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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]

Purpose The aim of this study was to evaluate the formulation characteristics and pharmacodynamic activity of the lecithinized coal tar formulation (LCT) employing different methodologies and compare it with that of a conventional coal tar formulation (CCT) employing different methodologies. Methods Characterization for skin-staining was carried out employing shaved back skin of rats. Rheological properties were determined using Texture Analyzer™. The dispersibility of the coal tar formulations in water was determined by macroscopic examination. Antipsoriatic pharmacodynamic activity of the formulations was evaluated employing mouse-tail model. Results The study revealed distinct superiority of the LCT vis-à-vis CCT. The LCT was found be nonstaining with no apparent adverse effect on rat skin. Rheological studies revealed significantly better spreadability and lower stickiness of the LCT than that of CCT. The LCT forms uniform dispersion with water, while the CCT tends to form large aggregates. Finally, the pharmacodynamic model demonstrated superior anti-psoriatic activity of the LCT. Conclusions The findings with the LCT were highly encouraging, as it proved to be nonstaining to skin, easily applicable, and water dispersible with markedly improved efficacy. The product was thus potentially more patient-compliant and efficacious. The evaluation methodologies adopted during the studies were found to be accurate, simple, specific, and reproducible with immense potential for assuring the quality of coal tar product(s). [ABSTRACT FROM AUTHOR]

Background: Coal tar is one of the most preferred and frequently used medicinal agents in various dermatological diseases. However, the coal tar formulations available for clinical use suffer from the limitation of staining clothes and skin, eventually leading to a high degree of patient non-compliance. Objective: To test the staining property of a lecithinized formulation vis-a-vis a conventional formulation of coal tar employing different types of fabric. Methods: Six fabrics with different blends of cotton and polyester were employed to test the staining and washability of two coal tar formulations following application for 24 hours and 48 hours. Results: The study revealed the distinct superiority of the lecithinized coal tar formulation vis-a-vis the conventional marketed formulation due to its markedly reduced staining and easier washability. A significant reduction in the staining of fabrics containing polyester was observed with the lecithinized formulation, with the stain becoming progressively worse as the proportion of polyester in the fabric increased. The stains washed off completely with detergent in the case of the lecithinized coal tar formulation, whereas stains from the conventional coal tar formulation remained intact. Conclusion: The developed lecithinized formulation, owing to its superior non-staining and washability characteristics, would potentially increase the acceptability of coal tar amongst patients. [ABSTRACT FROM AUTHOR]