calorimetría diferencial de barrido. Polímeros [online]. , vol, n.4, pp ISSN Polímeros. Print version ISSN mediante calorimetría diferencial de barrido convencional y modulada con temperatura: parte II. Polímeros [online]. DSC (Calorimetría Diferencial de Barrido) STA (Termogravimetría Simultánea – Calorimetría de Barrido Diferencial Composites – Polímeros Reforzados.
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Estudio de la degradación de poli(ácido-l(+)-láctico-co-glicólico) en cloroformo
Study of type and mixture ratio of organic solvent used to dissolve polymers for preparation of drug-containing PLGA microspheres. These masses were brrido transferred to 30 ml diethyl ether at 0 o C while being gently stirred.
Pharm Res ; 9: The samples were filtered, suitably diluted and assayed spectrophotometrically at nm. The model fitting parameters of solid dispersion formulations are summarized in Table 2.
Physical mixtures were prepared by mixing the powdered drug and polymers in a mortar.
All other chemicals used were of analytical grade and double distilled water was used throughout the studies. Effect of copolymer ratio on hydrolytic degradation of poly lactide-co-glycolide from drug eluting coronary stents.
The release of highly water soluble MET could not be controlled at lower polymer ratio. Chemical Engineering Research and Design 89, Hydrogels have become one of the most versatile materials, because new agents may be incorporated in its structures and providing specific characteristics, which produce different kinds of gels copolymers, terpolymers, semi-interpenetrating, double network, hybrid, etc.
Keeping in mind all these facts, extending or controlling the release of a highly water barrdio BCS class I high solubility, high permeability drug seems to be interesting using solid dispersion approach employing lipophilic carriers.
Análisis térmico I. (DCS). Técnicas de caracterización de polímeros.
Coprecipitation method Metformin HCl and different carriers were taken in different ratios 1: Determination of in vitro drug release of solid dispersions In vitro dissolution was performed using USP dissolution rate test apparatus I in ml of simulated gastric fluid 0. Complexity in biomaterials for tissue czlorimetria.
Burst release leads to higher initial drug delivery and also reduces the effective life time of the device. Mathematical modeling of polymer erosion: Controlled release drug delivery siferencial have the potential of solving these problems.
Crystallinity of drug in solid dispersion was always less than that observed in corresponding physical mixtures Fig. Coevaporation method Metformin HCl and different carriers were taken in different ratios 1: Bone regeneration by a combination of osteopromotive membranes with different BMP preparations: When solid dispersions prepared with different polymer fractions were compared, it was clear that the systems prepared with lower polymer amounts still showed the typical signals of crystals, while increasing the polymer ratio progressively weakened their intensity.
Moreover, the in vitro release of highly water soluble MET could be extended at higher drug: This abstract may be abridged. Therefore, in present study, Eudragit RLPO and Eudragit RSPO have been used as retardants to prepare a novel extended release system of highly water soluble medicine metformin hydrochloride using coevaporation and coprecipitation techniques in order to extend their dissolution rates and to study the influence of type diferenciaal concentration of Eudragit polymers on release dde of the developed solid dispersion systems.
It has been reported that the effect of solvent on polymers could determine the final physical and chemical properties in specific applications.
At predetermined time intervals, aliquotes were withdrawn and replaced with an equal volume of fresh dissolution medium to maintain a constant dissolution volume.
Extended release systems are the methods that can achieve therapeutically effective concentrations of drug in oolimeros circulation over an extended period of time. Determination of in vitro drug release of solid dispersions. In most of the controlled release formulations, immediately upon placement in the release medium, an initial large bolus of drug is released before the release rate reaches diterencial stable profile.
This phenomenon is typically referred to as ‘burst release’.
Análisis térmico I. (DCS). Técnicas de caracterización de polímeros. :
Int J pharm ; Calle San Rafael Atlixco No. Characterization of polymeric dispersions of dimenhydrinate in ethyl cellulose for controlled release. Formulations were coded using method, polymer and ratio.
Operative Techniques in Sports Medicine 12, The study was conducted using the evidence provided from the modifications of OH difrrencial bands cm -1 obtained from FTIR. Bioresource Technology One ml of sample was withdrawn from each volumetric flask, suitably diluted and assayed spectrophotometrically at nm.
Progress in Polymer Science 28,