DOI: https://doi.org/10.55373/mjchem.v25i5.23

Keywords: Phenytoin; antiepileptic drug; nanoemulsion; mixture experimental design

Abstract

Phenytoin is a classic antiepileptic drug, which exhibits potent therapeutic efficacy in controlling seizure attacks, thus signifying its importance in a basic healthcare system. However, due to the poor solubility and bioavailability of phenytoin, a large dosage had to be given orally to reach therapeutic concentration with numerous side effects. In this research, the formulation of phenytoin-loaded nanoemulsion was developed as a parenteral application for epilepsy treatment in order to control seizure attacks. The formulation was optimized by a mixture experimental design (MED) and the effects of isopropyl myristate, surfactants, glycerol, and water on the droplet size of the nanoemulsion were determined. The optimum formulation with desirable criteria for the parenteral application was obtained. The predicted response value showed no significant difference from the actual value derived from the experiment with a residual standard error (RSE) of less than 2.00 %. The drug release study showed that 50 % of the drug was released within 3 h of dissolution and the highest cumulative percentage release of phenytoin was recorded at 97 % at 6 h. The sustained release of the drug could be due to its affinity to the oil phase as phenytoin was shown to be highly soluble in the mixture of Tween 80 and Tween 85. The use of surfactants hinders the release of the drug due to its ability to form strong interfacial films surrounding the oil droplets, which can prevent the drastic release of the drug in a short period of time. Thus, the optimized nanoemulsion containing phenytoin has the potential to be used for parenteral treatment for epilepsy.