Drug leakage

An alternative approach to avoid drug leakage from the liposomes on storage is to minimize the volume of the external water phase by... 

Liposomes that remain impermeable to their contents cannot release these compounds without interaction with cells. This cellular interaction occurs by three different mechanisms (Fig. 11) [57], Of these, fusion and adsorption usually involve drug leakage, whereas effective drug delivery results from en-docytosis. 

The mean sizes obtained were 500 150, 350 77, 192 25, and 100 16, for 0.6, 0.4, 0.2, and 0.1pm liposomes, respectively. Drug concentration was determined by spectrophotometric assay of chromophoric complex between the BP and copper (II) ions (63) or by high performance liquid chromatography (HPLC) (64). Lipid concentration was determined by Bartlett method (65). Stability of the liposomes was determined by examining drug leakage. Then 400 pL of liposomal formulations were centrifuged... 

The hydrogels were able to prevent drug leakage to a common conservation liquid for SCLs and to sustain drug delivery in lacrimal fluid for 2 weeks. The hydrogels with pendant pCDs are particularly useful for the development of cytocompatible medicated implants or biomedical devices, such as drug-loaded SCLs. 

Azo-containing polyurethane-coated drug pellets Model drugs (hydrophilic in nature) Double-coated drug pellets which are undercoated with (carboxymethyl)(ethyl)-cellulose and overcoated with the azo polymer Colon-specific delivery Effective prevention of the drug leakage was observed withPU [25]... 

Liposomes The pH-sensitive liposomes so developed were able 56 to overcome the three main problems associated with liposomes, i.e., low stability, slow drug release and accumulation In liver/spleen. The ECM targeting liposome could prevent protein adsorption and drug leakage from liposome due to the biotin 2-PEG cross-linker located on interface of liposome. The uptake within the cancer cell is improved and could actively target tumor in tumor ECM to increase tumor accumulation. Also the drug release was enhanced at low pH, thus the potential bioavailability and drug resistance problem are also avoided. 

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