formulation and evaluation of microneedle .

1. MICRONEEDLE AS TDDS
GUIDED BY – PRESENTED BY –
Dr. Tejal Mehta Sagar S. Bhor
20mph113

2. Contents -
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Introduction
Types of micronnedle
Fabrication of microneedle
Evaluation
Application
Marketed preparations
Reference

3. INTRODUCTION TO MICRONEEDLE -
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Microneedle is transdermal drug delivery system (tdds)
Microneedle can be single or an array, consisting of hundreds
or even thousands of microprojections, with a length of
20-1500 microns .
Internal diameter not more than 30 microns

5. Dimensions-
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Microneedles are generally 150-1500 micrometer long to discharge
the drug in epidermis
as more than 1500 micrometer can cause damage to veins.
Length – <1500 micrometer
Breadth – 0-250 micrometer
Thickness – 1-30 micrometer

6. Advantages of MD as tdds -
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Avoid first pass metabolism
Ease of application
More patient compliance as compared to hypodermic needle
Faster healing at injection site than hypodermic needle
Larger molecules can be administered
Good tolerability without long term oedema

7. Disadvantages –
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Careful use of the devices may be needed to avoid particles
“bouncing off” the skin surface
The thickness of stratum corneum and other skin layers varies in
individuals and so depth may vary
Repetitive injection may collapse the veins
Tip of MD may break off and remain inside the skin

8. Classification of Microneedle -
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1. Based on drug delivery method
2. Based on structure of microneedle
3. Based on material used .

9. Types of microneedle -
Microneedle
Coated microneedle
Solid microneedle
Dissolvable microneedle
Hollow microneedle

10. Approaches for microneedle –
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A. poke and patch approach
B. Coat and poke approach
C. Poke and release
D. Poke and flow

11. Solid Microneedle-
• Poke & patch approach
Solid MN
poked &
penetrated in
skin
Microchannel
s created
Patch is
applied

12.  Coated Microneedle -
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Coating of drug & water soluble excipient is done on shaft of MN
Water soluble excipients facilitate Detachment of film from
surface of MN
Detachment takes seconds to minutes
Shaft
Base substrate

13. Selection of excipients for coated MD -
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SELECTION CRITERIA-
the material should be biocompatible,
preferably it should already be approved for use as an excipient in
injectable formulations by local regulatory agencies, such as the
Food and Drug Administration in the United states.
should be safe for use

14. Coating solution excipients -
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Viscosity enhansers
Viscosity enhansers are used to maintain the proper viscosity of coating solution
eg. Carboxymethylcellulose sodium
Hydroxypropyl methyl cellulose , Hydroxyethylcellulose , Pectin
Surfactant
For proper solubility
Eg. Tween 80 , Polysorbate 20/Tween 20
Stabilizers
To help stabilize and protect active molecules such as proteins, inactivated viruses,
and virus-like particles from desiccation forces and denaturation.
Eg . Maltodextrin ,lactose , glucose , dextran

15. Coating methods –
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Dip–coating
In this method, a microneedle is dipped into
the coating liquid. The microneedle, upon exiting the coating
liquid entrains a liquid film on its surface. When the solvent
in the liquid film evaporates, the dissolved or suspended solids
that are present in the liquid film get deposited as a coating
on the microneedle surface.

16. Inkjet Printing -
In this method the material to be coated
is ejected directly onto the surface of the microneedle in the
form of tiny liquid droplets from piezo-driven nozzles .
In contrast to the dip-coating method,
for inkjet printing the coating solution viscosity must be
relatively low to prevent nozzle clogging and to successfully
generate small-sized drops

17.  Dissolvable Microneedle
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Based on POKE & RELEASE APPROACH
Completely dissolve(degrade) upon insertion in skin
High drug loading than coated type
Do not leave any biohazardous waste in skin

18.  Hollow microneedle -
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Hollow MN deliver drugs via the “poke-and-flow”
approach. Similar to the hypodermic injection,
the liquid drug can continuously flow into the skin via the
holes in the hollow
flow rate of drug can be accurately controlled by special
equipment such as micropump

19. Working of hollow MD -
DRUG
HOLLOW
MD

20. Microneedle based on structure -
Microneedle
Microneedle
Out-of-plane
Out-of-plane
In-plane
In-plane
Shaft is
perpendicular
to base
Shaft & base
Are Parallel

21. Material of fabrication of MD -
Silicon Glass
Polyme
r
Metals

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Silicon
Most commonly used
Higher hardness so easy to penetrate
Breakoff may cause due to fragile nature
Non –biocompatible so cause inflammation
 Alumina, zirconia, and calcium sulfate hemihydrate are
commonly used to fabricate MNs
 Metals like Titanium , Stainless Steel , nickel also used but has problem of
non- biodegradable waste

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Polymers
Biocompatibility is major advantage over silicon & metals
wider variety of polymers available
Eg. polymethyl methacrylate,
polyglycolic acid ,
polylactic-co-glycolic Acid
polycaprolactone
PVA,
carboxymethyl cellulose (CMC)

24. Fabrication Of Microneedle
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Etching method -
Dry etching
Wet etching
Micromolding method –
Micromolding is the most common method to makeceramic MNs.
Generally, in this fabricating method, the MN master templates were first prepared by
microfabrication methods, after that the ceramic slurry was filled into
the cavities of molds, and then the ceramic MNs were formed

25. Bioceramic md with gelatin substrate

26. Evaluation of microneedle -
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coating uniformity
Mechanical evaluation
Insertion force
Failure force
Insertion depth
In-vitro skin penetration

27. Evaluation of microneedle -
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Coating Uniformity
A visual analysis of the coated microneedles under a microscope
(often a stereomicroscope) can provide details on coating
uniformity, and whether coatings are contaminating the base
substrate of the microneedle array. This is typically done by
adding a colored compound or a fluorescent dye into the
coating solution, or by conjugating a fluorescent dye onto the
active molecule being coated. This aids in visualization of
coatings under a stereomicroscope .

28. Mechanical evaluation -
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Parameter Tests
Failure force forcing the instrument on a stiff surface,
Displacement press tests
Insertion force color marking,
compulsion-installation tests or
Electrical values
Insertion depth Histological cryo-sectioning and dying,
focal microscopic technique and
Optical tomography

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Optical tomography –
Optical Coherence Tomography (OCT) can be described as the optical equivalent to
ultrasound, which maps changes of reflected light from a biological tissue as a function
of depth.
The ability of OCT to visualise depths of ̴2000 μm
OCT can be considered as the only technique capable of providing transverse
imaging of the SC, epidermis and upper dermis OCT is a valuable, non-invasive
technique that can be used to observe in real time, MNs inserted into human subjects’
skin to determine the MNs’ ability to penetrate the skin

30. In-vitro skin penetration examines
• In-vitro skin penetration examines
Diffusion cell device is utilized to find the penetration of the
medication pass on the skin. Pig ear dermis is generally utilized in
the analysis that is arranged between the receptor and contributor
division. The combined penetration profiles of microneedle treated
and without treated dermis are looked

31. Application of MD
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Microneedle based vaccine
Microneedle delivery based insulin
Local tissue delivery
Hormone delivery
Ocular drug delivery
Cancer treatment
Cosmetics

32. Microneedle in biologics-

33. microneedle in cosmetics -
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To promote the natural healing of the injured skin. The other is to enhance
skin permeation of cosmeceuticals. Minimally invasive delivery of
microneedle created transient holes to enhance the penetration, triggering
wound repair mechanism spontaneously
a novel cosmetic microneedle loading retinyl retinoate and ascorbic acid
were successfully produced for anti-wrinkle without side effects such as
allergies .
Dermaroller used for skin penetration pentration of cosmeceuticals
Dermaroller

34. Marketed preparations -

35. Reference
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Rohan S.J. Ingrole and H. S. Gill 2019, Microneedle Coating Methods: A Review with a
Perspective, THE JOURNAL O,F PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS
Xiaoxiang He et.al . 2019, Microneedle System for Transdermal Drug and Vaccine Delivery:
Devices, Safety and Prospects
slideshare - https://www.slideshare.net/AmyMehaboob1/microneedles
Photos from www.google.com
https://www.slideshare.net/samikshasawant146/microneedles-in-transdermal-drug-
delivery
https://www.researchgate.net/
publication/341998655_Microneedle_Array_Applications_Recent_Advances_and_Clinical_P
ertinence_in_Transdermal_Drug_Delivery

36. Thank you