Albumin is the most abundant protein found in human plasma and is capable of carrying and transporting drugs (like zafirlukast) throughout the body. In vivo research indicates that zafirlukast has low blood-brain barrier penetration. The blood-brain barrier is a protective system that prevents many chemicals from entering the brain. Metabolism
Zafirlukast undergoes extensive hepatic metabolism into inactive metabolites. Zafirlukast is primarily metabolized by the enzyme CYP2C9 to a hydroxylated metabolite. Elimination
Zafirlukast is primarily cleared through biliary excretion at a rate of 20 liters/hour. Zafirlukast is undetectable in urine. The mean terminal half-life ranges 8–16 hours, following linear kinetics up to doses of 80 mg.

Pharmacogenomics
LTC4 synthase
Genetic polymorphisms in the LTC4 synthase promoter may predict response to zafirlukast. The single-nucleotide polymorphism (SNP) A444C (the wild-type DNA base adenine, at the 444th position on the gene, is mutated; cytosine is there instead), which is associated with a severe asthma phenotype, has been shown to decrease the clinical response to zafirlukast (both when the genetic alteration was heterozygous or homozygous). CYP2C9
Zafirlukast is metabolized through the hepatic enzyme CYP2C9. SNPs that decrease the function of CYP2C9 (such as CYP2C9*3 and CYP2C9*13) may decrease the hepatic clearance of zafirlukast, leading to increased exposure of zafirlukast. Notably, the CYP2C9*3 polymorphism is more commonly encountered in people of south/central Asian ancestry (10.165%) compared to people of Caucasian (7.083%), African American (1.170%), African (1.033%), middle eastern (9.312%), and east Asian (3.365%) ancestry. Chemistry
Synthesis
Zafirlukast can be synthesized by the following method:

Physiochemical properties
Pure zafirlukast is described as a fine, white to pale yellow, amorphous powder.
Typically, patients with minor depression were treated by watchful waiting, prescribed antidepressants, and given brief supportive counseling, but Problem-Solving Treatment for Primary Care (PST-PC) is a Cognitive-Behavioral Therapy that has gained popularity. In one study, PST-PC and Paroxetine, an antidepressant, were shown to be equally effective in significantly reducing symptoms. In another study, PST-PC was compared with the more typical care of the time and shown to reduce symptoms more quickly. Although the use of antidepressants has been widely used, not all agree that it is an appropriate treatment for some minor depression disorder settings.Another alternative that has been researched is the use of St. Johns wort (Hypericum perforatum). This herbal treatment has been studied by various groups with various results. Some studies show evidence of the treatment being helpful to treat minor depression, but others show that it does no better than the placebo. History
At its core, minor depressive disorder is the same illness as major depressive disorder with its symptoms being less pronounced. This ties its history closely to that of major depressive disorder. Depression in the past has largely been shrouded in mystery, as its causes and appropriate treatment were largely unknown. By the 1950s, it was clear that depression could be both a mental and largely physical disease, thus being able to be treated through both psychotherapy and medication. When the DSM-IV-TR was created and major depressive disorder was spelled out more clearly, there still seemed to be an uncategorized range of depression.