In-Vitro Dissolution Profile Comparison of Fixed Dose Combination Suspension Containing Ibuprofen and Loratadine with Their Corresponding Marketed Suspensions

(1) Background: Fixed-dose combination (FDC) improves patient convenience and therapeutic adherence by combining suitable drugs in a single dose form. This study examined the in vitro dissolution of an ibuprofen-loratadine FDC oral suspension to commercial reference formulations. (2) Methods: The FDC suspension (ibuprofen 200 mg/5 mL, loratadine 5 mg/5 mL) was tested against Fenbro 8 Plus and Lorid on USP Apparatus II at 50 rpm and 37 ± 0.5 °C. Dissolution testing was carried out in 900 mL of phosphate buffer (pH 7.2) for ibuprofen and 0.1 N HCl (pH 3.3) for loratadine. Quantification was performed using validated high-performance liquid chromatography linked with ultraviolet detector (HPLC-UV) procedures complying with the ICH Q2 (R2) guidelines. (3) Results: The linearity of the HPLC methods for ibuprofen and loratadine was (R2 > 0.99), accuracy (99.6–100.18%), and precision (%RSD < 2). For both loratadine and ibuprofen, the FDC suspension’s Q15, Q30, T50, T90, and DE% values nearly matched those of the commercial products. Over 95% of both drugs were released within 60 min. The dissolution equivalence between the FDC and the reference formulations was demonstrated by the calculated similarity (f2) and difference (f1) factors, which were f1 = 3 and f2 = 70 for ibuprofen, and f1 = 4 and f2 = 64 for loratadine. (4) Conclusions: The FDC suspension of ibuprofen and loratadine showed dissolving behavior comparable to commercial formulations, confirming its applicability for the practical and efficient treatment of allergy symptoms and inflammatory pain.