Development and optimization of venlafaxine hydrochloride floating microspheres using response surface plots

Abstract

The current study deals with the development of floating microspheres of venlafaxine hydrochloride. This drug is known as a serotonin-norepinephrine reuptake inhibitor and used to treat depression. Due to the short elimination half life of 4-5 h, the drug has to be administred 2-3 times in a day to maintain the plasma concentration. Thus an attempt was made to decrease the dosing frequency. The microspheres were prepared by non-aqueous solvent evaporation method. The microspheres were evaluated for particle size and morphology using a photomicroscope and scanning electron microscopy, respectively. The incorporation efficiency of microspheres of batch F2 and F6 showed entrapment of 60.6% and 57.2%, respectively. The mean diameters of particles for all batches were found in the range of 226.15 ± 24.37 to 283.37 ± 21.56 μm. The Fourier transform infrared spectroscopy revealed absence of any drug polymer interactions. The microsphers remained buoyant for more than 12 h. The drug release from developed microspheres followed Fickian diffusion with swelling. The results suggested that the developed floating microspheres containing venlafaxine hydrochloride could enhance drug entrapment efficiency, reduce the initial burst release and modulate the drug release.