Allergic Diseases and Their Pharmacological Management: Antihistamine Therapy, Pharmaceutical Development and Drug-Delivery Perspectives

Allergic disorders, particularly allergic rhinitis and urticaria, are prevalent immune mediated conditions that can substantially affect patients’ quality of life. Histamine plays a central role in allergic responses, primarily through activation of histamine H₁ receptors, making H₁-receptor antagonists an important component of pharmacological management. Mizolastine is a second-generation benzimidazole-derived antihistamine characterized by potent and selective peripheral H₁ receptor antagonism, with additional antiallergic and potential anti-inflammatory properties. Following oral administration, mizolastine is rapidly absorbed, exhibits approximately 65% oral bioavailability, shows high plasma protein binding, and provides prolonged antihistaminic activity that supports once-daily administration. Clinical evidence supports its therapeutic efficacy in seasonal and perennial allergic rhinitis and chronic urticaria, with generally limited sedative and anticholinergic effects. Beyond conventional H₁-receptor antagonism, experimental studies suggest that mizolastine may modulate inflammatory processes involving leukotriene production, inflammatory-cell recruitment, and other mediators associated with allergic responses. From a pharmaceutical perspective, its low aqueous solubility represents an important consideration for formulation development and provides a rationale for investigating advanced drug-delivery approaches. Experimental evidence from animal models of colitis has also suggested anti-inflammatory effects beyond its established antiallergic indications, although their clinical relevance remains to be established. Overall, mizolastine remains a clinically relevant second-generation antihistamine with pharmacological and pharmaceutical characteristics that make it worth further investigation, particularly in advanced formulation development and emerging therapeutic applications.