Introduction:

Estradiol is a female sex steroid hormone widely used as hormonal therapy that has low bioavailability, due to its low aqueous solubility and high hydro-phobicity, belonging to class II of the Biopharmaceutical Classification System.

Aim:

To design and characterize a self-emulsifying drug delivery system (SEDDS) for the drug estradiol by physicochemical tests to obtain the most optimal ratio that would improve its aqueous solubility, dissolution rate, and potentially its bioavailability.

Method:

Solubility studies in different solvents; pseudo ternary phase diagrams made up of oils, surfactants, co-surfactants, and water, allowed to recognize the different regions of SEDDS formation and identify the percentages of excipients that lead to the formation of isotropic solutions; The resulting formulations were characterized in autoemulsification time, robustness to dilution, cloud point and dissolution profile in a hard capsule.

Results:

The formulations containing Capmul MCM®, Kolliphor® RH40, and Transcutol®, had an autoemulsification time of approximately 1 minute; were stable at three different pHs (1.2, 4.5 and 7.2), at different dilution volumes, exhibiting a transparent, slightly bluish appearance, without precipitates, or phase separation, higher cloud points compared to the formulations containing Gelucire® 44/14.

Conclusions:

The characterization strategies used in the development of this research proved to be efficient for the adequate selection of excipients and their optimal ratio for the effective design of a self-emulsifying drug delivery system (SEDDS).