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July 05-06, 2019 | Paris, France
Pharmaceutics and Advanced Drug Delivery Systems
2
nd
International Conference and Exhibition on
Asian Journal of Biomedical and Pharmaceutical Sciences | ISSN:2249-622X | Volume 9
Oral peptide delivery by a novel lipid-based system
Gert Fricker
Ruprecht-Karls University Heidelberg, Germany
B
ioavailability of peptide drugs is very low after oral
administration. Only very few products are on the market,
like immunosuppressive cyclosporine A (Sandimmun Neoral®)
or antidiuretic desmospressin (Minirin®). Most other peptide
drugs are given by i.v or s.c. injection of peptide solutions,
s.c. administration of drug loaded polymeric implants or
microparticles or by nasal administration.
In the present study we developed a liposomal system based
on a combination of standard lipids and membrane spanning
tetraether lipids, which are extremely stable biomolecules. The
shape of the liposomes was characterized by light scattering
and electron microscopy. Liposomes had an average diameter
of 200-250 nm. The absorption behavior was studied in vivo in
rats in absence and presence of various absorption enhancers
(cetylpyridinium chloride, phenylpiperazin, sodium caprate).
The liposomes containing tetraether lipids resulted in
a significantly increased absorption compared to the
compound alone or standard liposomes. The bioavailability
of several model peptides including the cyclic octapeptide
octreotide (Sandostatin®) and human growth hormone
(hGH) was determined after administration of peptide loaded
liposomes to rats via gavage. Blood samples were taken, and
theplasma concentrationof absorbedpeptidewas determined
by specific radioimmunoassays. The absolute bioavailability
(BA) of octreotide was increased by a factor of 25-30 after
administration of tetraether lipid liposomes, the BAof hGHwas
increased by a factor of 360, indicating that formulation in such
liposomes is a feasible approach to increase the bioavailability
of peptide drugs after oral administration. The formulation can
be further optimized by incorporation of the liposomes into
a jelly matrix, thus generating a semi-solid dosage form, from
which liposomes can be released in the GI-tract without loss of
shape and loading capacity.
e
:
gert.fricker@uni-hd.deAsian J Biomed Pharmaceut Sci, | ISSN: 2249-622X
Volume 9