A formulation can release a drug slowly in a laboratory apparatus. Translating that curve into a prediction about absorption in a person requires evidence about what happens beyond the apparatus.
The investigators prepared polymer nanoparticles containing diazepam and hesperidin and varied polymer and stabilizer amounts. For an optimized formulation, they compared drug release across a dialysis membrane with release from an aqueous drug solution. The nanoparticle preparation showed a slower release pattern in that setup. The experiment reflects drug leaving the formulation and passing through the membrane under controlled conditions.
Membrane transport, test conditions and formulation properties can all shape the observed curve. A human concentration–time profile also depends on absorption, distribution and elimination. In a forensic review, identify whether the cited experiment measured drug appearing across a membrane, in blood, or at a target tissue. Only the first of these was the release endpoint in this experiment.
Sharma and colleagues, Journal of Advanced Pharmaceutical Technology & Research (2015). Journal article · Full text.