Oral
insulin is a reality: it is simply a matter of when.
The realisation
that insulin injections are going to have to become
a part of everyday life can be extremely harrowing
for many diabetics. Injection takes time, interrupts
daily schedules and is considered unpleasant by many
people. Children or adolescents who require daily
insulin injections may find that the regimen impacts
on their daily lifestyle to an even greater degree.
Using insulin therapeutically is not a new practice
at all, but delivery methods to make the process more
bearable have not gained widespread prominence as
of yet.
Obviously,
the priority in delivering insulin to a patient is
to make sure it reaches the bloodstream intact.
Many
alternative delivery systems, although they work to
some extent, leave the insulin broken down by digestive
juices, usually too much for it to be of significant
use to the body. Furthermore, the complicated environment
within the stomach means that simple tablets would
be unpredictable and ineffective. The solution will
come, and may have already, when a pharmaceutical
research company creates a tablet in which insulin
can be enclosed and yet still pass through the stomach
wall.
Three principal target areas are obvious in developing
alternative insulin delivery systems: the nose, the
mouth and the lungs. Nasal delivery into the upper
airway presents severe problems: the transport system
is too convoluted and would require massive, expensive
quantities of insulin to reach the target area. Insulin
into the lungs is a promising area: the insulin can
be directly absorbed into the bloodstream through
the thin walls of the lung. Effective oral insulin
is extremely difficult to create due to the thickness
of the stomach wall.
This is by no means an impossible hurdle, but it is
a very complicated and costly one. Several companies
across the globe are solely concerned with the creation
of effective oral insulin delivery mechanisms, and
many major pharmaceutical companies are at the research
and development stage. It is thought that oral insulin
could be developed that would be absorbed through
buccal means (through the walls of the cheeks). This
method could see insulin reaching the bloodstream
intact.
Data obtained through testing oral insulin on animals
has yielded some extremely positive results. In 2003,
Diabetes Care released reports of a small study that
appeared to find oral insulin as effective as injectable
insulin for type 2 diabetics. Drug companies are obviously
interested in the potential of oral insulin to net
a massive share of the market, and therefore investment
in research is substantial and ongoing.
The
following companies are market leaders in the field
of oral insulin:
Generex
biotechnology have had their rapidmist delivery system
(an oral insulin spray that is the flagship product
of their company) approved for use in Ecuador. The
liquid spray is absorbed by the buccal mucosa. They
hail this system as pain free and a reality, and aim
to infiltrate the European market at a later date.
It is expected to begin being sold in Ecuador in early
2006.
Generex have an agreement with insulin giant Eli Lilly.
Coromed
is a privately funded biotechnology company started
in 1994. Their flagship product is called Alveair,
and offers a ‘needleless’ alternative
for insulin users. The device delivers a regulated
blast of insulin, and Coromed champion the fact that
it has lower side-effect levels than injectable insulin.
Nektar,
formed from Inhale Therapeutic Systems Inc, are another
company that are promising oral insulin. In collaboration
with pharmaceutical corporation Pfizer and the enormous
drug company Sanofi-Aventis, Nektar are eagerly attempting
to net a share of the oral insulin market. The Nektar
Pulmonary delivery system is one facet they have developed.
Exubera, a fast-acting dry powder insulin designed
for inhalation has been developed and is being reviewed.
Aradigm
Corporation aims to develop and manufacture innovative
drug solutions: they are backed by another insulin
market leader called Novo Nordisk.
Wockhardt,
a giant Indian company that recently acquired UK insulin
supplier CP pharmaceuticals, has recently launched
a cartridge and pen system into the Indian market
that it claims is almost painless.
