Vidarabine or 9-β-D-arabinofuranosyladenine (ara-A, trade name Vira-A) is a synthetic purine nucleoside analog with in vitro and in vivo inhibitory activity against herpes simplex virus types 1 (HSV-1), 2 (HSV-2), and varicella-zoster virus (VZV). The inhibitory activity of Vidarabine is highly selective due to its affinity for the enzyme thymidine kinase (TK) encoded by HSV and VZV. This viral enzyme converts Vidarabine into Vidarabine monophosphate, a nucleotide analog. The monophosphate is further converted into diphosphate by cellular guanylate kinase and into triphosphate by a number of cellular enzymes. in vitro, Vidarabine triphosphate stops replication of herpes viral DNA. When used as a substrate for viral DNA polymerase, Vidarabine triphosphate competitively inhibits dATP leading to the formation of 'faulty' DNA. This is where Vidarabine triphosphate is incorporated into the DNA strand replacing many of the adenosine bases. This results in the prevention of DNA synthesis, as phosphodiester bridges can longer to be built, destabilizing the strand.

Discovered as natural products from actinomycetes soil bacteria, the tetracyclines were first reported in the scientific literature in 1948. They were noted for their broad spectrum antibacterial activity and were commercialized with clinical success beginning in the late 1940s to the early 1950s. By catalytic hydrogenation of Aureomycin, using palladium metal and hydrogen, the C7 deschloro derivative was synthesized, producing a compound of higher potency, a better solubility profile, and favorable pharmacological activity; it was subsequently named tetracycline. Tetracyclines are primarily bacteriostatic and exert their antimicrobial effect by the inhibition of protein synthesis by binding to the 30S ribosomal subunit. Tetracycline is active against a broad range of gram-negative and gram-positive organisms. Tetracycline is indicated in the treatment of infections caused by susceptible strains. To reduce the development of drug-resistant bacteria and maintain the effectiveness of tetracycline hydrochloride and other antibacterial drugs, tetracycline hydrochloride should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.

Oxytetracycline, a tetracycline analog isolated from the actinomycete streptomyces rimosus, was the second of the broad-spectrum tetracycline group of antibiotics to be discovered The drug is used for the prophylaxis and local treatment of superficial ocular infections due to oxytetracycline- and polymyxin-sensitive organisms for animal use only. These infections include the following: Ocular infections due to streptococci, rickettsiae E. coli, and A. aerogenes (such as conjunctivitis, keratitis, pinkeye, corneal ulcer, and blepharitis in dogs); ocular infections due to secondary bacterial complications associated with distemper in dogs; and ocular infections due to bacterial inflammatory conditions which may occur secondary to other diseases in dogs. Allergic reactions may occasionally occur. Treatment should be discontinued if reactions are severe. If new infections due to nonsensitive bacteria or fungi appear during therapy, appropriate measures should be taken. Oxytetracycline inhibits cell growth by inhibiting translation. It binds to the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. The binding is reversible in nature. Oxytetracycline is lipophilic and can easily pass through the cell membrane or passively diffuses through porin channels in the bacterial membrane.

Bacitracin is a polypeptide antibiotic produced by Bacillus subtilis and Bacillus licheniformis. Bacitracin in combination with neomycin and polymyxin B is indicated for the treatment of many bacterial diseases. The antibacterial properties of bacitracin are mediated by its binding to C55-isoprenyl pyrophosphate, resulting in inhibition of cell wall biosynthesis.

Bibrocathol (trade names Noviform and Posiformin) is a well-established topical antiseptic for the treatment of acute eyelid diseases like blepharitis. Eye ointments containing 2 or 5 % bibrocathol and the excipients liquid paraffin, white soft paraffin, and lanolin have been marketed since 1967 for the treatment of eye irritation, chronic blepharitis, and uninfected corneal injuries. Reports of clinical experience with bibrocathol for inflammation of the edge of the palpebra exist since the beginning of the 20th century. Until recently, no controlled, randomized clinical studies according to the guidelines for Good Clinical Practice for Trials on Medical Products for Human Use (GCP) as defined by the International Conference on Harmonisation (ICH) have been performed with bibrocathol 2 % ointment, as these were not required for marketing authorization in the 1960s. A first double-blind, prospective, controlled, GCP-compliant clinical study was recently performed to assess the efficacy of bibrocathol 5 % (Noviform®) in acute blepharitis. It demonstrated superior efficacy of bibrocathol 5 % ointment as compared to an ointment vehicle (placebo) after 2 weeks of treatment as assessed by a combined measure of slit-lamp examination results and patients’ subjective complaints.

Dihydrostreptomycin is an antibiotic compound derived from streptomycin by reduction with hydrogen. The primary mechanism of action of the antibiotic dihydrostreptomycin is binding to and modifying the function of the bacterial ribosome, thus leading to decreased and aberrant translation of proteins, in addition it binds mechanosensitive channel of large conductance (MscL) and modifies its conformation, thus allowing the passage of K+ and glutamate out of, and dihydrostreptomycin into, the cell. It has about the same degree of antibacterial activity as streptomycin, but it is less effective against some gram-negative microorganisms. Because it has a higher risk of irreversible deafness, and its effectiveness is no greater that that of streptomycin, dihydrostreptomycin is no longer used clinically. To date dihydrostreptomycin is approved for veterinary use to treat bacterial infections.

Propionic acid (PA), also known as propanoic acid, with chemical formula C3H6O2, is an organic acid used as a food additive and found naturally on the skin and in the gastrointestinal tract. It is a byproduct of fermentation reactions and is also produced industrially from ethylene or ethanol and carbon monoxide. Propionic acid is a fungicide and bactericide, registered to controlfungi and bacteria in stored grains, hay, grain storage areas, poultry litter,and drinking water for livestock and poultry. As a food preservative, propionic acid prevents mold in bread and baked goods, and it is used as a flavoring agent in cheese and other packaged goods. The U.S. Environmental Protection Agency considers it safe and therefore, has no limitation on its use. It has been demonstrated that PA lowers fatty acids content in liver and plasma, reduces food intake, exerts immunosuppressive actions and probably improves tissue insulin sensitivity. Thus increased production of PA by the microbiota might be considered beneficial in the context of prevention of obesity and diabetes type 2. The molecular mechanisms by which PA may exert this plethora of physiological effects are slowly being elucidated and include intestinal cyclooxygenase enzyme, the G-protein coupled receptors 41 and 43 and activation of the peroxisome proliferator-activated receptor γ, in turn inhibiting the sentinel transcription factor NF-κB and thus increasing the threshold for inflammatory responses in general. Taken together, PA emerges as a major mediator in the link between nutrition, gut microbiota and physiology. The sodium salt of propionic acid was previously approved in Canada as an active ingredient in Amino-Cerv (used to treat inflammation or injury of the cervix).

Silver iodide is an inorganic compound with the formula AgI. It is used as a photosensitive agent in photography, as a local antiseptic, as a chemical intermediate, and in cloud seeding for rain-making. The major hazards encountered in the use and handling of silver iodide stem from its toxicologic properties. Effects from exposure may include skin rashes, conjunctivitis, argyria (a permanent ashen-gray discoloration of skin, conjunctiva, and internal organs), headache, fever, hypersensitivity, laryngitis, and bronchitis.

BORATE, a salt of boric acid, is used as a food additive in the European Union. This additive is authorized for use as preservatives of sturgeon eggs (caviar).

Gentamicin is an antibiotic of the aminoglycoside group, is derived by the growth of Micromonospora purpurea, an actinomycete. Gentamicin is a complex of three different closely related aminoglycoside sulfates, Gentamicins C1, C2, and C1a. Gentamicin is a broad-spectrum antibiotic, but may cause ear and kidney damage. Gentamicin binds to the prokaryotic ribosome, inhibiting protein synthesis in susceptible bacteria. It is bactericidal in vitro against Gram-positive and Gram-negative bacteria. Adverse reactions include adverse renal effects, neurotoxicity (dizziness, vertigo, tinnitus, roaring in the ears, hearing loss, peripheral neuropathy or encephalopathy), respiratory depression, lethargy, confusion, depression, visual disturbances, etc.