OPHTHALMIC PRODUCTS (Formulation and Evaluation) B.Pharmacy 5th Semester 2024 (2023-2024) Previous Year's Question Papers/Notes Download - HK Technical PGIMS

This is a ophthalmic preparation notes ..of unit 4th in industrial pharmacy..

Thankyou.

OPHTHALMIC PRODUCTS
 (Formulation and Evaluation)
 Dr Sanjesh G rath Associate professor
SIPS
• Definition:
• Ophthalmic preparations (eye preparations) are sterile,
liquid, semi-solid, or solid preparations that may
contain one or more active pharmaceutical ingredient
intended for application to the conjunctiva, the
conjunctival sac or the eyelids.

• They are specialized dosage forms designed to be
instilled onto the external surface of the eye (topical),
administered inside (intraocular) or adjacent
(periocular) to the eye or used in conjunction with an
ophthalmic device.
• The most commonly employed ophthalmic dosage
forms are solutions, suspensions, and ointments.
• The newest dosage forms for ophthalmic drug delivery
are: gels, gel-forming solutions, ocular inserts ,
intravitreal injections and implants.
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.
• increased shelf life.
• better patient compliance.
DISADVANTAGES:
• 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.
Drugs used in the eye:-
• Miotics e.g. pilocarpine Hcl
• Mydriatics e.g. Atropine
• Cycloplegics e.g. Atropine
• Anti-inflammatories e.g. corticosteroids
• Anti-infectives (antibiotics, antivirals and antibacterials)
• Anti-glucoma drugs e.g. pilocarpine Hcl
• Adjuncts e.g. Irrigating solutions
• Diagnostic drugs e.g. sodiumfluorescein
• Anesthetics e.g. Tetracaine
Anatomy and Physiology of the Eye:
Formulation:
• 1)Drug
• 2)Preservative
• 3)Sterilization
• 4)Isotonicity
• 5)Buffer
• 6)Viscosity
• 7)Container
• 8)Label
• 1) Drugs- These contains drugs of various
categories including antiseptic, antiinflammatory agent, mydriatic or miotic
properties
• 2) Preservative- Eye drop should be sterile
and should contain preservatives to avoid
microbial contamination when container is
open. The preservative for ophthalmic use
includes benzalkonium chloride, chlorbutanol,
phenylmercuric acetate, phenylmercuric
nitrate etc.,
• 3)Sterilization- Eye drops are sterilized by
autoclaving at 121°C for 15 minutes or by
bacteria filter to avoid thermal degradation for
example- preservative chlorbutanol hydrolyzes
at high temperature
• 4)Isotonicity- All the solutes including drug
contribute to the osmotic pressure of the eye
drip, therefore isotonicity of the formula
should be calculated and it is adjusted with
sodium chloride, for example sodium chloride
0.9% and boric acid 1.9& are iso-osmotic
• 5)Buffer- the buffer should be added to
maintain balance between comfort, solubility,
stability and activity of drug. For example the
hydrolysed chlorbutanol forms hydrochloride
acid making the drop acidic. Whereas certain
drug like pilocarpine hydrochloride are acidic
• 6)Viscosity- the size of the drop and its
residence in eye depends on viscosity of eye
drops. Methyl cellulose, hydroxypropyl
methycellulose and polyvenyl alcohol are
common viscosity inhancer
• 7) Container- the commonly used container
for ophthalmic solutions or suspension is
multi-dose container(5ml, 10ml). Glass
container is supplied with sterile plastic
dropper. Plastic bottles are with built up
nozzle.
• 8)Label- Not for injection. For external use
only. Shake well before use (if it is suspension)
DOSAGE FORMS APPLIED TO THE EYE
Topical Administration
Solutions
Suspension
Emulsion
Ointment
Gel
Perfusion
Spray
Inserts
Intraocular drug delivery
Intraocular injection
Implant
Iontophoresis
Liposome
Niosome
Drug delivery routes
• Solutions
• Ophthalmic solutions are sterile solutions
intended for instillation in the eye. Included in this
dosage form category are solid preparations that,
when reconstituted according to the label
instructions, result in a solution
• Solutions are Manufactured by dissolution of the
active ingredients and a portion of the excipients
into all portion of water.
• The sterilization of this solution done by heat or
by sterilizing Filtration through sterile depth or
membrane filter media Into a sterile receptacle.
• This sterile solution is then mixed with the
additional required Sterile components such as
viscosity –imparting agents, Preservatives and so
and the solution is brought to final Volume with
additional sterile water
Disadvantages of eye solutions:
• The very short time the solution stays at the eye
surface.The retention of a solution in the eye is
influenced by viscosity.
• Its poor bioavailability (a major portion i.e. 75% is lost
via naso lacrimal drainage).
Examples of topical eye solutions:
• Atropine sulphate eye drops.
• Pilocarpine eye drops .
• Silver nitrate eye drops.
• Zinc sulphate eye drops.
suspensions
• If the drug is not sufficiently soluble, it can be
formulated as a suspension.
• A suspension may also be desired to improve
stability, Bioavailability ,and efficacy.
• The major topical ophthalmic suspensions are the
steroid anti-inflammatory agents.
• An ophthalmic suspension should use the drug in
a microfine form; usually 95% or more of the
particles have a Diameter of 10µm or less.
Examples of eye suspension
• Prednisolone acetate suspension.
• Besifloxacin suspension.
• Blephamide suspension.
• Fluorometholone suspension
• Emulsions
• Topical ophthalmic emulsions generally are prepared
by dissolving or dispersing the active ingredient(s) into
an oil phase, adding suitable emulsifying and
suspending agents and mixing with water vigorously to
form a uniform oil-in-water emulsion. Each phase is
typically sterilized prior to or during charging into the
mixing vessel.
Ointments
• Ophthalmic ointments must be sterile
• The ointment base selected for an ophthalmic
ointment must be nonirritating to the eye and
must permit the diffusion of the active ingredient
throughout the secretions bathing the eye.
• Ophthalmic ointments have a longer ocular
contact time when compared to many
ophthalmic solutions
• One disadvantage to ophthalmic ointments is the
blurred vision that occurs as the ointment base
melts and is spread across the lens.
Example of ophthalmic ointment
• Chloramphenicol ointment.
• Tetracycline ointment.
• Hydrocortisone ointment.
 Gels
• Ophthalmic gels are composed of
mucoadhesive polymers that
provide localized delivery of an
active ingredient to the eye.
• Such polymers have a property
known as bioadhesion meaning
attachment of a drug carrier to a
specific biological tissue.
• These polymers are able to extend
the contact time of the drug with
the biological tissues and thereby
improve ocular bioavailability
Perfusion
• Continuous and constant perfusion of the eye with drug solutions can be
achieved by the use of ambulatory motor driven syringes that deliver drug
solutions through fine polyethylene tubing positioned in the conjunctival sac
• This system allows the use of a lower drug concentration than used in
conventional eye-drops, yet will produce the same potency. Side effects are
reduced and constant therapeutic action is maintained
Sprays
• Spray systems produce similar results to eye-drops in terms of
duration of drug action and side effects. Sprays have several
advantages over eye-drops:
1. a more uniform spread of drug can be achieved
2. precise instillation requiring less manual dexterity than
for eye-drop administration and is particularly useful for
treating patients with unsteady hand movements
3. contamination and eye injury due to eye-drop application
are avoided
4. spray delivery causes less reflex lacrimation.
5. Can be used by patients who have difficulty bending their
neck back to administer drops.
 Ophthalmic inserts
 are defined as sterile solid or semisolid
preparations, with a thin, flexible and
multilayered structure, for insertion in the
conjunctival sac.
 Advantages:
• Increasing contact time and improving bioavailability.
• Providing a prolong drug release and thus a better efficacy.
• Reduction of adverse effects.
• Reduction of the number administrations and thus better
patient compliance.
• FOR EXAMPLE
• Lacrisert is a sterile ophthalmic insert use in the treatment
of dry Eye syndrome and is usually recommended for
patients unable to obtain symptomatic relief with artifical
tear solutions.
• The insert is composed of 5 mg of Hydroxypropyl cellulose
in a rod-shaped form about 1.27 mm diameter by about 3.5
mm long.
Intraocular Dosage Forms
• They are Ophthalmic products that introduced into the
interior structures of the eye primarily during ocular
surgery.
 Intraocular Injections
• The ophthalmologist use available parental dosage
forms to deliver Anti-infective, corticosteroids, and
anesthetic products to achieve higher therapeutic
concentrations intraoculary than can ordinarily Be
achieved by topical or systemic administration.
• FDA approved intraocular injection include miotics,
viscoelastics and an antiviral agent for intravitreal
injection.
Intravitreal implant
• An intravitreal sterile implant containing
ganciclovir or antineoplastic agents is a tablet of
ganciclovir with Magnesium stearate and is
coated to retard release with Polyvinyl alcohol
and ethylene vinyl acetate polymers.
 Such that the device when surgically implanted in
the Vitreous cavity release drug over a 5 to8
month period .
Ocular iontophoresis:
• Iontophoresis is the process in which direct current
drives ions into cells or tissues.
• If the drug molecules carry a positive charge, they are
driven into the tissues at the anode; if negatively
charged, at the cathode.
• Ocular iontophoresis offers a drug delivery system that
is fast, painless, safe, and results in the delivery of a
high concentration of the drug to a specific site.
• Iontophoresis is useful for the treatment of bacterial
keratitis, Iontophoretic application of antibiotics may
enhance their bactericidal activity and reduce the
severity of disease

Liposomes
• Liposome's are microscopic and
submicroscopic vesicles consists of one or
more concentric sphere of Lipid bilayers
separated by Water or aqueous buffer
compartments
Niosomes
• They are non-ionic surfactant based vesicles ,
formed from the self assembly of non-ionic
amphiphiles in in aqueous media resulting in
closed bilayer structures