Journal

International Journal of Drug Delivery 3 (2011) 279-285
http://www.arjournals.org/index.php/ijdd

Original Research Article

ISSN: 0975-0215

In Vitro and In Vivo evaluation of hydroxypropylmethyl cellulose phthalate
capsules
E.O. Cetin1, M. Asikoglu2, E. Gundogdu1, O. Orumlu2, L. Kirilmaz1
*Corresponding author:

E.O. Cetin
1Ege University, Faculty of
Pharmacy, Dept. ofBiopharmaceutics and
Pharmacokinetics, Bornova,
Izmir.
2Ege University, Faculty of
Pharmacy, Dept. of
Radiopharmacy, Bornova,
Izmir.

Abstract
The aim of this study was to develop a novel HPMCP capsule. The
HPMCP capsule containing99mTc-DTPA and lactose was evaluated
in in vitro and in vivo studies. First of all, the HPMCP capsules were
prepared and characterized with lenght and diameter size,brittleness
facility, moisture content and microbiological test. In vitro resistance
and solubility studies of prepared capsules were tested at pH 1.2 and
pH 7.4 buffers. The radiolabeled HPMCP capsules were
administrated to fasted volunteers. The disintegration times and
positions of capsules were recorded by using gamma scintigraphy. In
vitro studies showed that HPMCP capsules were gastroresistant for
2 h at pH 1.2 and dissolved at pH 7.4 in 20-25 minutes. The
radiolabeled capsules did not disintegrate in stomach whereas
disintegrated in intestines. In conclusion, it was found that, the
prepared HPMCP capsules can be an alternative to the hard gelatine
capsules and used for intestinal targeting.
Keywords: Capsule, hydroxypropylmethylcellulose phthalate
(HPMCP), gammascintigraphy, radiolabelling, technetium-99m.

Introduction
Controlled drug delivery systems have important
advantages in treatment of several diseases. In
delayed-release systems, the enteric coating of
tablets or capsules modifies the release pattern of
active ingredient. These types of formulations can
be designed to release the drug in intestines. Two
general categories may be distinguished,namely
enteric coating and controlled release coatings.
Enteric coating process may be required for some
active substances irritating the stomach or
degrading due to acidic pH of the stomach and it
is insoluble in the gastric juices, but dissolves
readily on passage into the small intestine. The
polymers commonly used to achieve enteric
properties
are
anionic
polymethacrylates(copolymerisate of methacrylic acid and either
methyl-methacrylate or ethyl acrylate cellulose

based polymers, e.g. cellulose acetate phthalate or
polyvinyl derivatives, e.g. polyvinyl acetate
phthalate [1,2]. Polymers with ionizable phthalic
acid groups dissolve much faster at a lower pH
than those with acrylic or methacrylic acid groups
[3].
The most common mode of action of enteric
coatingsis pH related solubility; i.e., insoluble at
gastric pH but soluble at some pH above 4.5.
Cellulose acetate phthalate (CAP) and
hydroxypropylmethylcellulose
phthalate
(HPMCP) are widely used as enteric film coating
materials. HPMCP is completely insoluble in
gastric fluid but dissolves above pH 4.5 in
proximal end of duodenum. [4-7]. In one study,
enteric coated HPMC capsule has beendesigned
to achieve intestinal targeting by manufacturing
of two different Eudragit® HPMC capsules [1].

Cetin et al. International Journal of Drug Delivery 3 (2011) 279-285
obtained from sequential images. Determination
of gastric residence times, times of transit
through the small intestine and colon, times and
locations of in vivo release and correlation of
findings with kinetic data canbe evaluated
[11,12].

Methods based on pH-sensitive delivery systems
such as enteric coated dosage forms could be a
simple and practical means for colon-specific
drug delivery. However such methods do not
have sufficient site specificity because, with this
type of dosage form, most of the drug is released
in the upper small intestine after gastric
emptying, even though drug release...