Formulation optimization of extended release pellets prepared by Wurster technology for an Antiepileptic drug

Abstract

The objective this research is to develop extended release multiunit particulate system for an antiepileptic drug by using fluid bed processor equipped with bottom spray technology which is also known as wurster technology. This formulation comprises of an extended release component which retards the release of drug coated on the core pellets. The extent of extended release coat and concentration of extended release component is optimized to achieve predetermined dissolution profile. Formulating modified release drug delivery system for highly soluble drug is difficult. Present research comprises of ethyl cellulose acts as rate controlling hydrophobic barrier while povidone k-30 acts as pore former component which helps in release of drug in which attributes affecting the quality target product profile was identified by using initial risk assessment and batches were planned accordingly. Reservoir technology by using wurster coating process was used to develop extended release pellets where, subsequent coating is applied on core pellets. In drug layering stage, drug solution prepared was dispersion solution. Therefor viscosity played an important role in drug layering as low viscosity of dispersion solution lead to decreased coating efficiency as loss of amorphous drug during the process occurs. Viscosity of the dispersion depends upon the quantity and type of binder used. However, higher viscosity may lead to the agglomeration of pellets. Thus, optimized concentration of PVP k-90 were used during drug layering process. 3% barrier coating using Opadry clear was done to smoothen the drug layered pellets for the ease of subsequent coating process. Extended release coat applied on the barrier layer coated pellets, determines the release of the drug from the formulation. Thus, in present research ratio of EC: PVP K-30: Triethyl citrate: talc was optimized to 68:32:10:10 to obtain desired drug release profile.