Isoproterenol

Question 1

What is Isoproterenol?

Answer 1

adrenergic bronchodilator (B1/B2 agonist)

Question 2

How does Isoproterenol work?

Answer 2

The compound relaxes the smooth muscle in the lungs and opens airways to improve breathing.

Question 3

What is it used to treat?

Answer 3

• asthma
• chronic bronchitis
• emphysema
• other lung diseases

-relieve cough, wheeze, shortness of breath and troubled breathing by increasing the flow of air through the bronchial tubes.

Question 4

In Canada, what is Isoproterenol available as?

Answer 4

an injection

Question 5

In pharmaceutical analysis, a measured signal cannot be interpreted on its own but is often ______

Answer 5

calibrated

Question 6

What does calibration do?

Answer 6

Calibration enables the analysts to establish the relationship between values of quantities indicated by a measuring instrument, values represented by a material measure or a reference material, and the corresponding values realized by standards.

Question 7

What is relative calibration?

Answer 7

referred to measurements that are evaluated by comparison with those made on standards or references

Question 8

What is absolute calibration?

Answer 8

can be evaluated without comparative measurements, but rely instead on fundamental physical and chemical constants and principles

Question 9

In pharmaceutical analysis, most quantitative measurements use _______ calibration models, while instrumentation calibrations are likely categorized as an ______ calibration

Answer 9

relative

absolute

Question 10

What is one-point calibration?

Answer 10

It utilizes only one standard as a comparison value. In this instance, it is presumed that this standard is sufficiently reliable and reproducible, and a zero measurement (zero mass, amount or concentration) will produce a zero (or a very well-known value other than zero) response. Between these two values at intermediate mass of the analyze, a linear interpolation is assumed, but no extrapolation beyond the value of the standard is recommended.

Question 11

What is a multiple-point calibration?

Answer 11

It utilizes more than three different standards (other than zero) to generate the comparison range, which is also considered more accurate and reliable than one-point calibration, because measurement variation is minimized through multiple interpolations. Extrapolation beyond the values of the standards could be reasonably used for calculations as long as linear correlation among standards is satisfactory.

The linear relationship is usually expressed in the following mathematical equation is

y = mx + b

Question 12

The absorption of electromagnetic radiation of wavelengths between ____ and ____nm by molecules can be employed for both qualitative and quantitative drug analysis.

Answer 12

200 and 800

Question 13

The relationship between the concentration of an analyte and the intensity of its light absorption is thus the basis of ________

Answer 13

spectrophotometry

Question 14

Why is spectrophotometry used extensively in drug analysis?

Answer 14

Bc a wide variety of pharmaceutical substances absorb radiation int he near-UV (200-380 nm) and visible (380-800 nm) regions of electromagnetic spectrum

Question 15

What are some major strengths of UV/visible spectrophotometry ?

Answer 15

1) an easy, inexpensive and robust analytical approach for precise quantitative measurement of drugs in formulations
2) a routine method for physical and chemical characterization of drugs in preformulation and formulation

Question 16

What are some limitations of UV/visible spectrophotometry ?

Answer 16

1) assay selectivity is somehow low, because it depends on the chromophore (extended systems of double bonds) of individual compounds
ex. a collared drug with an extended chromophore is more distinctive than a drug with a simple benzene ring chromophore

2) analysis of mixtures is difficult because two compounds may have maximum absorbance at the same wavelength

Question 17

Absorption of radiation by a molecule is mainly governed by two factors. What are they?

Answer 17

• the structure of the chemical molecule

- the wavelength of the radiation

Question 18

_____ wavelength UV radiation < 150 nm can cause the strongest bonds in organic molecules to break and thus is very damaging to living organisms.

Answer 18

Short

Question 19

Spectrophotometry uses ______ wavelength UV radiation (>200 nm) for analysis, where weaker bonds in molecules can be excited.

Answer 19

longer

Question 20

When more double bonds are present in a molecular structure, absorption takes place at _____ wavelengths and with greater intensity.

Answer 20

longer

Question 21

What law is used to describe the absorption of radiation by the solution of the compound?

Answer 21

Beer-Lambert Law

Question 22

What is Beer-Lambert Law?

Answer 22

log lo/lt = A = E b c

lo = the intensity of incident radiation
lt = the intensity of transmitted radiation

A = absorbance (measure of the amount of light absorbed by the sample)

E = a constant known as the molar extinction coefficient (the absorb of a 1 M solution of the analyte)

b = the path length of the cell in cm (usually in 1 cm)

c = the concentration of the analyte (mol/litre)

Question 23

In pharmaceutical products, what are drug concentrations and amounts expressed in?

Answer 23

grams or milligrams instead of moles

Question 24

How is the Beer-Lamber Law written to reflect this?

Answer 24

A = A(1%, 1cm) b c

Where:
A = the measured absorbance

A(1%, 1 cm) = the absorbance of a 1% (1g/100mL, w/v) solution in a 1 cm cell

b = the path length of the cell in cm (1 cm)

c = the concentration of the analyte (g/100 mL)

Question 25

With the known values of A(1%, 1 cm) for drug substances, drug concentration of a particular preparation can therefore be calculated from what equation ?

Answer 25

c = A / A(1%, 1 cm)

Question 26

List the 3 basic components in a UV/visible spectrophotometer

Answer 26

- light sources - monochromator - optics

Question 27

Describe: | Light Sources

Answer 27

A deuterium lamp for the UV (190-350nm) light wavelength and a quartz halogen or tungsten lamp for the visible (350 - 900 nm) light wavelength

Question 28

Describe: | Monochromator

Answer 28

It disperses the light into its constituent wavelengths that are further selected by the slit. A monochromator can also rotate so that a range of wavelengths is passed through the sample as the instrument scans across the spectrum of the test compound

Question 29

Describe: | Optics

Answer 29

It is designed to split the light beam so that the light passes through two sample compartments. In such an instrument, a blank solution (standard) is used to correct the reading or spectrum of the sample; this blank is usually the solvent tin which the sample is dissolved

Question 30

List 3 examples of UV/visible spectrophotometry use in pharmaceutical analysis

Answer 30

- partition coefficient - solubility - drug release

Question 31

Describe: | Partition Coefficient

Answer 31

The partition coefficient of a drug between water and an organic solvent may be determined by shaking the organic solvent and the water layer together, and determining the amount of drug in either the aqueous or organic layer by UV spectrophotometry

Question 32

Describe: | Solubility

Answer 32

The aqueous solubility of a drug may be simply determined by shaking the excess of the drug in water until equilibrium is reached and then using UV spectrophotometry to measure the concentration of the rug that has gone into solution

Question 33

Describe: | Drug Release

Answer 33

Samples of drug dissolution testing are collected at different time intervals, and the concentration of the drug in each sample is measured using UV spectrophotometry. This approach is applicable only to simple tablet preparations in which excipients do not interfere with the active ingredient at its maximum detection wavelength. Otherwise, sample pretreatment (extraction) or chromatographic separation will be needed before UV detection

Question 34

List other types of spectrophotometry

Answer 34

1) Infared (IR) Spectrophotometry | 2) Atomic Spectrophotometry

Question 35

Describe Infared (IR) Spectrophotometry

Answer 35

the use of electromagnetic radiation ranging between 2500 and 20000 nm for structural confirmation

Question 36

Describe atomic spectrophotometry

Answer 36

the use of thermal excitation to atoms so that they emit light and radiation emitted is measured, which is normally used in control of ions such as sodium, potassium, and lithium in raw materials and formulations

Question 37

Lab procedure: | Describe your visual observation of Isoproterenol HCl injection

Answer 37

clear, no foreign substances

Question 38

Describe the preparation of: | Standard stock solution

Answer 38

- Pipette 10 mL of pre-prepared standard solution, containing 1 mg/mL of isoproterenol hydrochloride to a 200 mL volumetric last, dilute with water to volume, mix completely - This is your STANDARD STOCK SOLUTION

Question 39

Describe the preparation of: | Final calibration solutions

Answer 39

-Pipette 14, 16, 18, 20, and 22 mL of this solution into 5 separate 25 mL volumetric flasks and ADD -0.5 mL of freshly-prepared ferrous sulphate citrate solution -2.0 mL of amino acetate buffer to each flask -Allow to stand for 20 mins (CRITICAL STEP) then dilute to 25 mL with water. Mix well. -These five solutions are your final calibration solutions

Question 40

Describe the preparation of: | Stock test solution

Answer 40

- Carefully open the isoproterenol injection vial, transfer the 2 mL injection solution to a small test tube using the syringe/needle. - Accurately pipette 1.0 mL of the injection into a 100 mL volumetric flask, dilute with distilled water to the volume. - Mix well -This is your stock test solution

Question 41

Describe preparation of: | Final test solution

Answer 41

- Accurately pipette 20 mL of the above dilute solution into a 25 mL volumetric flask. - Add 0.5 mL of freshly prepared ferrous sulphate citrate solution - Add 2 mL of amino acetate buffer - Allow this to stand for 20 minutes (Critical step) and then dilute to 25 mL with water. - Mix well -This is your final test solution

Question 42

Describe the sample measurement using the spectrophotometer

Answer 42

- Measure both your calibration solutions and your test solution with a spectrophotometer at 540 nm (visible wavelength) at the same time - When transferring the calibration samples, start from the lowest concentration first (can use the same plastic disposable pipette for all calibration samples) - Use a new clean plastic disposable pipette for the test sample - Use distilled water for the blank cell - Record absorbance readings for all testing samples

Question 43

go over calculations

Answer 43

ok