title: Microsphere formation in a series of derivatized alpha-amino acids: properties, molecular modeling, and oral delivery of salmon calcitonin.
abstract: A series of benzoylated and phenylsulfonylated amino acids are novel, low molecular weight, self-assembling molecules. At low pH, these compounds form microspheres that dissolve readily under neutral conditions. In a given synthetic series, those molecules with low aqueous solubility formed microspheres more readily than did the molecules possessing high water solubility, suggesting that the hydrophobicity of these compounds contributes to the ability to form microspheres. In addition, molecular modeling studies on selected compounds have shown that microsphere formation may depend also on various aromatic ring and dipole-dipole interactions, which could effect the extent and types of favorable stacking conformations between molecules. The microspheres prepared from these compounds have been used to effect the oral delivery of salmon calcitonin, a model protein drug, in both rodents and primates.
mesh_terms: D000284:Administration, Oral; D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D002116:Calcitonin / Q000008:administration & dosage*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003198:Computer Simulation; D004337:Drug Carriers / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008253:Macaca mulatta; D046911:Macromolecular Substances; D008297:Male; D008863:Microspheres; D008958:Models, Molecular; D008968:Molecular Conformation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D013329:Structure-Activity Relationship; D013450:Sulfones / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D000596:Amino Acids; D004337:Drug Carriers; D046911:Macromolecular Substances; D013450:Sulfones; C028815:salmon calcitonin; D002116:Calcitonin; C010544:benzenesulfonyl chloride