Colon Targeted Drug delivery is the most convenient and desirable drug targeting method for the drugs which degrades in acidic environment, and also preferable for prolong or delayed release and also desease specisic to colon.

1. P R E S E N T E D B Y:
M R . D AR S H I L K . S H AH
M . P H AR M – I ( 2 0 1 9 - 2 0 2 0 )
P H AR M AC E T I C A L T E C H N O L O G Y
R O L L N O . 1 5
G U I D E D B Y:
M s . H E M AL TAN D E L
RECENT ADVANCES IN COLON
TARGETED DRUG DELIVERY SYSTEM
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2. CONTENT
 INTRODUCTION
 CRITERIA FOR SELECTION OF DRUG
 NEWLY DEVLOPED APPROCHES
 REFERENCES
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3. INTRODUCTION
 Colon drug delivery refers to targeted delivery of drug in to the
lower part of GIT, mainly large intestine.
 Colon-specific drug delivery is critical for treating diseases of
colon, such as colon cancer, amoebiasis, irritable bowel
syndrome, and inflammatory bowel disease.
 Medically targeted delivery to colon produces local effect on the
diseases and hinders the systemic toxic effects of drugs.
 Colon drug delivery can be used to create both systemic and
local effects.
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4. INTRODUCTION
 The colon has a long retention time and appears highly
responsive to agents that enhance the absorption of poorly
absorbed drug.
 Colon was considered as the BLACK-BOX, as most of the drugs
are absorbed from upper GI tract.
 Objectives of colon targeted drug delivery:
1. Increase the pharmacological activity.
2. Reduce dosing and side effects.
3. Prevent drug from degradation.
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5. CRITERIA FOR SELECTION OF DRUG FOR CDDS
 Drug candidate: Drugs which show poor absorption from the
stomach or intestine including peptide are most suitable for
CDDS.
 Drug carrier: The selection of carrier for particular drug
candidate depends on the physiochemical nature of the drug as
well as the disease for which the system is to be used.
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6. NEWLY DEVELOPED APPROACHES FOR CDDS
A. Pressure controlled drug delivery system (PCDS)
B. Novel colon targeted delivery system (CODESTM)
C. Osmotic controlled drug delivery system (OROS-CTTM)
D. Pulsincap system
E. Port system
F. Time clock system
G. Cronotropic system
H. Ticking capsule
I. Enterion capsule technology
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7. PRESSURE CONTROLLED DRUG DELIVERY
SYSTEM (PCDS)
 Takaya et al., have developed pressure controlled colon delivery
capsules
 The digestive processes within the GI tract involve contractile
activity of the stomach and peristaltic movements for propulsion
of intestinal contents.
 These strong peristaltic waves in the colon are of short duration,
occurring only three to four times a day. However, they
temporarily increase the luminal pressure within the colon, which
forms the basis for design of pressure-controlled systems.
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8.  The capsule is prepared using an ethyl cellulose, which is
insoluble in water.
 drug release occurs following disintegration of water insoluble
polymer capsule as a result of pressure in the lumen of the
colon.
 The thickness of the ethyl cellulose membrane is the most
important factor for disintegration of the formulation.
 Drug delivery should be in liquid state to facilitate absorption as
lumen content is already viscous.
PRESSURE CONTROLLED DRUG DELIVERY
SYSTEM (PCDS)
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9. NOVEL COLON TARGETED DELIVERY SYSTEM
(CODESTM)
 CODESTM is a combined approach of pH dependent and
Microbially triggered CDDS to avoid the inherent problems
associated with pH or time dependent systems.
 The system consists of a traditional tablet core containing
lactulose, which is over coated with and acid soluble material,
Eudragit E, and then subsequently over coated with an enteric
material, Eudragit L.
 The premise of the technology is that the enteric coating
(Eudragit L) protects the tablet while it is located in the stomach
and then dissolves quickly following gastric emptying.
 The acid soluble material coating (Eudragit E) then protects the
preparation as it passes through the alkaline pH of the small
intestine.
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10. NOVEL
COLON
TARGETED
DELIVERY
SYSTEM
(CODESTM)
 Once the tablet arrives in the colon, the
bacteria enzymatically degrade the
polysaccharide (lactulose) into organic
acid and subsequent releases the drug.
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11. OSMOTIC CONTROLLED DRUG DELIVERY
SYSTEM(OROS-CTTM)
 The OROS-CT system can be single osmotic unit or may
incorporate as many as 5-6 push-pull units, each 4mm in
diameter, encapsulated within a hard gelatin capsule.
 Each push-pull unit is bi-layered laminated structure containing
an osmotic push layer and a drug layer.
 The push and pull unit is prevented from absorbing water in the
acidic medium of stomach by enteric coating.
 The osmotic pumping action results when the coating dissolves
in the drug is delivered out of the orifice at a rate controlled by
the rate of water transport across the membrane.
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12.  In the small intestine the enteric coating get dissolved and water
enters through the semi-permeable membrane, causing
osmogen to swell and the drug compartment gets released in a
constant manner.
OSMOTIC CONTROLLED DRUG DELIVERY
SYSTEM(OROS-CTTM)
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13. PULSINCAP SYSTEM
 The system consists of a water insoluble capsule body
containing the drug, a hydrogel plug which seals the opened end
of this capsule body and a water soluble cap which covers the
hydrogel plug.
 the capsule is coated with an acid insoluble film coating which
prevents the drug from being released in the stomach.
 The hydrogel plug begins swelling when this enteric coating
dissolves in the small intestine.
 The swelling of the plug allows for a lag time before the drug is
released and the amount of lag time depends on the length of
the plug and the extent at which it is inserted.
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15. PORT SYSTEM
 It consist of a gelatin capsule
coated with a semi-permeable
membrane housing an
insoluble plug and an
osmotically active agent along
with the drug formulation.
 When in contact with aqueous
medium, water diffuses
across the semi-permeable
membrane, resulting in
increased inner pressure that
ejects the plug after a lag
time.
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16. TIME CLOCK SYSTEM
 It is composed of a solid dosage form coated with a hydrophobic
surfactant layer to which a water-soluble polymer is added to
improve adhesion to the core.
 The outer layer re-disperses in the aqueous environment in a
time proportional to the thickness of the film and the core is then
available for dispersion.
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17. CRONOTROPIC SYSTEM
 It consists of a drug containing core coated by hydrophilic swell-
able HPMC, which is responsible for a lag phase in the onset of
release.
 the application of an outer gastric resistant enteric film, the
variability in gastric emptying time can be overcome, and a colon
specific drug release can be obtained.
 The lag time is controlled by the thickness and viscosity grades
of HPMC.
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18. TICKING CAPSULE
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• It is electronically programmed to control the delivery of medicine
according to a pre-defined drug release profile.
• Determines its location in the intestinal tract by measuring the
local acidity (pH difference) of its environment.
 releases medicine from its drug reservoir via a microprocessor
controlled pump, allowing accurate programmable drug delivery.

19. ENTERION CAPSULE TECHNOLOGY
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 The capsule can be loaded with either a liquid formulation or a
particulate formulation.
 The floor of the drug reservoir is the piston face, which is held
back against a compressed spring by a high-tensile strength
polymer filament.
 when the capsule reaches the target site the drug is released by
the action of the magnetic field.
 This magnetic field induce power in a tuned coil antenna,
embedded in capsule wall. This power is fed to a tiny heater
resistor located in capsule.
 This heater resistor increases temperature & releases the spring
& drives the piston.

20. ENTERION CAPSULE TECHNOLOGY
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 The resulting increase in pressure within the drug reservoir
forces off the O-ring sealed cap and ejects the drug or drug
formulation into the surrounding GI fluids.

21. REFERENCES
21
 Colon Targeted Drug Delivery System A Novel Perspective, Review Article,
Bhushan Prabhakar Kolte*, Kalyani V. Tele, Vinayak S. Mundhe, Sandeep S.
Lahoti.
 Colon Specific Drug Delivery Systems: A Review On Various Pharmaceutical
Approaches, Review Article, Prasanth V.V, Jayaprakash. R, Sam T. Mathew,
Issn: 2231-3354.
 Novel Approaches And Developments In Colon Specific Drug Delivery
Systems, Review Article, Prasanta Kumar Choudhury, Tapana Kumar
Panigrahy, Padala Narasimha Murthy, Niraj Kanti Tripathy, Rajeshree
Panigrahi, Saiprasanna Behera.
 Colon-Targeted Oral Drug Delivery Systems: Design Trends And Approaches,
Review Article, Seth Amidon, Jack E. Brown, And Vivek S. Dave.

22. REFERENCES
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 Recent Advances In Colon Specific Drug Delivery System, Research Article,
Sardarmal Yadav*, Ashish Kumar Pareek, Dr.Shiv Garg, Manoj Kumar And
Pradeep Kumar.
 Wireless Endoscopy In 2020: Will It Still Be A Capsule?Anastasios
Koulaouzidis, Dimitris K Iakovidis, Alexandros Karargyris And Emanuele
Rondonotti. Https://Www.Wjgnet.Com/10079327/Full/V21/I17/5119.Htm
 Recent Trends In Colon Targeted Drug Delivery System, Review Article,
Samvedna Aggarwal, Shalini Sharma, Sukhbir Lal, Neeraj Choudhary*.
 Colon Targeted Drug Delivery Systems: A Review On Primary And Novel
Approaches, Review Article, Anil K. Philip, Betty Philip, Philip Ak, Et Al. Omj. 25,
70-78 (2010); Doi:10.5001/Omj.2010.24

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