clase 1 - farmacopea y análisis de medicamentos

8/18/2019 Clase 1 - Farmacopea y Análisis de Medicamentos

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Clase 1 AMDDA20

La palabra Farmacopea procede

del griego y significa "cómo hacer medicamentos ".

Farmacopea:

Conjunto de especificaciones(como mo nog rafías ) que debensatisfacer los medicamentos y susmaterias primas.

Farmacopea:

• Texto oficial

• Garantizar la fabricación y circulación

de medicamentos de buena calidad

• Proteger la salud de los consumidores


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Clase 1 AMDDA20

USP29

C10H11N3O3S 253.28

Sulfamethoxazole

Benzenesulfonamide, 4-amino-N -(5-methyl-3-isoxazolyl)-N 1-(5-Methyl-3-isoxazolyl)sulfanilamide [723-46-6 ].

» Sulfamethoxazole contains not less than 99.0 percent andnot more than 101.0percent of C10H11N3O3S,

calculated on the dried basis.

Packaging and storage— Preservein well-closed, light-resistant containers

USP Reference standards — USP S ulfamethoxazole RS. USP Sulfanilamide RS.

Identification—A: Infrared Absorption .

B: Ultraviolet Absorption —

Solution: 10 µg permL.

Medium: sodium hydroxide solution (1 in 250).

Absorptivities at 257 nm, calculated on the dried basis, do not differ by more than 2.0%.

C: Dissolve about100 mgin 2 mLof hydrochloric acid,and add3 mLof sodium nitrite solution (1in 100)and1 mLof sodium hydroxide solution (1in 10)containing 10mg of 2-naphthol: a red-orange precipitate

is formed.

Melting range, Class I : between 168° and172°.

Loss on drying — Dry it at 105 for 4 hours: it loses not more than 0.5% of its weight.

Residue on ignition : not more than 0.1%.

Selenium : 0.003%, a 200-mg test specimen being used.

Sulfanilamide and sulfanilic acid—

Standard solution— Dissolve 100 mg of USP Sulfamethoxazole RS in 0.10 mL of ammonium hydroxide,

dilute with methanol to 10.0 mL, and mix.

Reference solution— Dissolve 20 mg of USP Sulfanilamide RS and 20 mg of sulfanilic acid in 10 mL of

ammonium hydroxide, and dilute with methanol to 100 mL. Transfer 2.0 mL of the solution to a 50-mL

volumetric flask, add 10 mL of ammonium hydroxide, dilute with methanol to volume, and mix.

Test solution— Dissolve 100 mg in 0.10 mL of ammonium hydroxide, dilute with methanol to 10.0 mL, and

mix.

Procedure— Apply 10 µL of the Standard solution, 25 µL of the Reference solution, and 10 µL of the Test

solution to a suitable thin-layer chromatographic plate (see Chromatography ) coated with a 0.25-mm

layer of chromatographic silica gel. Allow the spots to dry, and develop the chromatogram in a solvent system

consisting of a mixture of alcohol, n-heptane, chloroform, and glacial acetic acid (25:25:25:7) until the solvent

front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, and allow

it to air-dry. Spray the plate with a solution prepared by dissolving 0.10 g of p-dimethylaminobenzaldehyde in


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Clase 1 AMDDA20

1 mL of hydrochloric acid and diluting with alcohol to 100 mL. Sulfamethoxazole produces a spot at about

RF 0.7, sulfanilamide at about RF 0.5, and sulfanilic acid at about RF 0.1. Any spots produced by

sulfanilamide or sulfanilic acid from the Test solution do not exceed in size or intensity similar spots,

occurring at the respective RF values, produced by sulfanilamide or sulfanilic acid from the Reference

preparation (0.2%).

Organic volatile impurities, Method IV : meets the requirements.

Residual solvents : meets the requirements.

Assay— Dissolve about 500 mg of Sulfamethoxazole, accurately weighed, in a mixture of 20 mL of

glacial acetic acid and40 mL of water, and add 15 mL of hydrochloric acid. Cool to15° , and

immediately titrate with 0.1 M sodium nitrite VS, determining the endpoint potentiometrically using a

calomel-platinum electrode system. Each mL of 0.1 M sodium nitrite is equivalent to 25.33 mg of

C10H11N3O3S.

Análisis de Medicamentos

Involucra conceptos de....

Química Orgánica

• Carácter ácido-base

• Reactividad

• Valores de pKa

Química Analítica

• Metododologías:

– Aplicabilidad

– Intervalo de detección [c] – Interferentes


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Clase 1 AMDDA20

K a

K a

orina

6 10,4

pKa14 pHpH

SULFANILAMIDA

1

orina

6 10,4

pKa 14 pHpH

SULFANILAMIDA

1


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Clase 1 AMDDA20

CH3

H

CH3CH3

CH3

H

R

H

R

CH3

O

OH

OH

N CH3 ÁCIDO

BÁSICO

ANFÓTERO

NEUTRO


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Clase 1 AMDDA20

O

OH

OH

N CH3 ÁCIDO

BÁSICO

ANFÓTERO

NEUTRO

N+

OCH3

O

CH3

CH3

CH3

ÁCIDO

BÁSICO

ANFÓTERO

NEUTRO

NH

NH

O O

ÁCIDO

BÁSICO

ANFÓTERO

NEUTRO


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Clase 1 AMDDA20

N

O

CH3

O

O

CH2OH

ÁCIDO

BÁSICO

ANFÓTERO

NEUTRO

ÁCIDO

BÁSICO

ANFÓTERO

NEUTRO

ÁCIDO

BÁSICO

ANFÓTERO

NEUTRO

H

clase 1 - farmacopea y análisis de medicamentos

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