Guar gum and sesame oil based novel bigels for controlled drug delivery

Bigels are novel semi-solid formulations which have been drawing attention of many research scientists due to their numerous advantages over the conventional gels. The objective of this study was to develop and characterize novel bigels by mixing guar gum hydrogel and sorbitan monostearate-sesame oil based organogel for controlled drug delivery applications. The confocal microscopy suggested the existence of both aqueous and oil phases together as bigel. Micro-scale deformation (viscometric) analysis in conjugation with macro-scale deformation studies suggested shear-thinning and viscoelastic nature of the bigels. Thermal study suggested an increase in thermal stability with the increase in organogel proportion in the bigels. The developed bigels were biocompatible in nature. The in vitro drug release study showed that the release of ciprofloxacin (lipophilic drug) increased with a decrease in the organogel content. Further analysis showed that the drug release from all the bigels followed zero order diffusion kinetics which is desirable for a controlled release system. The drug loaded gels showed good antimicrobial efficiency against Bacillus subtilis. In conclusion, the developed bigels may be tried as matrices for topical drug delivery. (C) 2014 Elsevier B.V. All rights reserved.