8.The absorbance of the solution in the cell versus air spectrophotometer at 250 nm was done and recorded A250:
RESULTS AND DISCUSSION
1.The results of the research are listed in Tables 1 to 3.
2.It was observed that 55% of these emulsions were manufactured in Africa and 45% were from foreign countries.
3.There were 19 emulsions manufactured in Africa, while 11 emulsions were manufactured in foreign countries.
4.25 samples studied were white, 2 peach, 1 off-pink and 1 light pink in colour.
5.20% of the sample studied had pH which is acidic (4.25 - 4.90), 50% is slightly acidic (5.01 - 6.92) and 30% is neutral (7.10 - 7.25).
6.The manufacturers of the samples whose pH are neutral and slightly acidic titrated the emulsion to a point that it cannot irritate the skin.
7.The pH of cosmetics creams and lotions indicates the amount of free fatty acids and bases present in them.
8.The pH of the skin is acidic, that is, 3 to 5
9.Acidic creams should not be used rather neutral creams are advisable.
10.Most of the cosmetic sample have high percentage moisture content (50 - 90) and thus will provide adequate moisture and hydration to the skin thereby making the skin feel soft
11.All the cosmetic emulsion with low percentage moisture content (20 - 40) will keep the skin dry and thus inhibit the comfort.
12.90% of the samples did not contain mercury.
13.Samples 1 and 17 (from Indonesia and Cote D’ Ivoire) mercury content is alarming as compared with the standard of World Health Organization which is 1 μg/g.
14.Skin lightening emulsions that contain mercury to any extent is detrimental to the skin since it accumulate gradually on skin on constant usage.
15.The result of this research also revealed that all the samples contain hydroquinone but not above the standard recommended by World Health Organization.
16.The manufacturers adhered to the standard of quantity of hydroquinone in cosmetic emulsions thus reducing the effect of hydroquinone on skin.
Conclusion
1.This study establishes the presence of hydroquinone in all the samples while mercury was found in only samples A and Q at an alarming rate.
2.The pH of the cosmetic creams is not too acidic to irritate the skin since most of them have pH from 5.01 to 7.25.
3.The percentage moisture content of most of the samples is normal for soft and hydrated skin.
4.Also there is need for more stringent control by regulatory bodies appointed by the government to check the quality of cosmetics in the market.
Table 1. Physiochemical results of the samples with the country of manufacture.
Table 2. Result of mercury detected in the samples.
Table 3. Result of hydroquinone content detected in the sample.