Improved bioavailability of cromolyn sodium using inhaled PA101 delivered via eFlow® nebulizer.

In 1960s, cromolyn sodium (CS) has been introduced as the first non-steroidal anti-inflammatory drug for the treatment of allergic and mast-cell driven diseases. Its applicability has been limited due to a poor bioavailability. Here we present pharmacokinetic data of a novel high concentration formulation of CS (PA101) delivered via a high-efficiency nebulizer (eFlow®) in healthy volunteers (HVs), allergic asthmatics and patients with indolent systemic mastocytosis (ISM). In HVs, PA101 40 mg and 80 mg (30 L) and PA101 40 mg (40 L), Intal^TM (via LC® Plus) 20 mg and Nalcrom® (oral suspension) 200 mg showed maximum measured plasma concentration (C_max) of 156, 236, 88.6, 17.8 and 5.23 ng/mL, respectively, with respective areas under the plasma time-concentration curve (AUC) of 338, 526, 212, 40.6 and 33.3 h·ng/mL. Systemic exposure (AUC) to CS with PA101 40 mg was approximately 8-fold and 11-fold higher compared to Intal^TM and Nalcrom® in HVs, respectively. PA101 via eFlow® yielded comparable PK profiles in HVs and patients. Systemic bioavailability of PA101 was approximately 25% compared to approximately 1% for Nalcrom® and approximately 10% for Intal^TM, respectively. These data warrant further research on the therapeutic potential of PA101 (via eFlow®) in allergic and mast-cell driven diseases.