Investigation on Processing Variables for the Preparation of Fluconazole-Loaded Ethyl Cellulose Microspheres by Modified Multiple Emulsion Technique

Abstract

Abstract. Fluconazole-loaded ethyl cellulose microspheres were prepared by alginate facilitated (water-in-oil)-in-water emulsion technology and the effects of various processing variables on the properties of microspheres were investigated. Scanning electron microscopy revealed spherical nature and smooth surface morphology of the microspheres except those prepared at higher concentration of emulsifiers and higher stirring speeds. The size of microspheres varied between 228 and 592 μm, and as high as 80% drug entrapment efficiency was obtained depending upon the processing variables. When compared up to 2 h, the drug release in pH 1.2 HCl solution was slower than in pH 7.4 phosphate buffer saline solution. However, this trend was reversed at high shear conditions. The microspheres provided extended drug release in alkaline dissolution medium and the drug release was found to be controlled by Fickian-diffusion mechanism. However, the mechanism shifted to anomalous diffusion at high shear rates and emulsifier concentrations. The aging of microspheres did not influence the drug release kinetics. However, the physical interaction between drug and excipients affected the drug dissolution behaviors. X-ray diffractometry (X-RD) and differential scanning calorimetry (DSC) analysis revealed amorphous nature of drug in the microspheres. Fourier transform infrared (FTIR) spectroscopy indicated stable character of fluconazole in the microspheres. The stability testing data also supported the stable nature of fluconazole in the microspheres. The fluconazole extracted from 80% drug-loaded formulation showed good in vitro antifungal activity against Candida albicans. Thus, proper control of the processing variables involved in this modified multiple emulsion technology could allow effective incorporation of slightly water soluble drugs into ethyl cellulose microspheres without affecting drug stability.KEY WORDS: entrapment efficiency; ethyl cellulose; fluconazole; microspheres; water-in-oil-in-water (w/o/w) multiple emulsion.

Influence on variation in process parameters for the design of xanthan-gum-facilitated ethyl cellulose microparticles for intestinal specific delivery

“…A similar observation obtained with fluconazole-loaded ethyl cellulose microspheres has been reported earlier [12] . This may be due to the increase in internal aqueous xanthan gum phase volume that caused a decrease in mean particle diameter of the formulations ( Table 1).…”

“…After that, the volume was adjusted to 50 ml with fresh PB solution (pH 7.4) heated at 50 -55 ° C. The solution was cooled, filtered, and an aliquot, after suitable dilution, was analyzed spectrophotometrically at 230 nm [11] . The estimation of percentage drug encapsulation efficiency was calculated by following the equation [12] :…”

Optimization of Process Parameters of Osthole-Loaded PLGA Microparticles Prepared Using Emulsification–Solvent Extraction

“…The formation of smaller emulsion droplets facilitates drug diffusion out of the microparticles before they harden and ensures lower drug encapsulation efficiency. [18] In this study, the interaction between the ratio of osthole to PLGA and the emulsification stirring speed was statistically significant (P < 0.05).…”

Polymeric Microsphere Formulation for Colon Targeted Delivery of 5-Fluorouracil Using Biocompatible Natural Gum Katira

“…At predetermined intervals, the sample was withdrawn, and the concentration of released 5-FU in the media was determined by analyzing at 270 nm using a double beam spectrophotometer (UV1, ThermoSpectronic, Great Britain). The cumulative release of 5-FU was determined using the standard calibration curves of the drug in respective dissolution media (0.1 N HCl -pH 1.2; phosphate buffer saline -pH 7.4), respectively (Maiti et al, 2009;Ahmadi et al, 2018).…”