Comparison of Drug Release: Microparticles vs Nanoparticles (original) (raw)
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Analysis of the Drug Release Profiles from Formulations Based on Micro and Nano Systems
Current Analytical Chemistry, 2013
The development of drug delivery systems in experimental therapy usually requires in vitro release models, that should posses specific characteristics including: low cost, simple procedure, high reproducibility and very importantly resemble as strictly as possible the in vivo behaviour. In this respect, the paper describes the effects of the use of different experimental procedures on the drug release profiles from controlled delivery formulations based on nano and micro systems. As examples of micro and nanosystems, microparticles constituted of poly-lactide-co-glycolide (PEM) or gelatine (GEM) and nanostructured lipid carriers (NLC) or cubosomes (CBS) were selected, respectively. All the analysed formulations contained bromocriptine (BC) that represents a poorly water-soluble drug. The influence of the experimental release method and of release media has been investigated using different experimental setup including direct and reverse dialysis, flow-through cell, USP XXII paddle and Franz cell methods.
Controlled release microparticles : impact of swelling on the drug release kinetics
2015
The drug release studies from polymeric system such as Poly(lactic-co-glycolic) acid (PLGA)-based microparticles have been widely investigated during recent decades. The main objective of this work is to better understand the mass transport mechanisms controlling the drug release kinetics from PLGA microparticles. New insight was to be gained based on the experimental monitoring of the swelling kinetics of single microparticle. Initially, PLGA microparticles containing different type of drugs (acidic, basic and neutral), such as ketoprofen, prilocaine free base and dexamethasone were prepared using simple oil in water emulsion extraction/evaporation solvent technique. The characterization of the key properties of microparticles was performed using different techniques (optical microscopy, electron microscopy). The gel permeation chromatography was used to determine the molecular weight of PLGA following exposure of microparticles to the release medium at various times to assess the ...
Dissolution Technologies
The aim of the present study was to experimentally compare the attributes, drawbacks, and limitations of the most commonly employed in vitro drug release test methods for nanoparticle systems and to explore the possibility of one method being adopted as a standard for quality control of nanoparticle-based products. Three in vitro drug release test methods, i.e., direct addition, dialysis bag, and low-pressure ultrafiltration, were employed for evaluation of drug release from tamoxifen-loaded poly(lactic-co-glycolic acid) nanoparticles. Relevant operational characteristics of each test method were compared. Drug release data were fitted in different release kinetics models, i.e., zero order, first order, Higuchi, Hixson-Crowell, and Korsmeyer-Peppas. The coefficient of determination (R 2), release rate constant (k), and release exponent (n) values were calculated. The direct addition method showed rapid initial drug release, whereas a slow release rate was observed in the dialysis bag method. Results of the low-pressure ultrafiltration method were consistent with the direct addition method and various operational characteristics were more realistic than the other two methods. Overall, the findings support that low-pressure ultrafiltration can be considered as a standard regulatory test method for in vitro release of nanoparticle-based formulations.
Important Factors in Drug Release Rate of Microspheres
2017
Small spherical particles with diameter range between 1μm to 1000μm referred to microsphere or microparticles. These systems can be generated by various methods. In this case, genomics, biotechnology and chemistry has been important role in improvement of more potent and specific therapeutics creation. In order to remove many problems associated to traditional methods of administration, controlled release drug delivery systems are being improved. Drug delivery systems such as microparticles, nanoparticles, and pellets as polymer based systems can encapsulate drug and release it at controlled rates for long periods of time. These systems present several potential advantages than to traditional methods of administration. Also, many factors can have effect on drug release rate by microspheres. Among these factors, microsphere producingmethod is prominent factor and release rates may be influenced by type of polymer used in microsphere producing and the way in which the polymer degrades...
AAPS PharmSciTech, 2010
Production and evaluation of novel formulations of tizanidine and tramadol microparticles was the chief purpose of this project. Microparticles of both drugs were prepared separately via temperature change method. To extend the release of formulations, ethyl cellulose was employed. Higuchi, zero-order, first-order, and Korsmeyer-Peppas kinetic models were applied to appraise the mechanism and mode of drugs release. Higuichi model was found to be best for all release profiles. Stability of microparticles at 40°C/75% RH over a 3-month duration was determined by Fourier transform infrared (FTIR), X-ray diffractometry (XRD), and drugs assay. Microparticles were compatible and stable as no significant differences were observed when subjected to drug assay, FTIR, and XRD during accelerated stability studies.
A Review on Microparticles Drug Delivery System
International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2023
Multiparticulate drug delivery methods frequently include microparticles, microspheres, and microcapsules, which have both medical and technological advantages. Microparticles are employed as multiunit drug delivery systems with welldefined physiological and pharmacokinetic benefits to increase efficacy, tolerance, and patient compliance. Their sizes range from 1 to 1000 m. In the creation of microparticles for drug delivery research, a variety of polymers have been used to increase therapeutic effectiveness while lowering side effects. Microparticles today are made of polymers, ceramic, and glass. Microparticles are more stable in the biological milieu than liposomes are. Surface-linked targeting moiety can be built into microparticles. In order to administer drugs to specific areas, this technique is employed. For controlled and long-term release, microparticles are also utilised. To treat many sick states such ophthalmic disorders, cancer, cardiac diseases, and inflammation, macromolecules are encapsulated inside microparticles. This review covers the pros, cons, types of microparticles, preparation method, evaluation of microparticles, and applications.
Journal of Applied Polymer Science, 2006
Different formulations of triamcinolone acetonide (TA) encapsulated in microparticles (MPs) based on poly(D,L-lactide-co-glycolide) (PLGA), poly(e-caprolactone) (PCL), and poly(methyl vinyl ether-co-maleic anhydride) (Gantrez AN119) blends were obtained by spray-drying with a mixture experimental design. The goal of this study was to investigate the influence of the mixture composition, particle size, particle shape, enthalpy of melting (DH m) of PCL, enthalpy of depolymerization of PLGA, and glass-transition temperature of Gantrez on drug release at pH 1.2 and 6.8. The presence of Gantrez in the MPs made PCL more amorphous because of the reduction of its DH m. The determination of the activation energy (E a) associated with TA release from the MPs was used to calculate the fitting equation of the drug-release profile, and subsequently, a thermodynamic (Arrhenius-like) model was established. Drug release increased as E a and DH m decreased. Our results suggest that this approach was capable of predicting in vitro TA release from these MPs, which allowed us to develop formulations with low-release patterns at pH 1.2 and to modulate drug release at enteric pH.
Advanced pharmaceutical bulletin, 2011
The purpose of this investigation was to evaluate microencapsulated controlled release preparation of theophylline using Eudragit RS 100 as the retardant material with high entrapment efficiency. Microspheres were prepared by the emulsion-solvent evaporation method. A mixed solvent system consisting of methanol and acetone and light liquid paraffin as oily phase were chosen. Sucrose stearate was used as the surfactant to stabilize the emulsification process. The prepared microspheres were characterized by drug loading, Fourier-transform infrared spectroscopy (FTIR), differential scanning colorimetry (DSC) and scanning electron microscopy (SEM). The in vitro release studies were performed at pH 1.2 and 7.4 aqueous medium. Increasing the concentration of emulsifier, sucrose fatty acid ester F-70, decreased the particle size which contributed to increased drug release rate. The drug loading microparticle Eudragit RS100(1:6) showed 60-75% of entrapment and mean particle size 205.93-352....
Drug release from α,β-poly(N-2-hydroxyethyl)-dl-aspartamide-based microparticles
Biomaterials, 2004
Spherical pH-sensitive microparticles have been prepared by reverse phase suspension polymerization technique. Starting polymer has been a,b-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) partially derivatized with glycidylmethacrylate (GMA). PHEA-GMA copolymer (PHG) has been crosslinked in the presence of acrylic acid (AA) or methacrylic acid (MA) at various concentration. The obtained microparticles have been characterized by FT-IR spectrophotometry, particle size distribution analysis and scanning electron microscopy. In order to have information about water affinity of the prepared samples, swelling measurements have been carried out in aqueous media which simulate some biological fluids. The possibility to employ the prepared samples as pH-sensitive microparticles has been investigated by performing in vitro release studies. Experimental data have showed that the release rate from these microparticles depends on the environmental pH and the chemical structure of the drug. r
International Journal of Pharmaceutics, 2011
In conclusion, the controlled-release microparticles of TmH can be developed via phase separation method. The development and optimization of controlled-release microparticles of tramadol hydrochloride (TmH) for the oral delivery and their in vitro and in vivo correlation was prime objective of the present study. Four formulations of controlled-released microparticles were developed and optimized in terms of encapsulation efficiency, dissolution study and release kinetics. Among all formulated microparticles F-3 (ratio of TmH:EC 1:2) and F-4 (ratio of TmH:EC 1:3) presented the better characteristics in reference to entrapment efficiency, release kinetics and dissolution profile compared to other formulations (F-1, F-2). For in vivo analysis a new HPLC analytical method was developed and validated. The optimized formulations were subjected to in vivo studies to calculate various pharmacokinetic parameters, i.e., C max , t max , AUC 0-∞ and MRT. The in vitro dissolution and in vivo absorption data was correlated with the help of Wagner-Nelson method. F-3 showed a good in vitro-in vivo correlation with a correlation determination of 0.9957. Moreover, lower T max , t 1/2 and MRT, and higher values of C max and K e were observed for F-3. The control formulation (immediate-release) presented lowest values of t 1/2 , MRT and T max but the highest values of C max and K e . The controlled-release microparticles (F-3 and F-4) could sustain the drug release within therapeutic level up to 24 h and good IVIVC is expected from them.