French pharmaceutical company Hoechst Marion Roussel (later Sanofi-Aventis) began phase II/III clinical trials of telithromycin (HMR-3647) in 1998. Telithromycin was approved by the European Commission in July 2001 and subsequently went on sale in October 2001. In the US, telithromycin received U.S. Food and Drug Administration (FDA) approval on April 1, 2004 Telithromycin is the first ketolide antibiotic to enter clinical use and is sold under the brand name of Ketek. After significant controversy regarding safety and research fraud, the US Food and Drug Administration sharply curtailed the approved uses of the drug in 2007. Telithromycin is a semi-synthetic erythromycin derivative. It is created by substituting a ketogroup for the cladinose sugar and adding a carbamate ring in the lactone ring. An alkyl-aryl moiety is attached to this carbamate ring. Furthermore, the carbon at position 6 has been methylated, as is the case in clarithromycin, to achieve better acid-stability. For the treatment of Pneumococcal infection, acute sinusitis, acute bacterial tonsillitis, acute bronchitis and bronchiolitis, lower respiratory tract infection and lobar (pneumococcal) pneumonia. KETEK tablets contain telithromycin, a semisynthetic antibacterial in the ketolide class for oral administration. Telithromycin blocks protein synthesis by binding to domains II and V of 23S rRNA of the 50S ribosomal subunit. By binding at domain II, telithromycin retains activity against gram-positive cocci (e.g., Streptococcus pneumoniae) in the presence of resistance mediated by methylases (erm genes) that alter the domain V binding site of telithromycin. Telithromycin may also inhibit the assembly of nascent ribosomal units.

Methyl aminolevulinate is a prodrug that is metabolised to Protoporphyrin IX (a photosensitizer) used in photodynamic therapy. Photosensitization following application of methyl aminolevulinate cream occurs through the metabolic conversion of methyl aminolevulinate (prodrug) to photoactive porphyrins (PAP), which accumulates in the skin lesions to which the cream has been applied. When exposed to light of appropriate wavelength and energy, the accumulated photoactive porphyrins produce a photodynamic reaction, resulting in a cytotoxic process dependent upon the simultaneous presence of oxygen. The absorption of light results in an excited state of porphyrin molecules, and subsequent spin transfer from photoactive porphyrins to molecular oxygen generates singlet oxygen, which can further react to form superoxide and hydroxyl radicals. Methyl aminolevulinate is used for topical use, in combination with 570 to 670 nm wavelength red light illumination, in the treatment of non-hyperkeratotic actinic keratoses of the face and scalp in immunocompetent patients when used in conjunction with lesion preparation (debridement using a sharp dermal curette).

Drometrizole trisiloxane is a lipophilic benzotriazole derivative marketed as Mexoryl XL by L'Oréal and is used in sunscreens as a (UV) filtering agent that provide a high sun protection factor (SPF) for daily photoprotection of skin against UV damage and delay the signs of aging. Drometrizole trisiloxane is a broad-spectrum UV absorber with two absorption peaks, one at 303 nm (UVB) and one at 344 nm (UVA). Sunscreens with drometrizole trisiloxane are approved within the EU, Australia and other contries but not in the United States.

Homosalate is used as a broad-band UV filter in concentrations of up to 10% in the EU or 15% depending upon where the product is used (e.g. in the USA) in sunscreen products alone or in combination with other UV absorbers to protect the skin against harmful effects of the UV radiation.