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Oxidation And Hydrolysis Of Acetylcysteine Biology

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Acetylcysteine is an counterpoison used for paracetamol overdose. Different trials had been chosen and conducted to guarantee the quality of the merchandise in the drug readying is within the acceptable scope as stated in the British Pharmacopoeia ( afterlife referred to as ‘the BP ‘ ) . The degree of pureness and alterations in the structure/condition of acetylcysteine can be known based on the value of specific optical rotary motion ; a negative value suggests that the compound has an anticlockwise rotary motion, and a positive value suggests otherwise.

The sum of acetylcysteine in a sample can be determined by I and Na hydrated oxide titration severally. The consequences obtained were so being analysed via HPLC analysis, where the extremums on the chromatogram reflect the degree of drosss present in the sample. On top of that, a standard add-on secret plan was constructed to find the degree of Zn in acetylcysteine. On the other manus, the weight of ‘pure ‘ acetylcysteine can besides be known based on the computation of weight loss upon drying, a low per centum allows us to presume about small to no drosss were present in the sample before drying.

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Introduction

Acetylcysteine is a derivative of the natural amino acid L-cysteine. It is a mucolytic agent and is used in combination with hypromellose to handle tear lack and impared or unnatural mucous secretion production. ( 1 ) It is besides used to handle paracetamol overdose. It acts as a dietetic addendum every bit good as it has been shown to increase the degrees of glutathione within the organic structure which is a powerful antioxidant. ( 2 ) Acetylcysteine is a white pulverization and freely soluble in H2O.

Acetylcysteine can used to handle paracetamol overdose by assisting protecting the liver and reconstruct the degrees of glutathione. It helps to adhere toxic metabolites produced from the big sum of paracetamol being metabolised. ( 2 ) The exact mechanism nevertheless is non known. It is used a mucolytic agent excessively where it helps to cut down the viscousness of the mucous secretion produced by interrupting the disulfide bonds present. ( 2 )

Below is the construction of acetylcysteine.

Acetylcysteine can undergo oxidization and hydrolysis. When oxidization occurs, a sulfur bond is formed between two sulfur atoms from two different acetylcysteine molecules. Under hydrolysis, the COCH3 is substituted with a H atom ensuing in a secondary aminoalkane.

Oxidation and hydrolysis of Acetylcysteine

In this experiment, different trials had been conducted to guarantee the quality of acetylcysteine prevarications within the acceptable scope as required in the BP. Quality control is a portion of Good Manufacturing Practice ( GMP ) to guarantee that a merchandise will be yielded following to its specifications and its degree of safeness, well-being and protection had been increased to maximum for the patients.

In this experiment, the optical rotary motions for acetylcysteine in old and newly prepared solutions were obtained utilizing a polariscope. The readings are so converted to specific optical rotary motions utilizing the equation below.

The specific optical rotary motion values straight reflect the way of rotary motion of the molecule, where a positive value would intend the molecule rotates light in a clockwise way when visible radiation is passed through it, and a negative value suggests otherwise. If zero value is obtained, it would intend the sample was a racemic mixture.

Other than that, assay for acetylcysteine was conducted every bit good to find the per centum dross of the sample. Two types of titration were used to prove the per centum of acetylcysteine in the sample which are iodine titration and Na hydrated oxide titration. Starch is used as the index for iodine titration while phenol ruddy and phenolphthalein are used in Na hydrated oxide titration. Different indexs will give different value of per centum of acetylcysteine containing in the sample due to their sensitiveness at different pH scope. Therefore, factors doing the difference in value are traveling to be discussed. Based on the chromatograms obtained through the HPLC analysis, the degree of drosss in acetylcysteine can be identified and calculated based on the extremums nowadays on the chromatograms.

The content of Zn in the acetylcysteine sample can be determined as good by utilizing the standard add-on method where a graph of optical density against concentration of Zn added into solution is plotted. From the standard add-on secret plan, the sum of Zn contained in the sample can be known and compared to the bound stated in the BP.

Weight of ‘pure ‘ acetylcysteine in sample, presuming no drosss were present in it ab initio, can besides be calculated based on the sum of weight loss upon drying where H2O is being removed from the sample via vaporization from the surface.

All these trials will give an overall decision to supply a warrant for the stableness of acetylcysteine in the readying.

Mention

[ 1 ] British National Formulary 57th Edition, 2009 ( pg 29-30, 595 )

[ 2 ] Ben Venue Laboratories. ( 2007 ) . Acetylcysteine. Available: ( hypertext transfer protocol: //www.drugs.com/pro/acetylcysteine-solution.html )

Last accessed 10th Jan 2011

[ 3 ] MPH114 Pharmaceutics I, Good Manufacturing Practice, Uni. Of Sunderland, 2009

[ 4 ] MPH215 Experiment 7 Lab Handouts, Uni. Of Sunderland, 2010

Experimental 1: Specific Optical Rotation

Method

Specific optical rotary motion: +21A° to +27A°

The optical rotary motions of the freshly prepared and old solutions of acetylcysteine were recorded. These were prepared by fade outing 1.25g acetylcysteine in a mixture of 1ml of a 10g l-1 solution of disodium edentate, 7.5ml of 1M Na hydrated oxide and sufficient assorted phosphate buffer pH 7.0 to 25ml.

Consequences

Solution

Reading ( A° )

[ I± ]

Old

-3.40

-34.00

Fresh

+2.42

+24.20

The equation below is used to happen [ I± ] ,

Where I± = reading obtained

a„“ = way length = 2dm

degree Celsiuss = concentration of sample, expressed in % w/v

Concentration of Sample, degree Celsius

1.25 g of acetylcysteine is used to do up the mixture solution of 25mL. Therefore, in 100mL of solution, the sum of acetylcysteine in it is 1.25 ten 4 = 5.0 g.

Hence, c = 5 % w/v

Calculation of [ I± ]

[ I± ] old =

= -34.00

[ I± ] fresh =

= +24.20

Discussion

3

Assign Chiral Centre as R or S

2

4

1

Assign precedence Numberss

Topographic point the H so you are looking down at it

Draw pointer from 1 through 2 to 3.

Clockwise is R and Anticlockwise is S.

Anticlockwise suggests S stereoisomer.

Chiral Centre is at the C attached to NH ( 1 ) , COOH ( 2 ) , CH2SH ( 3 ) , and H ( 4 ) .

There is merely one chiral Centre nowadays in the molecule, marked with star ( * ) . It is a non-symmetrical R-enantiomer. It may besides be called a 2R-enantiomer because the chiral Centre is located at the 2nd C in the C concatenation.

The specific rotary motions for the fresh and old samples are greatly different. This could be due to collection of the extra enantiomorphs in the solution, presence of drosss such as the growing of extremely revolving bugs or their production of revolving merchandises, or alterations of chemical construction of acetylcysteine under utmost storage conditions, e.g. direct or long term exposure to sunshine.

On the other manus, specific rotary motion for the fresh acetylcysteine sample, +24.20A° complies with the BP specification, i.e. +21A° to +27A° . This shows that there is about [ ( 100 % ) ( 24.40/27.00 ) ] = 89.63 % to [ ( 100 % ) ( 24.20/21.00 ) ] = 115.24 % of R-acetylcysteine nowadays in the sample. This may propose high pureness, but the truth of this method is strongly doubted as any extremely rotating drosss present in the solution may impact the result greatly. Therefore, other methods were enforced to increase the truth in finding of the presence of drosss.

Mentions

[ 1 ] Adapted from:

Lecture press releases of MPH 115, Prof. Roz Anderson, University of Sunderland.

Lecture press releases of MPH 115, Dr. Jonathan Harburn, University of Sunderland.

[ 2 ] Molecular Libraries Roadmap Initiative, National Center for Biotechnology Information ( NCBI ) . ( 2004 ) . Acetylcysteine – Compound Summary ( CID 12035 ) . Available at: hypertext transfer protocol: //pubchem.ncbi.nlm.nih.gov/summary/summary.cgi? cid=12035. [ Last accessed on 29 December 2010 ]

[ 3 ] British Pharmacopoeia Commission Secretariat of the Medicines and Healthcare merchandises Regulatory Agency, British Pharmacopoeia 2011 Online. Available at: hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=displayHYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” r=YoJDskQKKhYHYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” n=1HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” id=8073HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” tab=search. [ Last accessed on 29 December 2010 ]

Experimental 2: Assay- 98 % -101 % C5H9NO3S as dried stuff

Method

0.14g of the stuff was dissolved in approx 60ml of distilled H2O.

10ml of dilute hydrochloric acid was been added.

The mixture was cooled to room temperature.

10ml of K iodide solution was been added into the solution.

It was so been titrated by utilizing 0.05M I with amylum as an index

Consequences

Weight

A

Bacillus

Sample +Vial

0.9918g

1.0031g

Vial + Residual

0.8481g

0.8606g

Sum Used

0.1437g

0.1425g

A

Bacillus

Initial Volume

0.01ml

0.09ml

Concluding Volume

9.41ml

9.32ml

Iodine Used

9.40ml

9.41ml

Calculations

Sample A

Derivation of equivalent

1ml of 0.05M I2 = 16.32mg of C5H9NO3S

8.8ml of 0.05M I2 = 143.7mg of C5H9NO3S

8.8ml of 0.0476M I2 =136.8mg of C5H9NO3S

8.8ml of 0.0476M I2 = 0.1368g of C5H9NO3S

9.4ml of 0.0476M I2 = 0.1461g of C5H9NO3S

Iodine Used = 9.40ml

Mass in ( g ) = 0.1437g

Percentage output = ( theoretical yield/actual output ) x 100

( 0.1461/0.1437 ) x 100 = 101.67 % w/v

Sample B

Derivation of equivalent

1ml of 0.05M I2 = 16.32mg of C5H9NO3S

8.73ml of 0.05M I2 = 142.5mg of C5H9NO3S

8.73ml of 0.0476M I2 = 135.66mg of C5H9NO3S

9.41ml of 0.0476M I2= 146.23mg of C5H9NO3S

Iodine Used= 9.41mL

Mass in ( g ) = 0.1425g

Percentage output = ( theoretical yield/actual output ) x 100

( 146.23/142.5 ) x 100 = 102.62 % w/v

Discussion

Equation of acetylcysteine and I:

The values of the per centum pureness obtained from the experiment are 101.67 % w/v and 102.62 % w/v for the content of C5H9NO3S. Therefore, it does non follow with the B.P. bounds as the B.P scope is 98 % -101 % . The fact that we got higher per centum outputs in the check suggests that there were drosss responding in it. Acetylcysteine reacts with I to bring forth the coveted merchandise in this reaction. Acetylcysteine is prone to oxidization and besides to hydrolysis, this is what consequences in some drosss being formed. When I is dissolved in the K iodide solution and amylum is added as the index we achieve a blue/black solution at the terminal point. When I and amylum are assorted together in H2O a amylum I composite is formed which is bluish in coloring material. This alteration is due to the polyiodide ironss being formed when the amylum reacts with the iodine solution. Amylose in amylum is what is responsible for the deep blue coloring material.

Iodine is more specific if compared to that of Na hydrated oxide. This is because I will merely respond with the thiol group of acetylcysteine ( -CH2SH ) to alter the coloring material of solution from colourless to blue. Colourless solution indicates that I had been broken down to iodide ions. Iodine is more self-indicating and hence can bring forth a more dependable end point. Compared to sodium hydrated oxide, Na hydrated oxide will respond with both functional groups of acetylcysteine and hence ensuing in trouble in calculating out the right sum of acetylcysteine in the sample. So, trials have to be repeated by utilizing different indexs to obtain the right consequence. Therefore, BP prefers iodine titration instead than sodium hydroxide titration.

Mentions

[ 1 ] British Pharmacopoeia Commission Secretariat of the Medicines and Healthcare merchandises Regulatory Agency, British Pharmacopoeia 2011 Online. Available at:

hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=displayHYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” r=YoJDskQKKhYHYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” n=1HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” id=8073HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” tab=search

Last accessed: 31 December 2010

[ 2 ] hypertext transfer protocol: //antoine.frostburg.edu/chem/senese/101/redox/faq/starch-as-redox-indicator.shtml. Last Accessed: 29 December 2010

[ 3 ] Paul Hambleton, MPH 215 Lecture Notes, 2010, Uni. Of Sunderland.

Experimental 3: Assay of titration with Sodium Hydroxide

Method

a ) Approximately 0.3g acetylcysteine was accurately weighed and dissolved in about 50ml distilled H2O. The solution was so titrated with 0.1M Na hydrated oxide utilizing phenol ruddy index.

B ) Approximately 0.3g acetylcysteine was accurately weighed and dissolved in about 50ml distilled H2O. The solution was so titrated with 0.1M Na hydrated oxide utilizing phenolphthalein index.

Consequences

Using phenol red as index,

Sample

1

2

Weight of acetylcysteine + Weighing boat /g

3.7705

3.8931

Weight of acetylcysteine + Residual /g

3.4762

3.5932

Weight of acetylcysteine used /g

0.2943

0.2999

Final burette reading /mL

19.70

19.50

Initial burette reading/mL

3.00

2.50

Volume of NaOH used /mL

16.70

17.00

No.of moles of acetylcysteine = No.of moles of NaOH ( 1:1 Chemical reaction )

Molecular mass of acetylcysteine = 163.2

Concentration of NaOH = 0.1062M

Sample 1

Mass of sample used ( g ) = 0.2943

No.of moles of acetylcysteine = 1.7735 X 10-3

Weight of acetylcysteine reacted with NaOH = No. of moles of acetylcysteine X Molecular

mass

= 1.7735 Ten 10-3 Ten 163.2

= 0.2894g

Percentage of acetylcysteine in sample = X 100 %

= X 100 %

= 98.34 %

Sample 2

Mass of sample used ( g ) = 0.2999

No.of moles of acetylcysteine = 1.8054 X 10-3

Weight of acetylcysteine reacted with NaOH = No. of moles of acetylcysteine X Molecular mass

= 1.8054 Ten 10-3 Ten 163.2

= 0.2946g

Percentage of acetylcysteine in sample = X 100 %

= X 100 %

= 98.23 %

Average Percentage of Acetylcysteine in sample utilizing phenol ruddy as index

=

=

= 98.3 %

Using phenolphthalein as index,

Sample

1

2

Weight of acetylcysteine + Weighing boat /g

3.8680

3.8852

Weight of acetylcysteine + Residual /g

3.5674

3.5849

Weight of acetylcysteine used /g

0.3006

0.3003

Final burette reading /mL

20.40

34.40

Initial burette reading/mL

1.70

15.80

Volume of NaOH used /mL

18.70

18.60

No.of moles of acetylcysteine = No.of moles of NaOH ( 1:1 Chemical reaction )

Molecular mass of acetylcysteine = 163.2

Concentration of NaOH = 0.1062M

Sample 1

Mass of sample used ( g ) = 0.3006

No.of moles of acetylcysteine = 1.9859 X 10-3

Weight of acetylcysteine reacted with NaOH = No. of moles of acetylcysteine X Molecular mass

= 1.9859 Ten 10-3 Ten 163.2

= 0.3241g

Percentage of acetylcysteine in sample = X 100 %

= X 100 %

= 107.82 %

Sample 2

Mass of sample used ( g ) = 0.3003

No.of moles of acetylcysteine = 1.9753 X 10-3

Weight of acetylcysteine reacted with NaOH = No. of moles of acetylcysteine X Molecular

mass

= 1.9753 Ten 10-3 Ten 163.2

= 0.3224g

Percentage of acetylcysteine in sample = X 100 %

= X 100 %

= 107.36 %

Average Percentage of Acetylcysteine in sample utilizing phenolpthalein as index

=

=

= 107.6 %

Discussion

Equation of acetylcysteine and Na hydrated oxide:

Harmonizing to BP 2011, the per centum pureness content of acetylcysteine is runing from 98.0 % -101.0 % . Based on the consequences obtained from the experiment, the mean per centum pureness of acetylcysteine assay utilizing phenol red as index is 98.3 % . This shows that it falls within the scope of BP ‘s demand. However, compared to that of check utilizing phenolphthalein as index, the per centum pureness of the acetycysteine check is 107.6 % which is higher than the BP demand for acetylcysteine check. Both of the checks have the different per centum purenesss are due to different indexs being used in the titration. Phenol ruddy and phenolphthalein have different pH scope where phenol ruddy alterations colour from yellow to red over the pH scope 6.8-8.4 while phenolphthalein alterations from colourless to tap in the scope of pH 8.3-10.0. [ 1 ] Both of the indexs have different terminal points when hydrated oxide ions are been added to respond and take the H ions in the check. Therefore, it causes difference in clip for the check to make the index ‘s terminal point and hence impacting the consequence of the experiment where the per centum pureness of check utilizing phenol ruddy is lower than that of the check utilizing phenolphthalein as index.

Harmonizing to BP 2011,

Retention clip of drosss in acetylcysteine

Compound

Time ( min )

Acetylcysteine

About 6.4

L-cystine

About 2.2

L-cysteine

About 2.4

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

About 3.3

N, N’-diacetyl-L-cystine

About 12.0

N, S-diacetyl-L-cysteine

About 14.0

The chromatograms obtained from the HPLC analysis of a fresh solution of acetylcysteine and an old solution of acetycysteine was examined.

In cysteine 0.5mg/mL,

Peak Retention Time/ min

Predicted Compound

Area

Concentration / %

2.018

L-cystine

87001

5.2956

2.323

L-cysteine

38097

2.3189

2.650

L-cysteine

39167

2.3840

3.008

Unknown

409128

24.9029

3.207

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

1069503

65.0987

In Acetylcysteine 2.5mg/mL [ Old Sample ]

Peak Retention Time/ min

Predicted Compound

Area

Concentration / %

2.110

L-cystine

62935

0.7214

3.256

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

78046

0.8946

3.756

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

64342

0.7375

5.447

Unknown

1642356

18.8255

5.893

Unknown

1902857

21.8115

6.340

Acetylcysteine

2942118

33.7241

13.415

N, N’-diacetyl-L-cystine

1337263

15.3284

16.308

N, S-diacetyl-L-cysteine

694171

7.9569

In Acetylcysteine 8.57mg/mL [ Fresh Sample ]

Peak Retention Time/ min

Predicted Compound

Area

Concentration / %

1.930

L-Cystine

238606

0.5948

3.250

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

31861

0.0794

3.786

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

67023

0.1671

4.653

Unknown

151529

0.3778

5.023

Unknown

1433178

3.5728

6.972

Acetylcysteine

38007110

94.7507

13.623

N, S-diacetyl-L-cysteine

158211

0.3944

16.451

N, S-diacetyl-L-cysteine

25230

0.0629

Percentage Impurity =

In cysteine 0.5mg/mL,

Peak Retention Time/ min

Entire Area = 1642895

Percentage Impurity / %

Predicted Compound

Area

2.018

L-cystine

87001

5.2956

2.323

L-cysteine

38097

2.3189

2.650

L-cysteine

39167

2.3840

3.008

Unknown

409128

24.9029

3.207

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

1069503

65.0987

Percentage Impurity of L-cystine =

= 5.3 %

Percentage Impurity of L-cysteine =

= 4.7 %

Percentage Impurity of Unknown =

= 24.9 %

Percentage Impurity of 2-methyl-2-thiazoline-4-carboxylic acid =

= 65.1 %

In Acetylcysteine 2.5mg/mL [ Old Sample ]

Peak Retention Time/ min

Entire Area: 8724087

Percentage Impurity/ %

Predicted Compound

Area

2.110

L-cystine

62935

0.7214

3.256

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

78046

0.8946

3.756

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

64342

0.7375

5.447

Unknown

1642356

18.8255

5.893

Unknown

1902857

21.8115

13.415

N, N’-diacetyl-L-cystine

1337263

15.3284

16.308

N, S-diacetyl-L-cysteine

694171

7.9569

Percentage Impurity of L-cystine =

= 0.72 %

Percentage Impurity of 2-methyl-2-thiazoline-4-carboxylic acid

=

= 1.6 %

Percentage Impurity of Unknown =

= 40.6 %

Percentage Impurity of N, N’-diacetyl-L-cystine =

= 15.3 %

Percentage Impurity of N, S-diacetyl-L-cysteine =

= 8.0 %

In Acetylcysteine 8.57mg/mL [ Fresh Sample ]

Peak Retention Time/ min

Entire Area = 40113072

Percentage Impurity / %

Predicted Compound

Area

1.930

L-Cystine

238606

0.5948

3.250

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

31861

0.0794

3.786

2-methyl-2-thiazoline-4-carboxylic acid, arising in trial solution

67023

0.1671

4.653

Unknown

151529

0.3778

5.023

Unknown

1433178

3.5728

13.623

N, S-diacetyl-L-cysteine

158211

0.3944

16.451

N, S-diacetyl-L-cysteine

25230

0.0629

Percentage Impurity of L-cystine =

= 0.59 %

Percentage Impurity of 2-methyl-2-thiazoline-4-carboxylic acid

=

= 0.25 %

Percentage Impurity of Unknown =

= 4.0 %

Percentage Impurity of N, N’-diacetyl-L-cystine =

= 0.39 %

Percentage Impurity of N, S-diacetyl-L-cysteine =

= 0.063 %

There are 3 extremums assorted together in old sample where a new extremum was formed before the old extremum had completed its unit of ammunition. This may do some inaccuracy in the consequences obtained of happening the degree of drosss.

Mentions

[ 1 ] Acid Base Indicators. Available at:

hypertext transfer protocol: //www.chemguide.co.uk/physical/acidbaseeqia/indicators.html

Last accessed: 31 December 2010

[ 2 ] British Pharmacopoeia Commission Secretariat of the Medicines and Healthcare merchandises Regulatory Agency, British Pharmacopoeia 2011 Online. Available at:

hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=displayHYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” r=YoJDskQKKhYHYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” n=1HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” id=8073HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” tab=search

Last accessed: 31 December 2010

Experimental 4: Determination of Level of Zinc in Acetylcysteine:

Not more than than 10ppm Zincs

Method

1 ) 1.00g sample was dissolved in 0.001M HCL and diluted to 50ml with the same dissolver ( Solution 1 ) .

2 ) Three solutions were so been prepared for analysis containing

a ) 10ml solution 1 diluted to 20ml with 0.001M HCl

B ) 10ml solution 1 and 1ml of 5ppm zinc criterion diluted to 20ml with 0.001 M HCl

degree Celsius ) 10ml solution 1 and 2ml of 5 ppm zinc standard diluted to 20ml with 0.001M HCL.

3 ) An appropriate AA spectrophotometer was so used to mensurate the optical density of each solution at 213.8 nm giving the consequences tabulated below.

4 ) The content of Zn in the sample was calculated utilizing the method of standard add-on.

Zinc AA Results

Solution

Optical density

( a )

0.056

( B )

0.115

( degree Celsius )

0.173

Consequences

Gradient, m =

=

=

= 0.234 ppm-1

y-intercept, c = 0.056

Equation of tendency line is hence y = 0.234x + 0.056

|x-intercept| = degree of Zn in solution ( a )

Since Y = 0.234x + 0.056

At x-intercept, y = 0

ten =

ten =

ten = – 0.2393 ppm

Degree of Zn in solution ( a ) = |- 0.2393|

= 0.2393 ppm

Since 10mL of Solution 1 is diluted to 20mL to bring forth solutions ( a ) , ( B ) and ( degree Celsius ) , the degree of Zn in solution 1 hence peers to twice of that in the diluted solution, i.e. 0.2393 ppm x 2 = 0.4786 ppm.

Discussion

Standard add-on is a method used to extinguish the matrix consequence from the experiment, where in this instance matrix consequence is defined as soaking ups caused by constituents in the solution other than the analyte. For simple matrices, a standardization curve can be used, but when complex or unknown matrices are present, standard add-on method is preferred. In this trial, Zn Acts of the Apostless as the standard add-on whereas acetylcysteine remains as the analyte. From the standard add-on secret plan, extrapolation of the secret plan to the x-axis, where y=0, gives the degree of Zn in solution ( a ) . Since Solution ( a ) is made from Solution 1 via 1:2 dilution, the existent degree of Zn in the undiluted solution, Solution 1, can be determined by multiplying the degree of Zn in solution ( a ) by a 2. Therefore, the degree of Zn in acetylcysteine is 0.4786 ppm. This complies with the BP specification, i.e. non more than 10ppm.

In the BP monograph, it is besides stated that lead, Pb may be used as heavy metals trial for acetylcysteine. But a higher concentration of mention solution of lead is required, i.e. 10 ppm lead is needed. In standard add-on, the smaller the sum of standard add-on used the better, to understate perturbation in the matrix. In this instance, merely a little sum of the mention solution will be needed, but the smaller the sum, the higher the per centum mistake. Even if a bigger sum of the mention solution is used, a larger dilution factor will be used before the optical density of the sample solutions can be determined via a spechtrophotometer. Therefore, zinc trial is preferred over the lead trial in this experiment.

Mentions

[ 1 ] ( 2005 ) . McGraw-Hill Encyclopedia of Science and Technology. 5th Edition. The

McGraw-Hill Companies, Inc.

[ 2 ] British Pharmacopoeia Commission Secretariat of the Medicines and Healthcare merchandises Regulatory Agency, British Pharmacopoeia 2011 Online. Available at: hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=displayHYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” r=YoJDskQKKhYHYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” n=1HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” id=8073HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” & amp ; HYPERLINK “ hypertext transfer protocol: //www.pharmacopoeia.co.uk/bp2011/ixbin/bp.cgi? a=display & A ; r=YoJDskQKKhY & A ; n=1 & A ; id=8073 & A ; tab=search ” tab=search. [ Last accessed on 29 December 2010 ]

Experimental 5: Loss on drying: Not more so 1.0 % w/w

Method

1 ) A sample of acetycysteine was dried at 70A° degree Celsiuss in vacuo for 3 hours, the informations below were

produced.

Initial weight of acetylcysteine sample= 1.0965g

Weight after drying under specified conditions=1.0893g

2 ) The per centum loss on drying of this sample was so been calculated.

Consequences

Weight before drying- 1.0965g

Weight after drying- 1.0893g

Percentage loss on drying =

=

= 0.6566 %

Weight loss upon drying = 0.66 % w/w

Discussion

The per centum loss of acetylcysteine on drying of this sample, 0.6566 % w/w, complied with the British Pharmacopoeia specification, i.e. 1.0 % w/w. This consequence shows that merely approximately 0.6566 % of the sample consists of losable H2O, where the maintained 99.3434 % suggests that the sample is tolerably pure. However, the presence of drosss in the sample is non confirmed as drosss may be present in indissoluble signifier or might hold a boiling point much higher than that of H2O.

Cite this Oxidation And Hydrolysis Of Acetylcysteine Biology

Oxidation And Hydrolysis Of Acetylcysteine Biology. (2017, Jul 20). Retrieved from https://graduateway.com/oxidation-and-hydrolysis-of-acetylcysteine-biology-essay/

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