This document discusses various ocular drug delivery systems. It begins by outlining conventional systems like solutions, suspensions, emulsions and ointments/gels. It notes advantages like ease of use but also disadvantages like short residence time. Vesicular systems like liposomes, niosomes and pharmacosomes are described as able to better target drug delivery to the eye. Controlled release systems such as implants, iontophoresis, dendrimers and nanotechnology approaches are also summarized as ways to sustain drug effects. The document provides an overview of considerations and examples for different ophthalmic formulations.
Contents
Introduction
Objective
Anatomy of the Eye
Routes of drug delivery of the eye
Mechanism of ocular absorption
Factors affecting intra-ocular bioavailability
Barriers of ocular drug absorption
Methods to overcome drug barriers
Evaluation
Conclusion
Reference
Ocular administration of drug is primarily associated with the need to treat ophthalmic diseases.
Applied topically to the cornea, or instilled in the space between the eyeball and lower eyelid
Definition: Ocular DDS are designed to instilled on to topical or intra-ocular or peri-ocular to eye.
Most commonly used ocular dosage forms-
- Solutions
- Suspensions
- ointments
Ideal ophthalmic drug delivery must be able to sustain the drug release and to remain in the vicinity of front of the eye for prolong period of time.
Barrier of drugs permeation through ocular route by Sushil Kumar SinghSushil Singh
Barriers of Drugs Permeation Through Ocular Route. this topic explain about ocular route and barriers system. and classification of different injection routes takes the ocular drugs.
FORMULATION AND EVALUATION OF OCUSERTS OF CIPROFLOXACIN HClMohammad Adil
Conventional ocular drug delivery system i.e., eye drops, ointments, gels etc., had become less popular pertaining to their disadvantages like evaporation by tears, pre-corneal loss, drug metabolism, drug-protein interaction, drainage, sticking of eye lids, induced lacrimation, poor patient compliance, systemic side effect and blurred vision etc. That’s why fundamentals of controlled release by means of ocular inserts were utilized to increase problem pre-corneal drug residence time.
This project title “Formulation and Evaluation of Ocuserts of Ciprofloxacin HCl” revealed following results:
Compatibility study using FTIR was performed to check the compatibility of drug with various excipient. Characteristics peaks obtained with pure drug were compared with that produced with different excipients that confirmed the compatibility of drug with excipients.
Ocusert of Ciprofloxacin HCl was prepared using different material i.e., PVP K-30, PVA, PEG 400 and glycerin.
Prepared ocuserts were evaluated for various parameters viz., percentage moisture loss, percentage moisture absorbs, thickness, weight variation, drug content and In-vitro diffusion.
The percentage (%) moisture absorption and loss of ocular insert were found to be 26% and 27% respectively.
The thickness of ocular insert was found to be uniformed and its mean while measuring at different points was found to be 0.124mm.
The weight of ocular inserts was found to be in the range of 12.2 - 12.6mg which indicated decent distribution of the drug, polymer and plasticizer.
The drug content of ocular insert was found to be 99.89%.
Percentage drug release from Ciprofloxacin HCl Ocusert was found to be 41.969% in 8 hr.
It was concluded that prepared Ocusert of Ciprofloxacin HCl could be a better alternative to conventional ocular formulations that retained on ocular surface for longer duration and released drug in controlled manner.
Video Lecture is available at https://www.youtube.com/watch?v=DXu_CLgB4q0
Introduction, terminology/definitions and rationale, advantages, disadvantages, selection of drug candidates. Approaches to design-controlled release formulations based on diffusion, dissolution and ion exchange principles. Physicochemical and
biological properties of drugs relevant to controlled release formulations.
Various approaches to Targeted Drug Delivery Systems (TDDS) in its formuation and evaluation in a pharmaceutical industry and research is outlined in this presentation.
In Process Quality Control Tests (IPQC) For Parenteral or Sterile Dosage FormsSagar Savale
These are the tests performed between QA and QC and provides for the authorization of approved raw materials for manufacturing based on actual laboratory testing generally called as IPQC such as physical, chemical, microbiologic and biologic tests.
Contents
Introduction
Objective
Anatomy of the Eye
Routes of drug delivery of the eye
Mechanism of ocular absorption
Factors affecting intra-ocular bioavailability
Barriers of ocular drug absorption
Methods to overcome drug barriers
Evaluation
Conclusion
Reference
Ocular administration of drug is primarily associated with the need to treat ophthalmic diseases.
Applied topically to the cornea, or instilled in the space between the eyeball and lower eyelid
Definition: Ocular DDS are designed to instilled on to topical or intra-ocular or peri-ocular to eye.
Most commonly used ocular dosage forms-
- Solutions
- Suspensions
- ointments
Ideal ophthalmic drug delivery must be able to sustain the drug release and to remain in the vicinity of front of the eye for prolong period of time.
Barrier of drugs permeation through ocular route by Sushil Kumar SinghSushil Singh
Barriers of Drugs Permeation Through Ocular Route. this topic explain about ocular route and barriers system. and classification of different injection routes takes the ocular drugs.
FORMULATION AND EVALUATION OF OCUSERTS OF CIPROFLOXACIN HClMohammad Adil
Conventional ocular drug delivery system i.e., eye drops, ointments, gels etc., had become less popular pertaining to their disadvantages like evaporation by tears, pre-corneal loss, drug metabolism, drug-protein interaction, drainage, sticking of eye lids, induced lacrimation, poor patient compliance, systemic side effect and blurred vision etc. That’s why fundamentals of controlled release by means of ocular inserts were utilized to increase problem pre-corneal drug residence time.
This project title “Formulation and Evaluation of Ocuserts of Ciprofloxacin HCl” revealed following results:
Compatibility study using FTIR was performed to check the compatibility of drug with various excipient. Characteristics peaks obtained with pure drug were compared with that produced with different excipients that confirmed the compatibility of drug with excipients.
Ocusert of Ciprofloxacin HCl was prepared using different material i.e., PVP K-30, PVA, PEG 400 and glycerin.
Prepared ocuserts were evaluated for various parameters viz., percentage moisture loss, percentage moisture absorbs, thickness, weight variation, drug content and In-vitro diffusion.
The percentage (%) moisture absorption and loss of ocular insert were found to be 26% and 27% respectively.
The thickness of ocular insert was found to be uniformed and its mean while measuring at different points was found to be 0.124mm.
The weight of ocular inserts was found to be in the range of 12.2 - 12.6mg which indicated decent distribution of the drug, polymer and plasticizer.
The drug content of ocular insert was found to be 99.89%.
Percentage drug release from Ciprofloxacin HCl Ocusert was found to be 41.969% in 8 hr.
It was concluded that prepared Ocusert of Ciprofloxacin HCl could be a better alternative to conventional ocular formulations that retained on ocular surface for longer duration and released drug in controlled manner.
Video Lecture is available at https://www.youtube.com/watch?v=DXu_CLgB4q0
Introduction, terminology/definitions and rationale, advantages, disadvantages, selection of drug candidates. Approaches to design-controlled release formulations based on diffusion, dissolution and ion exchange principles. Physicochemical and
biological properties of drugs relevant to controlled release formulations.
Various approaches to Targeted Drug Delivery Systems (TDDS) in its formuation and evaluation in a pharmaceutical industry and research is outlined in this presentation.
In Process Quality Control Tests (IPQC) For Parenteral or Sterile Dosage FormsSagar Savale
These are the tests performed between QA and QC and provides for the authorization of approved raw materials for manufacturing based on actual laboratory testing generally called as IPQC such as physical, chemical, microbiologic and biologic tests.
In this presentation include all the things like introduction, type, method of preparation,Formulation, Characterization, Application and Market Product.
Ocular drug delivery system - NDDS - B.PHARMAJafarali Masi
Ocular drug delivery system - NDDS - B.PHARMA
Introduction, intra ocular barriers and methods to overcome –Preliminary study, ocular formulations and ocuserts
Occular Drug Delivery System
ODDS
advantages of OODS
disadvantages of ODDS
Factors effecting ODDS
Barriers of drug permeation
methods to overcome barriers
drug delivery system
novel drug delivery system
B. pharmacy
M. pharmacy
Challenges in trancorneal drug deliveryBibin Mathew
Ophthalmic drug delivery is one of the challenging endeavors which is being faced by the pharmaceutical scientist, owing to the anatomy, physiology, and biochemistry of the eye, that renders it impervious to foreign substances. Topical administration of ophthalmic medications is the most common method for treating conditions that affect the exterior parts of the eye. The unique anatomy and physiology of the eye makes it difficult to achieve an effective drug concentration at the target site. Therefore, the major challenge remains to efficiently deliver a drug past the protective ocular barriers accompanied with a minimization of its systemic side effects.Conventional eye drops currently account for more than 90% of the marketed ophthalmic formulations. However, after instillation of an eye drop, only a small amount of the applied drug penetrates the cornea and reaches the intraocular tissues, which is due to the rapid and extensive precorneal loss caused by drainage and high tear fluid turn-over. Tear drainage leads to absorption of the administered dose by the nasolacrimal duct, leading to side effects. As a consequence of the precorneal loss, the ocular bioavailability is usually less than 10%. Furthermore, rapid elimination of the eye drops administered often results in a short duration of action which leads to increase in frequency of administration.
A medication is applied to the eye to treat the diseases on the surface of the eye such as conjunctivitis, blepharitis, and keratitis sicca, as well as to provide intraocular treatment through the cornea for diseases such as glaucoma and uveitis. Topical administration of antibacterial medication to the conjunctival sac is usually an effective avenue for treating bacterial conjunctivitis.[2]
An ideal topical drug delivery system should possess the following characteristics:
1. Good corneal and conjunctival penetration.
2. Prolonged precorneal residence time.
3. Easy instillation.
4. Appropriate rheological properties.
Eye diseases are commonly encountered in day to day life, which are cured or prevented through the conventionally used dosage forms. Delivery to the internal parts of the eye still remains troublesome due to the anatomical and protective structure of the eye. Drugs may be delivered to the eye through the application of four primary modes of administration: topical, systemic, intravitreal, and periocular.
Routes of Ocular Delivery.
COMPOSITION OF EYE.
MECHANISM OF OCULAR ABSORPTION.
Barriers of Drug Permeation.
Anatomical Barrier.
CORNIAL CROSS SECTION.
Physiological Barrier.
Blood-Occular Barriers.
Routes of Ocular Drug Delivery.
Topical Route & Novel Route ocular drug delivery.
Methods to Overcome Barriers.
Bioavailability Improvement & Controlled Ocular Drug Delivery
INTRODUCTION :
Ocular administration of drug is primarily associated with the need to treat ophthalmic diseases.
Eye is the most easily accessible site for topical administration of a medication.
Ideal ophthalmic drug delivery must be able to sustain the drug release and to remain in the vicinity of front of the eye for prolong period of time.
The bioavailability of ophthalmic drugs is very poor due to efficient protective mechanisms of the eye.
Blinking, reflex lachrymation, and drainage rapidly remove drugs, from the surface of the eye.
To overcome these, two approaches can be followed.
The first involves using alternate delivery routes to conventional ones allowing for more direct access to intended target sites.
Second approach involves development of novel drug delivery systems providing better permeability, treatability and controlled release at target site.
Combination of both these approaches are being utilized and optimized in order to achieve optimal therapy with minimal adverse effects.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
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Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
2. INTRODUCTION
Ocular administration of drug is primarily associated
with the need to treat ophthalmic diseases.
Eye is the most easily accessible site for topical
administration of a medication.
Ideal ophthalmic drug delivery must be able to sustain
the drug release and to remain in the vicinity of front
of the eye for prolong period of time.
3. FACTORS AFFECTING
INTRAOCULAR BIOAVAILABILITY:
1. Inflow & outflow of lacrimal fluids.
2. Efficient naso-lacrimal drainage.
3. Interaction of drug with lacrimal fluid.
4. dilution with tears.
5. Corneal barriers.
6. Active ion transport at cornea.
5. BARRIERS IN OCULAR ABSORPTIONPrecorneal Constraints
It include –
• Solution drainage
• Lacrimation
• Tear dilution
• Tear turnover
• Conjunctival
absorption
Corneal constraints
• Cornea as rate limiting
barrier
• Anatomy of cornea
1.Outer-
Epithelium(lipophilic),
2.Middle-
Stroma(hydrophilic),
3.Inner-
Endothelium(lipophilic)
5
6. Cornea
Epithelium- only non ionized drug penetrate
Stroma- only ionized drug can pass
so drug must have capacity to exist in both ionized and
nonionized form for a better penetration
Eg- homatropine (proposed by KINSEY)
Eg- Fluorescein is a negative charged ion so can not
penetrate the intact epithelium and this property forms the
basis of fluorescein dye test
7.
8. SURFACE ACTIVE AGENT
Agents that reduce surface tenson, increase corneal
wetting and therefore present more drug for absorption.
Eg.- Benzalkonium Chloride used as preservative also act
as wetting agent.
9. PRO DRUG FORM
Prodrug is more Lipophilic so more absorbed by
epithelium and afterthat converted into another form.
Eg.- Dipivefrine(alpha adrenergic agonist antiglaucoma
drug) is lipophilic prodrug which hydrolysed by esterases
into adrenaline
12. ADVANTAGE
They are easily administered by the nurse
They are easily administered by the patient himself.
They have the quick absorption and effect.
less visual and systemic side effects.
better patient compliance.
13. DISADVANTAGE
The very short time the solution stays at the eye
surface.
Its poor bioavailability.
The instability of the dissolved drug.
The necessity of using preservative.
15. Dosage
Form
Advantages Disadvantages
solutions convenience Rapid precorneal
elimination, non sustained
action
suspension Patient compliance, best for
drug with slow dissolution
Drug properties decide
performance loss of both
solutions and suspended
particles
emulsion Prolonged release of drug
from vehicle
Blurred vision, patient non
compliance
ointment Flexibility in drug choice,
improved drug stability
Sticking of eyes lids, blurred
vision, poor patient
compliance
16. CONVENTIONAL
Eye Drops:
Drugs which are active at eye or eye surface are widely
administered in the form of Solutions, Emulsion and
Suspension.
Various properties of eye drops like hydrogen ion
concentration, osmolality, viscosity and instilled volume can
influence retention of a solution in the eye.
Less than 5 % of the dose is absorbed after topical
administration into the eye.
The dose is mostly absorbed to the systemic blood circulation
via the conjunctival and nasal blood vessels.
17. SOLUTIONS
ADVANTAGE-
Ease of bulk scale manufacturing
High pt. Aceptibility
Drug product efficacy
Stability
Cost effectiveness
18. EMULSION
A Fine dispersion of minute droplets of one liquid into
another liquid in which it is generally not soluble or
misceble.
19. EMULSION
Emulsion are of 2 types-
1.Oil in Water- use in ophthal bcoz of less irritance nd
better tolerance
2. Water in Oil
Eg.- Difluprednate 0.05%
Difluprednate 0.05% + Moxifloxacin 0.5%
E/d Cyclosporin is Emulsion
20. Eg.- Fluribrophen axetil + Castor oil have better
bioavailability and less irritation
Eg,- Chitosan coating and HPMC coating of
indomethacin increase precorneal residence time
21. Advantage of emulsion
Improve residence time
Drug corneal permeation increase
Sustain drug release
22. SUSPENSION
Disperssion of finely divided insoluble API in an
aqueous solvent consisting of suitable suspending and
dispersing agent
Its activity is particle size dependent. So if size is
optimum then optimal activity is achieved.
Suspension must be resuspended by shaking to
provide accurate dosage.
23. SUSPENSION
Eg.- Tobramycin 0.3% + Dexa 0.1% (but have high
viscosity)
Tobra 0.3% + Dexa 0.05% (TobraDex ST) have very low
settling rate
Moxi 0.5% + Prednisolone 1%
Prednisolone 1%
Nepafenac 0.1% eye drop is suspension
Natamycin
Brinzolamode
24. OINTMENTS AND GELS
Prolongation of drug contact time with the external
ocular surface can be achieved using ophthalmic
ointment vehicle but, the major drawback of this
dosage form like, blurring of vision & matting of
eyelids can limit its use.
25. GELS
Eg.- pilocarpine 4% gel
Eg.- several artificial tear preparations are formulated as
ophthalmic gels
Eg.- treatment with Timolol 0.5% gel once daily in the
morning acheives intraocular pressure level equal to twice
daily solution
26. OINTMENTS
Mixture of semisolid and solid hydrocarbons (parrfins)
that have melting point at ocular temp. (34 c).
When applied to inferior conjuctival sac, ointments
melt quickly and the excess spread out onto the lid
margin, lashes, skin of lids.
It has a therapeutic effect for 6hr.
This method may be of practical value in paediatric
and geriartic age group.
27. Early formulations of ointment contained waxy grades
of petroleum or unwashed lanolin which interfered
with corneal wound healing.
Newer ointments not contain these but should be used
cautiously in ulcer with impending perforation. And
should not be used in any surgical wound in which
there is a question of wound integrity, such as when
difficulty is experienced maintaining the Ant.
Chamber at surgery.
28. VESICULAR SYSTEM
Vesicular drug delivery system can be defined as highly
ordered assemblies consisting of one or more concentric
bilayers formed as a result of self-assembling of
amphiphilic building blocks in presence of water.
Vesicular drug delivery systems are particularly important
for targeted delivery of drugs because of their ability to
localize the activity of drug at the site or organ of action
thereby lowering its concentration at the other sites in
body.
30. LIPOSOMES
Liposomes are biocompatible and
biodegradable lipid vesicles made
up of natural lipids and about
25–10 000 nm in diameter.
They are having an intimate contact with the corneal and
conjunctival surfaces which is desirable for drugs that are
poorly absorbed, the drugs with low partition coefficient,
poor solubility or those with medium to high molecular
weights and thus increases the probability of ocular drug
absorption.
31. NIOSOMES AND DISCOMES
The major limitations of liposomes are chemical instability,
oxidative degradation of phospholipids, cost and purity of
natural phospholipids.
To avoid this niosomes are developed as they are chemically
stable as compared to liposomes and can entrap both
hydrophobic and hydrophilic drugs.
They are non toxic and do not require special handling
techniques.
32. Niosomes are nonionic surfactant vesicles that have
potential applications in the delivery of hydrophobic or
amphiphilic drugs.
Discomes may act as potential drug delivery carriers as
they released drug in a sustained manner at the ocular site.
Discosomes are giant niosomes (about 20 um size) containing poly-
24- oxy ethylene cholesteryl ether or otherwise known as Solulan 24.
Pharmacosomes: This term is used for pure drug vesicles
formed by the amphiphilic drugs.
The amphiphilic prodrug is converted to pharmacosomes
on dilution with water.
33. Non ionic surface active agent
phospholipid
Hydrophilic drugs in aqueous
region encapsulated
Lipophilic drugs located in
the hydrophobic lamella
NIOSOME Vs LIPOSOME
34. Niosomes are microscopic lamellar structures, which
are formed on the admixture of non-ionic surfactant of
the alkyl or dialkyl polyglycerol ether class and
cholesterol with subsequent hydration in aqueous
media.
Structurally, niosomes are similar to liposomes, in that
they are also made up of a bilayer. However, the
bilayer in the case of niosomes is made up of non-
ionic surface active agents rather than phospholipids
as seen in the case of liposomes.
36. IMPLANTS
Implants help in circumventing multiple
introcular injection and associated
complications.
Implants use for drug delivery in posterior
ocular tissue
37. IMPLANTS
For chronic ocular diseases like cytomegalovirus
(CMV) retinitis, implants are effective drug delivery
system. Earlier non biodegradable polymers were used
but they needed surgical procedures for insertion and
removal.
Presently biodegradable polymers such as Poly Lactic
Acid (PLA) are safe and effective to deliver drugs in the
vitreous cavity and show no toxic signs
38. Eg. Of Implants-
NONBIODEGRADABLE-
VITRASERT- controlled release of ganciclovir for t/t of CMV
retinitis.
RETISERT- release of Fluocinolone acetonide for t/t of chronic
uveitis of post. Segment.
BIODEGRADABLE-
SURODEX- release Dexamethasone for controle of postop
inflamation.
OZURDEX- for t/t of Macular Edema
39. IONTOPHORESIS
In Iontophoresis direct current drives ions into cells or
tissues. For iontophoresis the ions of importance should
be charged molecules of the drug.
Positively charged of drug are driven into the tissues
at the anode and vice versa.
Ocular iontophoresis delivery is not only fast,
painless and safe but it can also deliver high
concentration of the drug to a specific site.
41. DENDRIMER
Dendrimer are nanosized, highly branched, star shaped
polymerise system
Its highly branched structure allow incorporation of wide
range of drugs (Hydrophobic and Hydrophilic )
Dendrimers can successfully used for different routes of
drug administration and have better water-solubility,
bioavailability and biocompatibility.
42. MICROEMULSION
Microemulsion is dispersion of water and oil
stabilized using surfactant and co- surfactant to reduce
interfacial tension and usually characterized by small
droplet size (100 nm), higher thermodynamic stability
and clear appearance.
Selection of aqueous phase, organic phase and
surfactant/co-surfactant systems are critical
parameters which can affect stability of the system
43. NANOSUSPENSION
Nanosuspensions have emerged as a promising
strategy for the efficient delivery of hydrophobic
drugs because they enhanced not only the rate and
extent of ophthalmic drug absorption but also the
intensity of drug action with significant extended
duration of drug effect.
For commercial preparation of nanosuspensions,
techniques like media milling and high-pressure
homogenization have been used.
44. MICRONEEDLE
Microneedle had shown prominent in vitro
penetration into sclera and rapid dissolution of coating
solution after insertion while in vivo drug level was
found to be significantly higher than the level
observed following topical drug administration like
pilocarpine
45. Microneedle is minimum invasive mode to deliver in
posterior ocular tissue.
Penetrate only 100 um of sclera so deposite drug into sclera
or into suprachoroid space.
46. MUCOADHESIVE POLYMER
In this dosage form adhere to the precorneal mucus and
residue in the eye until the polymer dissolve or mucin
replace itself.
These are in early phase of research.
They are basically macromolecular hydrocolloids with plentiful
hydrophilic functional groups, such as hydroxyl, carboxyl,
amide and sulphate having capability for establishing
electrostatic interactions.
47. Some mucoadhesives are- carboxymethycellulose.
Carbopol, polymethymethacrylate, acrylic acid,
polycarbophil, sodium alginate.
A mucoadhesive drug formulation for the treatment of
glaucoma was developed using a highly potent beta
blocker drug, levobetaxolol (LB) hydrochloride and
partially neutralized poly acrylic acid (PAA).
48. INSERTS
The ocular insert represents a significant advancement in
the therapy of eye disease. Ocular inserts are defined as
sterile, thin, multilayered, drug-impregnated, solid or
semisolid consistency devices placed into the cul-de-sac
or conjuctival sac, whose size and shape are especially
designed for ophthalmic application.
49. Ocular Inserts as an Ocular Sustained Release Drug
Delivery System
The main objective of the ophthalmic inserts is to increase
the contact time between the preparation and the
conjunctival tissue, to ensure a sustained release suited for
topical or systemic treatment.
The advantages of ocular inserts over the traditional
ophthalmic preparation can be summarized as follows-
50. ADVANTAGE
Increased ocular residence, hence, prolonged drug activity
and higher bioavailability with respect to standard
vehicles.
Release of drugs at a slow, constant rate
Accurate dosing (insert contains a precise dose, which is
fully retained at the administration site).
Reduction of systemic absorption.
51. Better patient compliance, due to reduced frequency of
administration and less incidence of visual and systemic
side-effects.
Possibility of targeting internal ocular tissues through non-
corneal (conjunctival scleral) routes.
Increased shelf life with respect to aqueous solutions.
Exclusion of preservatives, thus reducing the risk of
sensitivity reactions.
Incorporation of various novel chemical / technological
approaches, such as pro-drugs, mucoadhesives,
permeation enhancers, micro particulates, salts acting as a
buffer.
52. Disadvantage
A major disadvantage of ocular inserts resides in their
‘solidity’, that is, they are felt by the (often oversensitive)
patients as an extraneous body in the eye. This may constitute a
difficult physical and psychological barrier to patient
compliance.
Their movement around the eye, in rare instances, the simple
removal is made more difficult by unwanted migration of the
insert to the upper fornix.
The occasional unintentional loss during sleep or while rubbing
the eyes.
Their interference with vision.
Difficulty in placement of the ocular inserts (and removal, for
insoluble types).
53.
54. A) Insoluble inserts-
e.g. Ocusert®:
20-40µg/hr for 7day
Annular ring : Impregnated with Ti02 : For Visibility
54
1. Diffusional Inserts :
•Central reservoir of drug
enclosed in Semi permeable or
microporous membrane for
diffusion of drug.
•Diffusion is controlled by
Lacrimal Fluid penetrating
through it.
•Release follows : Zero Order
Kinetics.
55. 3) Contact Lens :
Presoaked Hydrophilic lens.
Drug Release : within 1st 30 Min.
Alternate approach : incorporate drug either as soln or suspension
.e.g. Pilocarpine.
Release rate is up to : 180 hr.
55
2) Osmotic inserts
• A central part surrounded by a peripheral part
• Central part-single reservoir or two distinct compartments.
• Peripheral part- an insoluble semi permeable polymer.
•The tear fluid diffuse and induces dissolution.
•Solubilized deposits generate a hydrostatic pressure.
•Drug is then released through these apertures
56. Use in treatment of Bullous keratopathy, Dry eye
syndrome, corneal condition requiring protection such as
traumatic corneal abrasion or erosions.
57. B) Soluble Inserts
1.SODI: Soluble Ocular Drug Insert.
57
• Small water soluble made of soluble synthetic polymers.
• Composition : Acryl amide, Vinyl Pyrolidone, Ethylacrylate.
• Weight 15-16 mg.
In 10-15 sec Softens;
In 10-15 min. turns in Viscous Liquids;
After 30-60min. Becomes Polymeric Solution.
•Single SODI application : replaces 4-12 eye drops Instillation, or
3-6 application of Ointments.
•Once a day treatment of Glaucoma.
Advantages of SODI :
58. 2.The corneal collagen shield
A disposable, short-term therapeutic bandage lens for the
cornea.
It conforms to the shape of the eye, protects the corneal
surface, and provides lubrication as it dissolves.
The shields are derived from bovine collagen and are 14.5 mm
in diameter.
Sterilized by gamma irradiation.
Disadvantages
1. It is not optically clear.
2. The collagen shield causes some discomfort.
Clinical uses
1. Wound healing.
2. Treatment of dry eye.
58
59. Shaped like contact lens
Thin membrane of porcine or bovine scleral collagen that
conform to cornea when placed on the eye so multiple
base curves are not necessary.
Typically the drug is loaded into collagen shield by
soaking the shield into intended drug solution prior to
application.
Hydrated shield form clear, thin film of 0.1mm thickness,
with a diameter of 14.5 and base curve of 9mm.
60. Packaged in dehydrated state and require rehydration
before application.
Dissolution rate have 12hr, 24hr, 72hr depending on
collagen cross linking.
Shield dissolve as a result of proteolytic degradation by
the tear film.
Before insertion shields must be rehydrated for atleast 3
minutes in saline, lubricating solution, antibiotic or
steroid.
Prior topical anesthetic may required.
61. for water insoluble drug such as cyclosporin drug need to
be incorporated into the shield at the time of
manufacturing.
Collagen shield offers advantage of being entirely soluble
so that it so that it does not need to be removed from its
site of application.
62. C) Biodegradable inserts
1.Lacrisert:
• Sterile, Rod Shaped device.
• Composition: HPC.
• Weight:5mg,
• Dimension:Diameter:12.5mm, Length:3.5mm
• Use:-Dry eye treatment.
2.Minidisc:
It is made up of counter disc with Convex front & Concave back surface in
contact with eye ball.
4-5mm in diameter.
Composition : Silicon based polymer.
Drug release upto170 hr.
62
63. PARTICULATES (NANOPARTICLES
AND MICROPARTICLES)
Nanoparticle- <1 micrometre
Microparticle- >1 micrometre
The maximum size limit for microparticles for
ophthalmic administration is about 5-10 micrometer
above which a scratching feeling in the eye can result
upon ocular instillation.
That is why micro and nanoparticles are promising
drug carriers for ophthalmic application.
64. Nanopaticles are produced by emulsion
polymerisation.
Polyalkylcyanoacrylate are most commonly used
ophthalmic nanoparicles.
Many antiglaucoma drugs loaded onto nanoparicles
for testing efficacy.
65. CONCLUSION
All approaches improve ocular drug bioavailability by
increasing ocular drug residence time, diminish side
effects due to systemic absorption and diminishing the
necessary therapeutic amount of drug for therapeutic
response in anterior chamber.
They improve patient compliance by reducing the
frequency of dosing.
They reduce the dose and thereby reduce the adverse
effects of the drug.
66. ROUTES OF ADMINSTRATION
Instillation into conjuctival sac
Subconjuctival injection
Sub tenon’s injection
Retrobulbar injection
Peribulbar injection
Intraocular injection
Systemic adminstration
67. SUBCONJUCTIVAL INJECTIONS
Use for wider range of substances , as the sclera allows the
free and indiscriminate transit of molecules of
considerable size.
It is usefull when higher intraocular concentration of
antibiotic or steroids are required as in acute anterior
segment infections and inflamtion.
68. SUB-TENON’S INJECTION
2types-
1. Anterior
2. Posterior
Antrior injection offers no advantage over sub conjuctival
injection.
Infact it is associated with perforating the globe
However anterior subtenon’s injection of corticostroids are
occasionaly used in the treatment of severe uveitis.
70. RETROBULBAR INJECTION
This procedure was originally devloped to anesthetize the
globe for cataract extraction and other intra ocular surgery.
However retrobulbar corticosteroids are used occasionally
Retrobulbar alcohol or phenol is rarely adminstrated for
intractable ocular pain in blind eye.
71. PERIBULBAR INJECTIONS
Its also use the scleral route for acess into eye.
A short curved needle with its bevel towards the globe is
passed through a conjuctival incision, and medication
injected close to the inflamed tissue.
Use for t/t of intermediate and posterior inflamations.
72. INTRAOCULAR INJECTION
1- Intracameral- injected into anterior chamber
2- Intravitreal- into vitreous
Half life of many drugs in Aqueous is only a few hours,
but in Vitreous it maybe 1-4 days.
73. SYSTEMIC ADMINSTRATION
Disease which involve posterior part of retina, optic
nerve or orbit that can not be reached by local
application require systemic adminstration.