Floating Emulsion Beads of Gelucire for Metronidazole and Norfloxacin

Gelucire which comprising a blend of pure glycerides (mono-, di-and triglycerides of saturated fatty acids), mixtures of glycerides and fatty acid esters of polyethylene glycols (mono-and di-fatty acid esters) in various proportions or pure polyethylene glycol (PEG) esters with no glycerides present as in the case of Gelucire 55/18. These are inert tailor-made lipidic materials derived from natural hydrogenated food-grade oils and fats. Generally, it is synthesized by an alcoholysis reaction whereby coconut, palm or palm kernel oil is hydrolyzed and the fatty acids removed by fractional distillation. These fatty acids are then esterified with PEG under a nitrogen atmosphere. Besides alcoholysis, it can also be manufactured by the direct esterification of fatty acids with glycerol and PEG. Gelucires are excipients with amphiphilic character. The amphiphilicity of the base attributed to the long hydrocarbon chain and the alcohol moieties that make these bases suitable as a lipid carrier for both hydrophilic and lipophilic drugs. These bases have been developed to melt within specified ranges and to have predetermined fat soluble or water dispersible characteristics.