Pharmaceuticals liposome encapsulated

Presently, several clinical trials with liposome-encapsulated agents are under way and more are planned (Zonneveld and Crommelin, 1988 Klausner, 1988). During the last 5 years, key issues related to the pharmaceutical manufacturing of liposomes such as stability, sterilization, upscaling, and reproducibility have been successfully addressed. Although it is generally believed that a proper selection of the bi-layer components can minimize the occurrence of toxic effects due to the use of natural body constituents, the issue of liposome-related toxicity is not a trivial one and should be carefully studied,... 

Pharmaceuticals Antioxidant, emulsifier or surfactant, liposomal encapsulating agent, machining aid, nutritional supplement or vitamin aid, stabilizer, wetting agent, biologically active agent... 

DepoCyt (Pacira Pharmaceuticals, San Diego, CA) is a slow release liposome-encapsulated cytarabine formulation, recently approved for intrathecal administration in the treatment of neoplastic meningitis and lymphomatous meningitis (30-32). The Depo-Foam platform used in DepoCyt , is essentially a spherical 20-pm multi-lamellar matrix comprised of phospholipids/ lipid mixture, similar to normal human cell membranes (phospholipids, triglycerides and cholesterol) (33). 

Another application of liposomes is in the cosmetics industry. Liposomes can be formed that encapsulate a vitamin, herbal agent, or other nutritional element. When applied to the skin, the liposomes pass easily through the outer layer of dead skin, delivering their contents to the living skin cells beneath. As with the pharmaceutical liposomes, these liposomes, sometimes called cosmeceuticals, fuse with skin cells. Thus, they directly deliver the beneficial cosmetic agent directly to the cells that can benefit the most. 

Yamakami, K., Tsumori, H., Sakurai, Y., Shimizu, Y., Nagatoshi, K., Sonomoto, K., 2013. Sustainable inhibition efficacy of liposome-encapsulated nisin on insoluble glucan-biofilm synthesis by Streptococcus mutans. Pharmaceutical Biology 51, 267—270. 

As one of the main structural constituents of biological membranes, PLs play a crucial role in the biochemistry and physiology of cells. PLs have also found plications in numerous industries. For example, PLs are often used as emulsifier, stabilizer and wetting and dispersing agents in the food industry. Pharmaceutical and cosmetic industries utilize PLs in liposomal encapsulation of active ingredients for enhanced delivery and bioavailability (Gabizon et al, 1997). 

The liposomal encapsulation technology is focused on cosmetic and pharmaceutical systems, since the PC fractions are quite costly. Plant scale produced PC phospholipids are used as excipients for targeted drugs transport, encapsulation and cell membrane passage. 

Thus, if one can provide a water soluble polymer drug, it can be encapsulated into specific liposomes for pharmaceutical delivery. 

Several pharmaceutical activities of nucleic acid analogs such as poly(VAd) have been studied in vitro and in cell-free systems [19]. It was expected that the present polymers would be effectively transferred into phagocytes by encapsulating in polysaccharide-coated liposomes and would show increased pharmaceutical activities similar to poly(maleic acid-a/l-2-cyclohexyl-l, 3-dioxap-5-ene) (MA-CDA) [68]. The activation of human neutrophils by poly(VAd) was evaluated by monitoring the in vitro superoxide anion production from activated human neutrophils. Shown in Table 15 is the superoxide liberated from human neutrophils (1 x 106 cells/ml) activated by poly(VAd) (0.5 mg/ml) as a function of time. Poly(VAd) encapsulated in mannan derivative-coated liposomes showed a... 

Yu RZ, Geary RS, I. eeds JM, Ushiro-Watanabe T, Fitchett JR, Matson JE, Mehta R, Hardee GR, Templin MV, Huang K, et al. Pharmacokinetics and tissue disposition in monkeys of an antisense oligonucleotide inhibitor of ha-ras encapsulated in stealth liposomes. Pharmaceut Res 1999 16(8) 1309-15. 

Stability of Liposomes A shelf life of at least two years is requested for pharmaceutical products. Therefore, chemical stability and physical stability are important parameters for the overall performance of liposomal formulations. Additionaly, another very important factor is the retention of encapsulated drug. 

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