The preparation and evaluation of salbutamol sulphate containing poly(lactic acid-co-glycolic acid) microspheres with factorial design-based studies

Çelebi, Nevin; Erden, Nurhan; Türkyilmaz, Ali

doi:10.1016/0378-5173(96)04491-2

Cited by 21 publications

(4 citation statements)

References 11 publications

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“…In order to describe the kinetics of the drug release process from the controlled release formulations, various models and mathematical equations were applied. 31,32 The kinetics of BSA release from PLGA and PLGA/CS microspheres was evaluated according zero-order, first-order, dual-phase, and Higuchi models. For the mathematical evaluations, the drug release kinetics was obtained by fitting standard release equations to the experimental data.…”

Section: In Vitro Drug Release Profilesmentioning

confidence: 99%

Synthesis and characterization of poly(lactic acid-co-glycolic acid) complex microspheres as drug carriers

et al. 2016

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Poly(lactic-co-glycolic) acid (PLGA) is synthesized via melt polycondensation directly from lactic acid and glycolic acid with a feed molar ratio of 75/25. Bovine serum albumin, which is used as model protein, is entrapped into the poly(lactic-co-glycolic acid) microspheres with particle size of 260.9 ± 20.0 nm by the double emulsification method. Then it is the first report of producing more carboxyl groups by poly(lactic-co-glycolic acid) surface hydrolysis. The purpose is developing poly(lactic-co-glycolic acid) microspheres surface, which is modified with chitosan by chemical reaction between carboxyl groups and amine groups. The particle size and the positive zeta potential of the poly(lactic-co-glycolic acid)/chitosan microspheres are 388.2 ± 35.6 nm and 10.4 ± 2.9 mV, respectively. The drug loading ratio and encapsulation efficacy of poly(lactic-co-glycolic acid)/chitosan microspheres are 36.3% and 57.5%, which are higher than PLGA microspheres. Furthermore, the drug burst release of poly(lactic-co-glycolic acid)/chitosan microspheres at 10 h is decreased to 21.72% while the corresponding value of the poly(lactic-co-glycolic acid) microsphere is 64.56%. These results reveal that surface hydrolysis modification of poly(lactic-co-glycolic acid) is an efficient method to improve the negative potential and chemical reaction properties of the polymer. And furthermore, this study shows that chitosan-modified poly(lactic-co-glycolic acid) microspheres is a promising system for the controlled release of pharmaceutical proteins.

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Section: In Vitro Drug Release Profilesmentioning

confidence: 99%

Synthesis and characterization of poly(lactic acid-co-glycolic acid) complex microspheres as drug carriers

et al. 2016

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“…To compare the dissolution profiles, several release models were tested, such as Higuchi's equation [Higuchi, 1963], which can provide information about drug particles dispersed in a matrix [Eudragit [Baker and Lonsdale, 1974] was developed from the Higuchi model, and has been used for the linearization of release from microcapsules, microspheres [Liu et al, 2003], and microspheres prepared by the W/O/W technique [Celebi et al, 1996]. The modified Nernst equation (5) was developed to describe the release from dosage forms that do not change during the release process [Dredán et al, 1999].…”

Section: Analysis Of Release Profilesmentioning

confidence: 99%

Influence of preparation conditions on the properties of Eudragit microspheres produced by a double emulsion method

Sipos

Csóka

Srčič

et al. 2005

Drug Development Research

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The aim of the present work was to study the preparation and characteristics of sustainedrelease microspheres. As a model drug, sodium diclofenac was encapsulated in microspheres of the polymer Eudragit RS by using a double emulsion-solvent evaporation method. Investigations were carried out on the effects of the preparation method, the rate of the first step of emulsification, and the phase volume and composition (drug and additives) on the physical parameters of the product: its drug encapsulation, and the drug release. We evaluated the resulting microsphere structure [by differential scanning calorimetry (DSC)], the particle size, the surface area (by scanning electron microscopy), the entrapment and encapsulation efficiency (applying a novel method, energy-dispersive x-ray fluorescence analysis), the viscosity of the primary emulsion, and the organic solvent residue (by gas chromatography). We also evaluated and compared the samples by means of the kinetic data relating to drug release. The particle size could be decreased to one third by increasing the external aqueous phase ratio. In the first step of emulsification, elevation of the stirring rate led to microspheres with unfavorable characteristics. Increase of the active agent content and the plasticizer concentration had opposite effects. We applied a covalently not bound plasticizer, which was shown to influence the structure of the microspheres considerably. Drug Dev. Res. 64:41-54, 2005.

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“…PLG is insoluble in water and degrades slowly (weeks to years depending on polymer composition and temperature) under formation of glycolic and lactic acid, which in vivo transform into carbon dioxide and water. The most common use of PLG as a drug delivery matrix is in the form of (injectable) particles of micrometer size, but other dosage forms have been presented as well. − Polymer particles can be produced by double emulsification, − spray-drying, − and supercritical fluid techniques. , One drawback with the PLG system is that it offers a relatively harsh inner environment for sensitive drugs because of the decrease in pH during degradation . A number of methods have been introduced to overcome this difficulty. , …”

Section: Introductionmentioning

confidence: 99%

“…The most common use of PLG as a drug delivery matrix is in the form of (injectable) particles of micrometer size, but other dosage forms have been presented as well. [1][2][3][4][5] Polymer particles can be produced by double emulsification, [6][7][8][9][10] spray-drying, [11][12][13][14][15] and supercritical fluid techniques. 16,17 One drawback with the PLG system is that it offers a relatively harsh inner environment for sensitive drugs because of the decrease in pH during degradation.…”

Section: Introductionmentioning

confidence: 99%

Phase Behavior of the Quaternary Poly(dl-lactide-co-glycolide)/Monoolein/1-Methyl-2-pyrrolidinone/Water System: An Experimental and Theoretical Study

Johansson¹,

Linse²,

Piculell³

et al. 2001

J. Phys. Chem. B

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The phase behavior of the poly(dl-lactide-co-glycolide) (PLG)/monoolein (MO)/1-methyl-2-pyrrolidinone (NMP)/water system has been studied. The particular system was selected because it was a candidate for being a suitable system for creation of lipid−polymer hybrid particles. Phase diagrams of the four ternary subsystems, as well as phase behaviors of selected quaternary mixtures, have been determined. The PLG/NMP/water system exhibits a behavior similar to a polymer/solvent/nonsolvent system, and the PLG/MO/NMP system shows a segregative behavior similar to a polymer 1/polymer 2 (or surfactant)/solvent system. The ternary MO/NMP/water subsystem exhibits a rich, mainly mesomorphic phase behavior, including lamellar and cubic phases, and offers thus possibilities to create both liposomes and cubosomes. At high NMP content, the system gives rise to several liquid phases, such as a sponge phase and MO-poor and MO-rich liquid phases. Addition of PLG to the MO/NMP/water subsystem reveals that both liquid crystals and liquid phases may exist in equilibrium with PLG-rich liquids, the latter being highly viscous. At high water content, the PLG phase may be caught in a glassy state at room temperature. The Flory−Huggins theory has been used to model three of the ternary subsystems and some parts of the quaternary system.

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The preparation and evaluation of salbutamol sulphate containing poly(lactic acid-co-glycolic acid) microspheres with factorial design-based studies

Cited by 21 publications

References 11 publications

Synthesis and characterization of poly(lactic acid-co-glycolic acid) complex microspheres as drug carriers

Synthesis and characterization of poly(lactic acid-co-glycolic acid) complex microspheres as drug carriers

Influence of preparation conditions on the properties of Eudragit microspheres produced by a double emulsion method

Phase Behavior of the Quaternary Poly(dl-lactide-co-glycolide)/Monoolein/1-Methyl-2-pyrrolidinone/Water System: An Experimental and Theoretical Study

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