Enhancing the Anticonvulsant Effects of Nifedipine in Rats Through Encapsulation with Water-Soluble [beta]-Cyclodextrin Polymer

Encapsulation is one of the efficient methods recently developed for improving drug delivery. The present study was designed to encapsulate nifedipine (NIF) by water-soluble [beta]-cyclodextrin polymer ([beta]-CDP) and to evaluate the effects of this carrier on NIF-induced anticonvulsant effects. Adult male Wistar rats weighting 200 - 250 g (n = 7) received NIF or encapsulated NIF ([beta]-CDP/NIF) (5, 10 and 20 mg/kg, i.p.), diazepam (2 mg/kg, i.p.) as positive control), and vehicle. Then, pentylenetetrazol (PTZ, 80 mg/kg, i.p.) was injected about 30 min after the drug injection. Changes in the onset time of seizures and duration of their different stages (tonic and tonic-clonic) and total convulsions duration, percentage mortality and percentage of seizure protection were assessed in all test groups. Latency of the seizure onset and duration of tonic and tonic-clonic seizures were significantly decreased in [beta]-CDP/NIF group in comparison with NIF-treated rats (p < 0.05). On the other hand, percentage mortality was significantly decreased and percentage protection was increased by [beta]-CDP/NIF in comparison to NIF (p < 0.05). Therefore, it was concluded that the encapsulation of NIF by [beta]-CDP led to enhancement of the anticonvulsant effects of NIF in rats.