Background: Omeprazole has poor water solubility, is unstable in acidic solutions, and undergoes first pass metabolism which results in lowering its bioavailability. A solid Self-Nano Emulsifying Drug Delivery System (SNEDDS) was previously prepared to enhance its dissolution.
Objective: Development and validation of a RP-HPLC method with UV detection for the determination of omeprazole in 0.1N HCl and in 0.01 M phosphate buffer (pH 7.4).
Methods: Validation was according to the ICH Q2 (R1) guidelines in terms of linearity, accuracy and precision, lower limit of quantification, sensitivity, specificity, and robustness. The developed and validated method was used to study the in-vitro dissolution of the drug from the solid-SNEDDS, commercial products and of the unprocessed drug. The dissolution was studied in 500 ml of 0.1N HCl during the first 2 hours, and 900 mL of 0.01 M phosphate buffer (pH 7.4) during the last hour (37 ± 0.5 oC and 100 rpm).
Results: The method was linear in the range 1-50 μg/ml, accurate and precise as indicated by the ANOVA test. It was specific to the drug and the pharmaceutical excipients did not affect the determination of its concentration. The method was robust to small changes in pH, composition, and flow rate of the mobile phase. The dissolution rate of omeprazole from the Solid-SNEDDS was faster than that from two commercial dosage forms and than the dissolution rate of the unprocessed drug.
Conclusion: The method met the acceptance criteria and was applied successfully in studying the rate of dissolution of the drug.