The document discusses various radio imaging techniques, primarily focusing on gamma scintigraphy, which involves noninvasive imaging of dosage forms to study their transit and absorption in vivo. It covers the properties and applications of radiopharmaceuticals, x-ray imaging, PET/SPECT, MRI, and ultrasonography in pharmaceutical formulation development and evaluation. Additionally, it addresses advantages and disadvantages of these imaging methodologies, alongside examples of practical applications in drug delivery systems.

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Mr. Sagar Kishor SavaleMr. Sagar Kishor Savale
[Department of Pharmaceutics][Department of Pharmaceutics]
avengersagar16@gmail.comavengersagar16@gmail.com
2015-20162015-2016

2. Introduction
Radio imaging techniques are the noninvasive imaging of various organs,
tissues using radioisotopes for the purpose of formulation development,
improvement of dosage form or diagnosis and treatment of disease.
Radiopharmaceuticals:-
These are dosage forms consisting of two components, a carrier and
radionuclide which are used for diagnostic and therapeutic treatment of
disease.
Radionuclide(tracer/marker)
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3. Ideal properties of Radionuclide
 Pure gamma emitter( 100- 250 keV)
 Half life should be short and effective.
 High target to background ratio.
 Low dose rate to patient and personnel.
 Nontoxic, Convenient.
 Chemically stable.
 Inexpensive and readily available.
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4. Gamma Scintagraphy
It is a technique by which transit of a dosage form through its
intended site of delivery can be noninvasively imaged in vivo via
the judicious introduction of an appropriate short lived, gamma
emitting radioisotope.
The observed transit then correlated with the rate and extent of
drug absorption.
Ideal for specialized dosage forms such as CR, SR, Enteric
coated, Delayed release, Colonic and Nasal Delivery.
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5. How it is done?
Radiolabelling of dosage form:
1. Standard Labelling procedure-
Incorporation of short lived radioisotope into formulation.
Reducing agent is used.
Commonly Employed radionuclide
Radionuclide Half life (approx.)
81m
Kr (Krypton) 13 sec
99m
Tc (Technetium) 6.02h
111
In (Indium) 2.8h
123
I (Iodine) 13h
131
I (Iodine) 8.05h 5

6. 2. Neutron Activation technology:
Incorporation of stable isotope into dosage form prior to its manufacture,
followed by neutron irradiation.
Neutron flux exposure is conducted for very short 5-30sec.
Short period exposure prevent drug degradation under bombardment
Stable nuclide Radionuclide Half life
138
Ba (Barium) 139
Ba (Barium) 83min
170
Er (Europium) 171
Er (Europium) 7.5h
153
Sm
(Samarium)
153
Sm
(Samarium)
47h
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7. Applications of Gamma Scintagraphy
It has proven to be great value in assisting Formulation
Development.
To predict in vivo behaviour of dosage form.
1)Oral Drug Delivery System:-
To acquire information about transit and release behaviour of dosage
form
i. Effect of food on in vivo behavior of SR multilayer tablet:
Geomatrix tab.(Antacid): 2 portion- IR+SR (barrier,174
Yb )
12 normal human volunteer selected
2 conditions considered High fat and Low fat breakfast. 7

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Process High Fat Low fat
Initial
erosion
2.0h 1.8h
Complete
Release
4.1h 5.1h

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10. ii. Study of apparent drug absorption anomalies:-
Qualitative analysis
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Time Comment
Delayed GE in (b)
1 hr later Rupture and disruption of (b)
than (a)
After 0.5 hr Release From (b) out of stomach
(b) Remained high in fundus for
1 hour

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a. without
adhesive
b. with
adhesive

12. a. Without adhesive
b. with adhesive
Jejunum (white triangle)
Ileum (black triangle)
Drug (diamond)
Stomach (white circle)
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Quantitative analysis- Overlay plots
(a) (b)
Beginning of Ab.
Coincide with
GE
Slow E in
stomach- delayed
GE and onset

13. iii. Colon Targeting:-
1. To evaluate efficiency of polymers used for coating in Colon
DDS.
2. To study colon specific DDS and assessment of transit of
colon.
iv. Gastroretentive DDS:-
To evaluate gastric retention time of Floating SR dosage forms.
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15. Intelisite Capsule:-
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2) Nasal Drug Delivery System:-

17. To quantify nasal residence of formulation.
To investigate absorption of formulation.
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Formulation Spreading Clearance
Conventional Deposited in
posterior cavity
Rapid
(t ½ 9.2min)
1% Good Faster than 2%
2% Extended Residence
4-5h
3% Not Cleared intact
within 90min

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19. 3)Miscellaneous:-
 Rectal and Vaginal Drug Delivery System
Site specific Drug Delivery System
Evaluation of new drug during development phase.
Establishing bioequivalence of generic product.
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20. Advantages:
Less time required.
Simple and convenient.
Disadvantages:
Higher cost.
Highly skilled labour.
Strict environmental control.
Unpredictable effect on formulation.
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21. X ray Imaging
X-ray is the form of electromagnetic radiation which has ability to
penetrate into the body and produce images or picture for different
organs, tissues.
2D images can be produced by this technique.
X-ray produced by bombarding anode with high energy electrons
emitted from hot cathode in a tube.
X ray Energy
Soft 0.12- 12 keV
Hard 12- 120 keV
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22. Applications of x-ray imaging
In-vivo visualization and localization of solid dosage
forms.
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23. Simultaneous imaging of rat’s g.i.t and enteric coated capsule:
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24. PET/SPECT
 Positron Emission Tomography (PET):- It is a radio
imaging method which produces 3D images of
functional process in a body.
 Positron emitting radionuclide is used (11
C, 13
N, 15
O).
 Single Photon Emission Computed Tomography
(SPECT):- In this method 3D images produced by
using Gamma camera and images can be reconstructed
in different planes.
 In SPECT: 201
Tl, 99m
Tc, 123
I
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25. Applications of PET/SPECT
In pharmacology
In pharmaceutics:-
?
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26. Magnetic Resonance Imaging
It is non invasive and nondestructive technique which can
provide cross sectional images from inside body materials
and living organisms.
MRI is generated using NMR signal (which is formed by
certain nuclei like 1
H, 13
C ) when subjected to strong
magnetic field and irradiation of radiowaves.
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27. Applications of MRI
In vitro characterization:-
To study swelling behaviour of tablet.
To investigate hydration in modified release delivery systems
In study of pharmaceutical processes:-
 To measure distribution of water in Extrudates.
 Blending process.
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29. In vivo study of drug delivery in human and animals
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30. Ultrasonography
 This techniques uses high frequency sound waves to view internal
organs. It uses principles of sonar developed.
 As sound passes through body it produces echoes, which can be used to
identify distinguish between body parts and their size and shape.
Applications:- ?
1. In vitro characterization
2. In vivo evaluation
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31. AC Biosusceptometry
This technique uses induction coils to record
magnetic flux variation obtained by response of
magnetic material ingested.
Magnetic tablets prepared by compression using
Ferrite.
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32. Applications of ACBs
To acquire knowledge of gastrointestinal transit and
disintegration process of enteric coated tablet:-
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T1 Arrival to colon
T3 & T4 Onset of disintegration
T7 Spreading of MT, Complete
Disintegration

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34. Gastrointestinal Magneto MarkerGraphy
(GIMG)
In this method, the dosage form labeled with ferromagnetic material
and subsequent magnetization using strong magnetic field.
Advantages: Extremely sensitive
High resolution
3D imaging
Nontoxic
Disadvantages: Magnetic signals interference.
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36. Applications of MMI:-
In vitro characterization:
Modified dissolution and disintegration
In vivo investigation:
Esophageal transit
Gastric Residence
Intestinal transit
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37. References:
European Journal of Pharmaceutics
European Journal of Pharmaceutics and Biopharmaceutics
Journal of Controlled Release
Advanced Drug Delivery Reviews
International Journal of Pharmaceutics
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