ocular drug delivery advantages disadvantages barriers ocuserts contact lenses lacriserts sodi

1. OCULAR DRUG
DELIVERY
Presented by:-
Akash
M. Pharm 1st sem (Pharmaceutics)
Institute of Pharmaceutical Sciences
Kurukshetra University Kurukshetra (KUK)

2. CONTENTS :
Introduction
Barriers
Lacrimal drainage system
Compostion of eye
Anatomy of eye
Route of administration
Ocular drug delivery
Marketed new drugs
Reference

3. INTRODUCTION
 Maintain drug in the biophase
 Have sustain drug release
 Increase contact time of drug
 Dose leaves precorneal area within 2 min
 Eye capacity for eye drop 30µl
 Drugs lost from nasolacrimal drainage
 Drug entity, pH, tonicity and formulation adjuvant
stimulate tear production
 Tears dilute reduces the transcorneal flux of drug

4. BARRIERS
 Solution drainage
 Lacrimation
 Tear dilution
 Tear turnover
 Conjunctival absorption
 Tonicity

5. LACRIMAL DRAINAGE SYSTEM

6. COMPOSITION OF EYE
Water-98% , Solid-1.8%
Organic element- Protein-0.67%
Sugar-0.65% , NaCl- 0.66%
Sodium, Potassium and Ammonia-0.79%
Drugs used in eye for treatment
1. Miotics
2. Mydriatics
3. Cycloplegics
4. Glucoma

7. ANATOMY OF EYE

8. ANATOMY
 Cornea consist 5 distinct layers
 Epithelium
 Bowman’s membrane
 Stroma
 Descment’s membrane
 Endothelium

9.  Epithelium composed of 5 to 6 layers
 Endothelium one cell thick
 Epithelium and endothelium are cellular and
lipophilic
 Stroma represent 90% thickness of cornea
 Stroma contains 76-80% water and remaining
collagen fibrils
 Epithelium is rate limiting barrier for hydrophilic
drugs
 Stroma is rate limiting for lipophilic drugs

10. ROUTE OF ADMINISTRATION

11. OCULAR DRUG DELIVERY

12. IDEAL CHARACTERISTICS OF ODDS
 Sterility
 Isotonicity
e.g.: 1.9% boric acid, 0.9% NaCl
 Buffer/pH adjustment
 Less drainage tendency
 Minimum protein binding

13. APPROACHES TOWARDS
 Improving ocular contact time
 Enhancing corneal permeability
 Enhancing site specificity
 Role of polymers
 Improving ocular contact time of solution
 E.g.:- polyvinyl alcohol (PVA), PVP, MC, CMC,
Hydroxy propyl cellulse (HPC)
 Increased viscosity reduces solution drainage
 Natural polymers: sodium hyaluronate and
chondroition

14. MUCOADHESIVE
 Established non-covalent bonds with corneal
conjuctival mucin – extending preocular residence
times.
 Mucin is thin film of glycoprotein – external surface
of globe of eye
 Mucin hold 40-80 times water
 Tear film consist:
• Lipid portion
• Mucin
• Aqueous portion
 Prolonging release of drug

15. OPHTHALMIC INSERTS
Controlled release ocular insert are;
 Comfort
 Lack of explosion
 Ease of handling and insertion
 No interference
 Sterility
 Stability
 Ease of manufacture

16. NON ERODIBLE INSERTS – OCUSERTS
 Develop by Alza corporation
 Flat, flexible and elliptical device
 3 layers – two layers of EVA and one of inner core
 Release at const. rate 20 or 40 µg/hr
 Release controlled by thickness of rate controlling
membrane
 Used in treatment of chronic glaucomas
 Smaller and rod shaped devices retained better

17. CONTACT LENS
 Presoaked hydrophilic contact lenses
 Soft lenses used to aid corneal wound healing,
corneal ulcer
 Presoaked lenses not prolonged
 Preservative – benzalkonium chloride
 Alternative approach – solution or suspension of
drug in monomer mix
 Contact lenses fabricated by polymerization
 Have release upto 180 hrs

18. ERODIBLE INSERTS – LACRISERTS
 Develop by Merck , Sharp and Dohme
 Sterile rod shape
 Made of HPC without preservative
 Used for treatment of dry eye syndromes
 5mg, 12.7mm and 3.5mm of weigh, diameter and
length repectively.
 Used in keratitis sicca patients
 Inserted into inferior formix

19. SODI (SOLUBLE OCULAR DRUG INSERT)
 Develop by Soviet scientists
 Small oval wafer
 Made from acrylamide, N-vinylpyrrolidone and
ethylacrylate
 Sterile thin film of 15-16 mg
 Soften in 10-15 sec in cul-de-sac
 Single application replace 4-12 drops and 3-6
apllications
 Used in treatment of glaucoma and trachoma

20. OCULAR THERAPEUTICS SYSTEM (OTS)
 Consist of contoured disc with a convex front and
concave back surface
 4-5 mm diameter
 Major component is silicone based prepolymer
 OTS can be hydrophilic or hydrophobic
 Minidisc in contrast with elliptical or rod shaped
 Drug released up to 170 hrs (hydrophilic)
 Hydrophobic OTS released drug upto 320 hrs

21. NEW OPHTHALMIC DELIVERY SYSTEM(NODS)
 Provide accurate and reproducible dosing
 Free from preservative
 Drug incorporated into water soluble polyvinyl
alcohol film
 On contact with tear film dissolves quickly
 Both soluble (pilocarpine) and insoluble
(tropicamide) drugs can formulated

22. MARKETED NEW DRUGS
 Oxervate : treatment of neurotrophic keratitis
 Luxturna: treatment of vision loss due to confirmed
biallelic RPE65-mediated inherited retinal disease
 Rhopressa: treatment of glaucoma or ocular
hypertension
 Xiidra : treatment of dry eye disease
 Zerviate : treatment of ocular itching
 Omidria: use during eye surgery to prevent
intraoperative miosis

23. REFERENCE
 Vyas Suresh P. & Khar Roop K.,“Controlled Drug
Delivery concepts & Advances ”,Vallabh Prakashan,
2nd edition, Page no. 369-396
 Gaudana Ripal, Ananthula Hri Krishna, Parenky
Ashwin and Mitra Ashim K., Ocular drug delivery,
Sept 2010