| Popis: |
Liposomes can become physically unstable on storage either due to leakage of the encapsulated drug into the suspending medium and/or due to aggregation or fusion of the liposomes to form larger entities. Relatively large liposomes with either one or a few lamellae, as for example the reverse-phase-evaporation vesicles, occupy an intermediate position in regard to their clearance rate from the circulation between the multilamellar Vesicles and small unilamellar vesicles. Multilamellar liposomes were first described by A. D. Bangham et al. Variation of the lipid composition and electrical charge of the liposomes was shown to alter the in vivo distribution and clearance rates of otherwise similar liposomes. It is evident that a wide variety of techniques has been developed and adapted to suit the individual requirements in terms of size, width of size distribution, electrical charge, number of lamellae, and lipid composition of the liposomes. |
