quantitation
1. For the quantitative determination of all drugs, alkaline hydrolysis reactions can be used. To do this, take an excess of 0.5 M sodium hydroxide solution and hydrolyze the preparations in a boiling water bath with reflux.
The excess titrated alkali solution is titrated with a 0.5 M hydrochloric acid solution.
1.1. GF X - for methyl salicylate and phenyl salicylate, the alkalimetric method of hydrolysis is used.
excess alkali and phenolates are titrated with bromocresol purple:
Indicator – phenolphthalein
1.2. GF X - for acetylsalicylic acid use the alkalimetry method without preliminary hydrolysis - a variant of neutralization at the free OH group
The drug is dissolved in ethanol neutralized and cooled to 8-10°C and titrated with 0.1 M NaOH solution (phenolphthalein indicator).
2. Bromatometric method is used for salicylic acid esters (after hydrolysis with NaOH)
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3. SFM compared to standard solution
UV spectroscopy for aspirin after alkaline hydrolysis with hydrogen peroxide. λ max=290 nm
4. Glycine in acelysine is determined by the acidimetric method of non-aqueous titration with perchloric acid.
Storage. In a well-closed container, protected from light.
Application:
1. Aspirin is used orally as an antirheumatic, anti-inflammatory, analgesic and antipyretic agent, 0.25 - 0.5 g, 3 - 4 times a day.
2. Phenyl salicylate is used orally as antiseptic for diseases of the intestines and urinary tract, 0.3-0.5 g. “Besalol”, “Urobesal”.
3. Methyl salicylate is prescribed as an antirheumatic, anti-inflammatory and analgesic for external use in the form of rubbing (sometimes mixed with chloroform and fatty oils).
Research recent years showed that aspirin in small doses has an antithrombic effect, because inhibits platelet aggregation. The possibility of using it in combination with certain amino acids for parenteral administration has been shown.
Salicylic acid amides
Osalmid Oxaphenamidum
P- hydroxyphenylsalicylamide
white or whitish-purple powder, odorless. T.pl. = 175-178°C
Receipt:
phenyl salicylate n- aminophenol osalmide
Authenticity:
1. Carry out reactions on phenolic hydroxyl with FeCI 3 (alcohol solution), a red-violet color is formed.
2. The amide group is determined from the hydrolysis products in acidic environment.
A) n- aminophenol is identified by reaction with resorcinol in an alkaline medium.
Phenyl salicylate Phenylii salicylas
Write Latin name phenyl salicylate. Write down its graphic formula in your notebook.
Underline the functional group indicating that phenyl salicylate is an ester.
Phenyl salicylate was first obtained by M. V. Nenetsky (1886). He sought to find a drug that would, while maintaining antiseptic properties phenol would not have the irritating effect of salicylic acid. To do this, he blocked the carboxyl group in salicylic acid and obtained its ester with phenol. Phenyl salicylate, passing through the stomach, does not change, but in the alkaline environment of the intestine it hydrolyzes to form sodium salts salicylic acid and phenol, which have therapeutic effect. Since hydrolysis occurs slowly, the hydrolysis products of phenyl salicylate enter the body gradually and do not accumulate in large quantities, which ensures a longer effect of the drug. This principle of introducing substances with irritating properties into the body in the form of their esters entered the literature as the “salol principle” of M. V. Nenetsky and was subsequently used for the synthesis of many drugs.
Phenyl salicylate is often used to coat pills if it is necessary for the pills to pass unchanged through the stomach and excrete medicinal substances in the intestines.
Phenyl salicylate is obtained synthetically.
Write a synthesis scheme and name the intermediate products:
Study the samples of the drug physical properties: appearance, smell. Check solubility in water, alcohol, ether, chloroform. Write down your findings in your notebook. Check to see if it dissolves
Is phenyl salicylate found in sodium hydroxide? Give an explanation from a chemical point of view.
Phenyl salicylate with camphor, menthol, thymol forms vtectic mixtures.
The melting point of phenyl salicylate is 42-43°C.
Prove the authenticity of phenyl salicylate.
1. Carry out a reaction alcohol solution phenylsalicylate: with a solution of iron (III) chloride. What coloring is observed? Why is the reaction carried out in an alcoholic medium?
2. Carry out the reaction with concentrated sulfuric acid followed by the addition of formalin. What coloring do you observe?
Explain the chemistry of the reaction; what role does sulfuric acid play here?
Why do you smell phenol?
What does formalin react with to form a pink color (aurine dye)?
Write the equations chemical reactions.
3. Dissolve about 0.1 g of the drug in 5 ml of sodium hydroxide, boil for 3 minutes, cool, add hydrochloric acid, precipitation white precipitate and the smell of phenol is felt.
Complete the reaction equations:
Swipe quantitation phenyl salicylate (GPC).
Place an exact sample of the drug in a flask, add the exact volume of a titrated sodium hydroxide solution and reflux it in a boiling water bath. Explain what process is happening.
Then titrate the excess sodium hydroxide with hydrochloric acid to a stable yellow color according to the indicator (bromocresol purple). Write the reaction equations.
Indicate the method used for the quantitative determination.
For what purpose is the drug used and why?
Phenyl salicylate hydrolyzes in the alkaline environment of the intestine and releases phenol and salicylic acid, which denature protein molecules. In the acidic environment of the stomach, phenyl salicylate does not decompose and does not irritate the stomach (as well as the esophagus and oral cavity). Formed in small intestine salicylic acid has an antipyretic and anti-inflammatory effect, and phenol suppresses pathogenic intestinal microflora, both substances disinfect urinary tract, partially excreted from the body by the kidneys. Compared to modern antimicrobial agents phenyl salicylate is significantly less active, but it is low-toxic, does not cause dysbacteriosis and other complications, and is often used in outpatient practice.
Indications
Pathology urinary tract(pyelitis, cystitis, pyelonephritis) and intestines (enterocolitis, colitis).
Method of administration of phenyl salicylate and dose
Phenyl salicylate is taken orally, 3–4 times a day, 0.25–0.5 g (often together with astringents, antispasmodics and other means).
Contraindications for use
Hypersensitivity, renal failure.
Restrictions on use
No data.
Use during pregnancy and breastfeeding
No data.
Side effects of phenyl salicylate
Allergic reactions.
Interaction of phenyl salicylate with other substances
No data.
Overdose
No data.
Trade names of drugs with the active ingredient phenyl salicylate
Combined drugs:
Phenyl salicylate + [Racementhol]: Menthol 1 g, phenyl salicylate 3 g, Vaseline oil 96 g;
Belladonna leaf extract + Phenyl salicylate: Besalol.
Gross formula
C13H10O3Pharmacological group of the substance Phenyl salicylate
Nosological classification (ICD-10)
CAS code
118-55-8Characteristics of the substance Phenyl salicylate
White crystalline powder or small colorless crystals with a faint odor. Practically insoluble in water, soluble (1:10) in alcohol and solutions of caustic alkalis, easily soluble in chloroform, very easily in ether.
Pharmacology
pharmachologic effect- anti-inflammatory, antiseptic.Hydrolyzing in the alkaline contents of the intestine, it releases salicylic acid and phenol, which denature protein molecules. Phenyl salicylate does not disintegrate in the acidic contents of the stomach and does not irritate the mucous membrane of the stomach (as well as the oral cavity and esophagus). Phenol formed in the small intestine suppresses pathogenic intestinal microflora, and salicylic acid has anti-inflammatory and antipyretic effects; both compounds, partially excreted from the body by the kidneys, disinfect the urinary tract. Phenyl salicylate is significantly less active compared to modern antimicrobials, but it is low-toxic, does not cause dysbacteriosis and other complications, and is often used in outpatient practice.
Application of the substance Phenyl salicylate
Diseases of the intestines (colitis, enterocolitis) and urinary tract (cystitis, pyelitis, pyelonephritis).
Phenylium salicylicum Salolum Salol
Salicylic acid phenyl ester
C 13 H 10 O 3 M. c. 214.22
Description. White crystalline powder or small colorless crystals with a faint odor.
Solubility. Almost insoluble in water, soluble in alcohol and solutions of caustic alkalis, easily soluble in chloroform, very easily in ether.
Storage. In a well-closed container, protected from light. Antiseptic, used internally
517. Phenobarbitalum
Phenobarbital
Luminalum Luminal
5-Ethyl-5-phenylbarbituric acid
C 12 H 12 N 2 O 3 M. c. 232.24
Description. White crystalline powder, odorless, slightly bitter taste.
Solubility. Very slightly soluble in cold water, difficult to dissolve in boiling water and chloroform, easily soluble in 95% alcohol and in alkali solutions, soluble in ether.
Storage. List B. In well-sealed orange glass jars.
Highest single oral dose 0.2G.
The highest daily dose orally is 0.5G.
Sleeping pill, anticonvulsant.
521. Phenoxymethylpenicillinum
Phenoxymethylpenicillin
Penicillinum V Penicillin fau(V)
C 16 H 28 N 2 O 5 S M.v. 350.40
Phenoxymethylpenicillin is a phenoxymethylpenicillic acid produced by Penicilimm notatum or related organisms or obtained by other methods and has antimicrobial effects. The content of the amount of penicillins in the preparation is not less than 95% and the content of C 16 H 28 N 2 O 5 S is not less than 90% in terms of dry matter.
The average value of the activity found must be at least 1610 U/mg in terms of dry matter.
Description. White crystalline powder, sourish-bitter taste, non-hygroscopic. Stable in slightly acidic environments. It is easily destroyed by boiling in alkali solutions, under the action of oxidizing agents and penicillinase.
Solubility. Very slightly soluble in water, soluble in ethyl and methyl alcohols, acetone, chloroform, butyl acetate and glycerin.
Storage. List B. In a dry place, at room temperature.
For doses see page 1029.
Antibiotic.
519. Phenolphthaleinum
Phenolphthalein
a,a-Di-(4-hydroxyphenyl)-phthalide
C 20 H 14 O 4 M. c. 318.33
Description. White or slightly yellowish fine-crystalline powder, odorless and tasteless.
Solubility. Very slightly soluble in water, soluble in alcohol, slightly soluble in ether.
Storage. In a well-closed container.
Laxative.
531. Physostigminisalicylas
Physostigmine salicylate
Physostigminum salicylicum
Eserinum salicylicum
C 15 H 21 N 3 O 2 C 7 H 6 O 3 M. c. 413.5
Description. Colorless shiny prismatic crystals. They turn red when exposed to light and air.
Solubility. Slightly soluble in water, soluble in alcohol, slightly soluble in ether.
Storage. List. A. In well-closed orange glass jars, protected from light.
The highest single dose under the skin is 0.0005 g.
The highest daily dose under the skin is 0.001 g.
Anticholinesterase, mystical remedy. Used in the form of eye drops and ointments. In rare cases, it is injected under the skin.
Sterilization. Solutions are prepared ex tempore aseptically or subjected to tindization.
526. Phthalazolum
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