The solubility of docetaxel in various vehicles selected as oil, surfactant and co-surfactant for formulation of L-SNEDDS was determined and presented in the Table 1. Among the tested vehicles, Capmul PG8 NF (>250 mg/mL), Capmul MCM C8 (>250 mg/mL) and Transcutol P (>200 mg/mL) had the highest drug solubilization capacity for docetaxel. Whereas, Captex and Gelucire 44/14 shown the least solubility of docetaxel in them. Based on the solubility results, Capmul PG8 NF was selected as the oil phase, Cremophore EL as surfactant and Transcutol-P as co-surfactant. Capmul PG 8 NF (HLB 6) has partial aqueous solubility over Capmul MCM C8 which may help in easy dispersion of drug in an aqueous medium [34,35]. A good combination of surfactants with low and high hydrophilic lipophilic …show more content…
The results of the thermodynamic stability studies showed stability of L-SNEDDS formulations and their emulsions without any signs of phase separation and precipitation during alternative temperature cycles (4C and 40C), freeze thaw cycles (-21C and +25 C) and centrifugation at 3500 rpm. The cloud point is an essential factor in the SEDDS consisting of non-ionic surfactants, and it is responsible for the successful formation of a stable microemulsion [37]. The cloud point temperature (lower consolute temperature) indicates the temperature at which the transparent monophasic system was transformed into the cloudy biphasic system as dehydrated surfactant molecules associated together as precipitate. Hence, the cloud point for SEDDS should be above 37°C, which will avoid phase separation occurring in the gastrointestinal tract. The cloud point temperature of the tested L-SNEDDS was found to be above 80°C (Table 2). Therefore, it would suggest a stable microemulsion of docetaxel can be formed at physiological temperature in vivo