Prodrug

pivalvyl groups removed by esterases in cornea, leaving epinephrine to act at recept

Epinephrin penetraion increase 10 fold

Latanoprost (Xalatan)

Travoprost (Travatan)

Prodrugs

ester-linked group is cleaved off after penetrating cornea

free acid remains in aqueous

Loteprednol etabonate

Prodrug

active metabolite of prednisolone

less potential adverse effects due to ____

1. Surfactants

2. Chemical Toxins

3. Oxidative

Preservatives

surfactants

• ionically charged molecules that disrupt plasma membrane
• usually bacterial cidal

Preservatives

Chemical toxins

Mercury, iodine, EtOH

Block normal metabolic processes of cell

bactericidal/static

• penetrate cell membranes or walls
• interfere with cellular function
• hydrogen peroxide, Purite 

Surfactant, GL med

• quarternary surfactant
• cationic
• stable, antimicrobial, long shelf life
• increase corneal drug penetration by disrupting epithelial surface
• toxic inflammatory effect

Chlorhexidine

• Diguanide

• Surfactant
• does not alter corneal permeability as BAC
• gentler to ocular surface
• cannot intercalate into lipid layer as BAC

Preservatives

Chemical

Mercurials - Thimerosal

Alcohol - Chlorobutanol

Chemical Preservatives - Mercurials

Not used much anymore because of contact sensitivity/allergic reactions

Chemical Preservatives - Alcohol

less effective than BAC

fewer allergic rxns

more effective with EDTA

Preservatives

Oxidative

1. Stabilized Oxychloro Complex (Purite) - (Refresh Tears®)

2. Sodium Perborate (GenTeal®)

• neutralized by cells, no accumulation
• effective on microorganism, low toxicity

Preservatives

Miscellaneous

1. Methylparaben, propylparaben

2. Ethylenediaminetetraacetic acid (EDTA)

3. Sofzia

Preservatives

- Artificial Tears

Preservative

• chelating agent - chelates Ca2+ for cell junction formation
• alone is not a sufficient antimicrobial 
• assist action of Thimerosol and BAC
• contact dermatitis
• cytotoxic if prolonged use

Preservative

• in Travatan Z

Excipients

Viscous Agents

Name the 8 of them

1. Methylcellulose (MC)
2. Polyvinyl alcohol (PVA)
3. Polyvinylpyrrolidone (Providone) (PVP)
4. Polysorbate 80
5. Dextran
6. Gelatin
7. Carbomers (eg. 934, 940)

Excipients

Antioxidants

Name the 2

1. Sodium sulfites

2. EDTA

Excipients

Buffers

A. Definition

A) a chemical system that prevents the change in concentration of another chemical system

- to give a soln' the property of resisting a change in pH

Excipients

Buffers

The 5 names

• Acetic, boric, hydrocholoric acids
• Potassium and sodium bicarbonate
• Potassium and sodium borate
• Potassium and sodium phosphate
• Potassium and sodium citrate

Vehicles

1. Polyvinyl Alcohol (PVA)
2. Polyvinylpyrrolidone (povidone) PVP
3. Hydroxypropyl methylcellulose (HPMC)
4. Carboxymethylcellulose

Vehicles

for shear thinning 

1. Mucin
2. Sodium hyaluronate (SH)

Vehicles

Gel-Forming Systems

Gel-rite - Timoptic XE in GL

Xanthan gum vehicle

Vehicles

Polyacrylic acids

Vehicles

Cation exchange Resin (Amberlite)

1. Polyacrylic Acids

• Carbopol gels

2. Betaxolol susp. (Betoptic S)

Vehicles

Types