The objective of the present study is to include coating thickness non-uniformity in the development of a drug release model using coated ion-exchange pellets through the use of stochastic approaches. Drug release from ion-exchange resins was described using a Nernst-Plank model. Complexes of a model drug (dextromethorphan) and Dowex 50WX4-200 were prepared using a modified batch method and coated with Kollicoat SR 30D polymer. The deterministic model, validated using experimental drug release profiles for different coating thicknesses at 0%, 10%, 15%, 20% (w/w), was in agreement with the experimental data with a maximum root mean square error (RMSE) of 2.4%. An arbitrary Lagrangian-Eulerian approach was pursued to develop models of spherical pellets with non-uniform coating thicknesses. The Monte Carlo method was used to simulate the effect of the level of coating deformity on the cumulative drug release profile. Considering the co-existence of equal percentages of deformed and undeformed pellets in a batch, the cumulative release profile can vary by approximately +/-6% as a result of coating non-uniformity. The release profile obtained for a model of an arbitrary pellet with an actual non-uniform coating profile was in good agreement with the average release profile for the models of the theoretical randomly deformed pellets. The developed mathematical model is a useful tool to evaluate and predict release profiles of polymer coated ion-exchange resin complexes.
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http://dx.doi.org/10.1016/j.ijpharm.2006.05.064 | DOI Listing |
Orv Hetil
January 2025
1 Pécsi Tudományegyetem, Általános Orvostudományi Kar, Klinikai Központ, Aneszteziológiai és Intenzív Terápiás Intézet Pécs, Ifjúság u. 13., 7624 Magyarország.
Methods Cell Biol
January 2025
T Cell Lymphoma Group, Josep Carreras Leukaemia Research Institute, Barcelona, Spain. Electronic address:
T cell lymphoma constitutes a complex group of diseases, characterized by heterogeneous molecular features and clinical symptoms, and a dismal outcome no matter the therapeutic strategy chosen. In an attempt to improve patients' survival chances, treatment combinations (chemotherapy, radiotherapy, immunotherapy, gene therapy and thermotherapy) have been tested for their synergistic effects that may dramatically improve outcomes and reduce the side effects of each single modality treatment when therapeutic effects add up while side effects are distributed. In this context, nanoscale drug delivery agents have been developed and exploited to enhance the release of drugs in the treatment of several diseases, showing potential benefits in terms of pharmaceutical flexibility, selectivity, dose reduction and minimization of adverse effects.
View Article and Find Full Text PDFJ Colloid Interface Sci
April 2025
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China. Electronic address:
Conventional light-driven antimicrobial strategies of zinc oxide (ZnO) are limited by inadequate illumination in dark environments. In this study, carboxylated cellulose nanocrystals (MCNC) mediated flower-like ZnO (C@Z) with self-promoted reactive oxygen species release under dark is fabricated. The adsorption of Zn ions on MCNC prompts the growth of ZnO along the (002) crystal plane, forming a flower-like hybrid with superior dispersibility and oxygen vacancies compared to MCNC-free ZnO, which exposes the (100) plane.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
School of Chemistry and Chemical Engineering, Anhui University, Key Laboratory of Functional Inorganic Materials Chemistry of Anhui Province, Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University) Ministry of Education, Hefei, 230601, PR China; School of Chemical and Environmental Engineering, Anhui Polytechnic University, 241000, Wuhu, PR China. Electronic address:
A pivotal pathway of photodynamic therapy (PDT) is to prompt mitochondrial damage by reactive oxygen species (ROS) generation, thus leading to cancer cell apoptosis. However, mitochondrial autophagy is induced during such a PDT process, which is a protective mechanism for cancer cell homeostasis, resulting in undermined therapeutic efficacy. Herein, we report a series of meticulously designed donor (D)-π-acceptor (A) photosensitizers (PSs), characterized by the strategic modulation of thiophene π-bridges, which exhibit unparalleled mitochondrial targeting proficiency.
View Article and Find Full Text PDFEur J Pharm Sci
January 2025
Nanotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmaceutical Nanotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:
Premature drug release is the primary hindrance to the effective function of the lyso-thermosensitive liposomes (LTSLs) of doxorubicin (Dox), known as ThermoDox® for the treatment of cancer. Herein, we have optimized LTSLs by using a combination of phospholipids (PLs) with high transition temperatures (Tm) to improve the therapeutic outcome in an assisted ultrasound approach. For this, several Dox LTSLs were prepared using the remote loading method at varying molar ratios (0 to 90%) of DPPC (Tm 41°C) and HSPC (Tm 54.
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