Eyes and Nose Drugs Delivery

Question 1

Ocular Drug Delivery

Answer 1

1. Bacterial, fungal and viral infections of the eye or eyelids.
2. Allergic or infectious conjunctivitis or inflammation.
3. Elevated introcular pressure and glaucoma.
4. DRY eye syndrome.

Question 2

When reflex tearing causes volume to exceed ____ μl.

Answer 2

7-10

Question 3

GI tract: Potential systemic effects, salty/bitter taste. How can this be minimized?

Answer 3

By applying gentle pressure to the lacrimal sac for 3-5 mins after administration.

Question 4

Ocular absorption is < ___% of administered dose. This neccessitates repeated administration of the solution

Answer 4

1%

Question 5

What is recommended when more than 1 drop is to be administered?

Answer 5

apply one drop, then wait 3-4 min before putting another drop in eyes

Question 6

The particle size must be finely subdivided to

minimize eye ______and/or _______ of the cornea

Answer 6

irritation / scratching

Question 7

How does a suspension increases duration of action compared to solution?

Answer 7

• longer contact time
• best for drug with low dissolution

Question 9

Keeps the drug in contact with the eye _________ than suspensions.

Answer 9

Longer

Question 10

Suspensions should not be filtered .Why?

Answer 10

neccessary drug particles would be removed by the filter

Question 11

Lacrimal fluid has tonicity of normal Saline =_________.

Answer 11

0.9 %

Question 12

Ocusert®

Answer 12

• Nonerodible device.
• First controlled release topical dosage form marketed in US by Alza in 1975.
• Delivers pilocarpine for several days in the treatment of glaucoma.
• A soft and flexible elliptical membrane designed to be placed in the cul-de-sac
• Advantage:

– Steady levels for 7 days intraocular pressure (IOP)

– vs. qid dosing from drops

• Disadvantage:

– Cost.

– Not Comfortable.

– No longer marketed

Question 13

Lacrisert®

Answer 13

• Erodible device.
• Controlled erosion of the polymer matrix
• Poorly soluble, high-MW compounds
• q.d. or b.i.d. for moderate to severe dry eye syndrome
• 5 mg of hydroxypropylcellulose (anhydrous) in a rod shape
• Placed in cul-de sac.
• Advantage:

– Controlled release

• Disadvantage:

– Floats.

– Not comfortable.

Question 14

Preservatives

Answer 14

1. Benzalkoniumchloride
2. Thiomerosal
3. Chlorobutanol
4. Polyquat (polyquaternium -1)
5. Methyl- and propylparaben

Question 15

Tonicity Adjusting Agents

Answer 15

• NaCl
• Mannitol
• Glycerin (1%)
• Propylene glycol (1%)

Question 16

Why use of buffer?

Answer 16

1. To reduce discomfort to the patient.
2. To ensure drug stability.
3. To enhance aqueous solubility of drug.
4. To control the therapeutic activity of drugsubstance.
5. To maximize preservative efficacy.
   * Physiologic pH of blood and tears is approximately 7.4= Optimum pH.*
   * Appropriate pH prevent corneal damage is 6.5 to 8.5.*

Question 17

Viscosity

Answer 17

1. ↑retention time
2. ↓the drainage rate
3. ↑ocular bioavailability
4. Have lubricant effect

• Cellulose derivatives (e.g. hydroxypropylmethyl-and methylcellulose)
• polyvinyl alcohol.
• Disadvantages: Crust formation and transient blurring

Question 18

Antioxidants

Answer 18

• Used to delay or prevent deterioration of the drug
• Examples:
• Sodium metabisulfite
• Ascorbic acid
• Edetic acid

Question 19

Approaches to Enhance Nasal Drug Delivery

Answer 19

1. Structural modification:
2. Salt or ester formation
3. Formulation design such as:

• Surfactant: to modify permeability of nasal mucosa.
• Addition of bioadhesive/ mucoadhesive excipients to increase residence time. Microcrystalline cellulose.
• Choice of formulation: Gel formulation allows the drug to stay in contact longer with nasal tissues. E.g Zicam nasal gel