novel drug delivery system(NDDS) b.pharma semester 7, Intrauterine Drug Delivery Systems: Introduction, advantages and disadvantages, development of intra uterine devices (IUDs) and applications

1. INTRA-UTERINE DRUG DELIVERY SYSTEM
NDDS
B.PHARMA SEMESTER 7
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Introduction, advantages and disadvantages, development of intra uterine devices (IUDs) and
applications
What is an Intrauterine Contraceptive Devices (IUD)?
IUD’s are medicated or non-medicated devices which exerts it’s contraceptive action in the
uterine cavity continuously for a prolonged period of time without requiring patients motivation.
How Does an IUD Work?
An IUD prevents sperm from meeting an egg. An IUD may stop a fertilized egg from growing
inside the uterus
Types of IUD’s:
1. Non-medicated IUD’s: Contraceptive action by producing sterile inflammatory response
in Endometrium. These are available in ring shaped IUD’s made up of s.s and plastic
fabricated form polyethylene, polypropylene.
2. Medicated IUD’s: - Copper IUD’s
Progesterone releasing IUD’s
Copper bearing IUD’s:

2. A) 7-Shaped IUD:-
 Further development of the concept of intra-uterine contraception by metallic copper has
resulted in copper barring IUD, which contains 89mg copper wire, wound around the
vertical limb of a 7-shaped polypropylene device, to give an effective surface of
approximately 200mm2 used for 3years as intra-uterine contraceptive treatment.
 This device release copper ion at a mean daily dose of 9.87µg/day continuously in the
uterine cavity for up to 40 months.
 The Cu-7 appears to be substantially smaller then other.
 It can be easily inserted because of it’s special 7-configuration in addition to its small
size.
 Insertion can usually be accomplished without the need for cervical dilation and further
more removal is generally painless.
B) T-Shaped IUD’s
 T-shaped IUD containing 200mm2 contraceptive copper wire winding around the vertical
leg of a T-shaped polyethylene device in the manner as copper-7 device.
 It is used for 3years of contraceptive treatment.
 This T-shaped device has a volume of 0.16cm3,which is almost twice as large as the 7-
shaped device.
C) New development of copper bearing IUD’s:
 The Cu-T-380A with 2 collars of copper positioned on the transverse arms of the letter
T. Each collar provides an additional surface area of 30mm2. It has relatively small
surface area of copper but effective than Cu-T-200.
 Another new version of copper bearing IUD:
The combined multi load copper IUD (MLCU-250) was also introduced. It is a
compromise between Cu-T IUD, but without the central plastic membrane and has a
surface area of 250mm2 copper wire. The blunt apex of the device fits into the vault of
the uterine cavity without penetrating the endometrial walls and its two arms studded
side arms fully adapt to the contours of the uterine cavity.
Potentialdevelopment
1. Membrane controlled reservoir-type drug delivery system:
These drug delivery devices consist of a polymeric membrane that both encapsulates and
controls the release of contraceptive agent

3.  Single component system: In this system the contraceptive agent is encapsulated in its
pure solid form in a capsule fabricated form bio-compatible polymeric materials (silicon
elastomers and polyethylene- polymers) The release of contraceptive agent such as
progesterone follows essentially zero-order kinetics.
 Multi component system: In this system a constant drug release profile is maintained by
encapsulating a liquid medium saturated with excess drug profiles in a rate-controlling
polymeric membrane.
2. Polymer matrix diffusion controlled drug delivery devices:
This drug delivery device is prepared by homogenously dispersing the drug particles in a crossed
linked polymeric matrix.
 Retrievable matrix device: This drug delivery system is designed for feasibility of
retrieval at termination of treatment. It can be easily fabricated from silicone elastomers
by premixing a drug in powder form with a semisolid silicone elastomers before
vulcanization at room or low temperature or from polyethylene by dry mixing. The rate
of drug release is not constant but time dependent.
 Bio-degradable matrix device: This drug delivery system is designed to eliminate the
need for retrieving at the end of treatment it can be prepared by dissolving such a poly
lactic acid, in a common organic solvent to dryness, to produce drug dispersing
biodegradable matrix devices of varying shapes and sizes, The rate of drug-release from
this type of drug delivery system is a combination of polymer hydrolysis and drug
diffusion.
MECHANISM OF ANTIFERTILITYACTION OF COPPER:
 Copper is known to be cytotoxic in high concentration it enhances the spermatocidal and
spermato depressive action of an IUD.
 The copper concentration in endometrial epithelium and superficial stromata inhibits the
binding of steroids of their receptors.
 Cupric ion inhibits the binding of 17-β- estradiol to human endometrial cytosol.
 Cupric ions shows only little effect on sperm motility.
 Copper wire was also “Blastocystocidal”.
 A copper bearing IUD was reported to produce significant effects like:
o Increased alkaline phosphate activity in uterine fluids and endometrium tissue.
o No change of acid phosphate activity in uterine fluid but its concentration in
endometrium tissue increases.
Advantages of the IUD:
 Provides long-term birth control.
 Cost effective.

4.  Can be removed when a woman would like to become pregnant.
 Convenient - a woman does not need to remember it daily or weekly.
Disadvantagesofan IUD:
 Between 2 and 10% fall out, most commonly in the first year of use.
 Increased risk of miscarriage if an IUD is left in the uterus during pregnancy.
 In rare cases, the IUD may attach to or perforate the wall of the uterus.
 With the copper IUD, a woman may experience heavier bleeding and cramping with
periods.