Fipronil is a member of the phenyl pyrazole class of pesticides, which are principally chemicals with a herbicidal effect. Fipronil, however, acts as an insecticide with contact and stomach action. Fipronil is an extremely active molecule and is a potent disruptor of the insect central nervous system via the (-aminobutyric acid (GABA) regulated chloride channel. Fipronil is classed as a WHO Class II moderately hazardous pesticide. Cutaneous skin reactions appear to be the most common adverse drug experiences reported for fipronil in dogs and cats.Animals exposed to large doses of fipronil via accidental oral absorption are expected to display seizures, and neurological and hepatic function should be monitored. There appear to be no reported interactions between fipronil and approved companion animal drugs and ectoparasiticides.

Spinosad is a natural mixture of pediculicidal tetracyclic macrolides—spinosyn A and spinosyn D in the ratio of 5:1. It is derived from species of actinomycetes bacteria - Saccharopolyspora spinosa and is a bacterial waste product produced by fermentation on a nutrient food source. It has since long been used as a pesticide and classified by the US Environment Protection Agency as a reduced risk pesticide product. Spinosad has a high level of efficacy for lepidopteran larvae, as well as some Diptera, Coleoptera, Thysanoptera, and Hymenoptera, but has limited to no activity to other insects and exhibits low toxicity to mammals and other wildlife. Spinosad overstimulates nerve cells by prolonging electrical impulse across synapses by acting like acetylcholine. After periods of hyperexcitation, lice become paralyzed and die. Recently, FDA has approved the topical suspension of spinosad 0.9% for treatment of head lice infestation in patients four years of age and older. It is both pediculicidal and ovicidal.

Permethrin is a synthetic pyrethrin derivative acts as a neurotoxin by depolarizing the nerve cell membrane. Permethrin disrupts the sodium channel current by which membrane repolarization is regulated resulting in fatal paralysis of the nerves in the exoskeletal respiratory muscles of susceptible arthropods, including lice and mite. Permethrin is sold under brand names NIx and Elimite to treat pediculosis, scabies and demodicidosis.

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.

Dexmedetomide (biologically active dextroisomer of medetomidine) is an alpha2-adrenergic agonist which was approved by FDA for the sedation purposes. Upon administration the drug activates the alpha2 receptors thus inhibiting the release of norepinephrine and terminating the propagation of pain signals. Also it inhibits sympathetic activity and thus can decrease blood pressure and heart rate.

Moxidectin is a semi-synthetic methoxime derivative of LL F-2924α, commonly referred as F-alpha or nemadectin F-alpha is a product of fermentation of Streptomyces cyaneogriseus subsp. noncyanogenus, a bacterial organism isolated in 1983 from a sample of sand from Victoria, Australia. Moxidectin is a potent, broad-spectrum endectocide with activity against a wide range of nematodes, insects and acari. The compound acts by binding to ligand-gated chloride channels, more specifically the subtypes that are gamma-aminobutyric (GABA) mediated and glutamate-gated. The consequence of Moxidectin binding and activation is an increased permeability, leading to an influx of chloride ions and flaccid paralysis of the parasite leading to death. The macrocyclic lactones probably act by binding to and opening glutamate-gated chloride channels found only in neurons and myocytes of invertebrates. Because moxidectin is very lipophilic, it becomes highly concentrated in the serum. When the concentration of moxidectin in the serum is high, moxidectin is able to cross the blood-brain barrier. Once it is in the central nervous system, a macrocyclic lactone stimulates the synaptic secretion of the inhibitory neurotransmitter, GABA. By binding at the receptor site, GABA causes influx of chloride ions into neurons, causing the neurons to become hyperpolarised, which in turn, causes diminution in neuronal activity, resulting in sedation and relaxation of the skeletal muscles. Signs displayed by foals with moxidectin toxicity included dyspnoea, depression, ataxia, weakness, coma and seizures. In a Phase 3 study compared the efficacy, safety and tolerability of moxidectin and ivermectin in subjects infected with Onchocerca volvulus, which is the parasite that causes river blindness.

BENAZEPRIL, (±)- is an impurity referred to as Related Compound B, which is a diastereomer of benazepril, an ACE inhibitor, under the brand name Lotensin used primarily in treatment of hypertension, congestive heart failure, and heart attacks, and also in preventing the renal and retinal complications of diabetes. BENAZEPRIL, (±)- is used as USP Reference Standard.