MIC11108 Drug Delivery System Assignment Sample
Extended essay guidance
What is the extended essay?
The extended essay provides an opportunity to conduct independent research or investigation on a given topic. The topic for this year’s assessment is:
A major challenge for the use of therapeutic agents is their efficient delivery to cells and tissues in the human body. Discuss currently available delivery systems and comment on the advantages and disadvantages of each approach”.
How long should my essay be and what font should I use?
Your essay should be a maximum of 2500 words (+/- 10%) excluding figure legends and bibliography. Essays should be typed using Ariel font, size 11, single spaced.
How should I structure my extended essay?
Provide a general introduction to the topic. You might want to include:
i) What characteristics are desirable in a drug delivery system?
ii) What are the major challenges for drug delivery systems?
iii) Why is there a need for new effective drug delivery systems?
2. Main body
Provides a detailed description of selected drug delivery systems. Drug delivery systems are to be selected and researched independently by each student. I recommend that you describe 3 different drug delivery systems in your essay, however, if you want to focus on one or two delivery systems and carry out a more in-depth investigation, that is also acceptable. You might want to include:
i) An overview of the technologies i.e. how does the drug delivery systems work
ii) Examples of the drug delivery systems from the scientific literature (make sure that you reference primary research papers). You can refer to more than one example of each drug delivery system e.g. nanoparticles can be formulated in lots of different ways.
iii) Informative figures to help convey information (make sure figures are clearly annotated, and if adapted from a published paper make sure to include a reference)
iv) Discussion of the main advantages and disadvantages of each drug delivery system. e.g. ease of formulation, cost, stability, specificity, immunogenicity etc.
A conclusion should link back to the essay question, briefly restate your main points and highlight the significance of the topic.
References should be presented in the APA 7th style.
What criteria will be used to grade my essay?
Essays will be assessed on the following criteria for assignment help
Scientific content. (have you demonstrated a good understanding of complex scientific information?)
Correct interpretation of previously published data. (have you included reference to and discussion of relevant research papers? Have you interpreted the main findings of the research papers correctly?)
Structure and presentation. (have you structured your essay logically and have you used informative headings and subheadings?)
Use of informative figures. (do figures help to communicate key information, are they annotated properly?)
Use of appropriate language (scientific/medical terminology where appropriate).
(it is very important that you try to write using your own words. If your essay consists of large sections of text copy and pasted directly from other sources, it suggests a lack of understanding. Try to use scientific language and avoid colloquialism (language used for casual conversation)
Referencing. (Make sure that you use the APA 7th referencing style as instructed)
Without affecting non-targeted cells, tissues and organs "Drug delivery is a formula that provides therapeutic agents specifically to target cells.
The common used drug delivery system (DDS);
? Oral. (Mouth)
? Topical. (Skin)
? Trans-mucosal. (Nasal, Buccal, Sublingual, Vaginal, Rectal, Ocular)
? Parenteral. (Injection directly into the systemic circulation)
DDS is further divided into 2 main types;
1. Conventional Drug delivery system.
2. Novel Drug delivery system (Luo et al. 2020).
i. CONVENTIONALLY DRUG DELIVERY SYSTEM:
The conventional drug delivery method is the absorption of the drug through the cell membrane. This system includes;
? Oral Delivery
? Buccal/ Sublingual Delivery
? Rectal Delivery
? Intravenous Delivery
? Intramuscular Delivery
? Subcutaneous Delivery
Each of these delivery systems has some pros and cons.
ii. NOVEL DRUG DELIVERY SYSTEM (NDDS) :
Figure 1: Drug delivery system
(Source: Luo et al. 2020)
Figure 2: Overview of targeted drug delivery
(Source: Luo et al. 2020)
To help with this system, Medications are needed where the body distributes pharmaceutical agents to specific targets and achieves the desired response.
NDDS helps to improve the drug potency, A safe therapeutic effect is produced through the release of controlled drugs with greater protection and is directly targeted at the auction site.
Advantages of Novel in comparison with Conventional:
at the right time and at the right site It delivers the maximum dose. The amount of drugs given in the conventional method is allowed to be reduced in NDDS. The frequency of drug doses in NDDS is also reduced to create the desired effect in the workplace. Side effects are again reduced in NDDS because the desired amount of drug product is allowed to be delivered to the desired site (Sur et al. 2020).
More organic availability is required for this. It is released as soon as the drug is ingested in the conventional way and allows its effects to be created which cause fluctuations of the drug in the blood depending on the dosage form used. Therefore, NDDS is given priority to maintain the drug level in blood. Patients feel more comfortable due to better therapy and increased quality of life.
MODES OF NOVEL DRUG DELIVERY SYSTEM:
1. Drug Delivery System Targets
The concentration of drugs in this system increases over time in somebody parts compared to others. It is known as a smarter drug delivery system than others.
2. Controlled Drug Delivery System.
In this system, the correct dose of the drug is introduced into the body to provide long-term activity. This increases the effectiveness of the drug and reduces side effects.
3. Modulated drug delivery system:
This system involves various parameters that control the release of the drug, for example, physical, chemical, biochemical, physics or electrical.
Figure 3: Characteristics of drug delivery system
(Source: Sur et al. 2020)
CHARACTERISTICS DESIRABLE IN A DRUG DELIVERY SYSTEM:
The blood-brain obstruction, physiological or biological barriers drugs can easily penetrate and cross them. The target reaches the produces its effects according to the needs and requirements of the patient for a specified period. It should be ensured that the drug concentration should be within the (MEC) and (MTC). The bioavailability of drugs in the bloodstream is affected.
Transporting the drug directly to the site of action without affecting any other uninfected tissue. Provide a controlled supply of drugs. Drug transfer indirect drug activity without effect other connective tissue Transport High durability it can be balanced under various physics parameters. Easily managed, safe and reliable. It has to be cost-effective.
MAJOR CHALLENGES FOR DRUG DELIVERY SYSTEM:
Here is a definite challenge for the eye medicine delivery system. The maximum drug concentration at the auction site with greater therapeutic efficacy is to be achieved therapeutically. High-density solutions on the ocular surface can cause toxicity or damage to other cells. Poor bioavailability of ocular surface drugs can occur for a variety of reasons so vent solution extraction, tear distillation, lacrimation, conjunctival absorption, and more. For this,e reasons very small amounts are accepted to be Exploited unilaterally.
AREAS TO BE RESEARCHED FOR A BETTER DRUG DELIVERY SYSTEM:
Scientists are studying and use to identify always that how diseases are evolving and spreading further. They also use to study how our bodies are responding in response to those diseases and what is the effect of genetics and the environment on it (Rajpoot et al. 2020).
1. Crossing the Blood-Brain Barrier (BBB) in Brain Diseases and Disorders:
Different cells of the body use it to exchange basic substances like blood from the CNS. It helps to prevent the identification of elements that can enter the brain and damage cells. It is very normal and basic to administer drugs to the brain to get an effective response for a specific disease of the Brain (e.g. Parkinson's, Alzheimer's, brain tumours). Better strategies need to be developed to overcome this problem.
An ultrasound technique is performed that damages the brain in moments and safely passes the BBB so that the drug directly targets the tumour cells without using any treatment method.
2. Enhanced Drug Delivery to the Targeted Intracellular:
The immune system protects the organ against any harmful substances, so the cells detect and dispose of foreign particles or any other dangerous molecule. Drugs bound to carriers or vehicles to deliver targets are considered foreign particles for them. While scientists are working to develop authentic and useful treatment methods for delivering drugs to targets, more effective research is needed to ensure that drugs reach the site for their effects.
As a priority, in the carrier delivery systems are going to be improved to develop drugs in response to cellular defence, drug delivery to the intracellular target site, and molecular signalling.
3. Merging Diagnosis and Treatment
Drug delivery systems extend far beyond treatment. Someday with the use of imaging technology, physicians are going to identify and manage their patients in just one step. This new technique is known as theranostics (Rajpoot et al. 2020).
I. LIPOSOMAL AND TARGETED DRUG DELIVERY SYSTEM
A. Modification of liposomal drug targeting
Phospholipids are the result of polar shells between amphiphilic and follicle solutions in nature. An attractive drug delivery system analogous to cell membrane structurally and composition-wise as well is a liposome. liposomes are non-toxic,non-immunogenic, and biodegradable amphiphilic molecules. Biocompatibility, Biodegradability, Reduced toxicity, are included in liposomes, they have various important properties; motivate the pharmacokinetic profiles of the loaded drug.
Figure 4: Modification of liposomal drug targeting
(Source: Rajpoot et al. 2020)
Liposomes serve to deliver targeted drugs. Liposomes have been used as pharmaceutical transporters for decades, where liposomes can react selectively at the cellular and molecular levels with further growth and change.
The invention of liposomes was introduced in the 1960. With the passing days different adoptions can be seen in phospholipid bilayer structures and it becomes a single bilayer structure and it is further termed as liposomes. Gregorian has established the process of encircling of liposomes which can be termed as a drug delivery system. Different kinds of contemporary processes have been established for the preparation of different beak and unilamellar liposomes. It is considered as the end in enhancing the efficiency and homogeneity of normal liposomes.
In the initial stage, the application of liposomes was seen as the form at low-pressure conditions, which was low yield. On the other hand, higher pressure systems were invented for higher yield. With the sonication and homogeneity technique, it was not possible to produce LUV with diameters of less than 50 nm. At the same time, the advancement of the microfluidic mixing procedure has enhanced the ability to scale in terms of the production of LUV within the range of 20–50 nm (Rajpoot et al. 2020).
From the 1st generation of liposomes, it is seen that the invention was quickly cleared by the reticuloendothelial system (RES) after completing the step of administration. Now, it can be said that the first strategy executed orderly to generate long-circulating liposomes by making an alteration of their attributes along with composition and size. At the same time, it is analysed that different types of small liposomes are not as clear as the RES. With the help of further improvement, it is possible to offer some formulations which are comparatively more stable and help in enhancing the deep ocean at the sight of liposomes. With the help of increased permeability and retention impacts, it is possible to increase the deposition and this is considered as one of the significant procedures.
The impacts of ERP can be observed as a procedure, which is possible with the help of a stronger extraversion of macromolecules that were first introduced from tumour blood vessels. After that, they are retained in a massive way in tumour tissues, infarcts and in some infected areas which are greater than the normal tissues. In addition to that after considering some individual studies, it is observed that 100 NM liposomes had been introduced as the most proper one for tumour delivery. On the other hand, the planning of arranging the liposomes can be seen in utilising wide phospholipids which consist of higher TM compared with unsaturated phospholipids and its flow time and retention is comparatively higher for the large vesicles.
In addition to that, the surface alteration of different repo sums has been applied to keeping away from the take up of RES. After considering the earlier examinations or investigations on sialic and ganglioside subsidiaries, for example, GM1 for the enhancement of the stability copies of different erythrocyte membrane surfaces. After completing the next steps of the investigation it can be said that the utilised hydrophilic polymers, for example, PEG17 is used for increasing the stable flow of different liposomes
It is also observed that after making and alteration of liposomes by the end goal, that is considered as a steady clean it has been introduced on it. It helps in the evolution of plasma protein binding and ensuing RES uptake. 20 types of surface alterations help in the enhancement of purported stealth liposomes. It is seen that these liposomes work more effectively because they are much capable in imitating the biomembranes. In this context, it can be said that Doxil is considered as one of the common stealth liposomes, which consists of PEG surface covering and that has exhibited a further development circulation time and safety profile in terms of utilisation in DOX chemotherapy.
At the end, the next generation of liquids some have influenced to implement direct atomic focusing which is operated by making a connection with site explicit ligands to the liposomal surface. Along with the methodology medication within the cells are enhanced by keeping a target site with the support of receptor-mediated endocytosis. The material which is collected that is endocytosed is then exposed in the form of acidic lysosomal compartmentalization and hydrolysis with the help of various chemicals. It is possible by bringing about diminished biological action. In this context, a problem can be identified for drugs that are especially delicate to this procedure of degradation, for example, peptidic and nucleic acid drugs.
These medications and procedures are trying to empower the process of entering the load into the cytosol are worthwhile and also assist to relieve this issue. Besides, the further improvement included the demonstration of a liposome, which consolidated long flow properties and marketability. Doxil was utilized as an anticancer drug and showed work on in vivo activity.
B. CLASSIFICATION OF LIPOSOMES:
After considering the structures of Liposomes, the classifications can be made in accordance with different types of composition and applications, structural parameters and several procedures, which include sonication, thin-film hydration, detergent dialysis, French press, reverse-phase evaporation, ethanol injection and extrusion (Khodashenas et al. 2020). Liposomes are proven according to the number of lipid bilayers in the colloidal structure, unilamellar liposomes consisting of multilamellar liposomes with one lipid bilayer and multiple lipid bilayers.
Figure 5: Classification based on composition and applications of liposomes
(Source: Khodashenas et al. 2020)
Figure 2 Classification based on structural parameters of liposomes
(Source: Khodashenas et al. 2020)
C. HOW DOES LIPOSOME TECHNIQUE WORKS:
Liposomes go into the stomach when swallowing the capsule. The acid in the stomach causes the capsule to quickly detach its subject, which is usually not a perfect setup for proper absorption. However, with the help of liposomal technology are formed in a structure called liposome which integrates bilayer molecules that help guide and transport the active ingredients so that they are efficiently absorbed. For this it works so uniquely (Jafari et al. 2021).
MECHANISM OF ACTION:
The liposome structure consists of a part of the aqueous solution in the hydrophobic membrane. Hydrophobic chemicals can easily be malted in a lipid membrane, for this reason, liposomes can carry both hydrophilic and hydrophobic.
For example, liposomes helped in cancerous cells treatment. Cells of Cancerous require a large number of fats for the growth and when they identify liposomes which are filled with anti-cancer drug as a source of their nutrition, cancerous cells target those liposomes and are absorbed by them. After all of its contents are released into the liposome site, the cancerous cells begin to die rapidly.
D. TYPES OF LIPOSOMAL DRUG DELIVERY PLATFORMS:
Four types of liposomal delivery systems are,
i. Conventional liposome.
ii. Sterically stabilized liposome.
iii. Ligand-targeted liposome.
iv. Theranostic liposome.
It is seen that Liposomal strategies enhance the effectiveness of the drug and the therapeutic index in the body. It further increases the durability of the drug through encapsulation. These are non-toxic, biodegradable, flexible, fully biodegradable and non-resistant to systemic and non-systemic administration (Alinejad Raiss & Hashemzadeh, 2020). The toxicity of encapsulated agents is reduced.
Solubility is a bit less and it has a short half-life, for example, hydrolysis and oxidation type reactions. There may be leaks or infusions of encapsulated drugs can be seen. The production cost is comparatively higher, therefore, its retail price will also be higher. The cause of instability is fusion. Rapid changes of liposomes from the bloodstream by phagocytic cells of RES is a major barrier to liposome drug supply (Alipour, Alimohammady, Yumashev & Maseleno, 2020).
G. CHALLENGES IN LIPOSOMAL DRUG DELIVERY SYSTEM:
One of the challenges that will affect the development of a successful liposomal market is the possibility of cytotoxicity. In some cases, It has been found that liposomes have shown an effect quickly after their administration which is certainly not beneficial. It has detected which charged liposomes are ultimately toxic. Nevertheless, there is a possibility that some solvents such as ethanol and ether may be present in trace amounts during liposome production depending on the method (Raval et al. 2018).
Challenges related to production come down to drug infiltration, batch switching, effective disinfection methods, durability issues, and most common scalability issues. Multiple liposome production can also raise problems. To get over these problems liposomes are mixed with expensive raw materials so this strategy does not depend on effective costs.
Liposomes are shaped cells of phospholipids, the basic components of people cell walls. The drug is bound to a liposome that binds it as a ‘payload’ which actually protects it from initial decay in the body. The main advantage of the liposome technique is its bioavailability, which aids in treatment by increasing the effect of the drug and reducing the dose. The liposome is used in cancer patients treatment. Since this strategy alters the pharmacokinetics of the drug (i.e. absorption, distribution, metabolism, and defecation), it can solve many problems by providing controlled drugs. Liposomes are classified according to composition and application and structure.
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