Gotowa bibliografia na temat „Eudragit RLPO”

Mucoadhesive tablets of montelukast sodium were prepared in order to release the drug for a prolonged period of time so as to reduce the frequency of administration. Direct compression technique was applied using the mucoadhesive polymers which were Methocel K4M CR, Methocel K15M CR, Methocel K100M CR and Eudragit RLPO. Highest percent release of drug after 8 hours was 76% for Methocel K4M CR, 72.13% for Methocel K15M CR, 65.68% for Methocel K100M CR, 65.53% for the combination of Methocel K15M CR and Eudragit RLPO. Higuchi, Krosmeyer-Peppas was the best fitted model for drug release. The Methocel K15M CR containing drug showed good mucoadhesive strength. The highest ex-vivo mucoadhesive strength and ex-vivo residence time were observed with Methocel K15M CR and Eudragit RLPO combination. Fourier transform infrared (FT-IR) spectroscopy revealed the compatibility of drug with the polymers.Bangladesh Pharmaceutical Journal 20(2): 123-131, 2017

Introduction: Cefadroxil is a first-generation cephalosporin and is very effective against Gram positive and Gram negative infections. Cefadroxil is an antibiotic agent which has high absorption in the upper part of the gastrointestinal tract (GIT). Conventional Cefadroxil tablets produce rapid and relatively high peak blood level and require frequent administration to keep the plasma drug level at an effective range. The present study was carried out with an objective of preparation and in vivo evaluation of floating tablets of using Cefadroxil as a model drug using Eudragit polymers to improve oral bioavailability of Cefadroxil floating tablets by increasing gastric residence time. Methodology: Floating controlled-release cefadroxil tablets were prepared by direct compression method. Tablets were formulated using Eudragit polymers (Eudragit-RLPO & Eudragit-RSPO), with Sodium alginate (SA) and Carbomer (CP) as release-retarding polymers, sodium bicarbonate (NaHCO3) as the effervescent agent. Floating behavior, in vitro drug release, and swelling index studies were conducted. Initial and total drug release duration was compared with a commercial tablet in 0.1 N HCl (pH 1.2) at 37 ± 0.5°C for 24 hours. Tablets were then evaluated for various physical parameters, including weight variation, thickness, hardness, friability, and drug content etc. Consequently, 6 months of physical stability studies and in vitro-in vivo gastro-retentive studies were conducted. Results and Discussion: The result of in vitro dissolution study showed that the drug release profile could be controlled by increasing the concentration of Eudragit-RLPO. The optimized formulation (F20) containing Eudragit-RLPO showed 99.17% drug release at the end of 24h. Changing the viscosity grade of Eudragit-RLPO had no significant effect on drug release profile. The optimized formulations (F20) containing sodium bicarbonate 40mg per tablet showed desired buoyancy (floating lag time of about 20 min and total floating time of >24h). Optimized formulation (F20) followed diffusion controlled zero order kinetics and fickian transport of the drug. FTIR and DSC studies revealed the absence of any chemical interaction between drug and polymers used. The best formulation (F20) was selected based on in vitro characteristics and was used in vivo radiographic studies by incorporating BaSO4. These studies revealed that the tablets remained in the stomach for 24h in fasting human volunteers and indicated that gastric retention time was increased by the floating principle, which was considered desirable for the absorption window drugs. Studies to evaluate the pharmacokinetics in vivo showed better bioavailability, area under the concentration time curve, elimination rate constant and half-life than marketed product. Conclusion: In conclusion, in order to suggest a better drug delivery system with constant favorable release, resulting in optimized absorption and less side effects, formulated Eudragit based cefadroxil floating controlled-release tablets can be a promising improves candidate therapy. Keywords: Cefadroxil, Eudragit RLPO, Eudragit RSPO, sodium alginate, PVP K30, magnesium stearate and micro crystalline cellulose, Radiographic studies.

Floating microspheres loaded with Nizatidine were prepared using solvent- evaporation method using HPMC, Eudragit RL 100, Eudragit RLPO in different ratio polymers. Drug and polymer in proportion of drug and polymers were dissolved in 1:2 mixture of solvent system of ethanol and dichloromethane. Floating microspheres of Nizatidine were prepared by a solvent diffusion- evaporation method. The nature of polymer influenced the physical characteristics as well as floating behaviour of the microspheres. In vitro buoyancy and in vivo studies confirmed the excellent floating properties of HPMC, Eudragit RL 100, Eudragit RLPO microspheres. The drug release was sufficiently sustained and non-Fickian transport of the drug from floating microspheres was confirmed. Hence the floating microspheres of Nizatidine, may provide a convenient dosage form for achieving best performance regarding flow, release and floating properties. Further, their potential to improve Nizatidine bioavailability in humans needs to be investigated in further studies.

Metformin HCl microspheres were prepared with the aim of increasing its bioavailability and decreasing gastrointestinal side effects by means of sustained action. Eudragit RSPO and Eudragit RLPO, polymers of different permeability characteristics were used to prepare different microspheres. Emulsification solvent evaporation technique using acetone as the internal phase and liquid paraffin as the external phase was the method of choice. Six formulations were prepared using two polymers. The effect of drug loading and polymeric property on the surface morphology, entrapment efficiency, particle size and release characteristics of the microspheres were examined. FTIR and DSC studies established compatibility of the drug with the polymers. SEM studies clearly revealed the effect of drug loading and polymeric nature on the surface morphology of the microspheres. Entrapment efficiencies were within 77.09-97.11% and particle size of all the batches were in the acceptable range. Release data were treated with different mathematical kinetic models. The drug release profile showed that Eudragit RSPO and Eudragit RLPO have opposite effect on drug release. On the other hand, increase in drug loading results in increased drug release. Kinetic modeling of in vitro dissolution profiles revealed that the drug release mechanism varies from diffusion controlled to anomalous type. Dhaka Univ. J. Pharm. Sci. 12(2): 131-141, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17611

The present work was based on the development and characterization of unfolding type gastroretentive dosage form appropriate for controlled release of enalapril maleate. Drug loaded films were prepared by solid dispersion technique using methocel K15 and eudragit RSPO and eudragit RLPO as polymers and polyethylene glycol 400 (PEG 400) as the plasticizer. The film folded in a capsule shell was shown to unfold in the gastric juice and provide drug release up to 12 h in the acidic medium. Formulations provided satisfactory unfolding characteristics allowing expansion to remain in the stomach. Formulation containing above 60% content of eudragit RSPO and eudgrait RLPO combination of total polymer content provided satisfactory film integrity over 12 hours. The result revealed that formulation F1 showed a minimum percentage of drug release of 63.41% followed by formulation F2, F3, F4 and F5 with 66.76%, 80.21%, 83.26% and 86.92% release in 8 hour respectively. Formulation with high proportion of eudragit RLPO and RSPO combination in total polymer content was found to be slow in drug release and lower the release from the polymeric film over time. As the concentration of HPMC K 15 in total polymer content increased the release rate of enalapril maleate as well as % release from the polymeric film also increased over time. Most of the formulation followed Higuchi release kinetics followed by Korsmeyer release kinetics. The drug release mechanism from the film follows Fickian and Non Fickian release kinetics. The films were evaluated for mechanical properties, in vitro drug release and unfolding behavior based on the mechanical shape memory of polymers. Absence of drug polymer interaction and uniform drug dispersion in the polymeric layers was revealed by DSC, FT-IR and SEM studies.Bangladesh Pharmaceutical Journal 20(2): 148-154, 2017

The purpose of the present studies was to develop and characterize sustained release tablets of Carbamazepine, an antiepileptic drug. Tablets were prepared by direct compression method. In the formulation, the active drug was taken 200 mg in every formulation. Methocel K4M, Methocel K15M CR, Methocel K100LV CR, Eudragit RSPO and Eudragit RLPO polymers were used as rate retarding agents in twenty four formulations (F-1 to F-24). The effect of hydrophilic polymer PEG 6000 as channeling agent with Methocel K4M was observed in four formulations (F-5 to F-8). The granules were evaluated for angle of repose, bulk density, tapped density. The tablets were subjected to average weight, diameter, thickness, weight variation, hardness, friability and in vitro dissolution studies. The granules showed satisfactory flow properties, compressibility and drug content. The in vitro dissolution study was carried using USP Apparatus-I (Rotating basket method apparatus) for 6 to 12 hours in distilled water with 1% sodium lauryl sulphate as the dissolution medium. The release mechanisms were explored and explained by Zero order, First order, Higuchi, Korsmeyer-Peppas and Hixson-Crowell equations. Primarily twelve formulations were prepared by using four variable amount of three polymers; Methocel K4M (50, 100, 150 and 200 mg) in the formulations from F-1 to F-4, Methocel K15M CR (50, 100, 150 and 200 mg) in the formulations from F-9 to F-12 and Methocel K100LV CR (50, 100, 150 and 200 mg) in the formulations from F-13 to F-16. Then four formulations were prepared where Methocel K4M amount was same but using variable amount of hydrophilic polymer PEG 6000 (50, 100, 150 and 200 mg). After that another eight formulations were prepared by using polymer Eudragit RSPO and Eudragit RLPO by using variable amount. In F-17 to F-20 the use of Eudragit RSPO was in variable amount (50, 100, 150 and 200 mg) and in F-21 to F-24 the use of Eudragit RLPO was in variable amount (50, 100, 150 and 200 mg). Other excipients remained same in the formulations. Among these twenty four formulations’ sustainability was studied and compared with three market product of 200 mg tablet. It was found that effect of PEG 6000 as channeling agent subsequently decreased the sustaining action (Formulation F5-F8). DOI: http://dx.doi.org/10.3329/dujps.v11i2.14577 Dhaka Univ. J. Pharm. Sci. 11(2): 173-180, 2012 (December)

The objective of the present investigation was to formulate and evaluate microencapsulated Glibenclamide produced by the emulsion – solvent evaporation method. Microparticles were prepared using Eudragit RLPO by emulsion solvent evaporation method and characterized for their micromeritic properties, encapsulation efficiency, particle size, drug loading, FTIR, DSC, SEM analysis. In vitro release studies were performed in phosphate buffer (pH 7.4). Stability studies were conducted as per ICH guidelines. The resulting microparticles obtained by solvent evaporation method were free flowing in nature. The mean particle size of microparticles ranges from 134.49 – 179.72 µm and encapsulation efficiency ranges from 92.30-98.32%. The infrared spectra and differential scanning calorimetry thermographs confirmed the stable character of Glibenclamide in the drug-loaded microparticles. Scanning electron microscopy revealed that the microparticles were spherical in nature. In vitro release studies revealed that the drug release was sustained up to 12 hrs. The release kinetics of Glibenclamide from optimized formulation followed zero-order and peppas mechanism. The mechanism of drug release from the microparticles was found to be non-Fickian type. Eudragit RLPO microparticles containing Glibenclamide could be prepared successfully by using an emulsion solvent evaporation technique, which will not only sustain the release of drug but also manage complicacy of the diabetes in a better manner.DOI: http://dx.doi.org/10.3329/icpj.v2i12.17016 International Current Pharmaceutical Journal, November 2013, 2(12): 196-201

The bioavailability of the antihypertensive drug valsartan can be enhanced by various microencapsulation methods. In the present investigation, valsartan-loaded polymeric nanoparticles were manufactured from Eudragit® RLPO using an emulsion–solvent evaporation method. Polyvinyl alcohol (PVA) was found to be a suitable stabilizer for the nanoparticles, resulting in a monodisperse colloid system ranging in size between 148 nm and 162 nm. Additionally, a high encapsulation efficiency (96.4%) was observed. However, due to the quaternary ammonium groups of Eudragit® RLPO, the stabilization of the dispersion could be achieved in the absence of PVA as well. The nanoparticles were reduced in size (by 22%) and exhibited similar encapsulation efficiencies (96.4%). This more cost-effective and sustainable production method reduces the use of excipients and their expected emission into the environment. The drug release from valsartan-loaded nanoparticles was evaluated in a two-stage biorelevant dissolution set-up, leading to the rapid dissolution of valsartan in a simulated intestinal medium. In silico simulations using a model validated previously indicate a potential dose reduction of 60–70% compared to existing drug products. This further reduces the expected emission of the ecotoxic compound into the environment.