Investigating the influence of non-volatile excipients on inhaled drug disposition

Student thesis: Doctoral ThesisDoctor of Philosophy


Background: There is growing evidence that excipients incorporated into beclomethasone propionate metered-dose inhalers, for the purpose of modifying aerosol particle size, may have effects on drug pharmacokinetics. This body of work is focused on using in vitro and in vivo systems to investigate the effect of non-volatile excipients present in inhaled formulations of beclomethasone dipropionate (BDP) on inhaler biopharmaceutics.

Methods: A cellular model (Calu-3) and an artificial model, the Parallel artificial membrane permeability assay (PAMPA), were employed to determine glycerol effect on drug membrane permeability. Additionally, the interaction between glycerol, BDP and a lipid monolayer model was studied using X-ray diffraction. The effect of non-volatile excipient on drug dissolution rate was also assessed by testing prototype MDI formulations with varying excipient amounts (glycerol and isopropyl myristate – IPM) and evaluating in vitro dissolution profiles. Finally, different formulations with and without excipient were applied to a rodent model to assess the effect of excipient on in vivo drug pharmacokinetics
Date of Award1 Jan 2021
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorBen Forbes (Supervisor) & Richard Harvey (Supervisor)

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