EXPERIMENT NO-1

OBJECT: To calibration of absorbance scale of UV spectrophotometer.

REQUIREMENTS: UV spectrophotometer, 100 ml volumetric flask beaker etc.

Principle:

• Ultraviolet and visible absorption spectrophotometer is the measurement of the absorption of monochromatic radiation by solutions of chemical substances, in the range of 185 nm to 380 nm, and 380 nm to 780 nm of the spectrum, respectively.
• The magnitude of the absorption of a solution is expressed in terms of the absorbance, A, defined as the logarithm to base 10 of the reciprocal of transmittance (T) for monochromatic radiation:

     A = log10 (Io / I)

• where Io is the intensity of the incident radiation I is the intensity of the transmitted radiation. The absorbance depends on the concentration of the absorbing substance in the solution and the thickness of the absorbing layer taken for measurement.

PROCEDURE:

• Control of Absorbance’s :
• Preparation of 0.005 M H2SO4.
• 10ml of 0.5M H2SO4 diluted to 1000ml with distilled water. Operate the instrument as above.
• Dry a quantity of potassium dichromate by heating to constant weight at 1300
• This calibration is done by Potassium Dichromate solution.
• Weigh accurately a quantity not less than 57.0 mg and not more than 63.0 mg of Potassium Dichromate and dissolve in sufficient 0.005 M Sulphuric acid to produce 1000ml.
• Tabulated the result in following format.

FORMULA:

Result:

EXPERIMENNT NO.2

OBJECT: To assay of Paracetamol by using UV spectrophotomer. 

REFERENCE:

1. Becket A. H., Stenlake J. B., “Practical pharmaceutical chemistry” CBS, publication, pp-275-276.
2. Raj K. Prasad and Rajesh Sharma “Simultaneous estimation and validation of Rabeprazole Sodium and Diclofenac Sodium in capsule dosage form”. Chem. Pharm. Res., 2010, 2(2): 186-196.
3. PD shetthi quantative analysis of drug in pharmaceutical 3rd

REQUIREMENT:  Paracetamol tablets, UV spectrophotomer, cuvette, beaker, 0.1 N HCL.

Principle: Beer-Lambert Law

• Beer's law states that for a parallel beam of monochromatic radiation passing through homogeneous solutions of equal path length the absorbance is proportional to the concentration.i.e. For solutions 1 and 2 (Absorbance 1)/(Absorbance 2) = (Concentration 1)/(Concentration 2).
• Lambert's law states that for a parallel beam of monochromatic radiation passing through homogeneous solutions of equal concentration the absorbance is proportional to the pathlength.i.e. For pathlengths A and B (Absorbance A)/(Absorbance B) = (Pathlength A)/(Pathlength B)
• The Beer-Lambert law states that for a parallel beam of monochromatic radiation passing through a homogeneous solution the absorbance is proportional to the product of the concentration and path length.

Absorbance = constant × concentration × path length

• The value of the constant depends on the substance, the solvent, the wavelength and the units used for concentration and path length. Two common methods of expressing the constant are A (1%,1cm) and molar absorptivity.

PROCEDURE:

 Protocol:

• Product name                                
• Label Claim                                   
• Average Weight                            
• Name of the Manufacturer            
• Instrument Used                            

•  Selection of Solvent
• 0.1N of HCl is select as the solvent after considering the solubility and stability factors of both drugs as well as the interference due to the excipients matrix present in tablet formulation.
•  Preparation of Standard stock Solution
• Standard stock solution of Paracetamol (PCM) having concentration 100 mg/ml is prepared by dissolving 10mg of drug in 100 ml volumetric flask using 0.1N HCl solution.
• Selection of Sampling Wavelengths:
• Concentration of 20µg/ml of PCM solution is prepared from the standard stock solution by using appropriate dilution in volumetric flasks. The solution is scanned over the

  Impressum

  Verlag: BookRix GmbH & Co. KG

  Tag der Veröffentlichung: 06.02.2021
  ISBN: 978-3-7487-7394-8
  

  Alle Rechte vorbehalten

  Widmung:
  Mr. Raj K. Prasad (Gold Medalist), M. Pharm. In pharmaceutical chemistry, Dr. Amit Rai M. Pharm., Ph.D., In Pharmaceutical Chemistry and Mr. Kuldeep Singh, M. Pharm. Pharmacology. They are presently working at Shambhunath Institute of Pharmacy, Prayagraj, India.