Review Oil-in-water lipid emulsions: implications for parenteral and ocular delivering systems S. Tamilvanan * Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, Punjab 160 062, India Dedicated to Prof. Simon Benita of Hebrew University of Jerusalem, Israel Abstract Lipid emulsions (LEs) are heterogenous dispersions of two immiscible liquids (oil-in-water or water-in- oil) and they are subjected to various instability processes like aggregation, flocculation, coalescence and 0163-7827/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.plipres.2004.09.001 Abbreviations: LEs, lipid emulsions; CFA, complete FreundÕs adjuvant; IFA, incomplete FreundÕs adjuvant; OTC, over-the-counter; TG, triglycerides; LCT, long chain TG; MCT, medium chain TG; RES, reticuloendothelial system; apos, apolipoproteins; LPL, lipoprotein lipase; o/w, oil-in-water; w/o, water-in-oil; w/o/w, water-in-oil-in-water; o/w/o, oil-in-water-in-oil; FDA, food and drug administration; RAS, Ribi Adjuvant System; MPL + TDM emulsion, mon- ophosphoryl-lipid A + trehalose dicorynomycolate emulsion; MPL + TDM + CWS emulsion, monophosphoryl-lipid A + trehalose dicorynomycolate + cell wall skeleton emulsion; SAF, syntex Adjuvant formulation; POE, polyoxyeth- ylene; PEG, polyethylene glycol; MPS, mononuclear phagocyte system; AUC, area under the plasma concentration– time curve; TNBS, trinitrobenzenesulfonic acid; SM, sphingomyelin; HCO, hydrogenated castor oil; SO, soybean oil; PEG-PE, polyethylene glycol with phosphatidylethanolamine; DPPC, dipalmitoyl phosphatidylcholine; EYPC, egg yolk phosphatidylcholine; DOPC, dioleoyl phosphatidylcholine; DMPC, dimistoyl phosphatidylcholine; POPC, 1- palmitoyl-2-oleoyl phosphatidylcholine; DDAB, N,N-dimethyl-N,N-dioctadecylammonium bromide; TC-Chol, N,N,- N-trimethylaminoethanecarbamoyl cholesterol; asODN, antisense oligonucleotides; TO, triolein; CO, cholesteryl ole- ate; apo E, apolipoprotein E; VLDL, very low density lipoproteins; LDL, low density lipoproteins; HDL, high density lipoproteins; DOTAP, 1,2-dioleoyl-sn-glycero-3-trimethylammonium-propane; DOPE, 1,2-dioleoyl-sn-glycero-3-phos- phoethanolamine; TGRP, triglyceride rich particles; LRP, LDL-receptor related protein; HSPG, heparan sulfate proteoglycans; PC, phosphatidylcholine; LDL-R, low density lipoprotein receptor; TPN, total parenteral nutrition; NBT, nittroblue tetrazolium; NO, nitric oxide; PPAR, peroxisome proliferator activated receptor; RPE, retinal pigment epithelium; Ig, immunoglobulin; AMD, age related macular degeneration. * Present address. Department of Pharmaceutics, Central Drug Research Institute, Chattar Manzil, P.O. Box 173, Lucknow 226 001, Uttar Pradesh, India. Tel.: +91 522 2212411–18x4302; fax: +91 522 2223938. E-mail address: tamilvanan2k@hotmail.com. Progress in Lipid Research 43 (2004) 489–533 Progress in Lipid Research www.elsevier.com/locate/plipres