NEXT-GENERATION NATURAL BABY BARRIER CREAM FORMULATIONS 177 United Kingdom), and olive oil (Herbarium, Istanbul, Turkey) (all other solvents and the items were cosmetic or pharmaceutical purity). Zeta-Sizer (Malvern ZS-50, United Kingdom), homogenizer (Silverson, Chesham, United Kingdom), vortex (Heidolph, Schwabach, Germany), water bath (Bandelin, Berlin, Ger- many), weigh scale, incubator (Ohaus, Nänikon, Switzerland), microbiological HEPA fi lter cabinet (Metisafe, Ankara, Turkey), viscometer (Brookfi eld DV PRO II, London, United Kingdom), and pH meter (Heidolph) were used. METHOD Prep aration of cream formulation. The cream f ormulation is prepared by adding the water phase into the oil phase as w/o-type emulsion system. The substances that make up the oil phase (olive oil, lanolin, shea butter, beeswax, calendula oil, and emulsifi ers) are weighed from low to high in weight on an analytical balance and melted at 70°C until they are com- pletely liquefi ed. Similarly, w ater phase materials (magnesium sulfate, EDTA, glycerin, and water) are weighed and heated to 70°C, and after making sure that it mixes well, it is slowly poured over the oil phase and homogenized in a high-speed homogenizer for 30 min (around 2,000– 3,000 rpm). The mixture was cooled down to 40°C approximately half an hour later. Then, zinc oxide and vitamin E were added slowly on the emulsion and homogenized at 3,000 rpm for 30 min, and the process was completed. No antimicrobial protective agent was added (benzalkonium chloride, hydrogen peroxide, nitrofurazone, etc.) to the formulations to be suitable for the study. Also, essential oil and colorants were not added because of their un- wanted properties. Detailed formulation components and ratios are given in Table 1. CHARACTERIZATI ON OF CREAM FORMULATIONS Determination of pH values. The pH values of the formulation were measured with a pH meter, while the standard laboratory conditions were kept optimum each sample was repeated three times, and their average values were taken. Viscosity and rheological study. The rheologica l analysis was carried out using a device oper- ating on the principle of rotational viscometer. The torque from the device is applied to the spindle using a spring, and the deviation in the spring allows the viscosity of the liquid to be measured (between 0.05 and 1 rpm, 30–100 torque). Particle size and zeta potential (ζ) analysis. Particle/drople t sizes of the formulations were measured at room temperature (25 ± 2°C) at an angle of 173° using the zeta sizer instru- ment. During the same measurements, the zeta potentials (ζ) of the formulations were measured at 78.5 dielectric constant, with this device at 25 ± 2°C. Each sample was subjected to fi ve trials, and each trial was repeated fi ve times. HLB calculation. The H LB value is an i mportant factor for determining the amount of surfactant and cosurfactant required for a stable w/o-type emulsion. For this, Dehymuls PGPH HLB: 3.5 Lameform TGI HLB: 3.5 and cetyl ester wax HLB: 11.8 was used as a surfactant. First of all, the total RHLB (requiring HLB) value of the emulsion is calcu- lated by multiplying the HLB value of each component of the oil phase by the weight

Table 1 Component and R atios of BBC Cream Formulations Ingredient INCI name BBC-1 BBC-2 BBC-3 BBC-4 BBC-5 BBC-6 BBC-7 BBC-8 Vaseline Vaseline-white petrolatum 23 23 — — — — — — Paraffi n oil Paraffi n oil 8 8 — — — — — — Bees wax Bees wax 3,5 3,5 3,6 3,0 5 3,00 3,00 3,0 Arlacel 83 V Sorbitan sesquioleate 3 3 — — — — — — Oleum oil Olea Europaea oil 7,5 7,5 28 28 35 28 5 28 Lanolin Lanolin 1 1 2,5 2,5 6 2,5 2,5 2,5 BHT Butyl hydroxy toluene 0,02 0,03 0,03 0,01 0,01 0,03 0,01 0,01 Glycerine Glycerine 5 5 8 8 4,8 8,00 8 8 ZnO Zinc oxide 10 10 21 21 7,1 20,00 20 20 MgSO4.7HO2 Magnesium sulphate 1 1 1 1 — — 1 1 EDTA Etylenediaminetetraacetic acid 0,05 0,05 0,05 0,05 — — — 0,05 Deionized W. Deionized water 37,93 37,92 30.07 25,04 35,09 29,07 54,99 31,94 Shea butter Shea butter — — 0,75 0,75 — 0,75 0,75 0,75 Calendula oil Calendula oil — — 0,75 0,75 — 0,75 0,75 0,75 Dehylmus PGPH Polyglyceryl-2 Dipoly hydroxy stearate — — 4,25 4,00 — 4,00 4,00 4,00 Lameform TGI Polyglyceryl-3 Diiso stearate — — — 3,00 — 3,00 — — Boraks Sodium borax — — — 2,00 2,00 - — — Vitamin E Vitamin E — — — 0,50 — 0,50 — — D-panthenol Dex-panthenol — — — 0,40 — 0,40 — — Spermaceti Cety ester wax — — — — 5 — — — JOURNAL OF COSMETIC SCIENCE 178