Related Experiment Video
Updated: Apr 12, 2026

Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS
Published on: November 8, 2015
A Novel Slowly Self-Emulsifying Drug Delivery System: Prolonged Systemic Exposure of Tacrolimus With Reduced Risks of
Kohei Yamada1, Keiya Sonobe1, Akihisa Miura1
1Laboratory of Biopharmacy, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.
Abstract:
This study aimed to design and characterize a new type of self-emulsifying drug delivery system (SEDDS), slowly SEDDS (SL-SEDDS), for long-lasting systemic exposure of tacrolimus (TAC) with reduced nephrotoxicity. TAC-loaded SL-SEDDS (SL-SEDDS/TAC) was prepared by semi-solidifying TAC-loaded SEDDS (SEDDS/TAC) composed of Capryol 90, Cremophor EL, and polyethylene glycol 400 with Geleol. SEDDS samples were evaluated regarding physicochemical and biopharmaceutical properties. Both SEDDS/TAC and SL-SEDDS/TAC formed fine emulsions in water. The dissolution of SEDDS/TAC reached approximately 100% within the initial 30 min in simulated gastric fluid (SGF), and the SL-SEDDS/TAC samples exhibited slower dissolution than SEDDS/TAC in a Geleol content-dependent manner. SL-SEDDS/TAC with a Geleol content of 17.5 wt% showed 25% dissolution in SGF for 2 h, followed by an additional 31% dissolution in simulated intestinal fluid for 10 h. The sample was selected as a favorable SL-SEDDS/TAC for further studies because of its slow and continuous dissolution. Oral SEDDS/TAC and the selected SL-SEDDS/TAC (10 mg-TAC/kg) offered almost identical bioavailability of 18% and 19%, respectively, in rats. Compared with SEDDS/TAC, SL-SEDDS/TAC achieved a 32% decrease in the maximum plasma concentration, a risk factor of nephrotoxicity, from 383 to 262 ng/mL with significantly prolonged mean residence time. In a rat model of acute kidney injury, SL-SEDDS/TAC (10 mg-TAC/kg/day, 3 days) attenuated the elevation of blood nitrogen urea by 33% compared to SEDDS/TAC, suggesting a reduction in nephrotoxic risks. SL-SEDDS could be a promising dosage form to control oral absorption of TAC for effective and safe medication.
More Related Videos
Related Concept Videos
Transdermal Drug Delivery Systems
Ophthalmic Drug Delivery Systems
Oral Drug Delivery Systems: Delayed-Release Systems
Modified-Release Drug Delivery Systems: Site-Targeted
Oral Drug Delivery Systems: Continuous-Release Systems
Drug Delivery Systems: Different Types

