OBJECTIVES
The laboratory exercise aims to teach the students:
1. The proper way of hand cream preparation.
2. Appreciate the procedure
3. Learn the functions of each ingredient used in the preparation of the hand cream.
PROCEDURE
In order to fulfill the preparation of the Hand Cream, the group had to gather all of the materials and equipment needed. Afterwards, the chemicals were separated into two groups, being the non-polar and polar chemicals. The non-polar group consisted of Water, Lanolin and Triethanolamine, while the polar group consisted of Stearic acid and Mineral oil respectively. The set up for heating was arranged accordingly, making sure that al of the materials were in place.
Afterwards, water was placed in a 400 mL beaker that would serve as the water bath. The non-polar chemicals were combined together in a 50-mL beaker, then placed in the water bath using the crucible tongs. In the absence of the Bunsen burner, a hot plate was used. The water bath was used until all of the ingredients have been melted and combined with each other. The polar group was then placed in the water bath for about five minutes to melt the ingredients and combine them all together. The polar ingredients were then mixed with the non-polar ingredients in the 50mL beaker. Using a glass stirring rod, the new mixture was stirred for 5 minutes, resulting to a smooth uniform taste. The pH level of the different and creams made were also taken with the use of the pH paper. As for its consistency, smoothness, and homogeneity the creams were tested in the hand of one of the participants. The same procedure was made for the other three samples, after which the results were all recorded.
THEORY (BACKGROUND)
Hand creams have been in the cosmetic business for quite some time already. These are normally employed to help soften and prevent dry skin, and their cooling effect. Theories have been made that emulsification of hand creams may help in the elimination of oils in the body. Furthermore, the other ingredients of the cream are also used to exhibit a fragrant smell, and for therapeutic purposes. For this, the real purposes of the ingredients in this preparation has been taken into careful consideration. The properties of each ingredient used are said to have different effects on the preparation and on the medium. A slight change in the temperature or in the amount of ingredient placed would have a chemical effect on the preparation. From here alone, it may be stated that the properties of chemicals play a vital during chemical reactions. In this experiment, the students would be able to see first hand the different effects heat have on the different ingredients of hand cream.
RESULTS
Tabulated Results of Hand Cream Characterisitsc
PROPERTIES
SAMPLE 1
SAMPLE 2
SAMPLE 3
SAMPLE 4
SAMPLE 5
pH level
8
7
8
6
7
Smoothness
Smooth
Smooth
Smooth
Not smooth
Smooth
Homogeneity
homogenous
Homogenous
Homogenous
Non- homogenous
homogenous
Appearance
White,
creamy
Off white,
Sticky, viscous
non-viscous, presence of bubbles, frothy
Presence of layers:
Top layer is yellow in color, and is viscous ;
Bottom layer is clear and colorless yet still viscous
Milky in color, consistency is thick, and sticky.
CONCLUSION
Post-Lab Questions
In comparing the properties of the hand creams you produced, ascertain what is the function of each of the missing ingredients in the hard cream:
Mineral Oil – considered to be one of the most important ingredients in cosmetics. This type of oil is also used as a substitute for the more expensive ones, and its properties of being tasteless and odorless would not inhibit the full potential of the other characteristics of the other ingredients.
Triethenolamine – this ingredient is an organic chemical that is used as a neutralizer for a range of cosmetic products, including hand creams. In this regard, triethenolamine is also employed for its solubility in water, and does not penetrate the deep ends of the skin.
A hand cream appears smooth and uniform after you prepared it, but in a week of storage most of the water settles on the bottom and most of the oil separates on the top. What do you think may have gone wrong with the hand cream preparation?
Water and oil are normally mixed to form a new product. Their properties compliment each other, as part of the water’s characteristic of being an emulsifying agent. For the hand cream preparation, one of the most common problems experienced is that the mixture was not combined properly. The contents of the ingredients may have been miscalculated or the temperature of the water bath is not enough.
Could you prepare a hand cream without water? Would it serve the cosmetic functions listed in the “Background” section?
Yes, it is possible to make the hand cream without the water. However, there would be some problems with the characteristics of the preparation. As an emulsifying agent, water has the capability to combine all of the ingredients in the preparation. Unfortunately, the absence of water in the preparation would hinder the ingredients from interacting with each other, making combination impossible.
Discussion of Results
It is noticeable that the pH levels of each sample were near each other. This means that majority of the ingredients are similar with each other, yet the amount differs. Another characteristic that may be noticed is the fact that each cream was sticky. This means that the water has worked effectively as an emulsifying agent. Color may also differ, for some companies would opt to put color in their products to give it an appealing effect. Regardless of such differences, it may still be noted that all of the five samples have complied with the necessary requirements set by the FDA for hand cream products.
Sources of Error
The possible sources of errors in the preparation of hand creams are seen in the miscalculations of the ingredients. The amount of heat tenured on the preparation is also taken into consideration. Combustion plays a big role in the preparation of creams, for most of the chemical reactions after the application of heat.
