Quality Assessment of In-House Prepared Pediatric Oral Suspensions of Bisoprolol and Lisinopril: Assay and Dose Uniformity

Bisoprolol and Lisinopril are among the most frequently used substances in pediatric cardiovascular affections. The medication supply to this age population is limited given the lack of appropriate pharmaceutical forms; therefore, pharmaceutical compounding comes to fill in the gap between pediatric therapy needs and availability of adult-approved formulations. The aim of our study was to obtain and quantify two suspensions of Bisoprolol and Lisinopril in small pediatric dosage. The suspensions were obtained using a commercial suspending vehicle and the active substances. We developed the quality control methods according to the USP. Briefly, both methods were developed and validated using a UHPLC Flexar 10 system (Perkin Elmer) equipped with a Phenomenex Luna C8 column (150 × 4.6 mm, 3 μm) under isocratic conditions at a flow rate of 1 mL/min. For bisoprolol, the mobile phase consisted of water (65:35, v/v) with the specified additives, with detection at 273 nm, while lisinopril was analyzed using 10 mM ammonium formate buffer (pH 5) (96:4, v/v), with detection at 210 nm. The calibration ranges were 30–90 μg/mL for bisoprolol and 20–100 μg/mL for lisinopril. We obtained satisfactory results for method validation, and the method was applied for the assay of two types of suspensions. The obtained results ranged between 80 and 86% of the labeled amounts for Bisoprolol, and 106–108% for Lisinopril. The obtained suspensions reflected some issues related to the sample extraction and potential variability in suspension sampling and dosing consistency, which support the need for continuous optimization and quality control of compounded pediatric formulation.