Liposomal Glutathione-Case Study

Background

Glutathione is an important antioxidant composed of three amino acids. It plays a key metabolic regulatory function within the cell. Glutathione is the predominant antioxidant within cells, scavenging free radicals from the body, reducing damage from oxidative stress, and slowing down the aging process. Glutathione also enhances the functioning of the body's immune system and improves the body's resistance to viruses and bacteria. In addition to this, glutathione has detoxification and regulates cell signaling. However, the molecular structure of glutathione contains active sulfhydryl group (-SH), which is susceptible to oxidation reaction by external environmental factors, such as light, humidity, high temperature environment. In addition, gastric acid and digestive enzymes can destroy glutathione, leading to its premature breakdown during digestion and limiting its bioavailability.

Challenge

• Low bioavailability
• Chemical stability issues
• Biological stability issues
• Imprecise controlled release technology

Solution

This encapsulation property of liposomes makes them an effective drug delivery system that can improve drug stability and bioavailability while reducing toxic side effects and enabling targeted delivery. CD Bioparticles has extensive experience in developing liposomes over the years and has the capability for stable batch production and industrialization. Liposomal glutathione prepared using high-pressure homogenization technology exhibit the following properties:

Results

Note: P2 is a special process formulation 1. P6 is a special process formulation 2.

• As shown in Figure 1 , the experimental results indicate that liposomal glutathione are spherical in shape and homogeneous, and the liposome nanosize is around 36 nm. The encapsulation rate were 20-40%.

Figure 1. TEM picture of liposomal glutathione.

• The data on the amount of release in Figure 2 reveals the specific amount of glutathione or liposome-encapsulated glutathione that can be successfully absorbed by the body after passing through the gastric acid environment. As can be seen from the graph, the absorption of liposomal glutathione in the body is approximately three times higher than that of regular liposomes.

Figure 2. Pictures of glutathione release profiles in the organism.

• As can be seen from the table 1, the relative bioavailability of liposomal glutathione-P6-30%, liposomal glutathione-P2-50%, liposomal glutathione-P6-50% and liposomal glutathione-P2-70% was higher than that of the glutathione prodrug group. Among them, the highest one of liposomal glutathione-P6-50% was 12.94-fold, indicating that the bioavailability of the glycopeptide was significantly increased after it was prepared into liposomes. Liposomal glutathione had a higher peak concentration Cmax duration in vivo that was significantly longer than in the prodrug group.

Figure 3. Pictures of bioavailability of liposomal glutathione.

Table 1 Bioavailability of glutathione in different groups.

Methods

Reference

1. Kumar N, et al.; Improved in vitro and in vivo hepatoprotective effects of liposomal silymarin in alcohol-induced hepatotoxicity in wistar rats. Pharmacological Reports. 2019, 71(4): 703-712.