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Abstract: Lecithin organogels (LOs) are semi-solid systems with immobilized organic liquid phase in 3-D network of self-assembled gelators. This paper attempts to study the various attributes of LOs, starting from selection of materials, optimization of influential components to LO specific characterization. After screening of various components (type of gelators, organic and aqueous phase) and construction of phase diagrams, a D-optimal mixture design was employed for the systematic optimization of the LO composition. The response surface plots were constructed for various response variables, viz. viscosity, gel strength, spreadability and consistency index. The optimized LO composition was searched employing overlay plots. Subsequent validation of the optimization study employing check-point formulations, located using grid search, indicated high degree of prognostic ability of the experimental design. The optimized formulation was characterized for morphology, drug content, rheology, spreadability, pH, phase transition temperatures, and physical and chemical stability. The outcomes of the study were interesting showing high dependence of LO attributes on the type and amount of phospholipid, Poloxamer™, auxillary gelators and organic solvent. The optimized LO was found to be quite stable, easily applicable and biocompatible. The findings of the study can be utilized for the development of LO systems of other drugs for the safer and effective topical delivery. [Copyright &y& Elsevier]

Advantage of spray drying technique over the conventional surface adsorption technique for co-formulation of solid SNEDDS (S-SNEDDS) of curcumin (CRM) and duloxetine (DXH) is discussed. Liquid SNEDDS were prepared using castor oil (20% w/w), Tween-80 (40% w/w) and Transcutol® P (40% w/w) as oil, surfactant and co-surfactants containing both CRM and DXH. S-SNEDDS were formulated by adsorption of liquid SNEDDS onto porous hydrophilic and hydrophobic carriers through spray drying and surface adsorption techniques. The percentage drug loading for CRM and DXH in optimized L-SNEDDS was 87.22 ± 1.87 and 92.32 ± 0.19%, mean droplet size, 113.14 ± 1.14 nm; polydispersity index, 0.20 ± 0.026, and zeta potential − 13.2 mV, respectively. Prepared formulation was evaluated for parameters such as, oil adsorption tendency, micromeritic characteristics, disintegration and dissolution behaviour to identify suitable carrier for conversion of L-SNEDDS into S-SNEDDS. Among the carriers used, Syloid® 244FP revealed highest oil adsorption capacity. Spray drying of L-SNEDDS using Syloid® 244FP as carrier further improved micromeritic properties with lower angle of repose (22.18 ± 0.22°), higher flow rate (4.33 ± 0.26 g/s), lower true (1.23 ± 0.22 g/cm 3 ), bulk (0.202 ± 0.05 g/cm 3 ) and tapped density (0.216 ± 0.07 g/cm 3 ). In vitro dissolution and ex-vivo permeation studies revealed non-significant (P > 0.05) drugs' release from S-SNEDDS powders/tablets viz-a-viz their L-SNEDDS formulation. SNEDDS were found to be remarkably superior over the unprocessed drugs in their dissolution and permeation studies. They were found to be stable in terms of droplet size, dissolution pattern, tablet hardness and assay when subjected to stability testing. Scanning Electron Microscopy, Differential Scanning Calorimetry and powder X-ray diffraction studies revealed that crystalline drugs were converted to their amorphous state in the SNEDDS formulations. Spray drying technique has, therefore proved to distinctly improve the micromeritics and biopharmaceutical attributes in the co-formulation of curcumin and duloxetine S-SNEDDS. [ABSTRACT FROM AUTHOR]

Neuropathic pain associated with chronic alcohol consumption is a medico-socioeconomical problem that affects both central and peripheral nervous system and has no satisfactory treatment till date. The present study was designed to investigate the protective effect of co-administration of curcumin and sildenafil on alcohol induced neuropathic pain in rats. In order to carry out this, ethanol (35% v/v, 10 g/kg, p.o.) was administered for 10 weeks to induce neuropathic pain. Curcumin (30 and 60 mg/kg, i.p.) and sildenafil (5 and 10 mg/kg, i.p.) were given alone and in combination at their lower doses (30 mg/kg curcumin and 5 mg/kg, sildenafil, i.p.) to investigate the changes in thermal and mechanical hyperalgesia, allodynia and histopathological parameters. Biochemical estimations of thiobarbituric acid reactive species, glutathione and protein was also carried out to evaluate oxidative stress. The results revealed that chronic alcohol consumption for 10 weeks caused significant thermal and mechanical hyperalgesia, allodynia and increased oxidative stress. Individual administration of both the drugs at their low as well as high doses were able to improve the symptoms of alcohol induced neuropathic pain. Whereas co-administration of curcumin and sildenafil at their lower doses itself were found to significantly improve nerve functions, biochemical and histopathological parameters as compared to their individual administration. It is therefore proposed that co-administration of curcumin and sildenafil may bring new dimension towards attenuation of alcohol induced neuropathic pain affecting central as well as peripheral nervous system. [ABSTRACT FROM AUTHOR]