Фармакологічне дослідження крему з наночастинками церію діоксиду

Abstract

Дисертація присвячена теоретичному та експериментальному обґрунтуванню доцільності розробки нового фотопротекторного лікарського засобу з наночастинками церію діоксиду у формі дермального крему. У скринінговому дослідженні фотопротекторної активності на моделі фотодинамічної травми у мурчаків встановлений оптимальний склад лікарської форми для поглибленого фармакологічного вивчення. Безпека крему з наночастинками церію діоксиду оцінена у дослідженнях гострої, субхронічної, хронічної токсичності, гонадотоксичності та ембріотоксичності, мутагенної дії. Доведені ефективність та безпека лікарської форми при нашкірному нанесенні мурчакам у рамках моделі фотодинамічної травми та посиленої аміфурином фотодинамічної травми. Визначені деякі показники фармакокінетики крему з наночастинками церію діоксиду при топікальному застосуванні: абсорбція у системний кровообіг, накопичення церію у шкірі, крові та внутрішніх органах. Одержані експериментальні дані свідчать про доцільність розробки лікарських засобів з даним активним фармацевтичним інгредієнтом для профілактики ураження шкіри ультрафіолетовим випромінюванням.

Диссертация посвящена экспериментальному обоснованию целесообразности разработки нового фотопротекторного лекарственного средства с наночастицами диоксида церия в форме дермального крема. В скрининговом исследовании фотопротекторной активности на модели фотодинамической травмы у морских свинок установлен оптимальный состав лекарственной формы для углубленного фармакологического изучения. Безопасность крема с наночастицами диоксида церия оценена в исследованиях острой, субхронической, хронической токсичности, гонадотоксичности и эмбриотоксичности, мутагенного действия. Доказаны эффективность и безопасность лекарственной формы при наружном нанесении морским свинкам в рамках модели фотодинамической травмы и усиленной аммифурином фотодинамической травмы. Определены некоторые показатели фармакокинетики крема с наночастицами диоксида церия при топикальном применении: абсорбция в системный кровоток, накопление церия в коже, крови и внутренних органах. Полученные экспериментальные данные свидетельствуют о целесообразности разработки лекарственных средств с данным активным фармацевтическим ингредиентом для профилактики поражения кожи ультрафиолетовым излучением.

The thesis is dedicated to theoretical and experimental substantiation of an expediency of development of a new photoprotective drug with cerium dioxide nanoparticles in the dosage form of a dermal cream. The screening of a photoprotective action of creams with cerium dioxide nanoparticles on a model of photodynamic injury in guinea pigs was carried out. The cream with 0.25% cerium dioxide nanoparticles was specified as a leader, because it had photoprotection activity index of 43.6% compared to 23.1% and 35.9% for 0.1% and 0.5% creams. In the group of its use there was a lower number of ulcers and deep skin lesions, 17.4% less pronounced leukocytosis compared to pathology control group, the smallest increase in skin temperature (0.16 °С) in comparison with other test samples after 1 hour post-exposure, and an absence of blood histamine level increase. In an acute toxicity study it was showed that in the settings of cutaneous application and oral administration of 5 g/kg of the cream with cerium dioxide nanoparticles in rats the dosage form didn’t cause mortality, didn’t affect body weight, macroscopic structure and mass coefficients of internal organs. A decline in serum levels of total protein by 5.8% (cutaneous application) and albumin by 13.2% (oral administration) were observed, but the values stayed within physiological standard. In the following subchronic toxicity study it was found that cutaneous application of 0.06, 0.18, or 0.60 g/kg of the cream with cerium dioxide nanoparticles in rabbits during 90 days didn’t cause changes in condition and behavior of animals, consumption of food and water, body weight dynamics, and blood biochemical and hematological indices. The glucose level after 1 month of use of 0.60 g/kg dose of the cream was 44.5% higher compared to intact control, but after 3 months of observation the differences were gone. It was established that the cream with cerium dioxide nanoparticles in the setting of cutaneous application in rats during 6 months in the doses of 0.1, 0.5, and 1.0 g/kg didn’t cause mortality, negative body weight dynamics, was safe regarding its effect on serum biochemical indices, macroscopic and histological structure, and mass coefficients of internal organs. A decrease in leukocyte count by 15.2% and 13.3% after 1 month of an experiment was observed in the group of 0.1 and 0.5 g/kg cream application, respectively, compared to placebo group, with further normalization of this parameter by the 6th month. Cutaneous application of the cream with cerium dioxide nanoparticles in the doses of 0.1, 0.5, and 1.0 g/kg during 90 days in male rats didn’t cause gonadal toxicity. The duration of sperm motility preservation was by 13.5%, 9.7%, and 11.0% higher in respective groups compared to placebo group. The topical use of the cream in the doses of 0.1, 0.5, and 1.0 g/kg in pregnant female rats didn’t cause death or anatomical changes of embryos. The cream with cerium dioxide nanoparticles didn’t have mutagenic effect on somatic cell genome in the case of single cutaneous application in the doses of 0.1 and 1.0 g/kg in mice and repeated cutaneous application in the dose of 0.1 g/kg in mice. Pharmacological action of the cream with cerium dioxide nanoparticles in the setting of 2 mg/cm2 cutaneous application, on a model of photodynamic injury in guinea pigs was confirmed by 43.2% photoprotection activity index, complete skin epithelization in 5.86 days, which is 46.7% faster than in pathology control group, a normalization of skin temperature, and a decrease of destructive changes in the skin, confirmed by histology analysis. An efficacy of the cream with cerium dioxide nanoparticles in the setting of 2 mg/cm2 cutaneous application, on a model of ammifurin amplified photodynamic injury in guinea pigs was confirmed by 30.8% photoprotection activity index, an activation of adaptive processes in epidermis, 23.1% and 24.2% lower prostaglandin PgЕ2 and PgF2α skin levels compared to pathology control group, 0.55 °С less pronounced skin temperature increase in comparison with pathology control group, and complete wound healing in 9.14 days, which is 44.8% faster than in untreated animals. The data regarding pharmacokinetics of the cream with cerium dioxide nanoparticles in the setting of 2 mg/cm2 single cutaneous application in rats was clarified. Cerium wasn’t absorbed into circulation and wasn’t accumulated in liver, kidneys, and spleen, which is indicative of an absence of systemic absorption. Nanoparticles were not registered in the blood after ultraviolet exposure, which points at an acceptable safety profile in these conditions. Cerium accumulates in the skin during 24 hours with further gradual decrease in concentration – by 42.5% at the 48th hour of experiment for an intact skin and by 20.2% – for ultraviolet exposed skin, which is indicative of the prolongation of the photoprotective action of the cream with cerium dioxide nanoparticles in the setting of increased insolation. Thus, the obtained results substantiate an expediency of further preclinical and clinical studies of the cream with cerium dioxide nanoparticles with the aim of development of effective photoprotective drug for prevention of ultraviolet skin injury and malignancies, caused by it.