In vitro characterization of human intact erythrocytes loaded by enalaprilat.

In vitro characteristics of the human erythrocytes loaded by enalaprilat have been evaluated. Erythrocytes obtained from a healthy volunteer were loaded by enalaprilat using the hypotonic preswelling method, and the loading parameters, drug-release kinetics, hematological indices, particle size distribution, scanning electron microscopy view, osmotic and turbulence fragilities, and deformability of the resulting carrier cells were determined along with the sham encapsulated and unloaded cells. Carrier erythrocytes, having acceptable loading parameters, released their drug content according to zero-order kinetics. Mean corpuscular hemoglobin and mean corpuscular hemoglobin content values of the cells decreased, particle size dispersion increased, the cells transformed to cup-form, the erythrocytes became more fragile against osmotic pressure and turbulent flow, and, finally, the deformability of the cells decreased significantly upon drug loading.