This document provides an overview of transdermal drug delivery systems (TDDS). It discusses the advantages and disadvantages of TDDS, skin anatomy and the factors affecting drug permeation through the skin. The document outlines the basic components of TDDS including polymers, drugs, permeation enhancers and pressure sensitive adhesives. It describes different types of transdermal patches and formulation approaches used in their development. Examples are given of marketed TDDS products. The document concludes with a discussion of patents and recent research related to TDDS.
Approaches Of Gastro-Retentive Drug Delivery System or GRDDSAkshayPatane
Approaches Of Gastro-Retentive Drug Delivery System
Includes:
Floating and Non-Floating drug delivery system with their subtypes
Like Non-effervescent system, Effervescent system, Raft forming system,
High Density system, Expandable system, Muco-adhesive system,
Super porous hydrogel system and Magnetic Systems, etc.
Gastro retentive drug delivery system (GRDDS)Shweta Nehate
Oral route is the most acceptable route for drug administration. Apart from conventional dosage forms several other forms were developed in order to enhance the drug delivery for prolonged time period and for delivering drug to a particular target site. Gastro-retentive drug delivery system (GRDDS) has gainned immense popularity in the field of oral drug delivery recently. it is a widely employed approach to retain the dosage form in the stomach for an extended period of time and release the drug slowly that can address many challenges associated with conventional oral delivery, including poor bioavailability. different innovative approaches are being applied to fabricate GRDDS. Gastroretentive drug delivery is an approach to prolong gastric residence time, there by targeting site-specific drugs release in the upper gastrointestinal tract (GIT) for local or systemic effects. It is obtained by retaining dosage form into stomach and by releasing the in controlled manner.
Approaches Of Gastro-Retentive Drug Delivery System or GRDDSAkshayPatane
Approaches Of Gastro-Retentive Drug Delivery System
Includes:
Floating and Non-Floating drug delivery system with their subtypes
Like Non-effervescent system, Effervescent system, Raft forming system,
High Density system, Expandable system, Muco-adhesive system,
Super porous hydrogel system and Magnetic Systems, etc.
Gastro retentive drug delivery system (GRDDS)Shweta Nehate
Oral route is the most acceptable route for drug administration. Apart from conventional dosage forms several other forms were developed in order to enhance the drug delivery for prolonged time period and for delivering drug to a particular target site. Gastro-retentive drug delivery system (GRDDS) has gainned immense popularity in the field of oral drug delivery recently. it is a widely employed approach to retain the dosage form in the stomach for an extended period of time and release the drug slowly that can address many challenges associated with conventional oral delivery, including poor bioavailability. different innovative approaches are being applied to fabricate GRDDS. Gastroretentive drug delivery is an approach to prolong gastric residence time, there by targeting site-specific drugs release in the upper gastrointestinal tract (GIT) for local or systemic effects. It is obtained by retaining dosage form into stomach and by releasing the in controlled manner.
Transdermal Drug Delivery System (TDDS) is the one of the novel technology to deliver the molecules through the skin for long period of time.
Transdermal Drug Delivery System (TDDS) are defined as self contained, discrete dosage forms which are also known as “patches” 2, 3 when patches are applied to the intact skin, deliver the drug through the skin at a controlled rate to the systemic circulation
formulation development of Transdermal drug delivery systems i.e. transdermal patches, compostion of transdermal patch, physical methods used to prepare tansdermal patch
Mucoadhesive drug delivery system has gained interest among pharmaceutical scientists as a means of promoting dosage form residence time as well as improving intimacy of contact with various absorptive membranes of the bio- logical system
Powerpoint presentation on controlled drug delivery system. Its introduction, terminologies, rationale, advantages, disadvantages, selection of drug, approaches for designing controlled release formulations and physicochemical and biological properties of drug
Mucoadhesive drug delivery system interact with the mucus layer covering the mucosal epithelial surface, & mucin molecules & increase the residence time of the dosage form at the site of the absorption.
Mucoadhesive drug delivery system is a part of controlled delivery system.
Since the early 1980,the concept of Mucoadhesion has gained considerable interest in pharmaceutical technology.
combine mucoadhesive with enzyme inhibitory & penetration enhancer properties & improve the patient complaince.
MDDS have been devloped for buccal ,nasal,rectal &vaginal routes for both systemic & local effects.
Hydrophilic high mol. wt. such as peptides that cannot be administered & poor absorption ,then MDDS is best choice.
Mucoadhesiveinner layers called mucosa inner epithelial cell lining is covered with viscoelasticfluid
Composed of water and mucin.
Thickness varies from 40 μm to 300 μm
General composition of mucus
Water…………………………………..95%
Glycoproteinsand lipids……………..0.5-5%
Mineral salts……………………………1%
Free proteins…………………………..0.5-1%
The mechanism responsible in the formation of mucoadhesive bond
Step 1 : Wetting and swelling of the polymer(contact stage)
Step 2 : Interpenetration between the polymer chains and the mucosal membrane
Step 3 : Formation of bonds between the entangled chains (both known as consolidation stage)
Electronic theory
Wetting theory
Adsorption theory
Diffusion theory
Fracture theory
Advantages over other controlled oral controlled release systems by virtue of prolongation of residence of drug in GIT.
Targeting & localization of the dosage form at a specific site
-Painless administration.
-Low enzymatic activity & avoid of first pass metabolism
If MDDS are adhere too tightlgy because it is undesirable to exert too much force to remove the formulation after use,otherwise the mucosa could be injured.
-Some patient suffers unpleasent feeling.
-Unfortunately ,the lack of standardized techniques often leads to unclear results.
-costly drug delivery system
Transdermal Drug Delivery System (TDDS) is the one of the novel technology to deliver the molecules through the skin for long period of time.
Transdermal Drug Delivery System (TDDS) are defined as self contained, discrete dosage forms which are also known as “patches” 2, 3 when patches are applied to the intact skin, deliver the drug through the skin at a controlled rate to the systemic circulation
formulation development of Transdermal drug delivery systems i.e. transdermal patches, compostion of transdermal patch, physical methods used to prepare tansdermal patch
Mucoadhesive drug delivery system has gained interest among pharmaceutical scientists as a means of promoting dosage form residence time as well as improving intimacy of contact with various absorptive membranes of the bio- logical system
Powerpoint presentation on controlled drug delivery system. Its introduction, terminologies, rationale, advantages, disadvantages, selection of drug, approaches for designing controlled release formulations and physicochemical and biological properties of drug
Mucoadhesive drug delivery system interact with the mucus layer covering the mucosal epithelial surface, & mucin molecules & increase the residence time of the dosage form at the site of the absorption.
Mucoadhesive drug delivery system is a part of controlled delivery system.
Since the early 1980,the concept of Mucoadhesion has gained considerable interest in pharmaceutical technology.
combine mucoadhesive with enzyme inhibitory & penetration enhancer properties & improve the patient complaince.
MDDS have been devloped for buccal ,nasal,rectal &vaginal routes for both systemic & local effects.
Hydrophilic high mol. wt. such as peptides that cannot be administered & poor absorption ,then MDDS is best choice.
Mucoadhesiveinner layers called mucosa inner epithelial cell lining is covered with viscoelasticfluid
Composed of water and mucin.
Thickness varies from 40 μm to 300 μm
General composition of mucus
Water…………………………………..95%
Glycoproteinsand lipids……………..0.5-5%
Mineral salts……………………………1%
Free proteins…………………………..0.5-1%
The mechanism responsible in the formation of mucoadhesive bond
Step 1 : Wetting and swelling of the polymer(contact stage)
Step 2 : Interpenetration between the polymer chains and the mucosal membrane
Step 3 : Formation of bonds between the entangled chains (both known as consolidation stage)
Electronic theory
Wetting theory
Adsorption theory
Diffusion theory
Fracture theory
Advantages over other controlled oral controlled release systems by virtue of prolongation of residence of drug in GIT.
Targeting & localization of the dosage form at a specific site
-Painless administration.
-Low enzymatic activity & avoid of first pass metabolism
If MDDS are adhere too tightlgy because it is undesirable to exert too much force to remove the formulation after use,otherwise the mucosa could be injured.
-Some patient suffers unpleasent feeling.
-Unfortunately ,the lack of standardized techniques often leads to unclear results.
-costly drug delivery system
TDDS are topically administered medicaments in the form of patches that deliver drugs for systemic effects at predetermined and controlled rate.
Transdermal patch is an adhesive patch, that has a coating of medicine (drug), that is placed on the skin to deliver specific dose of the medicine, into the blood over a period of time.
Formulation and evaluation of transdermal drug delivery system (TDDS)SanketPawar47
This is slide about formulation and evaluations of transdermal drugs delivery system . Introduction , general structure of TDDS , basic components of TDDS , approch for formulation of TDDS , manufacturing processes for TDDS ,and evaluations of TDDS
Transdermal Drug Delivery System SG.pptxSneha Gaurkar
Transdermal drug delivery systems (TDDS), are dosage forms designed to deliver a
therapeutically effective amount of drug across a patient’s skin.
It delivers a drug through intact skin at a controlled rate into the systemic circulation.
Delivery rate is controlled by the skin or membrane in the delivery system.
1)Introduction
2)Advantages and Disadvantages
3)Structure of Skin
4)Permeation through skin
5)Factors affecting permeation
6)Basic Componentes of TDDS
7)Formulation approaches used in the development of TDDS
8)Evaluation of TDDS
9)Reference
TDDS are topically administered medicaments in the form of patches that deliver drugs for systemic effects at predetermined and controlled rate.
Transdermal patch is an adhesive patch, that has a coating of medicine (drug), that is placed on the skin to deliver specific dose of the medicine, into the blood over a period of time.
ADVANTAGES
Avoidance of first-pass effect,
Long duration of action,
Comparable characteristics with IV infusion,
Ease of termination of drug action, if necessary,
No interference with gastric and intestinal fluids,
Suitable for administered of drug having- Very short half-life, e.g. nitroglycerine. Narrow therapeutic window.
DISADVANTAGES
Poor diffusion of large molecules,
Skin irritation,
Requires high drug load,
Unsuitable –If drug dose is large,
Absorption efficiency is vary with different sites of skin,
Skin has mainly 3 layers
Epidermis
Stratum Cornium
Stratum Granulosm
Stratum Spinosum
Stratum Basal
Dermis 3)Subcutaneous layer
EPIDERMIS
Stratum Cornium- consists of 25 to 30 layers of flattened dead keratinocytes. Which makes it water repellent.
Stratum Granulosm- consists of 3 to 5 layers and under goes Apoptosis. It contains granules known as Keratohyalin. These granules release Lipid rich secretion, which acts as the water repellent.
Stratum Spinosum- contains 8 to 10 layers of cells and it is closely arranged.
Stratum Basal- consists of single layer of cubical or columnar keratinocytes.
DERMIS
Composed of strong connective tissue containing collagen and elastic fibres, hence it can easily stretch and recoil easily.
Blood vessel, nerves gland and hair follicles are embedded in this layer.
SUBCUTANEOUS LAYER
It is also called as Hypodermis.
It is made up of loose connective tissue, including
Adipose tissue.
This helps to insulate the body by monitoring heat gain and heat loss.
The dermis is the layer of tissue that is Deeper and Thicker than epidermis.
CLASSIFICATION OF TDDS
Rate-Programmed Systems
Drug in Reservoir
Drug in Matrix
Drug in Adhesive
Drug in
Microreservoir
B. Physical Stimuli- Activated Systems
Structure-Based Systems
Electrically-Based Systems
Iontophoresis
Electroporation
Sonophoresis
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2. Introduction
Advantages & Disadvantages
Skin & Drug Permeation
Percutaneous Absorption & Kinetics
Factor Affecting Percutaneous Absorption
Basic Components Of TDDS
Types Of Transdermal Patch
Formulation Approaches Used In Development Of TDDS
Marketed Products
Patents & Recent Research
CONTENTS
3. INTRODUCTI
ON TDDS facilitate the passage of therapeutic quantities of drug
substance through the skin and into the general circulation for their
systemic effects.
In 1965 Stoughton first conceived of the percutaneous
absorption of drug substance.
The first transdermal system, Transderm Scop (Ciba, now Novartis)
was approved by the FDA in 1979 for prevention of nausea and
vomiting associated with travel, particularly by sea.
4. Substitute for
oral
administration
Avoid the first-pass
effect
Delivers a steady
infusion of a drug
Self administration is
possibleDrug therapy may be
terminated rapidly
Improved patient
compliance
Lack of peaks in plasma
concentration (the riskof
side effects)
Used for drugs with
narrow therapeutic
window
5. Cannot use for
large molecule
(>500 Dalton)
Cannot be used for
drugs requiringhigh
blood levels
Long time adherenceis
difficult
Higher cost
Variation in
absorption efficiency
a different sites of
skin
Cannot
deliverionic
drugs
Skin irritation or
contact dermatitismay
occur
Natural limits of drug
entry imposed by the
skin’simpermeability
6. Epiderm
is
Dermi
s
Hypoderm
is
SKI
N
Stratum Corneum
Stratum Lucidum
Stratum Granulosum
Stratum Spinosum
Stratum Basale
Blood vessels
Sweat glands
Hair follicle
Sebaceous glands
Adipose Tissue
Artery
Vein
Anatomy & Physiology Of
Skin
10. Product/Device
Solute Vehicle
Stratum
Corneum
Penetration
Epidermis &Upper
Dermis Concentration
Systemic Blood Concentration
Hair Follicles,
Sweat Ducts
Therapeutic
Activity
Tissues
Underlying
Subcutaneou
s &Muscles
Device, Solute, Vehicle
Determination of Permeability
Desquamation Release
Target Delivery
Effects on Skin
Turnover Lipids
Diffusion Local Blood
Flow
Dermal Blood Flow
Epidermal & Dermal Metabolism
Action
Distribution
Metabolites Urine etc.
Clearance
Toxicity
11. Skin permeation kinetics is vital to the successful development of transdermal therapeutic
system. Transdermal permeation of drug involve following steps –
1) Sorption by stratum corneum.
2) Penetration of drug through viable epidermis.
3) Uptake of drug by capillary network in dermal papillarylayer.
The rate of permeation across the skin (dq/dt) is given by –
dq/dt = Ps (Cd-Cr)……………………..(1)
Where Cd and Cr are, the concentration of skin penetrant in the donor compartment and in
the receptor compartment respectively
Ps permeability coefficient
Kinetics Of Transdermal Permeation
12. Permeability coefficient is given by the relationship: -
Ps =Ks Dss / hs…………………………… (2)
Where Ks is the partition coefficient for the interfacial partitioning of the penetrant molecule
from a solution medium or a transdermal therapeutic system ,
Dss is the apparent diffusivity for the steady-state diffusion of the penetrant molecule through
a thickness of skin tissues
hs overall thickness of skin tissues
Ks, Dss and hs are constant under given conditions, the Ps should be constant.
From equation (1) it is clear that a Cd>>Cr i.e., the drug concentration at the surface of the
stratum corneum (Cd) is consistently and substantially greater than the drug concentration in
the body (Cr). Then equation (1) becomes.
dq/dt = Ps Cd ………………(3)
(dq/dt) is constant provided the magnitude of Cd remains fairly constant throughout the
course of skin permeation. For keeping Cd constant, the drug should be released from the
devices at a rate (Rr) that is either constant or greater than the rate of skin uptake (Ra) i.e.,
Rr>>Ra.
13. Since Rr>>Ra , the drug concentration on the skin surface (Cd) is maintained at a level equal to
or greater than the equilibrium solubility of the drug in the stratum corneum (Cs) i.e., Cd>>Cs.
Therefore, a maximum rate of skin permeation [(dq/dt) m] is obtained and is given by the
equation: -
(dq/dt) m = Ps Cs ……………… (4)
(dq/dt) m depends on (Ps) and its equilibrium solubility in the stratum corneum (Cs).
Thus skin permeation appears to be stratum corneum-limited.
14. Skin conditions Skin hydration Sunlight
Skin age Temperature and pH Cold
season
Regional skin site Diffusion coefficient Air
pollution
Skin metabolism Drug concentration Effect of
heat
Partition coefficient
Molecular size and
shape
15. Components Of TDDS
The components of transdermal devices include.
1. Polymer matrix / Drug reservoir
2. Drug
3. Permeation enhancers
4. Pressure sensitive adhesives
5. Backing laminate
6. Release liner
7. Other excipients
16. Polymer Matrix
Ideal properties of a polymer to be used in a transdermal system
-
Molecular weight, chemical functionality of the polymer should be such that the
specific drug diffuses properly and gets released through it.
Stable, non-reactive with the drug.
Non-toxic or non- antagonistic to the host.
Easily of manufactured and fabricated into the desired product.
Inexpensive.
Large amounts of the active agent are incorporated into it.
18. Drug Substance
Parameter
Dose
Half life
Molecular weight
Melting point
Partition coefficient
Aqueous Solubility
pH of the aqueous saturated solution
Skin Permeability Coefficient
Skin Reaction
Oral Bioavailability
Properties
Less than 20 mg/day
< 10 hrs
<400 Dalton
<200°C
1 to 4
>1mg/mL
5-9
>0.5×10-3cm/h
Non irritating and non-sensitizing
Low
Ideal Properties Of Drug Candidate For Transdermal Drug Delivery
19. Permeation Enhancers
These are compounds which promote skin permeability by altering the skin as a
Barrier to the flux of desired penetrants.
The flux, J, of drugs across the skin can be written as -
Where D = diffusion coefficient
C = concentration of the diffusing species
x = spatial coordinate
Enhancement of flux across membranes reduces to considerations them as
follows -
1. Molecular size and shape.
2. Reducing the energy required to make a molecular hole in the membrane.
3. Thermodynamics (lattice energies, distribution coefficients).
20. Types Of Absorption Enhancers
Class Examples Mechanism
Surfactants Anionic : Sodium lauryl sulphate Transcellular
Nonionic : Pluronic F68 & F127 Transcellular
Bile Salts : Sodium deoxycholate , Sodium Paracellular
taurocholate
Solvents Methanol, Ethanol, Propylene glycol, Transcellular
Glycerol etc.
Cyclodextrins Methylated b cyclodextrins, Paracellular
a-, b- and g cyclodextrins Transcelular
Chelating agents EDTA, Transcellular
Polyacrylates Paracellular
Positively charged polymer
Chitosan salts,
Trimethyl chitosan
Paracellular
21. Pressure Sensitive Adhesive
PSA helps in maintaining an intimate contact between transdermal system
and the skin surface.
It should be removable from the smooth surface without leaving a residue
e.g.: polyacrylamates, polyacrylates, polyisobutylene, silicone based adhesive.
The selection is based on numerous factors, including the patch design and
drug formulation.
PSA should be physicochemical and biologically compatible and should not
alter drug release.
22. While designing a backing layer the consideration of chemical resistance and
excipients may compatible because the prolonged contact between the backing
layer and the excipients, drug or penetration enhancer through the layer.
They should a low moisture vapour transmission rate. They must have optimal
elasticity, flexibility and tensile strength. eg: aluminium vapour coated layer, a
plastic film and heat real layer.
Release Linear
Prevents the loss of drug that has migrated into the adhesive layer and
contamination. However, as the linear is in intimate contact with the delivery
system, it should comply with specific requirements regarding chemical inertness
and permeation to the drug, penetration enhancer and water.
Backing Laminates
23. Other Excipients
Various solvents such as chloroform, methanol, acetone, isopropanol and
dichloromethane are used to prepare drug reservoir.
In addition plasticizers such as dibutylpthalate, triethylcitrate, polyethylene
glycol and propylene glycol are added to provide plasticity to the transdermal
patch.
24. Types Of Transdermal Patch
1. Single-layer Drug-in-Adhesive
The adhesive layer of this system also contains the drug.
Adhesive layer not only serves to adhere the various layers together, along with the
entire system to the skin, but is also responsible for the releasing of the drug.
The adhesive layer is surrounded by a temporary liner and a backing.
Example- Deponit
25. 2. Multi-layer Drug-in-Adhesive
Similar to the single-layer system in that both adhesive layers are also responsible
for the releasing of the drug.
It adds another layer of drug-in-adhesive, usually separated by a membrane (but
not in all cases).
This patch also has a temporary liner-layer and a permanent backing.
Example- Nicotrol
26. 3. Reservoir
Reservoir transdermal system has a separate drug layer.
The drug layer is a liquid compartment containing a drug solution or suspension
separated by the adhesive layer.
This patch is also backed by the backing layer. In this type of system the rate of release
is zero order.
Example- Transderm-Nitro
27. 4. Matrix
The Matrix system has a drug layer of a semisolid matrix containing a drug solution
or suspension.
The adhesive layer in this patch surrounds the drug layer partially overlaying it.
Example- Nitro-Dur
28. 5. Vapour Patch
Adhesive layer not only serves to adhere the various layers together but also
to release vapour.
The vapour patches are new on the market and they release essential oils for
up to 6 hours & used in cases of decongestion mainly.
Other vapour patches on the market are controller vapour patches that
improve the quality of sleep. Vapour patches that reduce the quantity of
cigarettes that one smokes in a month are also available on the market.
29. Approaches Used In Development Of TDDS
1.
• Membrane permeation – controlled systems
2.
• Adhesive dispersion – type systems
3.
• Matrix diffusion – controlled systems
4.
• Microreservoir type or Microsealed dissolution – controlled
systems
30. Example:
I. Nitroglycerine-releasing Transdermal system (Transderm-nitro) for once a day
medication in angina pectoris.
II. Scopolamine-releasing Transdermal system (Transderm-scop) for 72 hrs.
Prophylaxis of motion sickness.
31. The drug reservoir is formulated by directly dispersing the drug in an adhesive polymer &
then spreading the medicated adhesive by hot melt, on to a flat sheet of drug impermeable
metallic plastic backing to form a thin drug reservoir layer.
Example: Isosorbide dinitrate-releasing transdermal therapeutic system (Frandol tape) for
once a day medication of angina pectoris.
32. It is prepared by homogeneously dispersing the drug particles with a liquid polymer or a
highly viscous base polymer followed by cross linking of the polymer chains or
homogeneously blending the drug solids with a rubbery polymer at an elevated
temperature.
Example: Nitrogiycerine-releasing transdermal system (Nitro- Dur and Nitro- Dur II) a
daily dose of 0.5 mg/cm2 for therapy of angina pectoris.
33. It is combination of reservoir & matrix diffusion type drug delivery system.
Drug reservoir is formed by first suspending the drug solids in an aqueous solution of a
water soluble liquid polymer & then dispersing the drug suspension homogeneously in a
lipophilic polymer such as silicone elastomers by high energy dispersion technique.
Example: Nitroglycerine-releasing transdermal system (Nitro disc) for once a day of
angina pectoris.
37. Patent No. Invento Novelty
20060135911 Mittur et al Prepared a device which is known as a trans-body-surface
drug delivery device including a reservoir having at least one
drug and a thermo effector having a first surface.
20050186262 Osborne et al Prepared a transdermal delivery device for treatment of
hypertension with the drug delivery of dihydropyridine-type
calcium antagonist through the skin .
20120277695 Cottrell et al Prepared a transdermal patch for administration of an opioid
the composition comprising a phosphate compound of
tocopherol and a polymer carrier .
8252319 Yum et al The invention relates to the transdermal delivery of
Sufentanil which provides sufficient amount of sufentanil to
induce and maintain analgesia for extended periods when
applied to a subject .
38. 4956171 Chang, Yunik Describes transdermal drug delivery system with dual
permeation enhancers and has a basal surface that contacts an
area of skin and transmits the drug . The dual permeation
enhancers used are sucrose cocoate& methyl laurate .
39. Recent Research Reports From Pubmed
Drug Polymer or Major
Excipients
Type of Patch and
Preparation
Method
Remarks Reference
Domperidone HPMC & Eudragit RL Bilayered matrix type Patchs Madishetti
100 (polymer), d- patchs & Film casting prepared with et al , 2010
limonene method the required
(permeation
enhancer)
fiux (86.02
ug/hr/cm2)&
permeation
coefficient
(0.86x10-2
cm/hr)
Lercanidipine HPMC & Eudragit RL Matrix type & To determine Mamatha et
hydrochloride 100 (polymer), d- Solvent evaporation the effect of al , 2010
limonene technique penetration
(permeation enhancer,
enhancer) limonene on
drug
permeation