Pharmacokinetic And In-Vivo Performance Assessment Of Ebastine Formulated As A Self-Micro Emulsifying Drug Delivery System

Abstract

The present study focuses on the in-vivo pharmacokinetic evaluation of Ebastine and the development of a reliable HPLC method for its quantitative estimation in rat serum. Chromatographic analysis was performed using a Shimadzu LC-20AD HPLC system equipped with a UV–Visible detector. Separation was achieved on a Grace C18 reverse-phase column (25 cm × 4.6 mm, 5 μm) maintained at 40°C. The optimized mobile phase consisted of phosphoric acid buffer (pH 6.0, adjusted with diethylamine) and acetonitrile in the ratio of 40:60 v/v, delivered at a flow rate of 1.0 mL/min. Detection was carried out at 255 nm with a sensitivity of 0.001 AUFS [Absorbance Units Full Scale]. Phenylephrine served as the internal standard. Standard solutions were prepared by dissolving Ebastine working standard in diluent, followed by sonication and membrane filtration (0.45 μm). The method produced sharp, well-resolved peaks suitable for serum analysis.

Rat serum samples collected at predetermined time intervals after oral administration of both reference and test formulations were processed and analyzed under the optimized chromatographic conditions. Pharmacokinetic parameters were calculated using a non- compartmental approach in PK Solver 2.0 with the linear trapezoidal rule. Key parameters including Cmax, Tmax, AUC0–t, and AUC0–∞ were determined to assess systemic exposure.

The reference formulation exhibited a Cmax of 20.86 ± 2.22 ng/mL at 4 h, while the test formulation showed a Cmax of 14.83 ± 1.58 ng/mL with a delayed Tmax of 6 h. However, the test formulation demonstrated higher overall exposure, with AUC0–t of 110.22 ± 13.55 ng·mL/h compared to 92.35 ± 9.80 ng·mL/h for the reference. Similarly, AUC0–∞ increased from 93.01 ± 9.66 ng·mL/h (reference) to 111.10 ± 9.91 ng·mL/h (test).

These findings confirm that the developed HPLC method is robust for Ebastine quantification in biological matrices and that the test formulation exhibits improved total systemic exposure despite a lower peak concentration. The results support the suitability of the formulation for enhanced in-vivo performance evaluation.