Present pharmaceutical scenario is aimed at development of drug delivery systems which maximize the drug targeting along with high therapeutic benefits for safe and effective management of diseases.
Target drug delivery system indeed a very attractive goal because in this system targeting of an active bio molecule from effective drug delivery where pharmacological agents directed specifically to its target.
Various cellular carriers has been used for drug targeting among which cellular carriers(leukocytes, platelets and erythrocytes) offer a great potential.
Erythrocytes also known as red blood cells and have extensively studied for their potential carrier capabilities for delivery of drugs .
Table of Contents
1. Introduction
2. Source of erythrocytes
3. Isolation of erythrocytes
4. drug loading in erythrocytes
5. Factors effecting resealed erythrocytes
6. Advantages of erythrocytes
7. Method of drug loading
8. In vitro characterization of erythrocytes
9. applications
Objectives and Topics
This document provides a comprehensive overview of the use of resealed erythrocytes as effective, biodegradable cellular carriers for targeted drug and enzyme delivery systems, addressing methods of encapsulation, characterization, and therapeutic applications.
- Physiological properties of erythrocytes and their role as drug carriers.
- Methodologies for drug loading including hypotonic lysis and dialysis.
- Technical procedures for the isolation and purification of erythrocytes.
- In vitro characterization techniques to ensure stability and drug release profiles.
- Clinical applications and the limitations of erythrocyte-based targeting.
Excerpt from the Book
Drug loading in erythrocytes
When erythrocytes are suspended in a hypotonic medium they swell to about one and a half times their normal size, and the membrane rupture in the formation of pores with diameters of 200 to 500 A0.
The pores allow equilibration of the intracellular and extracellular solution. If the ionic strength of the medium then is adjusted to isotonic and the cells are incubated at 37oC, the pores will close and cause the erythrocyte to “Resealed”.
Using this technique, drug present in the extracellular solution, it is possible to entrap up to 40 % of the drug inside the resealed erythrocyte and to use this system for targeted delivery via intravenous injection.
resealed erythrocytes can be targeted selectively to either the liver or spleen depending on their membrane characteristics.
The ability of resealed erythrocyte to deliver drug to the liver or spleen can be viewed as a disadvantage is that other organs and tissues are Inaccessible.
Summary of Chapters
Introduction: Outlines the necessity for advanced drug delivery systems to maximize therapeutic benefits and identifies cellular carriers like erythrocytes as candidates for targeted transport.
Source of erythrocytes: Lists various mammalian species used as donors for erythrocytes in pharmaceutical research and notes the requirement for anticoagulants like EDTA or heparin.
Isolation of erythrocytes: Details the clinical collection procedures, centrifugation parameters, and buffer systems required to obtain washed, viable erythrocytes for further study.
drug loading in erythrocytes: Explains the mechanism of reversible pore formation under hypotonic stress and the subsequent resealing process for entrapping pharmacological agents.
Factors effecting resealed erythrocytes: Summarizes the critical parameters for carrier selection, including biocompatibility, membrane permeability, and stability during storage.
Advantages of erythrocytes: Highlights the biodegradability, non-immunogenic nature, and ability of erythrocytes to protect encapsulated therapeutic substances from premature degradation.
Method of drug loading: Categorizes the various techniques for loading, such as chemical membrane perturbation, electro-insertion, and osmotic lysis methods.
In vitro characterization of erythrocytes: Describes the analytical methods for measuring drug content, hemoglobin release, and the structural integrity of loaded cells under stress.
applications: Provides an overview of therapeutic uses ranging from enzyme replacement therapy to the delivery of antineoplastic agents and the targeting of specific body organs.
Keywords
Resealed Erythrocytes, Drug Delivery, Hypotonic Lysis, Cell-based Carriers, Targeted Therapy, Encapsulation, Haemoglobin, Electroporation, Biocompatibility, Pharmacokinetics, Enzyme Delivery, Reticuloendothelial System, Membrane Permeability.
Frequently Asked Questions
What is the primary focus of this work?
The work focuses on the potential of resealed erythrocytes as novel, natural, and biodegradable carriers for the targeted delivery of drugs, enzymes, and other macromolecules.
What are the core subject areas covered?
The document covers cell physiology, isolation techniques, various drug loading methodologies, in vitro quality assessment, and clinical applications.
What is the main goal of using resealed erythrocytes?
The primary goal is to achieve selective drug targeting to specific sites, such as the liver or spleen, while protecting the drug from premature degradation and extending its therapeutic action.
Which scientific methods are utilized for loading?
Several methods are discussed, including hypotonic dilution, hypotonic dialysis, hypotonic preswell, isotonic osmotic lysis, membrane perturbation via chemical agents, and electro-encapsulation.
What is treated in the main body of the document?
The main body treats the biological properties of red blood cells, specific experimental protocols for cell manipulation, factors affecting carrier stability, and the mechanisms behind drug efflux.
What are the key characterization parameters?
Key parameters include drug content estimation, hemoglobin release profile, osmotic fragility, turbulence shock resistance, and cellular recovery percentage.
How is membrane perforation managed?
Membrane perforation is achieved through osmotic stress, where the cell swells and develops pores; these pores are subsequently closed by restoring isotonic conditions and incubating the cells.
What are the limitations of this delivery system?
The document notes that a significant disadvantage is the selective targeting of the liver or spleen, which can make other organs and tissues inaccessible for the drug.
Why are erythrocytes considered suitable carriers?
They are natural, biodegradable, non-immunogenic, and possess a high loading capacity, allowing for the encapsulation of drugs without the need for chemical modification.
- Citar trabajo
- M.Pharm Sonam Gandhi (Autor), 2017, Resealed Erythrocytes, Múnich, GRIN Verlag, https://www.grin.com/document/419060
