Polixetonium is a cationic polymer used in rigid gas permeable contact lens solutions. It is a biocide and pesticide. It is also used as a swimming pool disinfectant and algistat. It appears to be more effective against moulds than PQ-1.

Hyaluronic acid (HA) is a high molecular weight biopolysacharide, discovered in 1934, by Karl Meyer and his assistant, John Palmer in the vitreous of bovine eyes. Hyaluronic acid is a naturally occurring biopolymer, which has important biological functions in bacteria and higher animals including humans. It is found in most connective tissues and is particularly concentrated in synovial fluid, the vitreous fluid of the eye, umbilical cords and chicken combs. It is naturally synthesized by a class of integral membrane proteins called hyaluronan synthases, and degraded by a family of enzymes called hyaluronidases. Hyaluronan synthase enzymes synthesize large, linear polymers of the repeating disaccharide structure of hyaluronan by alternating addition of glucuronic acid and N-acetylglucosamine to the growing chain using their activated nucle¬otide sugars (UDP – glucuronic acid and UDP-N-acetlyglucosamine) as substrates. The number of repeat disaccharides in a completed hyaluronan molecule can reach 10 000 or more, a molecular mass of ~4 million daltons (each disaccharide is ~400 daltons). The average length of a disaccharide is ~1 nm. Thus, a hyaluronan molecule of 10 000 repeats could ex¬tend 10 μm if stretched from end to end, a length approximately equal to the diameter of a human erythrocyte. Although the predominant mechanism of HA is unknown, in vivo, in vitro, and clinical studies demonstrate various physiological effects of exogenous HA. Hyaluronic acid possesses a number of protective physiochemical functions that may provide some additional chondroprotective effects in vivo and may explain its longer term effects on articular cartilage. Hyaluronic acid can reduce nerve impulses and nerve sensitivity associated with pain. In experimental osteoarthritis, this glycosaminoglycan has protective effects on cartilage. Exogenous HA enhances chondrocyte HA and proteoglycan synthesis, reduces the production and activity of proinflammatory mediators and matrix metalloproteinases, and alters the behavior of immune cells. In addition to its function as a passive structural molecule, hyaluronan also acts as a signaling molecule by interacting with cell surface receptors and regulating cell proliferation, migration, and differentiation. Hyaluronan is essential for embryogenesis and is likely also important in tumorigenesis. HA plays several important organizational roles in the extracellular matrix (ECM) by binding with cells and other components through specific and nonspecific interactions. Hyaluronan-binding pro¬teins are constituents of the extracellular matrix, and stabilize its integrity. Hyaluronan receptors are involved in cellular signal transduction; one receptor family includes the binding proteins aggrecan, link protein, versican and neurocan and the receptors CD44, TSG6, GHAP and LYVE-1. The chondroprotective effects of hyaluronic acid, e.g., that it stimulates the production of tissue in¬hibitors of matrix metalloproteineses (TIMP-1) by chondrocytes, inhibits neutrophil-mediated cartilage degradation and attenuates IL-1 induced matrix de¬generation and chondrocyte cytotoxicity have been observed in vitro. Articular chondrocytes cultured in the presence of HA have a significantly greater rate of DNA proliferation and ex¬tracellular matrix production, compared with chon¬drocytes cultured without HA.

Polihexanide is a broad-spectrum antiseptic with excellent cell and tissue tolerability, ability to bind to the organic matrix, low risk of contact sensitization, and wound healing promoting effect. Polihexanide interacts with acidic, negatively charged phospholipids in the bacterial membrane, leading to increased fluidity, permeability and loss of integrity, followed by the death of the organism. Polihexanide is also transferred to the cytoplasm, where it leads to disruption of the bacterial metabolism. Neutral phospholipids on the other hand are little or not affected by Polihexanide. This is commonly seen as the main reason for the low toxicity of Polihexanide against human cells and its high therapeutic range. Due to its nonspecific, strong interaction with negatively charged phospholipids, Polihexanide has a broad antimicrobial spectrum, including Gram-positive and Gramnegative bacteria, plaque-forming and biofilm-building bacteria, spore-forming bacteria (but not bacterial spores), intracellular bacteria such as chlamydiae and mycoplasma, and fungi including Candida spp. as well as Aspergillus spp. Polihexanide is classified as ‘practically nontoxic’. The therapeutic index of Polihexanide is more than 200-fold that of chlorhexidine.

Tocophersolan (Vedrop, tocofersolan) or d-alpha-Tocopheryl Polyethylene Glycol 1000 Succinate (TPGS) is a watersoluble derivative of the natural active (d-alpha) isomer of vitamin E. The active constituent of the medicinal product is essentially vitamin E (alpha tocopherol). Chronic congenital or hereditary cholestasis is a clinical condition where vitamin E deficiency results from an impaired bile secretion. Decreased intestinal absorption observed in chronic congenital or hereditary cholestatic patients is due to decreased bile secretion and the resulting decrease in intestinal cellular absorption. As a result, fatsoluble vitamins (i.e. vit. E) are not absorbed properly and deficiency can occur. Tocophersolan (Vedrop) is used to treat or prevent vitamin E deficiency (low vitamin E levels). It is used in children up to the age of 18 years who have congenital or hereditary chronic cholestasis and who cannot absorb vitamin E from the gut. Tocophersolan (Tocofersolan) can be absorbed from the gut in children who have difficulty absorbing fats and vitamin E from the diet. This can increase vitamin E levels in the blood and help to prevent neurological deterioration (problems in the nervous system) due to vitamin E deficiency. No treatment-related findings were reported, as all clinical observations and findings at autopsy were similar in treatment and control groups. In many of the studies, the LD50 was not determined as tocofersolan was well tolerated.