In vitro determination of sun protection factor and chemical

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Original Article
In vitro determination of sun protection factor and chemical
stability of Rosa kordesii extract gel
Pratik P. Maske*, Sachin G. Lokapure, Dhanashri Nimbalkar, Shobharaj Malavi,
John I. D’souza
Department of Pharmaceutics, Tatyasaheb Kore College of Pharmacy, Warananagar, Maharashtra, India
a r t i c l e i n f o
Article history:
Received 17 April 2013
Accepted 14 May 2013
Available online 18 July 2013
Keywords:
Flavonoid
Rosa kordesii
Stability
Sun protection factor
* Corresponding author. Tel.: þ91 0886711351
E-mail address: pratikmaske123@yahoo.i
0974-6943/$ e see front matter Copyright ª
http://dx.doi.org/10.1016/j.jopr.2013.05.021
a b s t r a c t
Aims: In the present study, to investigate its chemical stability and the in vitro sun pro-
tection factor (SPF) of Rosa kordesii petal extract in a gel formulation.
Methods: Due to its antioxidant and photoprotective properties, R. kordesii is a promising
candidate for use in cosmetic and pharmaceutical formulations. A high performance liquid
chromatography method was used to evaluate the chemical stability using R. kordesii
extract as marker at 5, 25 and 45 �C for 3e4 months. The sun protection factors were
analyzed by ultraviolet (UV) spectrophotometry using samples irradiated with UVB lamp.
Results: The chemical stability of the R. kordesii root extract gel was determined according to
the concentration of R. kordesii extracts at different storage temperatures (5, 25 and 45 �C)
for 3e4 months. It is screened for in vitro sun protection factor in the R. kordesii extract and
of its gel formulation and determines Photostability of the isolated R. kordesii extract and
SPF.
Conclusion: This study has shown that the R. kordesii petal extract gel is stable for at least 3e4
months when stored at 5 and 25 �C. It is essential for collection of similar data for different
plants and their flowers, as well as other parts. This proved activity of plant showed its
importance and prophylactic utility in anti-solar formulation. This will be a better, cheaper
and safe alternative to harmful chemical sunscreens that used now a days in the industry.
Copyright ª 2013, JPR Solutions; Published by Reed Elsevier India Pvt. Ltd. All rights
reserved.
1. Introduction against the adverse effects of solar and, in particular, UV ra-
The UV light is divided conventionally into UV-A
(320e400 nm), UV-B (290e320 nm), UV-C (100e290 nm), and
vacuo UV (10e100 nm). It has been reported that adverse ef-
fects by UV-B radiation on the human skin include erythema
(or sunburn), accelerated skin aging, and induction of skin
cancer. Sunscreens are chemicals that provide protection
2.
n (P.P. Maske).
2013, JPR Solutions; Publi
diation. Studies in animals have shown that a variety of
sunscreens can reduce the carcinogenic and immunosup-
pressive effects of the sunlight.1 Natural substances extracted
from plants have been recently considered as potential
sunscreen resources because of their ultraviolet ray absorp-
tion on the UV region and of their antioxidant power. Green
tea polyphenols, Aloe barbadensis extract, and aromatic
shed by Reed Elsevier India Pvt. Ltd. All rights reserved.
mailto:pratikmaske123@yahoo.in
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http://dx.doi.org/10.1016/j.jopr.2013.05.021
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Table 1 e Composition (%, w/w) of gel formulations used
for the chemical stability study and for the determination
of SPF.
Active ingredients Quantity
Carbomer 973 1.5 mg
Propylene glycol 10 ml
Triethanolamine 0.5 ml
Methyl paraben 0.25 mg
R. kordesii petal extract 1.42 mg
Distilled water qs 100 ml
j o u r n a l o f p h a rm a c y r e s e a r c h 7 ( 2 0 1 3 ) 5 2 0e5 2 4 521
compounds isolated from lichens are examples of natural
substances evaluated for their sunscreen properties.2e4 Anti-
oxidants from natural sources may provide new possibilities
for the treatment and prevention of UV-mediated diseases.5
Skin has the intrinsic properties to protect itself from the
sun, in the form of melanin. The sunlight which also stimu-
lates melanin and the pigment that acts as the skin natural
sunscreen. Sunlight stimulates hormone protection, and it
allows synthesis of vitamin D promotes skin cell regeneration.
Although it may be observed that the shorter wavelength and
the lower the number, the greater the energy level of the light
and themore damage it can do.6 Direct exposure to UV-C for a
length of time would destroy the skin. Fortunately, UV-C is
completely absorbed by gases in the atmospheres before it
reaches the ground. In any time the longer wavelength of UV-
B and UV-A pass right through the atmosphere.7e9 The mol-
ecules in sunscreen absorb most of UV-B and prevent it from
reaching the skin just as the molecules of the atmospheres
absorbs UV-C and prevent it from reaching the ground.10e12
Therefore, we report here the promise of the Rosa kordesii
petal extract in cosmetic formulations; there are no prior data
available about several aspects of the cosmetic formulation.
The goals of this research are to evaluate, its stability at 3e4
months stored at 5, 25 and 45 �C; the in vitro sun protection
factor; the Photostability of the isolated R. kordesii extract.
Table 2 e Physicochemical parameters of the extract gel.
Parameters %w/w (�) S.D.
Foreign organic matter 0.035% � 0.210
Ethanol soluble extractive 13.21% � 0.419
Water soluble extractive 31.15% � 1.520
Total ash 6.67% � 0.534
Acid-insoluble ash 2.34% � 0.122
Acid-insoluble ash 5.8% � 0.244
Loss on drying 7.125% � 0.215
Moisture content 5.67% � 0.257
2. Materials and methods
2.1. Test materials and extract preparation
Powdered petals of flower were percolated ethanolewater
(1:1) (100 ml/g of dried powdered petal) and the extract was
freeze-dried. The final concentration of the R. kordesii in the
crude extract was 7.1% (w/w), as evaluated by HPLC with
electrochemical detection.13
2.2. Formulations
For the chemical stability study, gel formulation containing R.
kordesii petal extract with final concentration of 0.1% (w/w)
and 1.5% (w/w) of carbomer 973 was prepared. All formula-
tions were stored in well-closed dark glass flasks and were
compounded fresh for all studies. The concentration was the
minimal active antioxidant concentration. A formulation was
prepared with the addition of active ingredient % (w/w) which
is shown in Table 1.
2.3. Physiochemical parameters of the extract gel
Physicochemical parameters of the extract gel were deter-
mined according to the standard method which is shown in
Table 2.
2.4. Chemical stability study
The stability of R. kordesii extract over time and the influence
of temperature on the degradation of R. kordesii extract gel
without and in the presence of antioxidant were investigated.
Gel formulations were stored in well-closed 10 g dark glass
flasks under different conditions: 5, 25 and 45 �C (�1 �C). The
amount of crude extract in samples was quantitatively
determined at 3e4 months stability studies. Briefly, 1.0 ml of
distilled water and 10ml of hexane were added to 50mg of the
samples. A fraction of the hexane layer was evaporated under
nitrogen, dissolved in ethanol and analyzed by HPLC with
electrochemical detection.13
2.5. Flavonoid identification test
The general flavonoid identification testwas performed on the
extract as previously described in Nevade Sidram et al.14,15
2.6. Determination of the in vitro sun protection factor
The in vitro methodmeasures the reduction of the irradiation
by measuring transmittance after passing through a film of
product. As in the operative conditions of the transmission
measurement are correct, this to be a very precise and single
value, always reproduciblefor the same product and
expressed as a single UV curve, in the percent transmittance
or absorbance scale (Fig. 1). The crude R. kordesii petal extract,
the gel formulation (1.5% carbomer 937) containing R. kordesii
petal extract were analyzed for the in vitro SPF. The crude R.
kordesii petal extract gel formulation was dissolved in meth-
anol UV solv:water (6:4). Scans of the samples in solutionwere
run from 320 to 290 nm using 1 cm quartz cuvettes in a Shi-
madzu UV-1700 spectrophotometer.16 The commercial sun-
screens, Himalaya� SPF 30, were used for the calculation of
the correction factor and a solution of 8% homosalate (v/v)
diluted to 0.2 mg/ml was used as standard. The SPFmodel used
in this study was based on the following equation proposed by
Mansur et al.17
http://dx.doi.org/10.1016/j.jopr.2013.05.021
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Fig. 1 e In vitro spectroscopic indices SPF, UVA PF.
Table 4 e SPF calculated for commercial sunscreens
(Himalaya� SPF 30) using Eq. (1) (Section 2.5) and data
given in Table 2.
l (nm) EE � I (normalized) Himalaya� SPF 30
Absorbance SPF
290 0.0150 0.7943 0.0198
295 0.0817 0.7723 0.0676
300 0.2874 0.7625 0.2145
305 0.3278 0.7443 0.2434
310 0.1864 0.7167 0.1356
315 0.0839 0.6906 0.0578
320 0.0180 0.6688 0.0199
Total 0.7586
EE: erythemal efficiency spectrum; I: solar simulator intensity
spectrum.
j o u rn a l o f p h a rma c y r e s e a r c h 7 ( 2 0 1 3 ) 5 2 0e5 2 4522
SPF ¼ CF�
X320
290
EEðlÞ � IðlÞ � absðlÞ (1)
where CF is correction factor, determined by sunscreens with
known SPF, so that a solution containing 8% of homosalate
gives SPF ¼ 8; EE(l) the erythemal efficiency spectrum; I(l) the
solar simulator spectrum as measured with a calibrated
spectroradiometer;
X320
290
EEðlÞ � IðlÞ ¼ 290e320 nm (2)
where, 290e320 nm in 5 nm increments; abs(l) is the spec-
troradiometer measure of sunscreen product absorbance.
Table 3 shows the normalized values of the product function
used in these studies and were calculated by Sayre et al.17,18
The data were analyzed statistically by factorial analysis of
variance (ANOVA). The TukeyeKramer test was then used to
determine significant differences between groups.
3. Results and discussion
3.1. Chemical stability of the R. kordesii extracts gel
formulation
The chemical stability of the R. kordesii root extract gel was
determined according to the concentration of R. kordesii ex-
tracts at different storage temperatures (5, 25 and 45 �C) for
3e4 months. The final concentration was expressed as
Table 3 e The normalized product function used in the
calculation of SPF data.
l (nm) EE � I (normalized)
290 0.0150
295 0.0817
300 0.2874
305 0.3278
310 0.1864
315 0.0839
320 0.0180
¼1.000
EE: erythemal efficiency spectrum; I: solar simulator intensity
spectrum.
micrograms of R. kordesii extracts per gram of gel formulation.
Carbomer frequently interacts with cationic drugs and ex-
cipients due to its numerous carboxylic acid groups.19 In vitro
studies using carbomers 973 showed that its interaction with
substances commonly used in the pharmaceutical industry,
such as lidocaine and mebeverine hydrochloride, was a
function of pH, drug, polymer concentration and electro-
lytes.20 All samples stored at 5 and 25 �C were stable over the
time of experiment (3e4 months). All of them showed an
initial decrease (20%) between days 0 and 1 and then remain
constant over time. The samples stored at 45 �Cwere stable up
7 days then the degradation of gel structure was observed
after 7 days.
3.2. In vitro sun protection factor in the R. kordesii
extract and of its gel formulation
3.2.1. Determination of the correction factor
The correction factor was calculated for commercial sun-
screen (Himalaya� SPF 30) using Eq. (1) data given in Table 3
and the total SPF given in Table 4.
3.2.2. Determination of SPF in the R. kordesii extract and of
its gel formulation
The crude R. kordesii petal extract has high SPF but after suit-
able formulation or by adding one or more ingredient like
carbomer, it gives lower SPF value for R. kordesii petal extract
gel formulation then crude R. kordesii petal extract. According
to Table 5 summarizes the SPF values determined for each
solution described. As expected, the SPF observed for the 8%
homosalate solution was approximately 8.23 � 0.5. Thus,
in vitro SPF value for the crude R. kordesii petal extract was
Table 5 e Results expressed as the average and S.D. of
three determinations replicated of the SPF values.
Sample SPF
Homosalate 8% 8.23 � 0.5
R. kordesii extract gel 3.25 � 0.01.
Crude R. kordesii extract 20.15 � 0.05
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Fig. 2 e Absorbance spectra of a methanol solution of 10 mg/ml R. kordesii extract: (A) just after preparation and (B) after
120 min of UVB irradiation.
j o u r n a l o f p h a rm a c y r e s e a r c h 7 ( 2 0 1 3 ) 5 2 0e5 2 4 523
20.15 � 0.05. When 1.42% R. kordesii petal extract was added to
the carbomer gel formulation, the SPF value was 3.25 � 0.01.
3.3. Photostability of the isolated R. kordesii extract
An ethanol solution of 10 mg/ml R. kordesii extract was irradi-
ated with a UVB lamp. Absorbance spectra of the R. kordesii
extract solutionwere stable over time of irradiation (Fig. 2). All
values are means of three replicated experiments. The con-
centration difference between times was considered not sig-
nificant in the statistical analysis.
4. Conclusion
This study has shown that the R. kordesii petal extract gel
formulation is stable for at least 3e4 months when stored at 4
and 30 �C. Sometime heat is a possible factor responsible for
the gel degradation over time. Further, R. kordesii petal extract
gel has, themajor antioxidant of R. kordesii, is also stable when
exposed to UVB irradiation. It is essential for collection of
similar data for different plants and their flowers, as well as
other parts. This proved activity of plant showed its impor-
tance and prophylactic utility in anti-solar formulation. This
will be a better, cheaper and safe alternative to harmful
chemical sunscreens that used now a days in the industry.
Conflicts of interest
All authors have none to declare.
Acknowledgments
The author is thankful to Prof. J.I. Disouza of TYCP Faculty of
Pharmacy, Warananagar for providing the necessary facilities
to carry out this work and we thank JPR Solutions for partial
funding in publishing this research.
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	In vitro determination of sun protection factor and chemical stability of Rosa kordesii extract gel
	1 Introduction
	2 Materials and methods
	2.1 Test materials and extract preparation
	2.2 Formulations
	2.3 Physiochemical parameters of the extract gel
	2.4 Chemical stability study
	2.5 Flavonoid identification test
	2.6 Determination of the in vitro sun protection factor
	3 Results and discussion
	3.1 Chemical stability of the R. kordesii extracts gel formulation
	3.2 In vitro sun protection factor in the R. kordesii extract and of its gel formulation
	3.2.1 Determination of the correction factor
	3.2.2 Determination of SPF in the R. kordesii extract and of its gel formulation
	3.3 Photostability of the isolated R. kordesii extract
	4 Conclusion
	Conflicts of interest
	Acknowledgments
	References