate method and evaluated for physicochemical parameters like thickness, weight variation, moisture uptake, moisture content, folding endurance, and drug content values. Three transdermal patches were prepared using different concentrations of ethyl cellulose. It was concluded that as the concentration of polymer increases the thickness of patch, weight uniformity and folding endurance increases. Percentage moisture content and percentage moisture uptake decreases with increase in polymer concentration.

Development of Sustained Release Pellets of Galantamine HBr by Extrusion Spheronization Technique Incorporating Risk based QbD Approach

Objective: The present research aims to integrate the concept of quality by design (QbD) to develop galantamine HBr modified release pellets and to scrutinize the critical factors that can affect the quality of the pellets prepared by extrusion spheronization technique. Materials and Methods: Modified release pellets of galantamine HBr were prepared using Compritol 888 ATO and ethyl cellulose (EC) as release retardants. Avicel pH 101 was selected as an extruder aid. Before converting the wet extrudates in pellets, pregelatinized starch was sprinkled on them to improve the physical properties of the pellets. Qualitative risk analysis was performed to screen and identify the significant factors using Failure Mode Effect Analysis (FMEA) model. Central composite design was adopted to optimize the formulation. Concentration of Compritol and concentration of ethyl cellulose were selected as independent factors and drug release at 2, 6, and 10 h were selected as dependent variables. The pellets were evaluated for size, shape, flow, % yield, % friability and drug content. Results and Discussion: Concentration of Compritol and concentration of EC were found to be critical factors from FMEA model. All the batches of central composite design showed excellent flowability, spherical shape, desired size, yield, friability and drug content. Multiple linear regression analysis and analysis of variance were performed to identify the effect of independent variables on different responses. Design space was generated from the data. In vivo plasma concentration time profile was predicted from in vitro data. Conclusion: Concentration of Compritol and EC were found to be significant for the development of modified release pellets. Innovative finding of the present research is to explore the potential use of pregelatinized starch as a dry binder in the post wet extrusion step.

A NOVEL APPROACH OF ARTESUNATE PELLETS FOR THE TREATMENT OF MALARIA

Tropical countries such as India are more prone to the malaria and around 2 million cases are reported annually. Malaria is one of the most prominent life threatening diseases in spite of many efforts made to fight against it. There are many clinically effective anti-malarial agents but the major reasons of malaria treatment failure are due to resistance development, incorrect dosing, poor drug quality, drug interactions, poor drug absorption and misdiagnosis. Current approach done in this study is to formulate a dosage form which can overcome these drawbacks. Here pellets of Artesunate were formulated by extrusion spheronization method using different concentration of ethyl cellulose and evaluated for preformulation studies, drug compatibility studies were carried out. Formulations were evaluated for particles size analysis, zeta potential and in-vitro dissolution studies. The pellets were obtained in the size range of 10 – 100µm. The evaluation results obtained showed that the formulation F4 having high concentration of ethyl cellulose showed the best release profile.

Effect of wet mass on dextromethorphan hydrobromide matrix pellets

Dextromethorphan hydrobromide (DM) sustained release matrix pellets containing 10% w/w drug were prepared by an extrusion/spheronization technique. The effect of mixing different concentrations of ethyl cellulose (EC), hydroxypropyl methylcellulpse (HPMC K10), and Carbopol 934 with Avicel PH101 on the rheological properties of pellet wet mass was evaluated using mixer torque rheometry (MTR). The prepared pellets were characterized for size, drug content, and in-vitro DM release rate. The results showed that increasing the concentration of the hydrophobic polymer (EC) with Avicel PH101 decreased wet mass consistency, represented by mass mean line torque. Lower binder ratio was required for optimum wet massing, while mixing with swellable polymers (HPMC and Carbopol) caused a noticeable increase in both mean line torque and binder ratio. Combinations of HPMC and Carbopol at higher concentrations resulted in controlled in vitro release of DM from the prepared pellets. Furthermore, mathematical treatment of the in vitro release data of DM from the prepared pellets showed that all formulations except those containing 5% Carbopol plus 5% HPMC (F10) follow first order release. n values of these formulation were in the range of 0.09-0.40, which support an anomalous non-Fickian release.

Optimization and evaluation of mucoadhesive buccal films loaded with resveratrol

Resveratrol, a phytoalexin from grapes, has shown several therapeutic benefits such as anti-inflammatory and chemopreventive effects. There is a need to develop novel methods for delivery of resveratrol since it poses problems such as high first pass metabolism and therefore low oral bioavailability. Drug delivery through buccal mucosa offers novel approach in circumventing hepatic metabolism and providing controlled drug release with a wide scope for application for local or systemic deliveries. The present investigation deals with optimization and evaluation of mucoadhesive buccal films of resveratrol. The mucoadhesive buccal films of resveratrol were prepared by solvent casting method using polymer Hydroxypropyl cellulose (HPC) and Ethyl cellulose (EC). Optimization was achieved using 32 full factorial design whereby the effect of HPC (X1) and EC (X2) concentrations on mucoadhesive strength (Y1), swelling (Y2) and in vitro drug release (Y3) profile were analyzed. The resulting films were characterized for weight uniformity, thickness, folding endurance, drug content, surface pH, swelling, mucoadhesive strength and in vitro drug release. The optimized formulation comprised of 2% (w/v) HPC and 1% (w/v) EC, exhibited satisfactory mucodhesive strength, swelling and optimum drug release upto 8 h. Histopathology of buccal mucosa treated with optimized buccal films exhibited no signs of mucosal damage.

Design, Development and Optimization of Pulsatile Core in Cup Tablets of Naproxen

The aim of the present study to prepare Pulsatile release tablet of naproxen for the treatment of rheumatoid arthritis. The drug delivery system was designed to deliver the drug at a time when it could be most needful for the patient. Drug excipient compatibility studies were carried out using DSC and found to be compatible with each other. Pulsatile tablet was prepared by direct compression method using different type and amount of superdisintegrants and coating polymers and evaluated for pre and post compression parameters. Box Behnken design was applied to optimize responses. Concentrations of Sodium starch glycolate (SSG) (X1), Ethyl cellulose (EC) (X2), and HPMC K100M (X3) were selected as independent variables while Lag time (Y1) and % drug release at 8 hrs (Y2) were selected as dependent variables. The prepared tablets were evaluated for post compression parameters and results indicated that concentration of SSG has major effect on in vitro drug release while concentration of EC and HPMC K100M has major effect on Lag time. Batch BE13 prepared with SSG 35mg, EC 175mg, and HPMC K100M 75 mg was found to be best batch as it achieves predetermined lag time of 5 hr 02 min and 99.32% of drug release. There was no significant variation in formulation at the end of six month accelerated stability study.

Ethyl cellulose nanodispersions as stabilizers for oil in \xa0water Pickering emulsions

Ethyl cellulose (EC) nanodispersions have been prepared through a facile procedure, a process involved the dissolution of EC into ethanol, followed by dipping it in Xanthan Gum (XG) solution (0.1%, used as anti-solvent), and then removed the ethanol. The influences of preparation conditions on the structure and properties of the EC nanodispersions were investigated. The prepared EC nanodispersion had a negative surface potential, which contributed to its stabilization. The particle size of the nanodispersions could be controlled by changing the concentration of EC. Furthermore, the EC nanodispersions had a potential application for the stabilization of oil/water Pickering emulsion. The obtained Pickering emulsions showed high stability.

Platinum/carbon black composites as counter electrodes for high-performance dye-sensitized solar cells

Low-cost counter electrodes for dye-sensitized solar cells (DSSCs) are prepared using platinum/carbon black (Pt/CB) composites via a spin-coating process. Ethyl cellulose (EC) is used as a binder to regulate the viscosity of the Pt/CB composites to facilitate the spin-coating process. The ratio of Pt to CB is ca. 1:3. The effects of film composition (Pt/CB:EC = 30:15, 30:4) and number of coating layers on the electrochemical properties of the Pt/CB electrodes and the performance of the corresponding DSSCs are studied. The results show that Pt/CB films with the lower concentration of EC (Pt/CB:EC = 30:4) exhibit high electrochemical activity, low charge transfer resistance, and good DSSC performance. These results are attributed to the lower loading of EC, which facilitates the charge transfer of the electrodes. DSSCs using these Pt/CB composite counter electrodes with lower loading of EC achieve a high conversion efficiency (8.06%) comparable to that of cells using Pt.