Nasal vaccine delivery tech clears milestone
intranasally and does not require refrigeration has passed its
first clinical hurdle, reports Phil Taylor.
DelSite Biotechnologies said results from the Phase I clinical trial showed that its GelVac powder delivery system was safe and well tolerated and that doses were consistently and reproducibly dispersed into the nasal cavity.
If the concept proves successful in further trials, it could lead to the development of dry powder vaccines that do not require refrigeration - making it easier to supply immunisations to remote areas of the world, and do not need preservatives such as mercury additives that have been linked to side effects. Moreover, doing away with the need for injections should boost the safety of vaccination programmes by cutting out the risk of blood-borne disease transmission and needlestick injuries.
The clinical trial looked at the safety, nasal deposition, nasal retention time and the performance of the single dose delivery device using radiolabelled test materials. It involved 15 healthy adult volunteers and compared two selected particle sizes of GelVac powder and a control powder.
Bill Yates, DelSite's president, said: "The delivery device performed to expectations and the subjects self-reported that the intranasal product was easy to use and highly preferred over injections."
The GelVac system is based on a polymer, called GelSite, that is water-based and is capable of in situ gelation - ie it changes from a liquid or a powder to a gel upon contact with body fluids. It is a member of a family of plant polysaccharides that has been classified by the US Food and drug Administration (FDA) as Generally Recognised As Safe (GRAS).
GelSite's mucoadhesive properties are used to entrap the vaccine antigen in the nose, providing a mechanism for prolonged exposure of the antigen to local immune tissues and, potentially, enhancing the protective immune response.
DelSite, a subsidiary of Carrington Laboratories, said this nasal delivery platform may also be suitable for delivering live attenuated viruses, live vectors and DNA vaccines.
