Objectives: The objective of the study was to compare solubilization approaches, namely cosolvency, micelle solubilization, complexation, pH adjustment and hydrotrophy, on BCS class II drug modafinil solubility. Methods: Altered solubility of modafinil was carried out in numerous water-cosolvent mixtures. Similar type of study was performed using different ionic and non-ionic surfactants using phase solubility analysis. Furthermore, solubility behavior with two cyclodextrins namely beta cyclodextrin and maltodextrin were examined. Solubility studies were conducted in buffers of different pH ranging from 1.2 to 8 at different temperatures (25o and 37o). The effect of hydrotrophy on the solubility of modafinil was also studied. Results: Outcomes showed that ethanol is depicted to enhance solubility by greater height. It is found that ionic surfactants were better solubilizers than non-ionic surfactants. The capacity of solubilization is depicted to enhance with rise in hydrocarbon chain length of surfactant, denoting that hydrocarbon core of micelles as the center of solubilization. Highest solubility and binding constants were achieved with use of beta cyclodextrins followed by maltodextrins. The buffers of pH 2 and pH 3 have shown highest solubility when compared to others. Sodium thiocyanate salt had shown highest solubility of the drug. Conclusion: As a consequence, the study provides dataset so as to contrast effects of numerous solubilizers on modafinil solubility and also gives an insight of the mode of solubilization by aforementioned techniques.
Key words: Modafinil, Complexation, Cosolvency, Hydrotrophy, Solubility, Surfactants.