Download or read book Investigations of Pharmaceutical Oil-in-water (o/w) Microemulsions as Drug Delivery Systems written by Chien-Ming Hsieh and published by . This book was released on 2009 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present study characterizes the physico-chemical and drug solubilisation properties of a range of oil-in-water (o/w) microemusions prepared using one of a number of C12 hydrophobic chain surfactants namely: (i) the zwitterionic surfactant dodecyldimethylammoniumpropylsulphate (DDAPS), (ii) the cationic surfactant dodecyltrimethylammonium bromide (DTAB) and (iii) the anionic surfactant sodium dodecylsulphate (SDS) and containing as oil, either of the ethyl esters, ethyl butyrate (EB) or ethyl caprylate (EC). -- A combination of physico-chemical techniques, including phase behaviour studies, drug solubilisation studies, surface tension measurements, viscometry, light scattering (dynamic and static) and small angle neutron scattering (SANS) in combination with contrast variation have been used to determine the detailed molecular architecture of the microemulsions formed by DDAPS. The microemulsions prepared using either DT AB or SDS were studied using in less detail using only phase behaviour and drug solubilisation studies and SANS in conjunction with contrast variation to determine their microstructure. For all surfactants studied, the effect of the solubilisation of the poorly-water drug, testosterone propionate, on the detailed structure of the microemulsions was examined using SANS in combination with contrast variation. -- The microemulsions formed by DDAPS were found from light scattering and viscometric studies to be ellipsoidal in nature, although neither technique was sensitive enough to allow the exact dimensions of the aggregates to be determined. SANS studies showed that the micelles and microemulsions formed by each of the C12 surfactants were prolate elliposoids and that the presence of drug did not alter their shape.