Pharmaceutical Analysis

Step 1: Understanding the autoclaving process.
Autoclaving is a sterilization process that uses high-pressure steam to kill bacteria. The primary mechanism by which it kills bacteria is the coagulation of proteins, which denatures and inactivates the bacteria.
Step 2: Analyzing the options.
(A) Oxidising proteins: This is incorrect, as autoclaving primarily works by heat and pressure, not oxidation.
(B) Alkylating essential materials: This is not the main mechanism in autoclaving. Alkylation occurs in chemical sterilization processes.
(C) Coagulation of proteins: Correct — The heat and pressure in autoclaving cause the proteins in bacterial cells to coagulate, leading to the bacteria's death.
(D) Radiation: Radiation is a separate sterilization process, not the method used in autoclaving.
Step 3: Conclusion.
The correct answer is (C) Coagulation of proteins as it accurately describes the mechanism of bacterial death during autoclaving.

Step 1: Understanding enteric coating.
Enteric coating is a polymer barrier applied to oral medication to prevent it from dissolving in the stomach. It protects the drug from acidic stomach conditions and releases it in the intestines.
Step 2: Analyzing the options.
(A) Sodium starch glycolate: This is used as a disintegrant, not for enteric coating.
(B) Cellulose acetate phthalate: Correct — This is a common material used for enteric coating as it resists stomach acid and dissolves in the alkaline environment of the intestines.
(C) Starch: Starch is a binding agent, not suitable for enteric coating.
(D) PEG-400: This is a plasticizer, not used for enteric coating.
Step 3: Conclusion.
The correct answer is (B) Cellulose acetate phthalate as it is the material used for enteric coatings.

Step 1: Understanding the working principle of the ball mill.
Ball mills are used in the grinding process to reduce the size of material. The principle of working involves the combination of attrition (grinding) and impact (striking). This process efficiently breaks down the material into smaller particles.
Step 2: Analyzing the options.
(A) Compression: This is incorrect as the working of the ball mill involves more than just compression.
(B) Cutting: Cutting is not the main principle of ball mill operation. While some cutting might occur, it is not the primary mechanism.
(C) Attrition and impact: Correct — Ball mills primarily work on the principles of attrition (rubbing) and impact (collision). This combination breaks down the material efficiently.
(D) Combustion: This is incorrect as combustion is not related to the working of a ball mill.
Step 3: Conclusion.
The correct answer is (C) Attrition and impact as these are the primary forces involved in the operation of a ball mill.

Step 1: Understanding the sieve number.
In the Indian Pharmacopoeia (IP), sieve numbers are used to categorize the size of particles. For fine powders, particles are expected to pass through sieves with higher numbers, indicating smaller particle sizes.
Step 2: Analyzing the options.
(A) 44: This is incorrect as it represents a larger sieve number than 50.
(B) 50: Correct — Fine powders typically pass through sieve number 50, which represents a finer particle size.
(C) 85: This sieve number would be for even finer particles but not typically for powders classified as fine.
(D) 10: This sieve number is too coarse for fine powders.
Step 3: Conclusion.
The correct answer is (B) 50 as it corresponds to the sieve number for fine powders.