Designing a new drug to selectively target the underlying cause of psoriasis while minimizing potential side effects on other organs and tissues involves several steps:1. Identify the molecular target: The first step is to identify the specific molecular target s involved in the pathogenesis of psoriasis. These targets can be proteins, enzymes, or receptors that play a key role in the development and progression of the disease. For example, in psoriasis, the overproduction of pro-inflammatory cytokines such as tumor necrosis factor-alpha TNF-alpha , interleukin-17 IL-17 , and interleukin-23 IL-23 has been implicated in the disease process.2. Design a selective drug: Once the molecular target s have been identified, the next step is to design a drug that selectively binds to and modulates the activity of the target s . This can be achieved through various techniques such as rational drug design, high-throughput screening, and structure-based drug design. The goal is to create a drug that has high affinity and specificity for the target, which will help minimize off-target effects and potential side effects on other organs and tissues.3. Optimize drug delivery: To ensure that the drug reaches its target in the skin, it is crucial to optimize the drug's delivery system. This may involve designing a topical formulation, such as a cream or gel, that can penetrate the skin and deliver the drug directly to the affected area. Alternatively, a systemic delivery method, such as oral or injectable administration, may be necessary if the drug cannot effectively penetrate the skin. In this case, it is essential to develop a drug with minimal systemic side effects.4. Evaluate safety and efficacy: Before a new drug can be approved for use in humans, it must undergo rigorous testing to evaluate its safety and efficacy. This typically involves preclinical studies in cell cultures and animal models, followed by clinical trials in human subjects. Throughout this process, researchers must carefully monitor the drug's effects on both the target tissue i.e., the skin and other organs and tissues to ensure that it is both effective in treating psoriasis and safe for use in humans.5. Monitor and manage side effects: Even with a highly selective drug, some side effects may still occur. It is essential to monitor patients closely during clinical trials and after the drug is approved for use to identify any potential side effects and develop strategies to manage them. This may involve adjusting the drug's dosage, developing combination therapies with other medications, or providing additional treatments to address specific side effects.By following these steps, researchers can work towards designing a new drug that selectively targets the underlying cause of psoriasis while minimizing potential side effects on other organs and tissues.