Polymer adhesion predictions for solid oral dosage forms


Solid oral dosage forms (SODF) are drug vehicles commonly prescribed by physicists in primary and secondary cares, as they are the most convenient for the patient and facilitate therapy management. Concerns regarding unintended adhesion of SODF during oro-esophageal transit remain, especially in multimorbid patients, bedridden patients and patients suffering from dysphagia. Hence, this factor should be considered during the development of SODF, and more attention should be given on the design of appropriate surface conditions considering patients with swallowing problems. The aim of this work was to estimate the low mucoadhesion strength of different pharmaceutical polymers frequently used in coating technologies, since this property is thought to have impact on the mucoadhesive profile of SODF during oro-esophageal transit. In an approach using in vitro methods based on particle interactions, polyethylene glycol grades (PEG) showed the lowest interaction forces suggesting a more favorable in vivo performance than hydroxypropyl methylcellulose (HPMC), which was found to have the highest particle interaction. Preference should be given to coating formulations with lower concentrations of polymer and grades with low molecular weight. In addition, rheological measurements should be adopted when targeting poor mucoadhesive polymers.



The oral administration of conventional SODF is threatened by the growing age of the population and its increased incidence of swallowing problems. These issues need to be urgently addressed during development of pharmaceutical coatings, as they will contribute for SODF with increase patient compliance and avoid unnecessary drug modifications. Based on the results obtained in this work, PEG grades should be highly considered during the development of dosage forms with such properties. In addition, preference should be given to reduced concentrations of polymer and grades with low molecular weight. The use of HMPC is not recommended due to its strong interaction with the simulated salivary buffer. Lastly, rheological measurements should be adopted when investigating the low mucoadhesive potential of polymers with particle interaction methods, since it was shown that better predictions for safe swallowing could be extrapolated.


Results of analysis of drug adhesion in relation to oral dosage form
Adhesion predictions for oral dosage forms