Bronchodilator Efficacy of Liposome Formulations of Metaproterenol Sulfate in the Anesthetized Guinea Pig

Publisher Website
Google Scholar
Abstract
Experiments were performed in anesthetized guinea pigs to determine the effects of encapsulation of the beta-2 adrenergic agonist drug metaproterenol sulfate (MPS) into various liposomes. Bronchodilator activity was measured as the ability of inhaled aerosolized MPS to reduce the bronchoconstriction resulting from repeated administration of inhaled aerosolized histamine solution. One percent MPS in saline (free MPS) reduced the airway resistance response to the inhaled histamine challenges. This bronchodilator effect returned toward control over the 2 hr study period, and had returned to control values 10-12 hr after drug administration. In addition, the free MPS caused significant tachycardia and systemic vasodilation. All three liposome-encapsulated MPS formulations caused significantly smaller cardiovascular side effects. One formation also showed immediate inhibition of the histamine bronchoconstriction similar to free drug. This effect persisted until the 10-12 hr study period, which suggests that the duration of action was greater than that for free drug. Thus, increased duration of inhaled MPS bronchodilator activity and reduction of its undesired cardiovascular side effects can be achieved by liposome encapsulation of the drug.

This publication has 6 references indexed in Scilit: