629 LINIMENT OF NAFTALAN OIL active components with subsequent prolonged release it protects incorporated substances from degradation it has an immediate moisturizing effect that lasts for a long time and it minimizes the risk of irritation (29,30). In accordance with the classification of Florence and Whitehill, the cream under study refers to a multiple emulsion of type B, the drops of which contain in the majority several small internal drops (31). LNO is mixed with the oil phase. In this case, a multiple emulsion of the water- oil-water type is formed, the structure of which is an aqueous phase in which drops of the oil phase are present, which, in turn, contain several small internal drops of the aqueous phase. Microphotographs of the test system were repeated 30, 90, and 180 d after preparation (Figure 4). The average diameter of the drops remained almost constant over time, which proves the stability of the cream with 0.4 wt% of LNO for a long period (Figure 4). A further increase in the content of dietary supplements leads to enlargement of the droplets of the emulsion, which leads to a decrease in colloidal stability. The effectiveness of the developed cream with 0.4 wt% of the LNO was evaluated by analyzing images of the skin structure (Figure 5). The data in Figure 5 indicate smoothing of the skin 120 min after the application of the cream with LNO. According to the results of a short-term in vivo study, it is seen that 1 h after applying the sample with LNO, skin hydration relative to the base values and the control significantly increased (Table V). The fat content of the skin remained almost unchanged. 0.2 wt% LNO 0.4 wt% LNO 0.9 wt% LNO Figure 3. Morphology of cream with LNO 48 h after preparation (magnification ×1,000).

630 JOURNAL OF COSMETIC SCIENCE Figure 4. The average diameter of 0.4 wt% LNO emulsion droplets over an aging time. Cream without liniment oil (control) Before application Before application Cream with liniment oil Figure 5. Assessment of skin relief 120 min after applying the cream without liniment oil (control) and cream with this active component.