comparative study for percentage purity …

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Naeem et al. World Journal of Pharmacy and Pharmaceutical Sciences

COMPARATIVE STUDY FOR PERCENTAGE PURITY

DETERMINATION OF DIFFERENT BRANDS OF PARACETAMOL

TABLETS AVAILABLE IN THE LOCAL MARKET BY UV-

SPECTROSCOPY AND TITRATION METHODS

Khoo Jing Han, Nabila Perveen and Naeem Hasan Khan*

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, AIMST University, Bedong,

Kedah D.A., Malaysia.

INTRODUCTION

Paracetamol is also known as acetaminophen. Its systematic (IUPAC)

name is N-(4-hydroxyphenyl) ethanamide or N-(4-hydroxyphenyl)

acetamide. In some contexts, it is simply abbreviated as APAP. In

1893, it was firstly introduced into medicine by Von Mering. It is a

popular over-the-counter drug.[1-4]

The structure of paracetamol is

shown in Figure 1. It consists of a benzene ring core, substituted by

one hydroxyl group and the nitrogen atom of an amide group in the

para (1,4) pattern. The amide group is acetamide (ethanamide). The

chemical formula of paracetamol is C8H9NO2.

Figure. 1: N-(4-hydroxyphenyl) ethanamide.

Paracetamol is not only a mild analgesic but also exhibit antipyretic and weak anti-

inflammatory activities. It is also a major ingredient in some cold and flu remedies. In

combination with opioid analgesics, it can also be used in managing severe pains as in cancer

and post-surgical. Paracetamol has become a common household drug as it can be obtained

without a prescription. some cold and flu remedies. In combination with opioid analgesics, it

WORLD JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES

SJIF Impact Factor 7.421

Volume 8, Issue 7, 1664-1683 Research Article ISSN 2278 – 4357

*Corresponding Author

Prof. Dr. Naeem Hasan

Khan

Department of

Pharmaceutical Chemistry,

Faculty of Pharmacy,

AIMST University, Bedong,

Kedah D.A., Malaysia.

Article Received on

14 May 2019,

Revised on 05 June 2019,

Accepted on 26 June 2019

DOI: 10.20959/wjpps20197-14241


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can also be used in managing severe pains as in cancer and post-surgical. Paracetamol has

become a common household drug as it can be obtained without a prescription.[1,5,6]

Paracetamol is official in different pharmacopeia. Some pharmacopeias have listed different

dosage form of paracetamol such as tablet, capsules, drops, elixirs, suspension and

suppositories. Hence, paracetamol can be used either by orally or rectally, and it also

available by injection into a vein. It is generally safe at therapeutic doses, 1000 mg per single

dose and up to 4000 mg per day for adults.[1,4,7]

Paracetamol always compared with other drugs such as aspirin and non-steroidal anti-

inflammatory drugs (NSAIDs). In fact, some sources classified paracetamol as a type of

NSAID by stating both drugs have same mechanism involving the inhibition of prostaglandin

synthesis cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Recently, some

studies found that paracetamol is highly selective for COX-2.[4,7,8]

However, some sources

also stated that paracetamol is different with NSAID by claiming that paracetamol does not

have anti-inflammatory activity.[6,8,9]

To date, the mechanism of action of paracetamol is not

totally understood. Paracetamol’s analgesic effects may arise from inhibition of prostaglandin

synthesis in central nervous system. The peripheral anti-inflammatory activity of paracetamol

is usually limited due to the high level of peroxides present in inflammatory lesions.[1,10]

Moreover, paracetamol also exhibit antipyretic activity. This action occurred at the level of

the hypothalamus to reduce pyrogen-initiated alterations in body temperature by inhibiting

prostaglandin synthesis.[1,5]

Nowadays, deliberate or accidental overdoses of paracetamol are

not uncommon due to its wide availability. Overdoses of paracetamol can lead to potentially

fatal liver damage, hepatic necrosis, renal failure and acute gastro intestinal problems,

especially when the concentrations in serum exceeds 150 μg / ml after 4 hours ingestion.

Beyond the toxicity effect mentioned above, serious skin rashes may rarely occur.[3,7,10]

Hepatic toxicity starts with plasma levels of paracetamol in the 120 μg / ml range 4 hours

after the ingestion.[6]

Moreover, an acute damage will be occurred when plasmatic

paracetamol levels up to 200 μg / ml 4 hours after the ingestion.[1,3]

In fact, there are some

cases reported by some rare individuals who had taken a normal dose of paracetamol then the

same hepatic toxicity of overdose had produced. The risk is increased for those who had

drinking alcohol.[1,12]

Reason and Method of Assay of Paracetamol: Recently, the consumption of paracetamol

for therapeutic purposes is increased. This increases the probability of overdose of


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paracetamol which can lead to hepatic damage and other harmful effects. Thus, the

determination and quality control of different brands of paracetamol is important.[3,7]

Nowadays, the production of counterfeit and substandard medicines is rising. This makes

quality of pharmaceutical products become a global concern. All counterfeit medicines are

not achieved the requirement of standard medicine. This is because the manufacturing

process and composition of these drugs in unpredictable. These drugs may cause therapeutic

failure and even worst, harmful effects to people consumed. According to World Health

Organization (WHO), substandard medicines are genuine medicines produced by legitimate

manufacturers that do not meet the quality specifications. These drugs also can cause toxic

effects to patients. Thus, it is vital to distinct the counterfeit medicines and other kinds of

substandard medicines out of market for the quality of treatment patients receive. The quality

of marketed drugs determines the well-being of patient.[6,13]

There are many analytical methodologies that can be used for assay of paracetamol such as

titrimetry, fluorimetry, colorimetry, UV-spectrophotometry, quantitative thin-layer

chromatography (TLC), high-performance liquid chromatography (HPLC) and gas

chromatography (GC). These methods can be used for analysis of paracetamol, whether alone

or in combination in pharmaceuticals.[8,14,15]

However, Indian Pharmacopoeia and British

Pharmacopoeia recommend titrimetric and UV spectrophotometric assay method for

paracetamol in bulk or tablet formulations. Thus, these two methods were used in the present

research work. Most common availability of paracetamol is in the form of tablet containing

500 mg paracetamol per tablet and this concentration paracetamol was used in present

work.[8,16]

According to British Pharmacopoeia, assay of paracetamol is preferably carried out by

tritration method. Paracetamol is determined by titrimetric method with ammonium cerium

(IV) sulphate.[1]

The UV spectrophotometric methods are also frequently used in quality

control testing and ordinary laboratories due to its broad availability and suitability. This is

because this method is simple, sensitive, reliable, rapid and low cost.[3,7,15,17,18]

Objectives

The objectives of the present study is to evaluate the percent purity of different brands of

paracetamol tablets available in local market (Sungai Petani, Kedah D.A., Malaysia) by using

UV spectrophotometric method and comparing with the titration method and also to

determine which method has proved to be more accurate.


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METHODOLOGY AND EXPERIMENTAL

Collection of Paracetamol Tablets and Preparation of Paracetamol Powders

Seven different brands of Paracetamol tablets were purchased on 15 October 2018 from 3

pharmacy outlets in Bedong, Sungai Petani, Kedah D.A., Malaysia. These seven different

brands were named as A, B, C, D, E, F, and G in the present research. Their further

description has been recorded in Table 1. The standard paracetamol powder was obtained in

the main laboratory of Faculty of Pharmacy, AIMST University for comparison. Each

brand’s 20 paracetamol tablets were weighed. Each weight of tablet was noted. Then the

average weight of each brand was noted.

The 20 paracetamol tablets of each brand were crushed into powder with the help of mortar

and pestle. The powder was kept inside a re-sealable plastic bag to avoid the powder to

contact with moisture which may cause the drug to denature. The re-sealable plastic bags

were labelled clearly with the name and the crushing date. These powders were kept in cool

and dry place.

Table. 1: Different brands of Paracetamol tablets.


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Assay of Paracetamol tablets by using UV spectrophotometric method

20 tablets were weighed and the average weight noted. 0.5 g of paracetamol was poured into

250 ml volumetric flask. 50 ml of the 0.1N sodium hydroxide (NaOH) was added. The

mixture was diluted to 100 ml with water and shaked for 15 minutes. The volume of the

mixture was made up with distilled water. This is solution A. Solution A was filtered. 5 ml of

solution A was pipetted out into 50 ml volumetric flask and made up volume with distilled

water. This was solution B. 5 ml of Solution B was pipetted out into 50 ml volumetric flask

and made up volume with distilled water. This was solution C. 5 ml of 0.1 N NaOH was

pipetted out into 50 ml volumetric flask and made up volume with distilled water. This was

blank. The spectrophotometer was switched on and allowed to stabilize for 15 minutes.

Baseline correction was done with using blank and the absorbance of the resulting solution C

was measured at ʎ max257 nm.

Assay of Paracetamol tablets by using titration method

Standardization of 0.1 N ceric ammonium sulphate

About 0.2 g of arsenic trioxide (which was previously dried for about an hour) was accurately

weighed and transferred into a 500 ml conical flask. The inner walls of the flask were washed

with 100 ml of water and mixed thoroughly. Then 300 ml of diluted sulphuric acid, 0.15 ml

of osmic acid, 0.1 ml of ferroin sulphate as indicator were added. Titration was carried out

against 0.1 N ceric ammonium sulphate until pink colour of solution changed to pale blue or

yellowish green colour.

Factor

Each ml of 0.1 N ceric ammonium sulphate is equivalent to 4.946 g of arsenic trioxide.


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Assay of Paracetamol

0.3 g of given sample was dissolved in a mixture of 10 ml of water and 30 ml of 1M

sulphuric acid. The mixture was refluxed for 1 hour, cooled and diluted to 100 ml with water.

20 ml of the above solution was added with 40 ml of water, 40 g of ice cubes, 15 ml of 2 M

hydrochloric acid and 0.1 ml of ferroin solution were added. The mixture was titrated with

0.1 N ceric ammonium sulphate until a yellow colour was obtained. A blank titration was

carried out.

RESULT AND OBSERVATION

Average weight of different brands of paracetamol are shown in Table 2..This table shows

that brand E had the highest weight (688.68 mg) per tablet while brand C had the lowest

weight (559.155 mg) per tablet. The average weight for brand A, B, D, F and G were 595.93

mg, 594.355 mg, 605.015 mg, 601.09 mg and 570.265 mg per tablet respectively. Table 3

and table 4 indicates the uniformity of Paracetamol tablets and absorbance of different brands

of Paracetamol tablets respectively.

Table. 2. Average weight of different brands of Paracetamol.

No. Brand

Weight (mg) A B C D E F G

1 600.0 593.0 547.3 601.3 679.5 605.1 576.0

2 599.3 594.3 579.6 612.3 697.7 604.4 563.2

3 599.8 596.6 556.0 597.8 675.5 605.4 565.0

4 597.4 596.0 558.7 599.5 688.1 604.7 573.1

5 605.9 599.0 563.6 608.5 692.3 599.3 573.5

6 598.7 591.1 559.4 602.0 692.3 600.2 568.8

7 606.7 578.2 561.2 609.9 696.1 586.9 566.8

8 593.9 596.8 558.6 604.4 688.7 609.4 574.1

9 597.1 586.9 547.2 599.6 685.9 609.3 576.4

10 592.6 599.3 554.3 601.8 683.0 595.6 572.2

11 592.4 593.9 558.3 610.6 678.8 601.8 573.3

12 594.2 592.8 549.8 594.9 701.2 596.9 572.5

13 599.3 592.9 585.8 604.0 690.4 604.7 573.6

14 596.0 594.7 557.4 607.5 691.1 604.8 568.1

15 598.2 593.5 553.9 601.9 692.3 603.8 567.4

16 590.8 597.0 558.0 615.2 693.3 600.6 574.4

17 596.4 598.3 559.6 611.6 677.8 586.6 563.2

18 586.2 587.4 564.7 597.2 673.8 601.7 564.2

19 579.7 601.8 549.3 610.1 707.6 601.3 572.0

20 594.0 603.6 560.4 610.2 688.2 599.3 567.5

Average

weight 595.93 594.355 559.155 605.015 688.68 601.09 570.265


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Table. 3: Uniformity of weight of Paracetamol tablets.

No.

Brand A B C D E F G

Average

Weight (mg)

Deviation (%)

595.93 594.355 559.155 605.015 688.68 601.09 570.265

1 0.68 -0.23 -2.12 -0.61 -1.33 0.67 1.01 0.68

2 0.57 -0.01 3.66 1.2 1.31 0.55 -1.24 0.57

3 0.65 0.38 -0.56 -1.19 -1.91 -0.72 -0.92 0.65

4 0.25 0.28 -0.08 -0.91 -0.08 0.6 0.5 0.25

5 1.67 0.78 0.79 0.58 0.53 -0.3 0.57 1.67

6 0.46 -0.55 0.04 -0.5 0.53 -0.15 -0.26 0.46

7 1.81 -2.72 0.37 0.81 1.08 -2.36 -0.61 1.81

8 -0.34 0.41 -0.1 -0.1 0.03 1.38 0.67 -0.34

9 0.2 -1.25 -2.14 -0.9 -0.4 1.37 1.08 0.2

10 -0.56 0.83 -0.87 -0.53 -0.82 -0.91 0.34 -0.56

11 -0.59 -0.08 -0.15 0.92 -1.43 0.12 0.53 -0.59

12 -0.29 -0.26 -1.67 -1.67 1.82 -0.7 0.39 -0.29

13 0.57 -0.24 4.77 -0.17 0.25 0.6 0.58 0.57

14 0.01 0.06 -0.31 0.41 0.35 0.62 -0.38 0.01

15 0.38 -0.14 -0.94 -0.51 0.53 0.45 -0.5 0.38

16 -0.86 0.44 -0.21 1.68 0.67 -0.08 0.73 -0.86

17 0.08 0.66 0.08 1.09 -1.58 -2.41 -1.24 0.08

18 -1.63 -1.17 0.99 -1.29 -2.16 0.1 -1.06 -1.63

19 -2.72 1.25 -1.76 0.84 2.75 0.03 0.3 -2.72

20 -0.32 1.56 0.22 0.86 -0.07 -0.3 -0.48 -0.32

Table. 4: Absorbance of different brands Paracetamol tablets.

Brand Blank Standard Sample

First trial Second trial Third trial

A 0.007 First Reading 1.211 1.057 1.032 0.949

Second Reading 1.215 1.053 1.028 0.950

Third Reading 1.213 1.057 1.022 0.947

Average 1.213 1.0557 1.0273 0.9487

B 0 First Reading 1.174 1.077 1.054 1.075

Second Reading 1.171 1.075 1.054 1.075

Third Reading 1.171 1.075 1.054 1.075

Average 1.172 1.0757 1.054 1.075

C 0 First Reading 1.166 1.172 1.171 1.082

Second Reading 1.159 1.172 1.159 1.087

Third Reading 1.159 1.175 1.165 1.104

Average 1.1613 1.173 1.165 1.091

D 0 First Reading 1.281 1.253 1.207 1.255

Second Reading 1.298 1.254 1.207 1.253

Third Reading 1.301 1.253 1.207 1.254

Average 1.2933 1.2533 1.207 1.254

E 0 First Reading 1.138 1.250 1.247 1.244

Second Reading 1.110 1.250 1.235 1.241


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Third Reading 1.102 1.249 1.240 1.248

Average 1.1167 1.2497 1.2407 1.2443

F 0 First Reading 1.269 1.291 1.289 1.288

Second Reading 1.269 1.294 1.295 1.292

Third Reading 1.268 1.292 1.295 1.293

Average 1.2687 1.2923 1.293 1.291

G 0 First Reading 1.095 1.297 1.320 1.297

Second Reading 1.099 1.303 1.319 1.302

Third Reading 1.096 1.306 1.322 1.300

Average 1.0967 1.302 1.3203 1.2997

Graph. 1: UV-absorbance of Sample A.

The first, second and third readings of standard paracetamol were 1.211, 1.215 and 1.213.

The average for standard was 1.213. There were total 3 trials conducted for assay of sample

A and each trial had 3 readings. In first trial, the first, second and third readings were 1.057,

1.053 and 1.057. The average for first trial of sample A was 1.0557. In second trial, the first,

second and third readings were 1.032, 1.028 and 1.022. The average for second trial of

sample A was 1.0273. In third trial, the first, second and third readings were 0.949, 0.950 and

0.947. The average for third trial of sample A was 0.9487 as mentioned in Graph 1.

Graph. 2: UV-absorbance of Sample B.


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The average for standard was 1.172. There were total 3 trials conducted for assay of sample B

and each trial had 3 readings. In first trial, the first, second and third readings were 1.077,

1.075 and 1.075. The average for first trial of sample B was 1.0757. In second trial, the first,


sample B was 1.054. In third trial, the first, second and third readings were 1.075, 1.075 and

1.075. The average for third trial of sample B was 1.075 as mentioned in Graph 2.

Graph. 3: UV-absorbance of Sample C.

The Graph 3 showed first, second and third readings of standard paracetamol were 1.166,

1.159 and 1.159. The average for standard was 1.1613. There were total 3 trials conducted for

assay of sample C and each trial had 3 readings. In first trial, the first, second and third

readings were 1.172, 1.172 and 1.175. The average for first trial of sample C was 1.173. In

second trial, the first, second and third readings were 1.171, 1.159 and 1.165. The average for

second trial of sample C was 1.165. In third trial, the first, second and third readings were

1.082, 1.087 and 1.104. The average for third trial of sample C was 1.091.

Graph. 4: UV-absorbance of Sample D.


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In the Graph 4, first, second and third readings of standard paracetamol were 1.281, 1.298

and 1.301. The average for standard was 1.2933. There were total 3 trials conducted for assay

of sample D and each trial had 3 readings. In first trial, the first, second and third readings

were 1.253, 1.254 and 1.253. The average for first trial of sample D was 1.2533. In second

trial, the first, second and third readings were 1.207, 1.207 and 1.207. The average for second

trial of sample D was 1.207. In third trial, the first, second and third readings were 1.255,

1.253 and 1.254. The average for third trial of sample D was 1.254.

Graph. 5: UV-absorbance of Sample E.


The average for standard was 1.1167. There were total 3 trials conducted for assay of sample

E and each trial had 3 readings. In first trial, the first, second and third readings were 1.250,

1.250 and 1.249. The average for first trial of sample E was 1.2497. In second trial, the first,


sample E was 1.2407. In third trial, the first, second and third readings were 1.244, 1.241 and

1.248. The average for third trial of sample E was 1.2443 as mentioned in Graph 5.

Graph. 6: UV-absorbance of Sample F.


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In Graph 6, the first, second and third readings of standard paracetamol were 1.269, 1.269


of sample F and each trial had 3 readings. In first trial, the first, second and third readings

were 1.291, 1.294 and 1.292. The average for first trial of sample F was 1.2923. In second


trial of sample F was 1.293. In third trial, the first, second and third readings were 1.288,

1.292 and 1.293. The average for third trial of sample F was 1.291.

Graph. 7: UV-absorbance of Sample G.

The first, second and third readings of standard paracetamol in Graph 7 were 1.095, 1.099


of sample G and each trial had 3 readings. In first trial, the first, second and third readings

were 1.297, 1.303 and 1.306. The average for first trial of sample G was 1.302. In second


trial of sample G was 1.3203. In third trial, the first, second and third readings were 1.297,

1.302 and 1.300. The average for third trial of sample G was 1.2997.

Table. 5: Percent purity determination of different brands of Paracetamol tablets by

using UV Spectrophotometric method.

Brand Equivalent weight (g) Percent Purity (%) Standard

(%) Standard Sample First trial Second trial Third trial Average

A 0.500 0.595 96.53 99.25 107.41 101.0633 98

B 0.500 0.594 91.69 93.6 91.77 92.35333 98

C 0.500 0.559 88.53 89.14 95.18 90.95 98

D 0.500 0.605 85.28 88.53 85.21 86.34 98

E 0.500 0.688 64.94 65.41 65.26 65.20333 98

F 0.500 0.601 81.71 81.65 81.78 81.71333 98

G 0.500 0.57 73.91 72.9 74.02 73.61 98


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Percent purity determination of different brands of paracetamol by using UV

Spectrophotometric method was tabulated in Table 5. The percent purity of standard

paracetamol was 98 %. There were total 3 trials conducted for each assay of sample. The

percent purity of first, second and third trials of sample A were 96.53 %, 99.25 % and 107.41

%. The average percentage purity of sample A was 101.06 %. The percent purity of first,

second and third trials of sample B were 91.69 %, 93.60 % and 91.77%. The average percent

purity of sample B was 92.35 %. The percent purity of first, second and third trials of sample

C were 88.53 %, 89.14 % and 95.18 %. The average percent purity of sample C was 90.95 %.

The percent purity of first, second and third trials of sample D were 85.28 %, 88.53 % and

85.21 %. The average percent purity of sample D was 86.34 %. The percent purity of first,

second and third trials of sample E were 64.94 %, 65.41 % and 65.26 %. The average percent

purity of sample E was 65.20 %. The percent purity of first, second and third trials of sample

F were 81.71 %, 81.65 % and 81.78 %. The average percent purity of sample F was 81.71 %.

The percent purity of first, second and third trials of sample G were 73.91%, 72.90 % and

74.02 %. The average percent purity of sample G was 73.61 %.

Graph. 8: Comparison of percent purity between standard and sample by using UV

Spectrophotometric method.

Comparison of percent purity between standard and sample by using UV Spectrophotometric

method was recorded in Graph 8. The percent purity of standard paracetamol was 98 %.

Besides, the average percent purity of sample A, B, C, D, E, F and G were 101.06 %, 92.35

%, 90.95 %, 86.34 %, 65.20 %, 81.71 % and 73.61 %. According to Graph 4.8, sample A had

the most similar percent purity with standard paracetamol while sample E had the most

different percent purity with standard paracetamol. According to British Pharmacopoeia (BP),

the percent purity of paracetamol in tablet should be in the range of 95.0 % to 105.0 %. Thus,


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only sample A passed the test. While according to United States Pharmacopeia (USP),

paracetamol tablets should contain not less than 90.0 % and not more than 110.0 % of the

labeled amount of paracetamol. Thus, sample A, B and C passed the test.

Percent purity determination of different brands of Paracetamol tablets by using

titration method.

Table. 6: Percentage purity determination of different brands of Paracetamol tablets

using titration method.

Brand

Reading Weight of Percent

First

Reading

Second

Reading

Third

Reading Average Sample (mg) Purity (%)

A 6.7 7 6.8 6.833 71.512 100.76

B 7.2 7 7.1 7.1 71.28 105.36

C 7.1 7.1 6.8 7 67.08 110.28

D 6.7 6.9 6.8 6.8 72.6 98.79

E 7.3 7.2 7.4 7.3 82.56 93.69

F 7 7 6.6 6.867 72.12 100.54

G 7.2 7.2 7 7.133 68.4 110.29

Blank 0.5 0.4 0.4 0.433 0 -

Standard 6.4 6.6 6.9 6.633 60 116.34

Table 6 tabulated percentage purity determination of different brands of paracetamol by using

titration method. There were total 3 readings taken for assay of samples and standard. The

first, second and third readings of standard paracetamol were 6.4 ml, 6.6 ml and 6.9 ml

respectively. The average reading for standard was 6.63 ml. Besides, the first, second and

third readings of sample A were 6.7 ml, 7.0 ml and 6.8 ml respectively. The average reading

for sample A was 6.83 ml. While the first, second and third readings of sample B were 7.2

ml, 7.0 ml and 7.1 ml respectively. The average reading for standard was 7.10 ml. Moreover,

the first, second and third readings of sample C were 7.1 ml, 7.1 ml and 6.8 ml respectively.

The average reading for sample C was 7.0 ml. The first, second and third readings of sample

D were 6.7 ml, 6.9 ml and 6.8 ml respectively. The average reading for sample D was 6.80

ml. Furthermore, the first, second and third readings of sample E were 7.3 ml, 7.2 ml and 7.4

ml respectively. The average reading for sample E was 7.30 ml. The first, second and third

readings of sample F were 7.0 ml, 7.0 ml and 6.6 ml respectively. The average reading for

sample F was 6.87 ml. The first, second and third readings of sample G were 7.2 ml, 7.2 ml

and 7.0 ml respectively. The average reading for sample C was 7.13 ml, lastly, the first,

second and third readings of blank were 0.5 ml, 0.4 ml and 0.4 ml respectively. The average

reading for blank was 0.43 ml.


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Graph. 9: Percent Purity of Paracetamol by Titration Method.

Graph 9 had shown percentage purity of paracetamol by titration method. The percent purity

of standard paracetamol was 116.34 %. The percent purity of sample A, B, C, D, E, F and G

were found to be 100.76 %, 105.36 %, 110.28 %, 98.79 %, 93.69 %, 100.54 % and 110.29 %.

According to Graph 9, sample G had the most similar percent purity with standard

paracetamol while sample E had the most different percent purity with standard paracetamol.

According to British Pharmacopoeia (BP), the percent purity of paracetamol in tablet should

be in the range of 95.0 % to 105.0 %. Thus, sample A, D and F passed the test. While

according to United States Pharmacopeia (USP), paracetamol tablets should contain not less

than 90.0 % and not more than 110.0 % of the labeled amount of paracetamol. Thus, samples

A, B, D, E and F passed the test.

Comparison of percent purity of Paracetamol tablets between UV Spectrophotometric

and titration methods

Graph. 10: Comparison of percent purity of Paracetamol tablets between UV

Spectrometric and titration methods.


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Comparison of percentage purity of paracetamol between UV spectrometric method and

titration method was shown in Graph 10. The average percent purity of sample A, B, C, D, E,

F and G by using UV spectrometric method were 101.06 %, 92.35 %, 90.95 %, 86.34 %,

65.20 %, 81.71 % and 73.61 %. Besides, the percent purity of sample A, B, C, D, E, F and G

by using titration method were found to be 100.76 %, 105.36 %, 110.28 %, 98.79 %, 93.69

%, 100.54 % and 110.29 %. According to Graph 10, sample A had the most similar percent

purity between UV spectrometric method and titration method. The sample G had the most

different percent purity calculated by both methods.

Percentage Purity of Paracetamol tablets with standard by titration and UV-

Spectrophotometric methods.

Graph. 11: Percentage purity of Paracetamol tablets with standard by titration and UV

spectrophotometric methods.

Graph 11 shows percentage purity of paracetamol with standard by titration and UV

spectrophotometric methods. The percent purity of standard paracetamol was 98 %. The

average percent purity of sample A, B, C, D, E, F and G by using UV spectrophotometric

method were 101.06 %, 92.35 %, 90.95 %, 86.34 %, 65.20 %, 81.71 % and 73.61 %. Besides,

the percent purity of sample A, B, C, D, E, F and G by using titration method were found to

be 100.76 %, 105.36 %, 110.28 %, 98.79 %, 93.69 %, 100.54 % and 110.29 %. According to

Graph 11, sample A had the most similar results, while sample G had the most different

results. Graph 11, has shown that the percentage purity calculated by titration method was

more approached to standard if compared with UV spectrophotometric method.


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DISCUSSION

The objective of this research is to evaluate the percent purity of different brands paracetamol

tablets which were available in local market by using UV spectrophotometric and titration

method. Both Indian Pharmacopoeia and British Pharmacopoeia recommend titrimetric and

UV spectrophotometric assay method for paracetamol in bulk or tablet formulations. Thus,

these two methods were compared in this research to observe the differences between UV

spectrophotometric method and titration method and also to determine which method more

accurate.[8]

In conclusion, all of the paracetamol of each brand had uniform weights.[25,26]

Percentage purity determination of different brands of paracetamol was performed by using

UV- Spectrophotometric method. The 50 ml of 0.1 N sodium hydroxide (NaOH) was added

to paracetamol sample, because paracetamol is a weak acid. The phenolic proton of

paracetamol was acidic enough to be neutralized with NaOH, producing sodium phenoxide

salt which was soluble in water. The filtration can remove the undissolved excipients from

paracetamol solution.[1,5]

Besides that, the present research work also included assay of

paracetamol tablets by using titration method (oxidation-reduction titration). The paracetamol

sample was the reducing agent while the ceric ammonium sulphate was the oxidizing agent in

this method. The procedure of this assay was provided by B.P.[27-31]

According to B.P, the percent purity of paracetamol in tablet should be in the range of 95.0 %

to 105.0 %. Only sample A, D and F passed the test. Samples B, C, E and G did not comply

with the official limits. While according to United States Pharmacopeia (USP), paracetamol

tablets should contain not less than 90.0 % and not more than 110.0 % of the labeled amount

of paracetamol. Thus, sample A, B, D, E and F passed the test. Sample C and G did not

comply with the official limits. According to sample G, had the most similar percent purity

while sample E had the most different percentage purity with standard paracetamol. This

indicated sample A was comparatively better than other brands which used in this research.

In conclusion, sample A, D and F were within the limit specified by the both B.P. and U.S.P.

Sample A was the fully complied with the official limits while sample E was the worst

among these seven paracetamol tablet brands in this assay of paracetamol by using titration

method.[25,26]

The first, second and third readings of standard paracetamol were 1.211, 1.215


of sample A and each trial had 3 readings. In first trial, the first, second and third readings

were 1.057, 1.053 and 1.057. The average for first trial of sample A was 1.0557. In second


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trial of sample A was 1.0273. In third trial, the first, second and third readings were 0.949,

0.950 and 0.947. Comparison of percent purity between standard and sample by using UV

spectrophotometric method was recorded. According to B.P., the percent purity of

paracetamol in tablet should be in the range of 95.0 % to 105.0 %. Only sample A passed the

test. Sample B, C, D, E, F and G did not comply with the official limits. While according to

United States Pharmacopeia (USP), paracetamol tablets should contain not less than 90.0 %

and not more than 110.0 % of the labeled amount of paracetamol. Only sample A, B and C

passed the test. Sample D, E, F and G did not comply with the official limits.

In conclusion, only sample A was within the limit specified by both B.P. and U.S.P. Sample

A was the best while sample E was not the better among these seven paracetamol tablet

brands by UV spectrophotometric method.[25,26]

Sample A is the only brand which had within

the limits of both B.P. and U.S.P by using both UV spectrophotometric and titration methods.

REFERENCES

1. Behera S. UV-Visible Spectrophotometric Method Development and Validation of Assay

of Paracetamol Tablet Formulation. Journal of Analytical & Bioanalytical Techniques,

2012; 03(06).

2. Sayed M. A comparative study for the quantitative determination of paracetamol in tablets

using UV-Visible spectrophotometry and high performance liquid chromatograph.

Physical Chemistry, 2005; 17(1): 1-5.

3. Bosch M, Sánchez A, Rojas F, Ojeda C. Determination of paracetamol: Historical

evolution. Journal of Pharmaceutical and Biomedical Analysis, 2006; 42(3): 291-321.

4. Islam A. Validation of UV-Spectrophotometric and RP-HPLC methods for the

simultaneous analysis of Paracetamol and Aceclofenac in marketed tablets Validation of

UV-Spectrophotometric and RP-HPLC methods for marketed tablets. International Journal

of Pharmacy and Life Sciences, 2014; 2(12): 1267-1275.

5. Kumar D. Analysis of different brands of paracetamol 500mg tablets used in Hyderabad,

using ultraviolet spectrophotometric and high performance liquid chromatographic

methods. International Journal of Pharmaceutical Sciences and Research, 2015; 5(3):

951-955.


1682


6. Sahle S. Comparative Quality Evaluation of Paracetamol Tablet Marketed in Somali

Region of Ethiopia. International Journal of Pharmaceutical Sciences and Research, 2012;

3(2): 545-550.

7. Al-anbakey A. Spectrophotometric Determination of Paracetamol in Some Manufactured

Tablets in Iraqi markets. International Journal of Pharmaceutical Sciences Review and

Research, 2017; 42(2): 53-57.

8. Sharma S, Pareek A, Joshi R, Bhardwaj Y, Jain V, Jadon G. Development and Validation

of A UV Spectroscopic Method for Analysis of Paracetamol in Bulk Powder and Tablet.

Oriental Journal of Chemistry, 2013; 29(2): 787-792.

9. Kumar T. M, Bairwa M, Theja D. H, Srinivas R. Development and Validation of RP-

HPLC and Ultraviolet Spectrophotometric Methods of Analysis for Simultaneous

Determination of Paracetamol and Lornoxicam in Pharmaceutical Dosage Forms. Journal

of Liquid Chromatography & Related Technologies, 2012; 35(1): 129-140.

10. Olufemi A. UV-Spectrophotometry and RP-HPLC methods for the simultaneous

estimation of acetaminophen: Validation, comparison and application for marketed tablet

analysis in South West, Nigeria. Journal of Chemical and Pharmaceutical Research, 2013;

5(5): 1-11.

11. Morelli B. Spectrophotometric determination of paracetamol in pure form and in tablets.

Journal of Pharmaceutical and Biomedical Analysis, 1989; 7(5): 577-584.

12. Nayak A. Comparative in vitro dissolution assessment of some commercially available

paracetamol tablets. International Journal of Pharmaceutical Sciences Review and

Research, 2010; 2(1): 29-30.

13. Roy J. Rapid screening of marketed paracetamol tablets: use of thin-layer chromatography

and a semiquantitative spot test. Bulletin of the World Health Organization, 1997; 75(1):

19-22.

14. Hassan W. Determination of Ibuprofen and Paracetamol in Binary Mixture Using

Chemometric-Assisted Spectrophotometric Methods. American Journal of Applied

Sciences, 2008; 5(8): 1005-1012.

15. Khoshayand M, Abdollahi H, Shariatpanahi M, Saadatfard A, Mohammadi A.

Simultaneous spectrophotometric determination of paracetamol, ibuprofen and caffeine in

pharmaceuticals by chemometric methods. Spectrochimica Acta Part A: Molecular and

Biomolecular Spectroscopy, 2008; 70(3): 491-499.


1683


16. Bloomfield M. A sensitive and rapid assay for 4-aminophenol in paracetamol drug and

tablet formulation, by flow injection analysis with spectrophotometric detection. Talanta,

2002; 58(6): 1301-1310.

17. Murtaza G. Development of a UV-spectrophotometric method for the simultaneous

determination of aspirin and paracetamol in tablets. Scientific Research and Essays, 2011;

6(2): 417-421.

18. Mayank M. Simultaneously Estimation of Paracetamol, Aceclofenac and Rabeprazole in

Tablet Dosage Form Using UV Spectroscopy. Asian Journal of Pharmacy & Life Science,

2011; 1(2): 113-117.

19. Benista M. Paracetamol: Mechanism of Action, Applications and Safety Concern. Acta

Poloniae Pharmaceutica - Drug Research, 2014; 71(1): 11-23.

20. Haywood A, Mangan M, Glass B. Stability Implications of Repackaging Paracetamol

Tablets into Dose Administration Aids. Journal of Pharmacy Practice and Research, 2006;

36(1): 25-28.

21. Sirajuddin, Khaskheli A, Shah A, Bhanger M, Niaz A, Mahesar S. Simpler

spectrophotometric assay of paracetamol in tablets and urine samples. Spectrochimica

Acta Part A: Molecular and Biomolecular Spectroscopy, 2007; 68(3): 747-751.

22. Shrestha B, Pradhananga R. Spectrophotometric Method for the Determination of

Paracetamol. Journal of Nepal Chemical Society, 2009; 24: 39-44.

23. Burgot G, Auffret F, Burgot J. Determination of acetaminophen by thermometric

titrimetry. Analytica Chimica Acta, 1997; 343(1-2): 125-128.

24. Kumar K, Letha R. Determination of Paracetamol in pure form and in dosage forms using

N,N-dibromo dimethylhydantoin. Journal of Pharmaceutical and Biomedical Analysis,

1997; 15(11): 1725-1728.

25. British pharmacopoeia 2010. London: Stationery Office; 2009.

26. The United States pharmacopeia. Rockville, MD: United States Pharmacopeial

Convention; 2008.

27. Ellis F, Osborne C, Pack M. Paracetamol. London: Royal Society of Chemistry; 2002.

comparative study for percentage purity …

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