Solubilization of Tamoxifen Citrate by Cosolvency And Micellisation: A Comparative Evaluation

Tamoxifen Citrate (TC), an antiestrogenic drug, is used in both pre and post menopausal breast cancer treatment in women. One of the major causes of its poor bioavailability is attributed to its poor aqueous solubility. In this study an effort has been made to improve the aqueous solubility of the hydrophobic drug using methods like cosolvency and micellisation. Cosolvents (ethanol, polyethylene glycol-400), and surfactants [polyoxyethylene sorbitan monooleate (Tween-80), Poloxamer-407 and Poloxamer-188] were tested for their solubilizing potential. Solubility enhancement approaches showed variable degrees of increase in solubility of TC. Solubility studies with different concentrations of Ethanol and PEG-400 at 37°C showed that higher efficiency of increasing solubility by cosolvency was achieved with ethanol (6.10 fold) than that with PEG 400 (5.62 fold) while in case of varying concentrations of surfactants (tween 80, Poloxamer 188 and Poloxamer 407). Poloxamer 407 exhibited maximum potential in solubilizing TC in water (7.1 fold). However, among the solubilizing techniques and solubilizing agents used, micellization with polysorbate 80 as surfactant was found to be the most effective. Data suggests that using simple techniques, improvement of solubility of TC can be attained which may help in improving its poor bioavailability.