Question

In parenterals, Water attack test is used for which type of glass?

• A. Type I
• B. Type II
• C. Type III
• D. Non Parentral

Hint:

- Type I and Type III $\rightarrow$ Powdered Glass Test (evaluates the bulk glass composition). - Type II $\rightarrow$ Water Attack Test (evaluates the de-alkalized surface layer of intact containers).

Answer 1

The Correct Option is B

Concept: Pharmacopoeias categorize glass containers into distinct types based on their chemical composition and resistance to water leaching (hydrolytic resistance). This resistance is evaluated using the Powdered Glass Test or the Water Attack Test. Compendial Glass Type Framework:
• Type I (Highly resistant borosilicate glass): Evaluated using the Powdered Glass Test.
• Type II (Treated soda-lime glass): Manufactured from standard commercial soda-lime glass that has been de-alkalized by treating its internal surfaces with sulfur dioxide gas ($\text{SO}_2$) at high temperatures. This treatment neutralizes surface alkali oxides. Because this protective layer is only present on the surface, crushing the glass would expose the untreated core. Therefore, hydrolytic resistance must be evaluated using the Water Attack Test on intact containers.
• Type III (Regular soda-lime glass): Evaluated using the Powdered Glass Test.
• Type IV NP (Non-parenteral glass): Intended for non-injectable preparations. Thus, the Water Attack Test is specifically designated for Type II treated soda-lime glass containers.