There are several differences between drug and medical device from my point of view one of the most important differences is the regulatory approval of drugs and medical devices.

The process for drug approval involves extensive testing to ensure safety, efficacy, and quality. Regulatory agencies, such as the FDA.

On the other hand, when it comes to medical devices, obtaining regulatory approval is a crucial step to ensure that they are safe and effective for use in treating patients. The approval process involves thoroughly evaluating the device's design, manufacturing, and performance to ensure that it meets the required safety and efficacy standards. The regulatory pathway varies depending on the classification of the medical device, with some devices requiring more rigorous testing and evaluation than others. 

Medical devices are by-and-large mechanical in nature and have an inert effect on the human body, while drugs are chemical in nature and are designed to actively interact with the metabolic or immune system. However, besides their nature, medical devices and drugs have many key differences.

The first key difference between the two would be the process in which they work or operate. Medical devices will only work if they are used correctly. Their effectiveness rely on various aspects including the skill and experience of the physician using them, the quality of the hospital, and many other factors. On the other hand, drugs either work or they do not. As a result of them being chemical in nature, their effectiveness is relatively straightforward to prove.

Another key difference is the risk to the body that each impose. The risk to the body from drugs are of a different order and magnitude than the risk to the body from medical devices. Medical devices can range from simple and everyday consumer products like glasses and dentures, to much more extensive care products such as syringes and bandages, to other devices including hip implants or X-Ray equipment. Therefore, risks within medical devices include manufacturing, material toxicity and degradation, sterilization and pyrogenicity, and risk associated with the medical device user. As for the risk in drugs, it is the chance that something unexpected or unwanted may happen to the user after using the drug. This could include non-serious risks like an upset stomach, or more serious things such as liver damage.

Both medical devices and drugs are essential parts of healthcare and medicine. Although both have quite a few similarities, they also have quite a few differences. They're similar in that they can be used to diagnose, prevent, and treat diseases or injuries. One of the main differences is in the way they are used to treat diseases and injuries. Medical devices are usually physical and provide support through mechanical, physical, or electrical means. Some examples include MRI, prosthetics, and implants. On the other hand, drugs provides its affects through biochemical and pharmacological means and examples include vaccines or antibiotics. 

Drugs interact with the biological and physiological systems of our body. Devices mainly try to achieve the same goal through mechanical and electrical means sometimes even physically. Drugs have to go through pre clinical and clinical trials that involve animal and human testing while devices go through 510(k) process if categorized as class II or PMA for class III. After drugs are marketed, they are closely surveyed for harmful reactions while devices are surveyed for malfunction, safety and performance. 

Drugs and medical devices are both crucial parts of the healthcare field, and they both have their own purposes whether used separately or combined. At this point in our engineering careers, we have an understanding that drugs are used to prevent and fight a disease or illness while devices are used to aid or monitor the body in a way. In simple terms if you had a headache you would take a Tylenol, but if you wanted to check your blood pressure you would use some type of meter device to read and process your body's data. As we have learned this week, there is a big difference in the regulation of these two. Medical devices are classified based on their application, and the amount of testing and validation needed changes based on the class. For example, a Class 1 device in most cases would not need nearly as much testing as a Class 3 device. This often causes the timeline to market the devices to increase dramatically. On the other hand drugs always requires very intense testing and approval from various organizations including the FDA.

Additionally, the way that medications and medical equipment are administered differs significantly from one another. Usually, drugs are given by ingestion, injection, or inhalation, allowing them to circulate throughout the body via the bloodstream. On the other hand, medical devices are frequently inserted into the body or placed externally to perform therapeutic functions, monitoring, or mechanical support. Also, they differ in terms of the duration of their impact on the body. Drugs often have a systemic and prolonged effect, especially if taken regularly. Medical devices, on the other hand, typically do not have a long-lasting effect on the body once they are withdrawn or switched off, even though they could provide instant relief or support.

There are many differences between drugs and medical devices. The are both regulated under the FDA but usually under different agencies / subsections. Development and testing of both medical devices and drugs may differ as well. Drug development usually focuses on the efficacy and safety. Clinical testing usually determines correct dosage and performance in vivo. Medical device development and testing involves the usability and performance of the device, as well as safety.

Drugs and medical equipment are very important for the safety of our health. Medicines and medical devices have many differences that may include their mechanism, their interaction with the human or animal body, their regulatory agencies that are within the FDA that are responsible for controlling and regulating their safety, etc. Drugs interact with the human body through biochemical means, while medical devices attempt to achieve this through mechanical, physical or electrical means. Additionally, drugs are administered by swallowing, injecting, or inhaling them. In contrast, medical devices are often implanted in the body or placed externally to provide mechanical support.The Center for Drug Evaluation and Research (CDER) is responsible for providing safety guidelines and approving each drug to enter the market. Whereas, the Center for Devices and Radiological Health (CDRH) is responsible for the regulation and approval of any medical device before it enters the market.

1. Drug has chemical reaction and medical device do not have chemical reaction. 

any other differences ?

Well, there are alot of differences between a drug and a medical device, both in application and definition. By definition, a medicinal drug is a a chemical or compound, which can be biologically based, that is used to treat, halt, cure, or prevent a medical condition. Meanwhile, a medical device is typically a technical or physical component that exists physically within or externally of a biological environment to treat or cure a medical condition.

Most medical devices, but not all, require some external source of power or energy to function, such as pacemakers, EKG, MRI, etc. while there are other 'medical devices" that would not need power to function like a catheter or implanted joint. Both drugs and medical devices are broad umbrella terms to describe the overall individual item, but the components that go into making that item can create a complex web of descriptions and functions that may make the item far more difficult to classify, and may even stretch its definition and application. This is why the original question, both have many differences but can also have many similarities dependent on their application and use case.