8 Types Of Drug Delivery System
Drug delivery system is a technical term that is used to describe a “ Dosage form”. In pharmaceutical studies, The term “ dosage form “ is used to refer to the prepared form of drug or medicine in a form suitable for administration like tablets, capsules, etc. The advancement in pharmaceutical sciences now changes the whole concept of it. Before stating our main topic of types of drug delivery system we must clear the following terms :
Here we used this term to stand for “ medicine” or active pharmaceutical ingredient (API) or the actual medicinal compound responsible for the treatment of any disease.
These are the other substances used with actual drug molecules to provide strength, enhance stability, prevent degradation, give colour and taste, etc.
These are tablets, capsules, injections, etc. It comprises of the drug (API) and excipient ingredient
Drug delivery system
A modified dosage form to control the release of drugs in the body. Previously we only know that that medicine can be taken orally or by means of injection. But nowhere is a complete transformation in the intake of medicine. The technology enables us to control the release of actual drugs from tablets or capsules by using certain biopolymers.
It enables us to increase or sustain the retention time of any medicine in the stomach or intestine for prolonged therapeutic benefits. Now your tablet and capsule is not just a simple medicine but a complete system that controls the release of actual active drug molecules from its core (dosage form like a tablet).
What is meant by the drug delivery system?
A drug delivery system is a modified form of dosage form like tablets, capsules, etc. Drug delivery systems are designed with the objective to control the rate of drug delivery in the body by using biopolymers and several other technologies. Drug delivery systems possess some definite advantages in comparison with the traditional dosage form that is why more studies are in progress to do more advancement in the drug delivery system.
Advantages of drug delivery system
Drug delivery systems are designed and formulated with specific consideration and follow strict guidelines. They are in common use in the health care system due to their variety of advantages and benefits.
- Increase patience compliance by reducing the frequency of dose
- Limit the side effects by adopting various strategies
- It enables the health care professionals to give local or systemic treatment
- The drug delivery system allows the release of the drug in a particular location in the body for example in the small intestine. so dug will not dissociate in the stomach and will only release in the small intestine.
- The drug delivery system controls the rate of drug delivery in the body. This phenomenon helps us to predict the concentration of drugs in blood after a specific time interval.
- It helps to enhance bioavailability either by skipping the first-pass metabolism or by increasing the absorption in body fluids.
Types of drug delivery system (DDS)
The following types of drug delivery systems allow the administration of drugs through different routes. Each type of drug delivery system has its own specific application and significance in the healthcare system and medical science.
1. Oral drug delivery system (ODDS)
It is one of the oldest and conventional types of drug delivery system. ODDS is mostly preferred by the patients due to its non-invasive nature and cost-effectiveness and ease of administration is elder patients can easily swallow tablets or capsules but on the other hand, this type of DDS is not applicable for infants, newborns, and patients with cognitive impairment. The aqueous solubility of the drug compound must be evaluated to improve its bioavailability and successful therapeutic outcomes.
2. Sublingual/buccal drug delivery system
It is different from the oral drug delivery system because it allows the administration of drugs through buccal mucosa into systemic blood circulation. Formulations of this type of DDS allow the drug to slowly release in the mouth, mix with saliva and reach to the blood. So in this way, it avoids first pass metabolism and avoids gut hindrance. Examples of this DDS are lozenges and patches.
Injectables were previously called “parenteral” that is “ away from intestine”. It refers to the direct administration of drugs into the blood. It is invasive in nature but gives a rapid onset of action. This method is adopted for drugs having short half-lives, low stability and limited permeability to biological membranes. and It can be further categorized as
- IV: Intravenous
- IM: Intramuscular
- IT: Intrathecal
- SC: Subcutaneous
- IA: Intraarterial
4. Pulmonary drug delivery system
The pulmonary drug delivery system refers to the administration of the drug through inhalation by mouth and directed into airways. This type of drug delivery system is effective for the treatment of both local and systemic disease due to increased alveolar surface area for absorption. The advantage of pulmonary DDS is that it remains unaffected by the food drug interactions and successfully skips the metabolism in the liver that leads to improved bioavailability.
5. Nasal drug delivery system
The administration of drugs through the nasal cavity is termed a nasal drug delivery system. It is used for the treatment of local diseases such as infections of the nose and upper respiratory tract. These types of drug delivery systems don’t target the drug deep into the lungs or alveoli and this is the main difference between pulmonary and nasal drug delivery systems. Moreover, the nasal mucosa is richly supplied with blood vessels so this route can be also used for systemic effect in cases where rapid onset is required. The benefits of this DDS are to skip first-pass metabolism and improved bioavailability.
6. Transdermal drug delivery system
The transdermal drug delivery system administers the drug via the skin. It can be used either for the treatment of local disease (skin allergies, dermatitis) or systemically by allowing the penetration of the drug through the stratum corneum and further progress to epidermis, dermis, and finally reach into the blood. Its advantages included its non-invasive nature and perfect application for unconscious patients.
7. Ophthalmic/ocular drug delivery system
The ocular drug delivery system tends to administer the drug directly to the eyes. The main objective of ocular DDS is to provide continuous drug delivery and enhance corneal absorption. It is completely localized and doesn’t involve any systemic absorption. This approach is somehow difficult and challenging due to the unique physiology and anatomy of eye Ph such as tear glands, alkaline pH, etc. Examples of ophthalmic drug delivery systems include eye drops, hydrogels, contact lenses, and ocular inserts.
8. Vaginal/anal/rectal drug delivery system
The vagina is considered a preferable drug to administer the drug for both local and systemic effects. The reproductive disease can be specifically treated through this DDS. Vaginal suppositories are an example of this type of drug delivery system. It offers some benefits like avoiding first-pass metabolism, interference of gut, and reduced side effects.
Anal or rectal routes are similar to it with similar benefits and mechanisms. Its examples include pessaries, suppositories, and hydrogels.
The advancement in pharmaceutical sciences now changes the whole concept of traditional dosage form and transforms it into a drug delivery system” that mainly allows the administration of the drug through different routes. Moreover, its rate-controlling properties allow kinetic prediction and numerous other advantages. Nanotechnology in pharmaceutical sciences proves to make the delivery system more modified, effective, predictable, accurate, and increase therapeutic outcomes.
A student of Pharm D from University of Karachi. She has keen interest in all the attributes towards pharmacy especially community pharmacy and hospital pharmacy with an objective to make medications sound and safe. She loves to provide information about Pharmaceutical Analysis and Pharmacology in a best way so people with no medical background can understand.