Besifloxacin (INN/USAN) is a fourth-generation fluoroquinolone antibiotic. The marketed compound is Besifloxacin hydrochloride. It was developed by SSP Co. Ltd., Japan, and designated SS734. SSP licensed U.S. and European rights to SS734 for ophthalmic use to InSite Vision Incorporated in 2000. InSite Vision developed an eye drop formulation (ISV-403) and conducted preliminary clinical trials before selling the product and all rights to Bausch & Lomb in 2003. Besifloxacin is indicated in the treatment of bacterial conjunctivitis caused by sensitive germs, as well as in the prevention of infectious complications in patients undergoing laser therapy for the treatment of cataracts. Besifloxacin inhibits bacterial DNA gyrase and topoisomerase IV and has a broad spectrum of bactericidal activity against strains commonly isolated from patients with bacterial conjunctivitis. In addition, some exploratory in vitro data suggest that Besifloxacin inhibits cytokine formation in human corneal epithelial cells and monocytes, but the relevance of this finding to therapeutic efficacy is unknown.

Moxifloxacin is a synthetic antibacterial agent developed by Bayer AG (initially called BAY 12-8039) for oral and intravenous administration. Moxifloxacin, a fluoroquinolone, is available as the monohydrochloride salt of 1-cyclopropyl-7-[(S,S)-2,8diazabicyclo[4.3.0]non-8-yl]-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3 quinoline carboxylic acid. Moxifloxacin is marketed worldwide (as the hydrochloride) under the brand names Avelox, Avalox, and Avalon for oral treatment. In most countries, the drug is also available in the parenteral form for intravenous infusion. Moxifloxacin is also sold in an ophthalmic solution (eye drops) under the brand names Vigamox, and Moxeza for the treatment of conjunctivitis (pink eye). Its antibacterial spectrum includes enteric Gram-(−) rods (Escherichia coli, Proteus species, Klebsiella species), Haemophilus influenzae, atypical bacteria (Mycoplasma, Chlamydia, Legionella), and Streptococcus pneumoniae, and anaerobic bacteria. It differs from earlier antibacterials of the fluoroquinolone class such as levofloxacin and ciprofloxacin in having greater activity against Gram-positive bacteria and anaerobes.

Ofloxacin is one of a new generation of fluorinated quinolones structurally related to nalidixic acid, primary mechanism of action is inhibition of bacterial DNA gyrase. It is an orally administered broad spectrum antibacterial drug active against most Gram-negative bacteria, many Gram-positive bacteria and some anaerobes. Clinical trials to date have demonstrated the efficacy of ofloxacin in the treatment of lower respiratory tract infections, urinary tract infections, and sexually transmitted diseases. Adverse effects to ofloxacin are usually mild and include gastrointestinal, central nervous system, and hypersensitivity reactions. Also available in solution for treatment of otic and ophthalmic bacterial infections.

Ganciclovir is a synthetic acyclic nucleoside analogue of 2'-deoxyguanosine active against cytomegalovirus. Ganciclovir has been shown to be active against cytomegalovirus (CMV) and herpes simplex virus (HSV) in humans. To achieve anti-CMV activity, ganciclovir is phosphorylated first to the monophosphate form by a CMV-encoded (UL97 gene) protein kinase homologue, then to the di- and triphosphate forms by cellular kinases. Ganciclovir triphosphate concentrations may be 100-fold greater in CMV-infected than in uninfected cells, indicating preferential phosphorylation in infected cells. Ganciclovir triphosphate, once formed, persists for days in the CMV-infected cell. Ganciclovir triphosphate is believed to inhibit viral DNA synthesis by (1) competitive inhibition of viral DNA polymerases; and (2) incorporation into viral DNA, resulting in eventual termination of viral DNA elongation. Ganciclovir is indicated for the treatment of CMV retinitis in immunocompromised patients, including patients with acquired immunodeficiency syndrome (AIDS) and for the treatment of acute herpetic keratitis.

Ciprofloxacin (1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid) is the synthetic antimicrobial agent for oral or intravenous administration. Ciprofloxacin is a member of the fluoroquinolone class of antibacterial agents. The bactericidal action of ciprofloxacin results from inhibition of the enzymes topoisomerase II (DNA gyrase) and topoisomerase IV (both Type II topoisomerases), which are required for bacterial DNA replication, transcription, repair, and recombination. Ciprofloxacin is used to treat a wide variety of infections, including infections of bones and joints, endocarditis, gastroenteritis, malignant otitis externa, respiratory tract infections, cellulitis, urinary tract infections, prostatitis, anthrax, and chancroid. In the United States, ciprofloxacin is pregnancy category C. This category includes drugs for which no adequate and well-controlled studies in human pregnancy exist, and for which animal studies have suggested the potential for harm to the fetus, but potential benefits may warrant use of the drug in pregnant women despite potential risks. Fluoroquinolones have been reported as present in a mother's milk and thus passed on to the nursing child. Oral and intravenous ciprofloxacin is approved by the FDA for use in children for only two indications due to the risk of permanent injury to the musculoskeletal system: Inhalational anthrax (postexposure) and Complicated urinary tract infections and pyelonephritis due to Escherichia coli.

Cefuroxime is a semisynthetic, broad-spectrum, cephalosporin antibiotic. Cefuroxime is a bactericidal agent that acts by inhibition of bacterial cell wall synthesis. Cefuroxime has activity in the presence of some beta-lactamases, both penicillinases and cephalosporinases, of Gram-negative and Gram-positive bacteria. Cefuroxime has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infection: Enterobacter spp., Escherichia coli, Klebsiella spp., Haemophilus influenzae, Neisseria meningitidis, Neisseria gonorrhoeae, Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes. Cefuroxime is indicated for the treatment of patients with septicemia, meningitis, gonorrhea, lower respiratory tract, urinary tract, skin and skin-structure, bone and joint infections caused by susceptible strains of the designated organisms.

Acyclovir is a synthetic antiviral nucleoside analogue. A screening program for antiviral drugs begun at Burroughs Wellcome in the 1960s resulted in the discovery of acyclovir in 1974. Preclinical investigation brought the drug to clinical trials in 1977 and the first form of the drug (topical) was available to physicians in 1982. Activity of acyclovir is greatest against herpes 1 and herpes 2, less against varicella zoster, still less against Epstein-Barr, and very little against cytomegalovirus. Acyclovir is an antiviral agent only after it is phosphorylated in infected cells by a viral-induced thymidine kinase. Acyclovir monophosphate is phosphorylated to diphosphate and triphosphate forms by cellular enzymes in the infected host cell where the drug is concentrated. Acyclovir triphosphate inactivates viral deoxyribonucleic acid polymerase.

Trifluridine (also called trifluorothymidine or TFT) is an anti-herpesvirus antiviral drug, used primarily on the eye. It was sold under the trade name, Viroptic, by Glaxo Wellcome, now merged into GlaxoSmithKline. It is a nucleoside analogue, a modified form of deoxyuridine, similar enough to be incorporated into viral DNA replication, but the -CF3 group added to the uracil component blocks base pairing, thus interfering with DNA replication. It is a component of the experimental anti-cancer drug TAS-102. Trifluridine is a fluorinated pyrimidine nucleoside with in vitro and in vivo activity against herpes simplex virus, types 1 and 2 and vaccinia virus. Some strains of adenovirus are also inhibited in vitro. VIROPTIC is also effective in the treatment of epithelial keratitis that has not responded clinically to the topical administration of idoxuridine or when ocular toxicity or hypersensitivity to idoxuridine has occurred. In a smaller number of patients found to be resistant to topical vidarabine, VIROPTIC was also effective. The mechanism of action of trifluridine has not been fully determined, but appears to involve the inhibition of viral replication. Trifluridine does this by incorporating into viral DNA during replication, which leads to the formation of defective proteins and an increased mutation rate.

Natamycin (Pimaricin, Pimafucin, Natadrops, Natacyn) is a polyene antifungal agent originally isolated from Streptomyces natalensis found in a soil sample from Natal, South Africa. Natamycin was discovered in DSM laboratories in 1955. Similar to other polyenes, natamycin binds to ergosterol in the fungal cell membrane. Natamycin blocks fungal growth by binding specifically to ergosterol with¬out permeabilizing the membrane where it inhibits vacuole fusion at the priming phase and interferes with membrane protein functions. Natamycin is also used in the food industry as an effective preservative. Natamycin is active against most Candida spp. Aspergillus spp., Fusarium spp. and other rarer fungi that cause keratitis. Secondary or acquired resistance is probably rare, but not extensively studied. Natamycin is not effective in vitro against gram-positive or gram-negative bacteria. Topical administration appears to produce effective concentrations of natamycin within the corneal stroma but not in intraocular fluid. Natamycin is poorly soluble in water and not absorbed through the skin or mucous membranes, including the vagina. Very little is absorbed through the gastrointestinal tract. After ocular application, therapeutic concentrations are present within the infected cornea, but not in intra-ocular fluid Natamycin may cause some irritation on skin or mucous membranes

Amikacin, USP (as the sulfate) is a semi-synthetic aminoglycoside antibiotic derived from kanamycin. Amikacin "irreversibly" binds to specific 30S-subunit proteins and 16S rRNA. Amikacin inhibits protein synthesis by binding to the 30S ribosomal subunit to prevent the formation of an initiation complex with messenger RNA. Specifically Amikacin binds to four nucleotides of 16S rRNA and a single amino acid of protein S12. This interferes with decoding site in the vicinity of nucleotide 1400 in 16S rRNA of 30S subunit. This region interacts with the wobble base in the anticodon of tRNA. This leads to interference with the initiation complex, misreading of mRNA so incorrect amino acids are inserted into the polypeptide leading to nonfunctional or toxic peptides and the breakup of polysomes into nonfunctional monosomes. Amikacin is used for short-term treatment of serious infections due to susceptible strains of Gram-negative bacteria, including Pseudomonas species, Escherichia coli, species of indole-positive and indole-negative Proteus, Providencia species, Klebsiella-Enterobacter-Serratia species, and Acinetobacter (Mima-Herellea) species. Amikacin may also be used to treat Mycobacterium avium and Mycobacterium tuberculosis infections. Amikacin was used for the treatment of gram-negative pneumonia.