Supercritical drug delivery patent awarded to Aphios
The method looks to vastly improve on current conventional methods of drug delivery such as tablets or injections. Whilst convenient and relatively cheap to manufacture, this method of drug delivery suffers from an initial spike of therapeutic agent followed by a period of decay.
Dosage is also frequently limited by adverse side effects caused by the sudden elevation of drug suddenly introduced to the body.
The patent details an alternative that uses a polymer made from microspheres/nanospheres. Following administration via ingestion or injection, the polymer is slowly eroded by body fluids to yield biocompatible the therapeutic product. The drug is then released from a polymeric particle by diffusion through the polymer matrix as well as by surface erosion.
In producing the polymer, Aphios uses supercritical fluids - a material which can be either liquid or gas that exhibit unique properties under certain conditions. It is used in a state above the critical temperature and critical pressure where gases and liquids can coexist.
By dissolving a biodegradable polymer such as PLGA in the fluid and mixing it with the therapeutic, polymer nanospheres are formed after undergoing a number of processes. These polymer nanospheres encapsulate the protein therapeutics.
“In addition to reduction or elimination of organic solvent usage, use of SuperFluids for making nanospheres imparts advantages of no residual toxic organic solvent and pathogen safety,” Aphios claimed.
“The SuperFluids polymer nanospheres (PNS) process can be utilised for improving the oral bioavailability of peptides and proteins, depot delivery of peptides and proteins for sustained, controlled release and the subcutaneous and/or oral delivery of sensitive vaccine antigens,” they added.
The use of degradable polymers as a method for controlled release of therapeutic agents is an area of great importance to the pharmaceutical industry, and the patients that depend on the medication.
These polymers that use supercritical fluids in their production are currently being applied in numerous ways, such as increasing bioavailability of poorly soluble molecules, to designing formulations for sustained release.
The most difficult challenges relate to therapeutic proteins, which are complex to deliver due to their instability and very short half-life when introduced to the human body.
Industrial-wise, current conventional large-scale production of polymeric microspheres that utilise numerous processing steps and large quantities of organic solvents is very time consuming, costly and inefficient.
In addition, the exposure of therapeutic agents to organic solvent adversely effects protein integrity and bioactivity.
The patent: “Polymer Microspheres/Nanospheres and Encapsulating Therapeutic Proteins Therein,” can be viewed here.
