When treating medical conditions, a drug’s efficacy depends on many factors. One of these factors is the drug’s delivery method which dictates how the patient absorbs the drug. Depending on a drug’s chemical composition, or intended use, a specific delivery system can increase the drug’s performance. Pharmaceutical companies will research which drug delivery methods are best for a given chemical compound, whether via pill, injection, or skin absorption. It is crucial to develop drug delivery systems that optimize a drug’s absorption and distribution into the body while minimizing adverse side effects.
Phoreus Biotech is harnessing the natural properties of peptide capsules to create a revolutionary drug delivery system.
What Is a Drug Delivery System?
Drug delivery systems are engineered ways drugs enter a user’s body. Drug systems refer to the drug delivery method, how the drug is administered, and the vehicle in which the drug is packaged. In optimizing a drug’s efficacy, it is crucial to determine which delivery method will increase the rate at which the body absorbs the drug. For a specific drug to produce the desired medical treatment, the drug must be held in packaging to withstand traveling within the body. The combination of a drug’s delivery method and vehicle ultimately determines the drug’s efficacy.
Drug Delivery Methods
There are many different medication delivery systems that pharmaceutical companies will employ to increase drug efficacy. Drug delivery methods are tailored to a drug’s specific chemical nature and desired treatment. Common methods such as oral and intramuscular injection are not effective for all drugs.
Administering drugs orally or by swallowing is the most common drug delivery method. Oral administration is convenient for users and is often the most cost-effective and safest. Nevertheless, oral ingestion has its limitations, as absorption of the drug can be unpredictable in the digestive tract and all absorbed compounds from the digestive tract is filtered and metabolized by the liver before it enters the general circulation. As a result, the drug’s efficacy may decrease as less of it reaches its target site.
Inhalation of drugs is a unique drug delivery method. It requires close medical supervision and or specialized equipment, which only sometimes allows for safe home use. Drugs that employ this method act directly upon the lungs, where they absorb into the bloodstream. Examples include metered-dose asthma inhalers, nebulizers, and anesthesia gasses.
Transdermal “Skin” Absorption
Ailments that directly affect this area are treated by administering medications through the skin. Examples include steroid creams used to treat conditions such as eczema or psoriasis. Nevertheless, drugs that produce a whole-body effect can quickly enter the bloodstream through a skin “patch.” Patches are an effective way to administer a drug gradually over time, and they can help with anything from nicotine addiction to pain relief.
Biologics delivery systems, such as injection, require using a needle or implantation device to administer the drug. Healthcare practitioners can adjust how quickly or slowly a medicine is absorbed based on where it enters the skin and muscle tissues. Examples include hormonal birth control, insulins, and morphine.
Drug Delivery Devices
Drug delivery systems include the delivery method and the vehicle used to transport the drug into the body. These vehicles, or devices, can ensure that a specific drug is transported safely within the body after administration. Advancements in drug delivery technologies can also improve a drug’s ability to reach its targeted area and allow for the packaging and transportation of drugs that readily degrade once they enter the body.
Micelles are laboratory-made drug delivery devices that form a sphere-like shape that encapsulates a drug for safe delivery throughout the body. Micelles contain a single layer of amphipathic or water-soluble lipids. These lipids bind efficiently to the cell membrane and release the drug within. Nevertheless, the limitations of micelles include quick degradation, fast drug release, and limited drug compatibility.
Liposomes are another artificial drug delivery device that acts similarly to micelles. Liposomes contain two layers of water-soluble lipids which also orient as a sphere to coat drugs. Liposomes are one of the most effective drug delivery devices, as they are universally known and used to transport drugs safely within the body. Comparatively to micelles, liposomes show slow drug release, limiting the range of treatment options for certain drugs.
Nanoparticles are tiny particles that transport drugs throughout the body. Unlike micelles or liposomes, these particles are not exclusively lipids. Instead, laboratories can manipulate the qualities of these particles, such as size and composition, to optimize performance. Nanoparticles, such as our BAPC technology, are an attractive new drug delivery device as they are readily absorbed and can move through the pulmonary system more effectively than other delivery devices.
Targeted Drug Delivery
Targeted drug delivery is concerned with accumulating a drug within a specific body region while minimizing side effects to other body areas. Drug delivery technologies focused on targeting drugs to a specific area of the body require a smaller amount of a drug than when administered systemically. When a drug reaches the treatment site directly through an effective delivery device, less drug degrades by being absorbed elsewhere. Nanoparticles have found the most success as a target drug delivery device as they have high solubility and can be customized for the active ingredient and the target tissue.
Similar to passive drug targeting, active drug targeting relies on delivering drugs via attaching targeting moieties to the nanoparticle. In active drug targeting, the nanoparticle drug device’s surface is manipulated by adding a ligand or binding molecule. This ligand can bind to receptors in diseased cells or tissues and directly release the drug to the affected area. Active drug targeting requires greater engineering to modify the drug device’s surface for binding interactions. Nevertheless, there is a lessened risk of drug toxicity as the drug delivery is concentrated at the affected site, not elsewhere in the body. Examples of active drug targeting include Phoreus’ BAPtofect™ delivery technology, which can deliver a range of drug treatment therapies.
Passive drug targeting encapsulates a drug into a delivery device, such as a nanoparticle that passively reaches the target area. In passive targeting, the drug’s efficacy depends on how much time it spends in the body. By taking advantage of tissue permeability, these drugs can circulate longer throughout the body and be taken up by cells that can deliver the drug to the specific target area. Engineering the drug delivery devices for passive targeting is less extensive than active transport. However, there is a greater risk of drug toxicity as a larger drug dose is required.
Additional Types of Drug Delivery Systems
Drug delivery methods such as oral, pulmonary, and skin administration are most commonly prescribed to patients. However, to increase drug targeting, other drug delivery systems are employed. The following are examples of drug delivery systems:
- Buccal Drug Delivery – Administration of drugs into the cheek lining to avoid rapid drug uptake and prolong drug absorption
- Nasal Drug Delivery – Administration of drugs into the nasal cavity to treat local upper respiratory conditions
- Ocular Drug Delivery – Usually delivered as liquid “drop” into the eye for local drug delivery for a prolonged period
- Sublingual Drug Delivery – Administration of drugs under the tongue which is rapidly absorbed into the bloodstream and avoids first pass processing by the liver
- Vaginal/Anal Drug Delivery – Used to deliver laxatives to patients and hormones to females, allowing for faster treatment and avoids first pass metabolism by the liver.
Medical Applications of Drug Delivery Systems
Active and passive drug targeting has shown great strides in cancer treatment. Both active and passive drug targeting targets only affected areas of the body. These drug delivery systems avoid healthy or unaffected areas of the body by targeting areas directly affected by cancer. When combined with nanoparticles as a delivery device, active drug targeting systems can target cancer cells by engineering ligands unique to cancerous cell receptors, allowing the drug to be delivered to the affected cells.
Phoreus’ Improved Drug-Delivery Technology
Our Branched Amphipathic Peptide Capsules (BAPC) and Corralling Amphipathic Peptide Colloids (CAPC) technology works to deliver drugs with low cellular permeability without presenting immunogenic risks. Engineered with naturally occurring, novel peptides, our capsules and colloids offer increased drug absorption for vaccines, cancer therapies, and other small molecules. To learn more about our BAPC and CAPC technology, reach out to us today.