In a pharmacokinetic study comparing flunisolide nasal solution (flunisolide nasal spray .025%) (29 mcg per spray) with flunisolide nasal solution (flunisolide nasal spray .025%) (25 mcg per spray), the original formulation, the two formulations were not bioequivalent. The total absorption of flunisolide nasal solution (29 mcg per spray) was 25% less than that of flunisolide nasal solution (25 mcg per spray), and the peak plasma concentration was 30% lower. The clinical significance of these differences is likely to be small, particularly since clinical efficacy is attributable to a local effect on nasal mucosa (see Pharmacodynamics ).
Single dose intranasal administration of 220 micrograms of Nasacort Allergy or Triamcinolone Nasal Spray in normal adult subjects and in adult patients with allergic rhinitis demonstrated minimal absorption of triamcinolone acetonide. The mean peak plasma concentration was approximately ng/mL (range to 1 ng/mL) and occurred at hours post dose. The mean plasma drug concentration was less than ng/mL at 12 hours and below the assay detection limit at 24 hours. The average terminal half life was hours. Dose proportionality was demonstrated in normal subjects and in patients following a single intranasal dose of 110 micrograms or 220 micrograms Nasacort Allergy or Triamcinolone Nasal Spray. Following multiple doses in paediatric patients, plasma drug concentrations, AUC, C max and T max were similar to those values observed in adult patients.