Formulation Approaches for Optimizing Omeprazole Stability in Oral Liquid Dosage Forms

Abstract

Background/Objectives: This study aimed to evaluate the degradation of omeprazole suspension under various pH conditions and to propose recommendations for preparing compounded suspensions. Given the clinical need for alternative dosage forms for pediatric and geriatric patients and those with dysphagia, the research focused on assessing whether modifications in formulation composition—specifically the inclusion of sodium bicarbonate—could improve omeprazole stability, thus enhancing its bioavailability. Methods: Three formulations were prepared: O1, based on crushed enteric-coated pellets from a commercial product; O2, with crushed pellets suspended in an 8% sodium bicarbonate solution with glycerin; and O3, with pure omeprazole suspended in an 8% sodium bicarbonate solution with glycerin. Release studies were conducted using basket or paddle apparatus under conditions simulating fasted (pH 1.2 and 6.8) and fed (pH 6, 4.5, and 3) gastric and intestinal juices at 37 °C over 120 min. At predetermined intervals, samples were withdrawn and analyzed by a validated HPLC method with UV detection to quantify the released omeprazole. Results: The commercial enteric-coated product showed no release at a low pH, confirming its protective coating. In contrast, formulation exhibited significant degradation in acidic environments. The O2 formulation, benefiting from the buffering effect of sodium bicarbonate, showed improved stability compared to O1. Notably, formulation O3 yielded the highest drug recovery, with approximately 74% released at pH 6 and 65% at pH 6.8, demonstrating significantly better performance, as confirmed by statistical analysis (p Conclusions: The composition of omeprazole suspensions substantially influences the drug stability and release profiles. The O3 formulation, based on pure omeprazole with sodium bicarbonate, is recommended for immediate-release suspensions to enhance bioavailability. Further studies are needed to optimize conditions for pediatric use.

Keywords

• omeprazole stability
• pH-dependent degradation
• immediate-release suspension
• sodium bicarbonate
• pharmaceutical compounding
• gastrointestinal dissolution