Step II: Oil phase was prepared by heating Sodium
Propyl Paraben (0.06%), Stearic acid (2%), Cetyl
alcohol (1%), Cetomacrogal-1000 (2%), Cetostearyl
alcohol (5%) and M. concanensis seed oil (20%) at 80
OC.
Step III: Oil phase was added in water phase at 80 OC
with continuous stirring for 20-25 min and then it was
homogenized till uniform emulsion is formed. To
improve the aesthetic value of the product, perfume
was added in quantity sufficient. The finished product
has white colour and gel-like consistency. It was then
poured into the wide mouth container and stored at
temperature not exceeding 370C.
Determination of In-Vitro SPF of Sunscreen Cream
Method
Approximately 100 mg of the investigational sample
was applied and spread on 50 sq.cm area to obtain a
sample film thickness of 2 ml /cm2 on Transpore
surgical tape to get an even film as suggested in the
operation manual of Optometrics LLC SPF-290S for
the sample preparation and application technique. The
samples thus prepared were exposed to Xenon arc
lamp with UV range 290nm to 400nm for determining
the SPF.
WIN SPF uses the Diffey’s method for the standard
deviation calculation for SPF.