DoE Guided Development of an HPLC Method for Evaluation of Amoxicillin and Metronidazole Co-loaded Mucoadhesive GRDDS Formulation for H. pylori Eradication

H. Pylori infection is a major reason for chronic Peptic Ulcer Disease (PUD) and related complications worldwide. Traditional treatment options fail to eradicate the organism completely which leads to antibiotic resistance. Novel formulations are being developed with an aim for effective treatment. Mucoadhesive GRDDS system is an option to increase the antibiotic bioavailability. The objective of this work is to develop a RP-HPLC–PDA based analytical method to evaluate the entrapment efficiency of the GRDDS systems developed for H. pylori treatment containing amoxicillin and metronidazole. DoE was used for optimizing the HPLC conditions. The optimized method used a HyperClone ODS C 18 column as stationary phase and methanol: phosphate buffer (15:85) at pH 6.4 as the mobile phase. The flow rate was 0.9 mL/min. Method was validated as per the ICH Q2(R1) guideline. Method was linear from 0.5 to 20 µg/ml for both amoxicillin and metronidazole with an R 2 value of 0.9995 and 0.9996 respectively. The validated HPLC method showed specificity for both drugs in the presence of degradation products as well as from other excipients of the GRDDS system. The validated method was applied to determine the entrapment efficiency as a part of formulation optimization. The entrapment efficiency of the final formulation was determined to be 78–84% and 75–82% for amoxicillin and metronidazole respectively. Graphical Abstract