Which of the following is not an antibacterial

Options

A. Prontosil
B. Salvarsan
C. Sulphanilamide
D. Lansoprazole

Answer

To determine which of the following options is not an antibacterial, we will analyze each option provided:

1. **Prontosil**: This is an antibacterial drug that belongs to the sulfonamide group. It is used to combat bacterial infections. Therefore, Prontosil is an antibacterial.

2. **Sulversan (Ars Phenomen)**: This drug was used in the early 20th century to treat syphilis, a bacterial infection. Hence, Sulversan is also classified as an antibacterial.

3. **Sulfenolamide**: This is another sulfonamide drug and a derivative of aniline, which is used to treat bacterial infections. Thus, Sulfenolamide is an antibacterial as well.

4. **Lansoprazole**: This medication is classified as an antacid. Antacids are used to neutralize stomach acid and are not effective against bacteria. Therefore, Lansoprazole is not an antibacterial.

Based on the analysis, the answer to the question "Which of the following is not an antibacterial?" is **Lansoprazole**.

### Step-by-Step Solution:
1. Identify the term "antibacterial" and its meaning.
2. Analyze each option to determine if it is an antibacterial.
- Prontosil: Confirmed as antibacterial.
- Sulversan: Confirmed as antibacterial.
- Sulfenolamide: Confirmed as antibacterial.
- Lansoprazole: Identified as an antacid, not antibacterial.
3. Conclude that Lansoprazole is the correct answer.