Abstract: Dehydrated liposomes are prepared by drying liposome preparations under reduced pressure in the presence of one or more protective sugars, e.g., the disaccharides trehalose and sucrose. Preferably, the protective sugars are present at both the inside and outside surfaces of the liposome membranes. Freezing of the liposome preparation prior to dehydration is optional. Alternatively, the protective sugar can be omitted if: (1) the liposomes are of the type which have multiple lipid layers; (2) the dehydration is done without prior freezing; and (3) the dehydration is performed to an end point which results in sufficient water being left in the preparation (e.g., at least 12 moles water/mole lipid) so that the integrity of a substantial portion of the multiple lipid layers is retained upon rehydration.

Abstract: This invention provides a compound having the formula R.sup.1 -Y.sup.1 --CHZ.sup.1 -CH(NY.sup.2 Y.sup.3)--CH.sub.2 -Z.sup.2, wherein: R.sup.1 is a straight-chained alkyl, alkenyl or alkynyl group having from 8 to 19 carbon atoms in the aliphatic chain; Y.sup.1 is --CH.dbd.CH--, --C.tbd.C-- or --CH(OH)CH(OH)--; Z.sup.1 is OH or a conversion-inhibiting group; Z.sup.2 is a conversion-inhibiting group; Y.sup.2 is H, a phenyl group, an alkyl-substituted phenyl group having from 1 to about 6 carbons in the alkyl chain, or an alkyl chain having from 1 to 6 carbons; Y.sup.3 is H or a group having the formula --C(O)R.sup.2 or --S(O).sub.2 R.sup.2 ; R.sup.2 is a straight-chained alkyl, alkenyl or alkynyl group having from 1 to 23 carbon atoms in the chain; and when Z.sup.2 is an amino, R.sup.2 is an aliphatic chain having from 1 to 9 or from 19 to 23 carbon atoms in the aliphatic chain.