What Is Isoniazid?

Isoniazid. This product is colorless crystal, or white to off-white crystalline powder; odorless, slightly sweet and bitter; it gradually deteriorates when exposed to light. This product is soluble in water, slightly soluble in ethanol, and very slightly soluble in ether. Melting point The melting point of this product is 170-173 ° C. Isoniazid was invented in 1952. The invention of isoniazid revolutionized the treatment of tuberculosis. In this nearly 50-year history of use, although some patients have become resistant to tuberculosis bacteria, most doctors still believe that it is an indispensable main drug for the treatment of tuberculosis. It is the first-line antituberculosis drug with rifampicin, ethambutol, sterptomycin, and pyrazinamide.

Isoniazid

Isoniazid, this product is colorless crystal, or white to off-white crystal

Isonicotinic acid hydrazide, also known as 4-pyridyl hydrazide, Rimiton, is

Appearance: white crystal or crystalline powder. No smell. No smell. The taste is slightly sweet and then bitter. Meets light and fades.

Derived from the condensation of isonicotinic acid with hydrazine hydrate. Dissolve isonicotinic acid in hydrazine hydrate, add the previous batch of crude mother liquor, and distill under reduced pressure to 79-82 ° C (13.3-14.7kpa). The temperature was raised to 129-130 ° C, and the reaction was performed for 3 hours. Add half the amount of the mother liquor of the reaction solution to dilute, add activated carbon to decolorize, and filter. The filtrate was cooled to crystallize, filtered at about 10 ° C, and the filter cake was washed with a crude mother liquor to obtain a crude isoniazid. It is then recrystallized, decolorized by activated carbon, filtered, and dried to obtain a finished product. 90% yield ^[4]

Oral absorption is fast and complete, with peak plasma concentrations in 1 to 2 hours, and is widely distributed throughout body fluids and tissues, including

(1) Gastrointestinal symptoms (such as loss of appetite, nausea, vomiting, abdominal pain, constipation, etc.);

Method name: Isoniazid APIDetermination of IsoniazidRedox Titration

Scope of application: This method uses a titration method to determine the content of isoniazid in the isoniazid bulk drug.

This method is applicable to isoniazid bulk drugs.

Principle of the method: After the test sample is dissolved in water, methyl orange indicator liquid is added, and the titanate is slowly titrated with potassium bromate until the pink color disappears. The isoniazid content is calculated according to the amount of titrant used.

Reagent:

Potassium iodide

Potassium bromate titration solution (0.01667mol / L)

Dilute sulfuric acid

Starch indicator

Titrate of sodium thiosulfate (0.1mol / L)

(1) Oral: 0.1-0.3g once for adults, 0.2-0.6g once a day, 0.2-0.3g once for acute miliary tuberculosis or tuberculous meningitis, 3 times a day.

(2) Intravenous injection or intravenous drip: 0.3 ~ 0.6g once for heavy infiltrating tuberculosis, extrapulmonary active tuberculosis, etc., plus 5%

In 1912, isoniazid was originally produced by Prague

Research and development of the next generation of anti-tuberculosis drugs is underway. Clinical trials include fluoroquinolone antibiotics, as well as antibiotics such as capreomycin, cycloserine (oxazomycin), and linezolid. These drugs have been shown to be lethal to tuberculosis bacteria with multidrug resistance (MDR-TB). The vast majority of doctors still believe that isoniazid was an indispensable main medicine for the treatment of tuberculosis before the emergence of new specific drugs. For patients with drug-sensitive TB, isoniazid is also usually the first medicine prescribed by doctors. In many cases, this is the option that can save the patient's life as quickly as possible.