Uridine triacetate (formally PN401) is an acetylated prodrug of uridine. Following oral administration, uridine triacetate is deacetylated by nonspecific esterases present throughout the body, yielding uridine in the circulation. Uridine triacetate under VISTOGARD trade name is a uridine replacement agent approved for the emergency treatment of fluorouracil or capecitabine overdose (regardless of the presence of symptoms) or early-onset severe or life-threatening cardiac or central nervous system (CNS) toxicity and/or early-onset unusually severe adverse reactions (eg, gastrointestinal [GI] toxicity and/or neutropenia) within 96 hours following the end of fluorouracil or capecitabine administration in adult and pediatric patients. Uridine competitively inhibits cell damage and cell death caused by fluorouracil. Fluorouracil is a cytotoxic antimetabolite that interferes with nucleic acid metabolism in normal and cancer cells. Cells anabolize fluorouracil to the cytotoxic intermediates 5-fluoro-2’-deoxyuridine-5’- monophosphate (FdUMP) and 5-fluorouridine triphosphate (FUTP). FdUMP inhibits thymidylate synthase, blocking thymidine synthesis. Thymidine is required for DNA replication and repair. Uridine is not found in DNA. The second source of fluorouracil cytotoxicity is the incorporation of its metabolite, FUTP, into RNA. This incorporation of FUTP into RNA is proportional to systemic fluorouracil exposure. Excess circulating uridine derived from VISTOGARD is converted into uridine triphosphate (UTP), which competes with FUTP for incorporation into RNA. Uridine triacetate is also approved for the treatment of hereditary orotic aciduria under XURIDEN trade name. Uridine triacetate provides uridine in the systemic circulation of patients with hereditary orotic aciduria who cannot synthesize adequate quantities of uridine due to a genetic defect in uridine nucleotide synthesis.

Artemether is an antimalarial agent used to treat acute uncomplicated malaria. It is administered in combination with lumefantrine for improved efficacy against malaria. Artemether is rapidly metabolized into an active metabolite dihydroartemisinin (DHA). The antimalarial activity of artemether and DHA has been attributed to endoperoxide moiety. Artemethe involves an interaction with ferriprotoporphyrin IX (“heme”), or ferrous ions, in the acidic parasite food vacuole, which results in the generation of cytotoxic radical species. The generally accepted mechanism of action of peroxide antimalarials involves interaction of the peroxide-containing drug with heme, a hemoglobin degradation byproduct, derived from proteolysis of hemoglobin. This interaction is believed to result in the formation of a range of potentially toxic oxygen and carbon-centered radicals. Other mechanisms of action for artemether include their ability to reduce fever by production of signals to hypothalamus thermoregulatory center. Now, recent research has shown the presence of a new, previously unknown cyclooxygenase enzyme COX-3, found in the brain and spinal cord, which is selectively inhibited by artemether, and is distinct from the two already known cyclooxygenase enzymes COX-1 and COX-2. It is now believed that this selective inhibition of the enzyme COX-3 in the brain and spinal cord explains the ability of artemether in relieving pain and reducing fever which is produced by malaria. The most common adverse reactions in adults (>30%) are headache, anorexia, dizziness, asthenia, arthralgia and myalgia.

Titanium dioxide, also known as titanium(IV) oxide or titania, is the naturally occurring oxide of titanium, chemical formula TiO 2. When used as a pigment, it is called titanium white, Pigment White 6 (PW6), or CI 77891. Generally it is sourced from ilmenite, rutile and anatase. It has a wide range of applications, from paint to sunscreen to food coloring. When used as a food coloring, it has E number E171. World production in 2014 exceeded 9 million metric tons. Titanium dioxide has excellent ultraviolet (UV) resistant qualities and acts as a UV absorbent. In the pharmaceutical industry, titanium dioxide is used in most sunscreens to block UVA and UVB rays, similar to zinc oxide. It is also commonly used as pigment for pharmaceutical products such as gelatin capsules, tablet coatings and syrups. In the cosmetics industry, it is used in toothpaste, lipsticks, creams, ointments and powders. It can be used as an opacifier to make pigments opaque. The FDA has approved the safety of titanium dioxide for use as a colorant in food, drugs and cosmetics, including sunscreens. However, controversy exists as to the safety of titanium dioxide nanoparticles used in the cosmetics industry, for example in sunscreens. Titanium and zinc oxides may be made into the nanoparticle size (0.2-100 nanometers) to reduce the white appearance when applied topically, but retain the UV blocking properties. Recent studies suggest titanium dioxide nanoparticles may be toxic, although further research is needed.

Chromium sulfate(III) hexahydrate or chromium sulphate, a trivalent compound of chromium that was investigated as a toxic compound. Experiments on rodent have shown chromium sulfate produced severe and widespread effects in the nasal cavity, larynx, lungs, and mediastinal lymph node. Effects were characterized by the accumulation of foreign material, infiltration of alveolar macrophages, septal cell hyperplasia, and granulomatous and chronic inflammation. Besides, chromium sulphate exerted a disadvantageous effect on the skeleton, as it decreases bone density and resistance.

Levocarnitine propionate or Propionyl L-carnitine (PLC) is the propionyl ester of L-carnitine. Propionyl-L-carnitine stimulates energy production in ischaemic muscles by increasing citric acid cycle flux and stimulating pyruvate dehydrogenase activity. The free radical scavenging activity of the drug may also be beneficial. Propionyl-L-carnitine improves coagulative fibrinolytic homeostasis in vasal endothelium and positively affects blood viscosity. It exhibits a high affinity for the muscle enzyme, carnitine acyl transferase, and as such readily converts into propionyl-CoA and free carnitine. Most studies of the therapeutic use of PLC are focused on the prevention and treatment of ischemic heart disease, congestive heart failure, hypertrophic heart disease, and peripheral arterial disease. PLC is marketed under the trade name Dromos®. It is indicated for patients with peripheral arterial occlusive disorders and for exercise intolerance enhancement in patients with chronic congestive heart failure. Dromos is marketed in Italy.

Levocarnitine propionate or Propionyl L-carnitine (PLC) is the propionyl ester of L-carnitine. Propionyl-L-carnitine stimulates energy production in ischaemic muscles by increasing citric acid cycle flux and stimulating pyruvate dehydrogenase activity. The free radical scavenging activity of the drug may also be beneficial. Propionyl-L-carnitine improves coagulative fibrinolytic homeostasis in vasal endothelium and positively affects blood viscosity. It exhibits a high affinity for the muscle enzyme, carnitine acyl transferase, and as such readily converts into propionyl-CoA and free carnitine. Most studies of the therapeutic use of PLC are focused on the prevention and treatment of ischemic heart disease, congestive heart failure, hypertrophic heart disease, and peripheral arterial disease. PLC is marketed under the trade name Dromos®. It is indicated for patients with peripheral arterial occlusive disorders and for exercise intolerance enhancement in patients with chronic congestive heart failure. Dromos is marketed in Italy.