Effects of the pharmaceutical cosolvent hydroxypropyl-β-cyclodextrin on porcine corneal endothelium

Abstract 

· Background: The influence of the pharmaceutical cosolvent hydroxypropyl-β-cyclodextrin (HPBCD) on porcine corneal endothelium was investigated. The purpose was to find out if this substance causes severe damage to the cornea. · Methods: One hundred and ninety-five pig corneas were preserved in Eagle’s minimal essential medium with dextran and HPBCD. They were stained with trypan blue, examined using a light microscope and then reincubated. Changes in cell density and cell morphology as a function of the duration of preservation and the HPBCD concentration were evaluated. We developed a morphological classification combining the morphological aspects observed using the light microscope and the scanning electron microscope. The vitality of the endothelium was analyzed by cell separation and monolayer cultivation. · Results: The cell density stayed stable without significant alterations in 0.1% HPBCD, 1% HPBCD and control solutions. In 10% HPBCD, however, the endothelium showed significant loss of cells. The morphological classification revealed high-grade endothelial damage in 10% HPBCD and low-grade damage in 1% HPBCD. The changes observed in 0.1% HPBCD and control medium were comparable. The degree of alteration conformed to the results of monolayer cultivation: endothelial cells of damaged corneoscleral buttons were limited in their ability to proliferate. · Conclusion: Severe endothelial destruction in 10% HPBCD and changes in membrane integrity at lower concentrations limit the use of HPBCD in ophthalmic solutions.