2. CONTENTS
INTRODUCTION OF PROTEIN & PEPTIDE
BARRIERS OF PROTEIN DELIVERY
FORMULATION OF DRUG DELIVERY
EVALUATION OF DRUG DELIVERY
OTHER MACROMOLECULES
3. PROTEIN & PEPTIDE
PROTEINS – proteins are the large organic
compound made up of amino acid linear chain & joined
together by peptide bonds.
Protein > 50 amino acids
PEPTIDES- These are short polymer formed from
the linking , in a defined order of amino acids.
peptides < 50 amino acids
4. FUNCTION OF PROTEINS
Transport & storage of small molecules.
Mechanical support form fibrous protein.
Generation & transmission nerve impulses.
Immune protection through antibodies.
Control of growth & differentiation
via hormones.
6. Enzymatic barrier –
A. Hydrolytic cleavage :
B. Chemical modification :
a) Hydrolytic cleavage : peptides bonds by process such as
insulin degrading enzyme converting enzyme & renin.
There should be irreversible reaction. potentially causes
of damage protein & peptide drug.
b) Chemical modification : protein such as phosphoxylation
by oxidation by oxidase. Its limits absorption of protein
drugs from GI tracts.
7. Intestinal epithelial barrier – barrier for transport of
protein drug across the intestinal epithelial.
Several mechanisms:
A. Passive & Carrier medicated
B. Endocytosis & transcytosis
C. Paracellular
8. Capillary endothelial barrier –
To cross capillary endothelial the peptides / proteins must pass
between the cells.
Transfer across endothelial cells themselves.
Membranes may get modified cytoplasmic enzymes.
Blood brain barrier –
Monolayer cells together tight junctions.
Allow passage small, hypophilic & gases.
Large molecules do not pass BBB easily.
9. FORMULATION OF DRUG DELIVERY
The oral delivery of therapeutic proteins & peptides can
be successfully achieved by using various carrier system
like:
A. DRY EMULSIONS –dry emulsion is prepared by
drying liquid o/w emulsion containing a solid carrier
in the aqueous phase.
B. CELLULAR CARRIER ( eg. Resealed erythrocytes)
C. MICROSPHERE LIPOSOME NANOPARTICES
D. HYDROGELS ( drugs enclosed in gelling polymers)
10. EVALUATION OF DRUG DELIVERY
A. Stability testing.
B. Bioassay.
C. UV spectroscopy.
D. Bradford assay.
E. Differential scanning calorimetry.
F. Chromatography.
G. Electrophoresis.
11. Stability testing: The capability of a particular
formulation in a specific container/closure system to
remain within its physical , chemical , microbiological
toxicological and protective specification.
Bioassay: Due to complexity of proteins, bioassay are
required to assess potency of the formulation.
Bioassay are the two types: in vitro and in vivo.
In case of in vitro bioassays response of cells to hormones
and growth factors is monitored. In case of in vivo bioassay
pharmacological response of animal to proteins is monitored.
12. UV spectroscopy: Proteins containing aromatic amino acid
residue as phenyl alanine , tyrosine can be detected by UV
spectroscopy. It can be used as analytical determination methods.
Bradford assay: In the presence of protein is an acidic medium,
absorption maximum of coomassive brilliant blue G-250 dye
changes. Lastly determination of concentration of the protein in the
sample.
Differential scanning calorimetry: DSC used as tools for
investigating transition of conformation as a function temperature
& more important the effect of potential stabilizing exciepient in a
protein solutions.
Chromatography: use to study stability of protein & peptides
modes are :
1. Normal phase HPLC
2. Reversed phase HPLC
3. Ion exchange chromatography
