will be expressed as the following
content (mg QE/ g dried CP) =
The experiment results will be reported as the mean ± standard deviation of
solvent extraction and assays since the replica will be created during the
experiment. All of the results will be measured using IBM SPSS Analytical statistics
software (IBM SPSS Statistics 24) for One-Way analysis of variance (ANOVA) along
with Tukey’s post hoc test which will be used to determine the significant differences
between the means of 5% level. If the results show the probability of
significance less than 0.05, conclusion can be made as significantly different.
The estimation probability that the evidence will give the statistical
comparison only 5% will rejects the null hypothesis.
Figure 11. The Flow
Chart of Gel Basis
The gel that will be used is Carbomer 940 with the concentration of 1%
with constant stirring at 600 rpm for 20 minutes as the best condition
according to the previous research done by Annelies (2017), to avoid any
possible bubble appearance during the mixing time. The required amount of
Carbomer 940 will be measured separately, and sufficient amount of distilled
water will be added to each of Carbomer 940, where it will be mixed in separate
beaker. After the gelling base is formed, it will be keep for 24 hours to avoid
bubbling at room temperature based on the previous research done by Annelies
(2017). One major challenge in the production of the skin gel will be the
optimum concentration of the coffee pulp extract. The extract of coffee pulp will
be divided into four levels, 0.125%, 0.25%, 0.50% and 1%.
Coffee Pulp Extract
Ethylenediaminetetraacetic acid (EDTA)
Table 3.2 Coffee Pulp Skin Gel
Experiment Formulation Design
The basic formulation for the
gelling basis is according to Handbook of Pharmaceutical Excipients.
Figure 12. The Flow
Chart of Making Antioxidant Skin Gel From Coffee Pulp Extract
TEA with the ratio of 1:1 will be added to the gel basis. Methyl paraben
and propyl paraben will be dissolved in propylene glycol, EDTA will be
dissolved in distilled water and coffee pulp will be dissolved in distilled
water, which will be added to the gel and stirred. The skin gel will undergoes
The observations in this research
will focus on the physicochemical properties of the skin gel which divided into
a various tests explained below.
formulation of skin gel will be measured for its viscosity using the viscometer
(Brookfield). The gel sample will be poured into 100 ml beaker with the spindle
placed in the beaker glass with specified limit. The measurement will begin
with varieties of speed begin from 0.5, 1, 2, 2.5, 4, 10 and 20 rpm. For each
measurement with different speed, the viscosity value can be read when the
digit value will appear in a steady viscometer.
of skin gel will be put in a watch glass that will be covered with graphic
paper. Then, the wrapped watch glass will be measured for more or less than 1
minute. Later, it will be given with different weight of 50, 100, 150, and 200
g and will be left for 1 minute. The diameter of spreading skin gel will be
recorded and will be calculated.
the visual analysis such as the shape of gel appearance, colour, and the smell
of the gel formulation.
value will be analysed using pH meter (standard electrode). The electrode will
be calibrated at the beginning with pH value of 4 and 7 as the standard value.
First, 0.25 g of skin gel will be dissolved with 25 ml of aquadest. Next, the
pH meter will be immersed until it shows a stable reading. The value in pH
meter will be recorded, and the pH meter will be cleansed with aquadest after
the test is done. The pH meter will be dried using tissue paper. The
measurement will take place in room temperature.
Due to the
short amount of time of the skin gel preparation, an accelerated stability
tests must be performed (Association,
2004). The most common practice in
accelerated stability tests are by storing the samples at ambient temperatures.
The samples will be stored at various temperatures such of ±4°C, ±25°C, and
±40°C. The parameters of antioxidant skin gel such as smell, colour and pH will
be examined in the second week and forth week.
Skin Allergy Test
The aim of
this test is to discover the possibility of skin irritation. In this study, the
test is conducted using closed patch epicutaneous test under occlusion or semi
occlusion by Hannuksela (1979). A formula to measure the irritation parameter
will be Primary Irritation Index (PII) (Moore
Erythema and eschar formation
slight erythema (barely detectable)
to severe erythema
erythema (beet redness), slight eschar (injuries in depth)
slight edema (barely detectable)
edema (raised approx. 1 mm)
edema (raised ?1mm)
Table 3.1 Grading Scale for Skin Irritation (Bagley et al., 1996; Moore E., 1999)
testing is considered as an obligation for cosmetic companies to obtain data
from ingredient suppliers, for instance substances with restrictions in
concentration or site of application (Salvador and Chisvert, 2007). The methods of absorption
test are classified into two: in vivo and in vitro. The purpose of this test is
to study the diffusion of a test substance through the skin barrier into the