THEORETIC AND EXPERIMENTAL SUBSTANTIATION OF A COMPOSITION OF A CREAM WITH CERIUM DIOXIDE NANOPARTICLES

Abstract

Relevance. Cutaneous malignancies are one of the most widespread form of cancer with increasing prevalence and Ukraine and worldwide. A negative impact of ultraviolet radiation is one of the risk factors of this pathology, and it can be prevented by photoprotectors. It is expedient to develop a new effective and safe sunscreen with cerium dioxide nanoparticles, which is deprived of photocatalytic properties and has prominent photoprotective and antioxidant action.
 Objective: theoretic and experimental substantiation of a composition of a cream with cerium dioxide nanoparticles by the means of a screening of photoprotective action on a model of a photodynamic injury in guinea pigs with further identification of a leader cream.
 Material and methods. A photodynamic injury in guinea pigs was modeled with ultraviolet emitter with an exposition of 5 minimal erythema doses. Twenty minutes prior to exposure a cream with 0.1%, 0.25% or 0.5% cerium dioxide nanoparticles or a comparator cream with 3% titanium dioxide was applied topically. A leader cream was then chosen based on the following criteria: photoprotective action, skin temperature, blood leukocyte count, and serum histamine level.
 Results. The cream with 0.25% cerium dioxide nanoparticles was identified as a leader cream, because its photoprotective action was 43.6%, compared to 23.1% and 35.9% for 0.1% and 0.5% creams, respectively. After an application of the cream with 0.25% cerium dioxide nanoparticles there were less ulcers and deep skin lesions and 17.4% less leukocytosis than in pathology control group; the lowest increase (0.16 °С) in skin temperature was observed in comparison with other test creams; no increase in serum histamine level was detected.
 The cream with 0.25% cerium dioxide nanoparticles was more effective than a comparator. Four hours post-exposure there was 57.1% less pronounced erythema in the leader cream group than in the cream with 3% titanium dioxide group. photoprotective action of a comparator was only 23.1%. Skin temperature in a comparator group 4 hours post-exposure was 0.26 °С higher than in the cream with 0.25% cerium dioxide nanoparticles group. Moreover, 8.6% more pronounced leukocytosis was observed in the cream with 3% titanium dioxide group, compared to the leader cream group.
 Conclusions. The cream with cerium dioxide nanoparticles 0.25% was recognized as the leading sample and recommended for choosing technology and final composition of the finished dosage form, for further in-depth pharmacological study by totality of studied parameters.