BackgroundLumefantrine, an antimalarial molecule has very low and variable bioavailability owing to its extremely poor solubility in water. It is recommended to be taken with milk to enhance its solubility and bioavailability. The aim of present study was to develop a Self Nanoemulsifying Delivery system (SNEDs) of lumefantrine (LF) to achieve rapid and complete dissolution independent of food-fat and surfactant in dissolution media.MethodsSolubility of LF in oil, co-solvent/co-surfactant and surfactant solution and emulsification efficiency of surfactant were analyzed to optimize the LF loaded self nanoemulsifying preconcentrate. Effect of LF-oleic acid complexation on emulsification, droplet size, zeta potential and dissolution were investigated. Effect of milk concentration and fat content on saturation solubility and dissolution of LF was investigated. Dissolution of marketed formulation and LF-SNEDs was carried out in pH 1.2 and pH 6.8 phosphate buffer.ResultsLF exhibited very high solubility in oleic acid owing to complexation between tertiary amine of LF and carboxyl group of oleic acid (OA). Cremophore EL and medium chain monoglyceride were selected surfactant and co-surfactant, respectively. Significantly smaller droplet size (37 nm), shift in zeta potential from negative to positive value, very high drug loading in lipid based system (> 10%), no precipitation after dissolution are the major distinguish characteristics contributed by LF-OA complex in the SNED system. Saturation solubility and dissolution study in milk containing media pointed the significant increment in solubility of LF in the presence of milk-food fat. LF-SNEDs showed > 90% LF release within 30 min in pH 1.2 while marketed tablet showed almost 0% drug release.ConclusionSelf nanoemulsification promoting ionic complexation between basic drug and oleic acid hold great promise in enhancing solubility of hydrophobic drugs.

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The relationship of geomorphic and climatic history and formation of tlie ferruginous soils, formed on the acidic Peninsular Gneiss, of tlie Mysore Plateau, India. is discussed. The profiles studied are found on two different land systems. Tlie soils of tlie older, fairly smooth landscape are composed of colluvium over truncated laterite profiles. with a gravel layer and a prominent kaolin layer over tlie weathered rock. These soils show an accumulation of pedogenic liaematite grains in the sand fraction and lime considerable kaolinite and amorphous feni-aluminosilicate minerals in the clays.The soils of the younger, rugged landscape have similar clay mineralogy. but du not have a gravel layer, or haematite grains. The influence of the coarsegrained parent rock is seen in the large amounts of quartzgravel. The absence of granulation is attributed to lack of accumulation of iron.The soils have been formed in an earlier, more liuniid climate than prevails today. The original laterite profiles were formed on a plane surface, and subsequent change in climate has led to change in the land forms and dissection. Truncation of tlie profiles was followed by deposition of red colluvium over the resistant ferruginous layer.These ancient soils do not fit the criteria for Oxisols in tlie US. classification. but t'it well in the French system as 'Sols Ferrallitiques', subclass 'fiablement disaturcs en (13)'. The soil from a low lying area, formed from colluvium under hydroinorpliic conditions. is classified as 'Vertisols et Paravertisols'.

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