Formulation of Self-micro Emulsifying Drug Delivery Systems (SMEDDS) of Paclitaxel utilizing factorial design

Abstract

Background: The antineoplastic drugs possess poor aqueous solubility along with low bioavailability. This limits delivery of antineoplastic drugs through oral route. SMEDDS is a well-accepted means for addressing the lower aqueous solubility and bioavailability issues of a lipophilic drugs. Paclitaxel (PTX) is an antineoplastic drug. PTX is found to be very useful in the treatment of ovarian and breast cancers. PTX have very low aqueous solubility (0.3 µg/ml). 
 Objective: This study aims to formulate SMEDDS incorporating PTX to enhance its aqueous solubility. 
 Methodology: Isopropyl myristate (IM), tween 80 (T80) and transcutol (TC) were used to formulate SMEDDS. IM was considered as oil, T80 as surfactant and TC as co surfactant. 32 factorial design analysis helps in studying the effect of an independent factor on a dependent factor on statistical principles. Independent factors, first – concentrations of oil, second – mixture of surfactant and co-surfactant (Smix), and two dependent factors, first – emulsification time and second – in vitro drug release were chosen. All the nine formulated B1-B9 were subjected to various physicochemical tests. 
 Result and discussion: The globule size was found to be 136.38 – 223.14 nm, zeta potential ranges between -31.54 to -7.58, drug content ranges between 65.34 – 83.56%. Statistical analysis shows that an increasing amount of surfactant decreases emulsification time. This may also decrease the average droplet size of resultant SMEDDS. When the concentration of tween 80 was increased, it was observed that the release of PTX also increased. Rapid and more extent of PTX released from formulated SMEDDS indicates that the aqueous solubility of PTX has increased. B9 formulation releases 99.46% PTX at end of 60 minutes whereas 35.23% of pure PTX powder was solubilized in dissolution medium. 
 Conclusion: This study states that the prepared SMEDDS possess acceptable properties to be considered as immediate release dosage forms. This conclusion was drawn based on in vitro release study.