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## Prediction of release rate of an active agent from micro/nanoparticles

### Monika Anna Laszczka

#### Abstract

This paper deals with problems of predicting the rate of active agent release (drug) from microparticles and nanoparticles based on selected release models. The analysis of models usefulness was conducted comparing the release rate calculations with the available experimental data of drug release from micro/nanospheres. The work contains a description of basic definitions relating to micro/nanoparticles, active agent encapsulation and mechanisms of its release from matrix type carriers. Among mentioned encapsulation methods were also discussed emulsification process in helical flow apparatus used for preparation of microspheres with dispersed drug which release kinetics was analyzed. It also provides examples of key applications of solid particles with the active ingredient. The review of literature indicates that encapsulation technologies are used mainly in medicine, pharmaceutical industry and environmental protection. In field relating to prediction of release rate the review of literature stresses the need to develop methods of release process mathematical modeling especially for carriers with complex release kinetic. Calculations of the release rate related to process of drug (salol) release from two classes of crosslinked gelatin microspheres differing in size and content of the drug in different conditions of mixing intensity of release environment. The microspheres were prepared by thermal solidification of the multiple emulsions produced in helical flow (Couette-Taylor flow) contactor. The considered case refers to diffusion mechanism of active agent release from eroding matrix (combined erosion and diffusion mechanism). The release rate of an active agent from microspheres was calculated by using 6 selected semiempirical equations. Selection of correlation was performed based on the formulated criteria which included above all the release of the compatibility mechanism, availability of data needed for calculations, ability to anticipate the complex release kinetics and effectiveness of calculations. The results of calculation are presented as release profiles representing the cumulative fraction of released active agent in the time of release process duration. Performed calculations of release profiles and their comparison with the experimental data show that some models involving the diffusion mechanism of the process does not allow for accurate prediction of the release rate from carriers representing complex release mechanisms. However application of equations taking 90 into account the effects of erosion of the matrix material by entering of one or two parameters characteristic of the pre-release stage, which is the result of erosion of environmental impacts of release are also insufficient to correctly predict the release kinetics of these microspheres. However application of equations which are taking into account the effects of matrix material erosion by entering one or two characteristic parameters of the initial stage of release, which is the result of eroding influence of release environment are also insufficient to correctly predict the kinetics of release from these type of microspheres. Calculations of the release rate from nanospheres were performed for two classes of PLGA nanopheres differing in size and content of the drug (paclitaxel) on the basis of semiempirical equations for diffusion controlled release mechanism. The results of calculations and their comparison with experimental data shown that semiempirical equations can not be applied for predicting release rate of drug from nanospheres that are not monodispersed systems. The observed deviates resulted also from limited applicability of the assumptions of psudosteady state diffusion for real release process. The results obtained clearly show that the selected simple models can not be used to design the active agent carriers, especially for controlled release, where it is very important to good know the release profiles.
Record ID
WUT8c38d1613fa74b9485e25ee9c35a9818
Diploma type
Master of Science
Author
Monika Anna Laszczka (FCPE) Monika Anna Laszczka,, Faculty of Chemical and Process Engineering (FCPE)
Title in Polish
Przewidywanie szybkości uwalniania składnika aktywnego z mikro/nano cząstek
Supervisor
Ewa Dłuska (FCPE/DPKT) Ewa Dłuska,, Department of Process Kinetics and Thermodynamics (FCPE/DPKT)Faculty of Chemical and Process Engineering (FCPE)
Certifying unit
Faculty of Chemical and Process Engineering (FCPE)
Affiliation unit
Department of Process Kinetics and Thermodynamics (FCPE/DPKT)
Study subject / specialization
, Inżynieria Chemiczna i Procesowa
Language
(pl) Polish
Status
Finished
Defense Date
01-02-2012
Issue date (year)
2012
Pages
90
Internal identifier
DICHP-2078
Reviewers
Tomasz Ciach (FCPE/DBBE) Tomasz Ciach,, Department of Biotechnology and Bioprocess Engineering (FCPE/DBBE)Faculty of Chemical and Process Engineering (FCPE) Ewa Dłuska (FCPE/DPKT) Ewa Dłuska,, Department of Process Kinetics and Thermodynamics (FCPE/DPKT)Faculty of Chemical and Process Engineering (FCPE)
Keywords in Polish
-
Keywords in English
-
Abstract in Polish
File
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Monika Laszczka.pdf
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Identyfikator pracy APD: 2894

Uniform Resource Identifier
https://repo.pw.edu.pl/info/master/WUT8c38d1613fa74b9485e25ee9c35a9818/
URN
urn:pw-repo:WUT8c38d1613fa74b9485e25ee9c35a9818

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