Vol. 3 (4) Oct – Dec 2012 www.ijrpbsonline.com 1602
International Journal of Research in Pharmaceutical and Biomedical Sciences
ISSN: 2229-3701
Native Starch
It may not be suitable in controlled release drug
delivery systems due to substantial swelling and rapid
enzymatic degradation resulting in too fast release of
many drugs. This has led to the use of derivatives of
starch that are more resistant to enzymatic
degradation as well as crosslinking and formation of
co-polymers. Starch acetate prepared by acetyl
esterification
has
shown
retarded
enzymatic
degradation with the potential to be used as a colon-
targeted drug delivery carrier.
25
High amylase
carboxymethyl starch produced by spray drying
showed a high loading capacity for the soluble drug,
acetaminophen,
in
controlled
release
direct
compressible matrix systems.
26
To deliver proteins or peptide drugs orally,
microcapsules containing a protein and a proteinase
inhibitor were prepared. Starch/bovine serum
albumin mixed-walled microcapsules were prepared
using interfacial cross-linking with terephthaloyl
chloride. The microcapsules were loaded with native
or amino-protected aprotinin by incorporating
protease inhibitors in the aqueous phase during the
cross-linking process. The protective effect of
microcapsules with aprotinin for bovine serum
albumin was revealed in vitro.
27
Pectin
Pectin is the purified carbohydrate product obtained
by acid hydrolysis from the inner portion of the rind
of citrus peels i.e. Citrus Simon or Citrus Aurantium,
(Rutaceae). The main component of pectin is a linear
polysaccharide
composed
of
α-1,4-linked
D-
galacturonic acid residues interrupted by 1,2- linked
L-rhamnose residues with a few hundred to about one
thousand
building
blocks
per
molecule,
corresponding to an average molecular weight of
about 50,000 to about 1,80,000.
28
The galacturonic
acid polysaccharides are rich in neutral sugars such
as rhamnose, arabinose, galactose, xylose and
glucose. The composition of pectin can vary based on
the botanical source, for example pectin from citrus
contains less neutral sugars and has a smaller
molecular size as compared to pectin obtained from
apples.
29, 30
Pectin has been investigated as an excipient in many
different types of dosage forms such as film coating
of colon-specific drug delivery systems when mixed
with ethyl cellulose, microparticulate delivery
systems for ophthalmic preparations and matrix type
transdermal patches. It has high potential as a
hydrophilic polymeric material for controlled release
matrix drug delivery systems, but its aqueous
solubility contributes to the premature and fast
release of the drug from these matrices.
9
It was investigated that the suitability of amidated
pectin as a matrix patch for transdermal chloroquine
delivery in an effort to mask the bitter taste when
orally administered. The results suggest that the
pectin-chloroquine patch matrix preparation has
potential applications for the transdermal delivery of
chloroquine and perhaps in the management of
malaria.
31
Calcium pectinate nanoparticles to deliver
insulin were prepared as a potential colonic delivery
system by ionotropic gelation.
32
Micro particulate polymeric delivery systems have
been suggested as a possible approach to improve the
low bioavailability characteristics shown by standard
ophthalmic vehicles (collyria). In this context pectin
microspheres of piroxicam were prepared by the
spray drying technique. In vivo tests in rabbits with
dispersions of piroxicam-loaded microspheres also
indicated a significant improvement of piroxicam
bioavailability in the aqueous humour (2.5-fold)
when compared with commercial piroxicam eye
drops.
33
Depending on the type and structure of the pectin
molecule, pectins can gel in various ways. Gelling
can be induced by acid or cross-linking with calcium
ion or by reaction with alginate. When a pectin
solution is titrated with acid, the ionization of
carboxylate groups on pectins is repressed causing
pectin molecules to no longer repel each other over
their entire chains. The pectins can thus associate
over a portion of their chains to form acid-pectin
gels. Gel forming systems have been investigated
widely for sustained drug delivery. A mixture of
xyloglucan with pectin resulted in an in situ gel
forming system with sustained paracetamol drug
delivery in rats.
34, 35
In relation to cosmetics, using citronella as a model
compound, pectin gel formulations were evaluated
for controlled fragrance release by kinetic and static
methods. These formulations showed a prolonged
duration of fragrance release and limitation of
fragrance adsorption to the receptor skin layers. The
increase in pectin concentrations suppressed the
fragrance release by a diffusion mechanism, thereby
proving that pectin/calcium microparticles are
promising
materials
for
controlled
fragrance
release.
36
In relation to the food industry, folic acid
incorporated microcapsules were prepared using
alginate and combinations of alginate and pectin
polymers so as to improve stability of folic acid.
Folic acid stability was evaluated with reference to
encapsulation efficiency, gelling and hardening of
capsules, capsular retention during drying and
storage. The blended alginate and pectin polymer
matrix increased the folic acid encapsulation
efficiency and reduced leakage from the capsules as
