Comparative Study of Ibuprofen Solubility in Synthetic and Natural Lipid Vehicles

Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), is used in mild to moderate pain and fever. The rapid onset of action of ibuprofen depends on its solubility. Though ibuprofen has high membrane permeability, its solubility in aqueous media is poor (2.5mg/ml). To improve the solubility, several approaches such as solid dispersion, prodrug, inclusion complex, microencapsule etc. were done for ibuprofen. In the present experiment, solubility of ibuprofen in 2 synthetic and 5 natural lipid vehicles were compared and the effect of nonaqueous solvent (ethanol) on the enhancement of solubility was shown. This solubility analysis is the first step to develop lipid based drug delivery system with any drug. Ibuprofen was obtained from Xamim Co. (China). Propylene glycol monocaprylate (Capmul PG8) was received from Abitec Corp (Janesville, WI), medium chain triglyceride (Neobee M5) was supplied by Stepan Co. (May wood, NJ) and Oleic acid was purchased from Merck (Germany). The other edible vegetable oils were procured locally. To prepare the standard solution of ibuprofen, 20 mg of the drug was dissolved in absolute methanol to obtain a concentration of 400 μg/ml. The sample was suitably diluted with methanol to obtain concentration in the range of 5-30 μg/ml. The λmax of the sample was found at 222 nm after scanning in UV spectrophotometer (Shimadzu, Japan). The drug