Objective: Identify the types of nanoparticles used in dermocosmetics and their main applications. Methods: A bibliographic review was carried out in the databases Google Scholar, and PubMed, as well as databases subscribed to the system of libraries, documents, and information of the Universidad de Costa Rica such as ScienceDirect, Elsevier, EBSCO, MEDLINE, Clinical-Key, among others. The search was conducted in both English and Spanish. Conclusion: Nanotechnology in the cosmetic industry has been an area that has grown exponentially in recent years. Various types of nanoparticles are used in different skincare applications in the cosmetics industry; however, much research remains to be done on the safety and toxicity of their use for humans and the environment.

Background: Arsenic trioxide is a chemical compound that has been used as a treatment for various diseases. Despite being potentially toxic, this compound has been used as a therapy to treat Acute Myeloid Leukemia and is being investigated as a possible treatment for different types of cancer. Objectives: The present review aims to describe the use and studies reported in the literature of Arsenic Trioxide as a possible therapeutic agent for Acute Myeloid Leukemia, Acute Promyelocytic Leukemia, Chronic Myeloid Leukemia, Multiple Myeloma, Myelodysplastic Syndrome, Hepatocellular Carcinoma, Lung Cancer, Neuroblastoma, Breast Cancer, Aplastic Hepatitis C, and HIV-1. Methods: A systematic review was conducted using databases (Elsevier, Google Scholar, PubMed) to compile documents published before December 2023. Results: Multiple pharmacological applications of arsenic trioxide have been reported to treat acute and chronic myeloid leukemia. Arsenic trioxide has been shown to inhibit angiogenesis, which helps treat multiple myeloma. Several studies have shown and suggested the effectiveness of arsenic trioxide as a treatment of hepatocellular carcinoma, lung cancer, neuroblastoma, prostate cancer, breast cancer, aplastic anemia, hepatitis C, and HIV-1.Conclusion: Despite potentially toxic effects, Arsenic compounds are therapeutic agents for multiple diseases, from syphilis to cancer. In recent years, more efficient ways have been investigated to deliver and find the specific dose to treat the disease, causing the fewest possible adverse effects.