title: Respirable microspheres for inhalation: the potential of manipulating pulmonary disposition for improved therapeutic efficacy.
abstract: Several particle engineering technologies have recently emerged, which have enabled inhaled microspheres to seek to manipulate pulmonary biopharmaceuticals, and to improve therapeutic efficacy for both local and systemic treatments. These microspheres may be designed to sustain drug release, to prolong lung retention, to achieve drug targeting and/or to enhance drug absorption and thereby, to seek the potentials of reducing dosing frequency and/or drug dose, while maintaining therapeutic efficacy and/or reducing adverse effects. While product development is still in process, in many cases, considerable therapeutic benefits and/or new therapeutic opportunities can be envisaged. 'Proof-of-concept' results are now available for various drug classes including beta(2)-adrenoceptor agonists, corticosteroids, antimycobacterial antibacterials, estradiol and therapeutic macromolecules such as insulin. Nevertheless, their development success must overcome several critical and unique challenges including toxicological evaluations of microsphere materials, and, clearly, successful products should meet the needs of the patient and the market place. Unfortunately, such issues have not always been addressed or examined adequately in the current studies, and thus we may anticipate paradigm shifts in the research of several groups seeking to develop products with improved therapeutic profiles. Nevertheless, it seems likely that improved inhalation products, with greater therapeutic efficacy and reduced adverse effects, will result from next-generation respirable microspheres. These may be expected to contain drugs intended for both local and systemic activity.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Aerosol Research Group, Virginia Commonwealth University, Richmond, Virginia 23298-0533, USA. msakagam@vcu.edu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sakagami
authors.forename: Peter R
authors.initials: PR
authors.lastname: Byron
mesh_terms: D000280:Administration, Inhalation; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D000818:Animals; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D000995:Antitubercular Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D004958:Estradiol / Q000008:administration & dosage / Q000493:pharmacokinetics; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D008168:Lung / Q000378:metabolism*; D008171:Lung Diseases / Q000188:drug therapy / Q000378:metabolism; D008863:Microspheres; D014018:Tissue Distribution
chemical_list: D000318:Adrenergic beta-Agonists; D018927:Anti-Asthmatic Agents; D000995:Antitubercular Agents; D007004:Hypoglycemic Agents; D007328:Insulin; D004958:Estradiol