Formulation considerations of intranasal corticosteroids for the treatment of allergic rhinitis.
OBJECTIVE
To examine how various aspects of an intranasal corticosteroid (INS) formulation may influence the efficacy, tolerability, and patient preference and adherence to INS therapy.


METHODS
A PubMed search of the literature was conducted for studies on allergic rhinitis published between January 1977 and January 2006 using the keywords intranasal corticosteroid, preservatives, benzalkonium chloride, and tonicity.


METHODS
Prospective studies, retrospective studies, and case reports were selected for inclusion in this review.


RESULTS
Currently available INSs are effective first-line treatments for allergic rhinitis. Differences in patient preference for a particular INS are largely attributable to sensory attributes of the nasal spray, which arise from characteristics of the formulation. Additives and preservatives can cause tolerability issues by irritating the mucosal membranes and causing nasal drying, or they can confer an unpleasant odor or taste to an INS formulation. The relative osmotic pressure, or tonicity, of an INS can modulate nasal absorption and retention, thereby potentially influencing the clinical efficacy. Characteristics such as delivery device and spray volume can affect a patient's perception and experience with a particular INS. Newer INSs, such as ciclesonide, are in development for the treatment of allergic rhinitis, and consideration of the formulation characteristics of these agents is an important part of the development process.


CONCLUSIONS
INSs are an effective treatment option for patients with allergic rhinitis; however, there is room for formulation improvement. Optimization of formulation may increase the efficacy, tolerability, and patient preference and adherence to INSs.
Meltzer
Eli O
EO
Allergy and Asthma Medical Group and Research Center, San Diego, California 92123-2661, USA. eomeltzer@aol.com
D000281:Administration, Intranasal; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000737:chemistry*; D018926:Anti-Allergic Agents / Q000008:administration & dosage / Q000145:classification*; D002626:Chemistry, Pharmaceutical; D006801:Humans; D006967:Hypersensitivity / Q000188:drug therapy*; D012220:Rhinitis / Q000188:drug therapy*
D000305:Adrenal Cortex Hormones; D018926:Anti-Allergic Agents