Extemporaneous Compounding and Physiological Modeling of Amlodipine/Valsartan Suspension
Background and Objectives. In case of absent liquid dosage form, crushing a tablet or dispersing a capsule would be the most convenient option for using these drugs in patients with dysphagia difficulties. The aims of the study were to prepare an extemporaneous suspension of amlodipine and valsartan from the available commercial tablets and to evaluate the stability and dissolution properties of the compounded suspension. Method. Amlodipine/valsartan extemporaneous suspension was prepared from available commercial tablets such as Valzadepine®. The dissolution profiles for the extemporaneous preparation and the commercial tablet were determined in different pH media. The physical, chemical, and microbial stability of the compounded formulation was evaluated over one-month period at room temperature. Moreover, in silico modeling using GastroPlus™ software was used to build absorption models for both drugs based on the in vitro dissolution data. The simulated plasma profiles for both active ingredients were compared with the in vivo plasma profiles to examine the similarity of the extemporaneous suspension and the commercial tablets. Results. The amlodipine/valsartan extemporaneous suspension was successfully prepared with acceptable organoleptic properties. The suspension was stable for four-week period preserving its physical and chemical features. The release profiles of valsartan and amlodipine from the suspension were similar to those from source tablet Valzadepine®. In silico modeling predicted the similarity of the extemporaneous suspension and the commercial tablets. Conclusion. Amlodipine/valsartan extemporaneous suspension could be prepared from available commercial tablets. Moreover, GastroPlus™ can be applied along with the in vitro dissolution in order to affirm similarity in extemporaneous compounding situations.
By Wafa J. Aabed, Asma H. Radwan, Abdel Naser Zaid and Naser Y. Shraim