Pseudoephedrine Hydrochloride

Pseudoephedrine hydrochloride is an oral sympathomimetic amine that acts as a vasoconstrictor to relieve nasal congestion. The decongestant effect is mediated through the action of pseudoephedrine on α-adrenergic receptors within the nasal mucosa, producing vasoconstriction of the dilated nasal arterioles. Following oral administration, effects are noted within 30 minutes with peak activity occurring at approximately one hour. Pseudoephedrine provides specific benefits in rapidly alleviating nasal congestion in the short term by constricting nasal blood vessels through α-receptor stimulation. Unlike first-generation antihistamines, pseudoephedrine does not possess anticholinergic properties and does not cross the blood-brain barrier to exert central effects. Pharmacovigilance data indicate that pseudoephedrine may induce a higher incidence of less common but potentially life-threatening adverse effects compared to antihistamines.

Fig. 1 Mechanism of action of pseudoephedrine (PSE). (Douhard R.; et al. 2024)

Pseudoephedrine hydrochloride abuse-deterrent formulations were developed using thermal modified rice starch with cross-linking agents and lipids. The starch-based TMR7-L5 formulation, equivalent to five tablets, showed extraction percentages of 75.3 percent in distilled water, 2.7 percent in ethyl alcohol, and 63.0 percent in 40 percent ethyl alcohol at 60°C for 30 minutes. The TMR7-L5 formulation also delayed drug release compared to the commercial product in in vitro dissolution studies. This starch-based formulation approach offers a novel strategy for deterring pseudoephedrine abuse, given the structural similarity between pseudoephedrine and methamphetamine.

Fig. 2 Process for preparation of thermal modified starch (TMR) formulations and evaluations. (Sohn J S, Choi J S. 2021)