Which formulation property gives prednisolone ACETATE drops greater intraocular anti-inflammatory penetration than prednisolone sodium PHOSPHATE drops?

• A Higher water solubility allowing better diffusion across the tear film
• B Greater lipid solubility permitting passage across lipophilic epithelial barriers ✓
• C Smaller molecular size enabling paracellular transport between corneal epithelial cells
• D Active uptake by corneal transport proteins absent for phosphate esters

Explanation

The corneal epithelium is a lipophilic barrier, so esterified steroids such as prednisolone acetate, being more lipid soluble, penetrate intact epithelium far better than the highly water-soluble phosphate salts. This is why prednisolone acetate 1% achieves higher intraocular levels and stronger anti-inflammatory effect, while phosphate preparations are reserved for surface disease where epithelium is compromised. Water solubility helps only across hydrophilic stroma, not the rate-limiting epithelium.

Reference: Parsons' Diseases of the Eye, 22nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.