Home' Australian Pharmacist : Australian Pharmacist July 2012 Contents 576 Australian Pharmacist July 2012 I ©Pharmaceutical Society of Australia Ltd.
The articles in this series are independently researched and compiled by PSA commissioned authors and peer reviewed.
Much of the attention turned to studying
natural and modified polysaccharides
with a GRAS status which are substrates
for the bacterial enzymes, and resistant
to digestion by human GIT enzymes.
While promising, polysaccharides have
been criticised for their high water solubility
as it makes them unreliable for delivery
to the lower parts of the GIT (e.g. the
colon).17,21 Additionally, characteristics
observed during in vitro studies could not
be translated into practical applications. For
instance, a polysaccharide may be highly
susceptible to degradation by bacterial
enzymes, but when used in a practical
application (e.g. as a tablet coating),
the polysaccharide was found to be
unexpectedly resistant to bacterial enzyme
degradation.21 Nevertheless, the continuing
work on polysaccharides has further shown
that a delivery system which targets the
microorganisms of the large intestine holds
promise as a reliable colon targeted drug
Following from polysaccharides, there
has been increasing interest in the use of
proteins as a drug delivery system, as they
too can be naturally occurring and have a
designated GRAS status. One protein which
has been the subject of research is zein – a
storage protein extracted from corn.29
Zein protein is extracted as a co-product
of starch processing, and is expected
to become more readily available with
increased demands for corn starch in the
food and pharmaceutical industries; and as
a by-product from biofuel production.29,30
In the pharmaceutical industry, zein
is one of the natural polymers which
has been investigated for its potential
as an orally delivered controlled- or
sustained-release delivery system due to a
resistance to digestion in the stomach.31,32
Example applications include use as an
excipient in tablet formulations,33 and
formulating zein nano- or micro-particles
to encapsulate bioactive agents.34,35
Other options explored include using
zein as a sustained-release reservoir
of medications in coronary stents,36
and to formulate an injection with
sustained-release properties for animals.32
In light of the potential barriers an oral
delivery system will encounter along the
GIT, GRAS substances (such as naturally
occurring proteins) that are relatively
indigestible by human digestive enzymes,
and are susceptible to breakdown
by the microbes residing in the large
intestine could potentially be useful as
an oral delivery system that targets the
IBD is a severe chronic condition which
represents a large burden of disease and
cost to the economy through treatment
costs and productivity loss, and can be
extremely debilitating and impact poorly
on quality of life.4 A report commissioned
by the Australian Crohn’s and Colitis
Association projected that compared to
2005, by 2020, approximately 33,500 people
will be affected by CD (20% increase),
and over 41,000 with UC (25% increase).4
Pharmacists are often the first point of
call for patients and since the number of
people affected by IBD is anticipated to rise,
pharmacists are well placed to help provide
information, support and reassurance.
While patients wait for the silver bullet that
will ‘cure’ IBD, more effective and targeted
delivery of existing therapies will aid in the
quality use of medicines, and may improve
existing treatment options.
1. Rogers S, ed. Therapeutic guidelines: gastrointestinal. 5th ed.
Victoria (AUS): Therapeutic Guidelines; 2011.
2. Morrison G, Headon B, Gibson P. Update in inflammatory bowel
disease. AFP. 2009;38(12):956–61.
3. Wallace JL, Sharkey KA. Pharmacotherapy of inflammatory bowel
disease. In: Brunton LL, Chabner BA, Knollmann BC, editors.
Goodman & Gilman’s The pharmacological basis of therapeutics.
12 ed. New York: McGraw-Hill; 2011.
4. Access Economics, Australian Crohn’s and Colitis Association. The
economic costs of crohn’s disease and ulcerative colitis. 2007
[cited 2011 Oct 12]; At: www.crohnsandcolitis.com.au/content/
5. Rossi S, ed. Australian medicines handbook online. South
Australia (AU): Australian Medicines Handbook; 2011.
6. Jeffrey E, Bereznicki L. Inflammatory bowel disease. Aust Pharm.
7. Jain SK, Jain A. Target-specific drug release to the colon. Expert
Opin Drug Deliv. 2008;5(5):483–98 .
8. Wilding IR, Davis SS. Targeting of drugs to the gut. In: Swarbrick J,
Boylan JC, eds. Encyclopedia of Pharmaceutical Technology. New
York (US): Marcel Dekker. 1999;287–308.
9. Patel MM. Cutting-edge technologies in colon-targeted drug
delivery systems. Expert Opin Drug Deliv. 2011;8(10):1247–58.
10. Evonik Industries. Enteric Formulations – Eudragit – Targeted
Drug Release and Tailored Service. Essen, Germany: Evonik
Industries AG; [cited 2012 Jun 5]; At: http://eudragit.evonik.com/
11. Hanauer SB, Lim WC, Sparrow M. Medical management of
inflammatory bowel disease. In: Wolff BG, Fleshman JW, Beck DE,
Pemberton JH, Wexner SD, eds. The ASCRS textbook of colon and
rectal surgery. New York (US): Springer Science+Business Media,
12. Australian Government Department of Health and Aging.
Pharmaceutical Benefits Scheme (PBS). Commonwealth of
Australia; 2011 [updated Sep 2011; cited 2011 Sep 30]; At: http://
13. Verma RK, Garg S. Current status of Drug Delivery Technologies
and Future Directions. Pharm Tech. 2001;25(2):1–14 .
14. Philip AK, Philip B. Colon targeted drug delivery systems: A review
on primary and novel approaches. Oman Med J. 2010;25(2):70–8.
15. Kendall RA, Murdan S, Basit AW. Modified-release microparticles
for oral drug delivery. Drug Delivery Technology. 2005;5(8):76–80 .
16. Basit AW, McConnell EL. Drug delivery to the colon. In: Wilson
CG, Crowley PJ, eds. Controlled release in oral drug delivery. NY:
Controlled Release Society, Springer; 2011;385–99 .
17. Sinha VR, Kumria R. Microbially triggered drug delivery to the
colon. Eur J Pharm Sci. 2003;18(1):3–18.
18. Kumar P, Mishra B. Colon targeted drug delivery systems - an
overview. Curr Drug Deliv. 2008;5(3):186–98 .
19. Raghavan C, Muthulingam C, Jenita JAJL, Ravi TK. An in vitro
and in vivo investigation into the suitability of bacterially
triggered delivery system for colon targeting. Chem Pharm Bull.
20. Aswar PB, Khadabadi SS, Kuchekar BS, Wane TP, Matake
N. Development and in-vitro evaluation of colon-specific
formulations for orally administered diclofenac sodium. Archives
of Pharmaceutical Sciences and Research. 2009;1(1):48–53.
21. Watts PJ, Illum L. Colonic drug delivery. Drug Dev Ind Pharm.
22. Jeong YI, Ohno T, Hu Z, et al. Evaluation of an intestinal pressure-
controlled colon delivery capsules prepared by a dipping
method. J Control Release. 2001;71(2):175–82.
23. Sinko PJ. Martin’s physical pharmacy and pharmaceutical
sciences. 5th ed. Troy D, ed. US: Lippincott Williams & Wilkins;
24. Yang L, Watanabe S, Li J, et al. Effect of colonic lactulose
availability on the timing of drug release onset in vivo from a
Education for pharmacists and
Counter Connection – A monthly
distance education module for
Facts Behind the Fact Cards – Monthly
detailed clinical and practice education
for pharmacists. CPD points are available.
Self Care Your professional edge
Health information for your customers
Fact Cards – Fact Cards provide
independent, concise and factual
information for the pharmacy team
Health campaigns – Comprehensive
health promotion pharmacy
packages designed to educate and
raise public awareness.
Promotion tools for your pharmacy
John Bell’s Health Column – Self Care
Adviser, John Bell, writes an informative
weekly column that can be personalised
to member pharmacies and used in
local media such as newspapers and
Pharmacy’s leading health information and education program Join now at www.psa.org.au/selfcare or call 1300 369 772
Links Archive Australian Pharmacist June 2012 Australian Pharmacist August 2012 Navigation Previous Page Next Page