Simple and reliable extraction and a validated high performance liquid chromatographic assay for quantification of amoxicillin from plasma.

•Solubility and stability of amoxicillin was improved by the addition of a buffer.•The extraction of amoxicillin from plasma was enabled via pH-control.•A stability-indicating HPLC assay enabled the analysis of amoxicillin in plasma.•Pharmacokinetic analysis validated the extraction protocol.