Quality Assessment of Some Selected Toothpaste Used in Nigeria

Quality Assessment of Some Selected Toothpaste Used in Nigeria

Chapter One

Aim

This work aimed at assessing the quality of some selected locally and foreign-manufactured toothpastes, used in Nigeria Markets.

Objectives

The aim of this research will be achieved through the following objectives;

Evaluation of some physical parameters of toothpaste (colour, moisture and volatile content, pH) using recommended
Investigation of the bacteriological and microbial status of the toothpaste, using standard
Investigation of fluoride concentration in toothpaste
Determination of Heavy metals levels (Pb, Cd, Mn, Cu, Ni and Zn) and TiO₂ contamination in toothpastes using AAS and x-ray Spectrometer respectively.
Investigation of sodium saccharin, sodium lauryl sulphate concentration in the selected toothpaste using UV-Spectrophotometer.
Carryout correlation analysis to compare the levels of these substances in the foreign and local
Comparing the obtained results with set standards by regulatory bodies.

CHAPTER TWO

LITERATURE REVIEW

Saccharin

Saccharin (1, 2-benzisothiazolin-3-one-1, 1-dioxide) is an artificial sweetener. Saccharin and its salts are intense sweeteners, being about 300-500 times sweeter than sucrose in aqueous solution (Martindale, 2002). Saccharin is not only soluble in water but its commercially available sodium salt, used as a non-nutritive sweetener, is freely soluble in water. Saccharin, a petroleum- based sugar substitute is used in soft drinks, diet food and personal hygiene products such as lip balm and tooth paste. Saccharin derives its name from the word saccharine, meaning, relating to or resembling that of sugar. Saccharin is unstable when heated but it does not react chemically with other food ingredients. As such, it stores well. Blends of saccharin with other sweeteners are often used to compensate for each sweeteners weakness or faults. Saccharin is believed to be an important discovery, especially for diabetics, as it goes directly through the human digestive system without being digested. Although saccharin has no food energy, it can trigger the release of insulin in human and rats, presumably as a result of its taste (Just et al., 2008; Lonescu et al., 1988), as can other sweeteners like aspartame.

History

Saccharin was first produced in 1878 by Constantin Fahlberg, a Chemist working on coal tar derivatives in Ira Remsen’s Laboratory at the Johns Hopkins University. The sweet taste of saccharin was discovered when Fahlberg noticed a sweet taste on his hand one evening, and connected this with the compound that he had been working on that day (Myers and Richard, 2007). Although saccharin was commercialized not long after its discovery, it was not until the sugar shortage during World War I that its use became widespread. Its popularity further increased during the 1960s and 1970s among dieters, since saccharin is a calorie-free sweetener.

Chemistry

Saccharin can be produced in various ways. The original route by Remsen & Fahlberg (1880) starts with toluene. Sulphonation by chlorosulphonic acid gives the ortho and para substituted chlorosulphonic acids. The ortho isomer is separated and converted to the sulphonamide with ammonia. Oxidation of the methyl substituent gives the carboxylic acid, which cyclicizes to give saccharin free acid (Gert-Wolfhard, 2005).

Saccharin can be used to prepare exclusively disubstituted amines from alkyl halides via a Gabriel synthesis.

Biochemical data

Saccharin and saccharin salts (sodium, ammonium, and calcium) have been in use since the late nineteenth century, salt forms being more soluble but of the same sweetening power as the acid form. The absorption of ingested saccharin in animals and man occurs rapidly. At pKa of 2.2, saccharin exists in acidic media predominantly in the unionized form, which is the more readily absorbed form in a number of animal species. Saccharin is more completely absorbed from the guinea-pig (pH 1.4) and rabbit (pH 1.9) stomach, than from the rat’s stomach (gastric pH 4.2) (Minegishi et al., 1972). In vitro perfusion of rat stomach and small intestine with a solution of saccharin demonstrated considerable absorption from the stomach at pH 1.0 and slow absorption from the small intestine, (less than 9% in 2 hours) (Kojima and Ichibagase 1966). The gastrointestinal absorption of saccharin appears to be somewhat greater in monkeys than in rats (Pitkin et al., 1971). In monkeys, and also most probably in man, both gastric acidity and degree of absorption are intermediate between those of the rabbit and guinea-pig on one side, and the rat on the other. This also means that the degree of absorption of saccharin could be dependent on food intake which affects the acidity of the gastric contents.

It has long been assumed that saccharin undergoes very little metabolic conversion under normal dietary usage in animals and man. Studies conducted with human subjects suggested that some degree of saccharin metabolism may occur in man, since oral doses of saccharin could not be recovered quantitatively as saccharin in the urine (McChesney and Golberg, 1973). Subsequently, more definitive studies, using ¹⁴C-labelled saccharin demonstrated that the reduced recovery was an artifact thought to be due to the binding of a portion of the urinary saccharin to unidentified urinary constituents (Byard et al., 1974).

CHAPTER THREE

MATERIALS AND METHODS

MATERIALS / EQUIPMENT

List of apparatus and equipment

AAS: Varian Fast Sequential Atomic Absorption Spectrometer.
Analytical balance: Sartorius Analytical

Beaker –50 cm³, 100 cm³, 250 cm³

Conical flask – 12 cm³ , 250 cm³
Crucibles
Desiccators

Filter paper– whatman 42 grades
Fume cupboard

Funnel
Furnace
Glassrod

Hotplates
Measuring cylinder – 100 cm³ , 10 cm³, 5 cm³
Mortar and pestle

Oven: Schutzart DW 40050-IP20

Petri-dish
pH meter: Jenway 3505 pH
Photometer: HI
Pipette1 cm³, 5 cm³, 10 cm³ and 25 cm³.

Plastic bottles for digest – 50 cm³

Spatula
Steam bath
UVS pectro photometer: Jenway 6405 UV/Vis.
Volumetric flask 50 cm³, 100 cm³ , 250 cm³, 1000 cm³
Wash bottle
X-ray Spectrometer: PW 4030

CHAPTER FOUR

RESULTS AND ANALYSIS

General Characteristics of Samples

A total of ten (10) toothpaste samples, consisting of six (6) local and four (4) foreign toothpastes were obtained for the study. All the samples were in molten form (gel- like). The toothpastes sampled were labeled T1 to T10. The parameters analyzed were compared with set standards were applicable and the results obtained are as reported. Appendix A gives general characteristics of the sampled toothpaste.

CHAPTER FIVE

DISCUSSSION

The result obtained from the bacteriological examination (Table 4.1) shows that all the sampled toothpaste were all sterile as no bacterial or fungal isolates were identified in any of the sampled toothpaste. This result is as expected; toothpaste medium must not support bacterial growth. According to the SON standard for toothpaste, the tolerable limit for the total viable count (TVC) of microorganisms per gram of toothpaste is 300 cfµ/g. E. coli, Salmonella and Pseudomonas arugenisa must be absent. Hence, the result obtained from the present study shows that the microbial load of toothpaste sold in Nigeria meets the criteria set by SON.

The pH value gives an indication of the inorganic constituents in toothpaste. Hight acidic pH encourages the growth of mouth bacterial that causes dental carries (Oyewale, 2005). Recommended pH for toothpaste is between 6.50 and 7.50 (NIS, 2006). Only 60% of the sampled toothpaste fell within this range. The moisture and volatile matter constituents of the toothpastes analyzed fell within 28.03% and 46.19%. The tolerable limit for the moisture and volatile matter in toothpaste as specified by SON is 50% (NIS, 2006). All the sampled toothpastes were found to conform to this specification. The summary of these results are as shown in Figure 4.1.

Figure 4.1 shows that the pH obtained for the foreign toothpastes sampled, conform to the pH specification for toothpastes, except for T5 (5.92 ± 0.001) and T10 (8.22 ± 0.002) which are slightly below and slightly above the minimum and maximum specified values respectively. The average pH of the sampled foreign toothpaste is 6.92 which conform to toothpaste specification, while that of local toothpaste is 7.01 (neutral), which also conforms to the pH specification for toothpaste.

CHAPTER SIX

CONCLUSION AND RECOMMENDATION

Conclusion

In the present study, the pH of various brands of toothpastes analyzed ranged from 5.20 to 8.42, only six (6), out of the ten (10) sampled toothpastes complied with the NAFDAC set standard of 6 to 7. The moisture and volatile matter content of the toothpaste were also less than 50% as specified by WHO. The microbial load of the toothpastes showed that they were all sterile as no bacterial or fungal isolates were identified in any sampled toothpastes and the concentration of the fluoride in the sampled toothpastes were within the specified limits, hence complying to set standards.

Toothpastes of nowadays are a heavy mix of chemicals, some are prepared to suit a particular need of the consumer e.g. T10, is a smokers toothpaste, which is designed to remove stubborn stains from the tooth, hence making it stain free. T8, which is a herbal based toothpaste, contain a lot of plant extracts. It was designed to meet the needs of consumers who prefer to stick to natural products.

In any case, the daily use of these toothpastes can easily result in exposure to thousands of chemicals and many will make their way into the body and remain there, since the body lack means to break them down. This load can become a significant contributing factor to health problem and serious diseases.

The current investigation showed that toothpaste could serve as a source through which humans are exposed to heavy metals, most especially when ingested. The metals determined were Pb, Cd, Ni, Mn, Zn and Cu. Although lead was absent in all the sampled toothpastes (probably because manufactures were careful during the manufacturing process so as to avoid lead contamination), traces of cadmium were found in some. Cadmium is not an acceptable ingredient in toothpaste, it only exist in some, due to its persistent nature. Hence, only samples T1, T3, T5, T6, T7, T8 and T9 showed traces of cadmium. It was absent in all the others.

Among the different samples analyzed, manganese was found to be at higher concentration than all the other test metals. This is not at all surprising as manganese is found in common toothpaste ingredients like peppermint-herb, sorbitol and water. The concentration of manganese ranged from 9.90 ± 0.0005 to 94.50 ± 0.0005 mg/kg with T10, which is a smoker‟s toothpaste having the highest manganese concentration. Traces of nickel was also found, and ranged from 2.85 ± 0.0004 to 5.80 ± 0.0004 mg/kg. The level of zinc in the toothpastes analyzed ranged from 1.30 ± 0.002 mg/kg to 12.05 ± 0.0001 mg/kg, while copper, ranged from 0.30 ± 0.0002 mg/kg to 12.05 ± 0.001 mg/kg with samples T3,T4,T5 and T9 having very low copper concentration.

A comparison of the level of these metals in both local and foreign toothpastes showed that the concentrations of these metals are higher in the foreign toothpastes than in the local toothpastes. Statistics carried out to compare the presence of these heavy metals in the different toothpaste brands showed significant relationship in some of the metals, meaning that, they could be from the same source.

The positive test result obtained for titanium in all the samples is not at all surprising, as it is used as an ingredient in toothpastes. It serves as whitening and ticking agent in toothpaste. All the sampled toothpastes showed some level of titanium in it, with T4 having the highest concentration of 6.25 mg/g.

Hence, based on these results obtained, it can be concluded that toothpastes serve as a source of human exposure to heavy metals.

Aside these heavy metals, all the sampled toothpastes tested positive for the presence of sodium saccharin and sodium lauryl sulphate. They are ingredients added to serve as sweetening and foaming agents respectively. It is important to note that these two substances are hazardous to the human health especially when orally administered. The concentration of saccharin in the sampled toothpastes ranged from 83.31 ± 17.29 mg/g to 232.20 ± 11.47 with T2 having the highest saccharin concentration, while the concentration of SLS ranged from 15.64 ± 10.11 mg/g to 21.30 ± 40.22 mg/g.

In all cases, except for microbial and lead analysis, which conform to set standards, the substances determined in the sampled toothpastes showed higher amount of these hazardous substances, furthermore, the analytical data recorded in the present survey is very alarming, in the sense that the amount of each of these substances determined in the different brands of toothpastes is not uniform, except for lead and microbial contamination which were absent in all the sampled toothpastes. This means that, it is possible that manufactures of these toothpastes, do not use the same guidelines/specifications to manufacture these toothpastes.

Hence, caution must be exercised when using toothpastes, particularly foreign toothpastes. Vulnerable people like children, pregnant women, the elderly and sick, must exercise caution when using toothpastes.

Recommendations

It is recommended that a guideline be made for the permissible level of saccharin; SLS and TiO₂ used in toothpastes and these should be monitored from time to time to ensure that toothpaste do not pose health challenge to consumers.

The need to stick to the directions given for the use of toothpastes most especially where children and pregnant women are concerned should be emphased.

Further studies should be conducted to include other toxic substances like triclosan, diethylene glycol, xylitol and PEG which are other harmful substances used in some toothpastes.

REFERENCES

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