Proniosomal Telmisartan Tablets: Formulation, in vitro Evaluation and in vivo Comparative Pharmacokinetic Study in Rabbits

Abstract

Objective

The purpose of this study was to prepare proniosomal vesicles of Telmisartan (TEL) to be compressed into tablets which will be further evaluated in vitro and in vivo.

Materials and Methods

An experimental design was adopted using surfactants of different HLB values (span 40-brij 35), different cholesterol ratios (20–50%) and different phospholipid types (egg yolk-soyabean). Different responses were measured followed by tablet manufacturing. The highest EE was shown in F3 (85%) while the lowest value was obtained in F7 (8.4%). Finally, zeta potential results were in the range of −0.67 to −27.6 mv. Compressibility percent revealed that F5 showed an excellent flowability characteristic with a value of 9.74±1.61 while F3 and F6 showed good flowability characteristics. By the end of the release, F6 showed approximately 90% drug release.

Results

F6 was selected for the in vivo study; C_max was increased by 1.5-fold while AUC_0-∞ also increased significantly by 3-fold when compared with commercial tablet and finally, t_max was increased by 3-fold indicating sustained release pattern. The relative bioavailability was also increased by 3.2-fold.

Conclusion

The results of this study suggested that the formulation of compressed tablets containing more stable proniosomal powder extended the release of TEL and increased its bioavailability as well.

Keywords:

• telmisartan
• TEL
• proniosomal-derived niosomes
• entrapment efficiency
• EE
• sustained-release tablet
• bioavailability
• multifactorial design

Acknowledgments

The authors are thankful to the management of International Drug Agency for Pharmaceutical Industry (IDI) (Egypt) for completing the HPLC analysis required for the in vivo study; to Mahmoud M. Elkhodary, PhD (Horus University-Egypt) for his fruitful support in interpreting the outcomes of the developed optimization design and editing figures in accordance with journal adopted guidelines; and to Sarah Y. Gohar, Teaching Assistant (Horus University-Egypt) for the language editing service of the final manuscript.

Disclosure

The authors declare that they have no conflict of interests.