Comparative efficacy of liposome-entrapped amiloride and free amiloride in animal models of seizures and serum potassium in mice.

The present study was aimed to evaluate a liposomal formulation of amiloride on experimental seizure models including the increasing current electroshock seizure threshold test (ICES), pentylenetetrazole (PTZ)-induced seizures and PTZ-induced status epilepticus in mice. Further, the effect of liposomal amiloride on serum K(+) levels was also investigated using flame photometry. We found an improved anticonvulsant action with liposome-entrapped amiloride as compared to free amiloride. Further, free amiloride showed an increase in serum K(+) levels, however the latter was unaffected with liposomal formulation treatment. These results, together with previously published data, suggest that as drug delivery vehicles, liposomes can enhance the effectiveness of drugs in the CNS without producing peripheral toxicity (hyperkalemia).