Distearyl phosphatidyl ethanolamine DSPE BELIEVE you are very familiar with, this article AVT xiaobian to talk about distearyl phosphatidyl ethanolamine DSPE PEG (polyethylene glycol) derivatives DSPE-MPEG2000, because polyethylene glycol terminal using methoxy capping, the PARTIAL deactivation of PEG can not continue the reaction, polymerization degree of 2000, Therefore, it is called mPEG2000.
The use of DSPE-MPEG2000 to prepare long cycle liposomes can be said to be a wide application in preparation. After entering the systemic circulation system, common liposomes will rupture due to the action of proteins, opsonins, antibodies and enzymes in the blood, leading to the leakage of the encapsulated active substances. Or recognized and removed by the human reticuloendothelial system (RES), unable to produce efficacy. In this case, long-circulating liposomes, or invisible liposomes, emerged.
By attaching a polyhydroxyl group, known as PEG, to the phospholipid molecule, the researchers made the liposomes appear to be somewhat hydrophilic, playing a long-cycle role in two ways:
1.PEG molecules can form hydrogen bonds with water phase, forming a hydration membrane structure in liposome to reduce the binding of liposome with proteins and enzymes in plasma, so as to enhance its stability in blood;
2. PEG as seaweed staggered covered in the surface of liposome, the soft hair brush conformation, block adsorption and such as proteins, antibodies, cell adhesion, and cover up the hydrophobic part of the phospholipid molecules to avoid combined with blood components, and thus effectively avoid the RES recognition and consuming, prolonged systemic circulation of liposomes and drug half-life.
For example, the pharmacokinetic behavior of API adriamycin was significantly different between DOXIL and MYCOET. DOXIL with DSPE-MPEG2000 has a half-life of about 2.5 days of adriamycin, while MYCOET without DSPE-MPEG2000 has a half-life of 0.07 hours.
Generally speaking, the dosage of DSPE-MPEG2000 can play a good role in about 5%, its dosage is not directly related to the drug encapsulation rate, and it is soluble in organic solvent with other phospholipid excipient.