Improving the aqueous solubility of piroxicam and griseofulvin using different surfactants and cosolvents

ABSTRACT

This study is an attempt to solubilize a non steroidal anti-inflamatory drug, namely, Piroxicam [PX] and an anti-fungal drug, namely, Griseofulvin [GR], using different surfactant and cosolvent systems. It could be shown that the aqueous solubility of PX is increased by 56, 57, 65, 87 and 138 fold using solution with a concentration of 18% w/v of either Tween 20, sodium lauryl sulphate [SLS], tween 80, Brij 35, or poloxamer 188, respectively. Moreover, the aqueous solubility of PX has been shown to increase by 104, 102, 92 or 34 fold using 60% w/v of either ethanol, polyethylene glycol 400 [PEG 400], propylene glycol [PG], or glycerin, respectively. Propanol, however, gave 140 fold increase in PX aqueous solubility at a cosolvent concentration of only 30% w/v. The solubility of PX has also been shown to increase from 3.6 mg/ml to 10.6 mg/ml by increasing the pH from 6 to 8 respectively. On the other hand, 9, 21, 24, 26 or 219 fold increase in the aqueous solubility of GR could be achieved by using 18% w/v of either poloxamer 188, tween 20, brij 35, tween 80, or SLS, respectively. Moreover, propanol, ethanol, PEG 400, PG, and glycerin gave 104, 99, 26, 14 and 13 and 104 fold increase in GP aqueous solubility at a cosolvent concentration 60% w/v. the addition of cosolvent to the micellar solutions of different surfactants influenced the solubility of either PX or GR in different ways depending on the type of the drug and the cosolvent added. Increasing the temperature at which the equilibration is conducted showed an increase in the aqueous solubility of either PX or GR