<p class=\"MsoNormal\" style=\"text-align: justify;\"><span style=\"font-family: \'Times New Roman\', serif; font-size: 12pt; line-height: 115%;\">Tetradecyl aspartic acid ( TDAA)</span><span style=\"font-family: \'Times New Roman\', serif; font-size: 12pt; line-height: 115%;\">&nbsp; </span><span style=\"font-family: \'Times New Roman\', serif; font-size: 12pt; line-height: 115%;\">is a substrate for System L. System L is the second most</span><span style=\"font-size: 12.0pt; font-family: \'Times New Roman\',\'serif\';\">abundant transport system available at the BBB transporting neutral amino acids.&nbsp; These transporters can be exploited for the delivery of drugs.&nbsp;&nbsp; The steric requirements for System L are that the substrate must possess an </span><span style=\"font-size: 12.0pt; font-family: Symbol; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'; mso-bidi-font-family: \'Times New Roman\'; mso-char-type: symbol; mso-symbol-font-family: Symbol;\">a</span><span style=\"font-size: 12.0pt; font-family: \'Times New Roman\',\'serif\';\">-amino group and a carboxylic group attached to the same carbon atom, plus a hydrophobic side chain. TDAA&nbsp;&nbsp; satisfies steric requirement of System L. By using TDAA as a recognition ligand, drug molecules or drug molecules loaded on to carriers can be delivered to the brain.&nbsp;&nbsp; We attempted to prepare liposomes with TDAA with or without cholesterol.&nbsp; However all the preparations were difficult to hydrate and liposomes did not form with TDAA either with or without cholesterol.&nbsp;&nbsp; But we could load TDAA on to the liposomes up to a concentration of 20% of the total lipid without affecting the liposomes stability.&nbsp; The liposomes were prepared by film hydration method followed by sonication in which aqueous Azidothymidine (AZT) solution was encapsulated. Formation of liposomes was confirmed by optical microscope.&nbsp; The liposomes after sonication were characterized for size and size distribution, charge and zeta potential, percent entrapment and invitro release.</span></p>
 
<p class=\"MsoNormal\"><span style=\"font-size: 12.0pt; line-height: 115%; font-family: \'Times New Roman\',\'serif\';\">Keywords: Liposomes, System L; Nano Drug delivery; Drug targeting;Tetradecyl aspartic acid</span></p>