Question

Water attack test is used to test _______ glass

• A. \( \text{Type I} \)
• B. \( \text{Type II} \)
• C. \( \text{Type III} \)
• D. \( \text{Type IV} \)

Hint:

Associate the water attack test with the surface treatment characteristic of Type II glass aimed at improving its resistance to aqueous leaching.

Answer 1

The Correct Option is B

The water attack test is specifically used to evaluate the hydrolytic resistance of Type II glass (treated soda-lime glass). Type II glass is surface-treated to improve its resistance to leaching of alkali, which can occur when in contact with aqueous solutions. The water attack test assesses the amount of alkali released from the glass surface under specified conditions, providing a measure of the effectiveness of the surface treatment and the suitability of the glass for pharmaceutical packaging, particularly for acidic and neutral aqueous preparations. Type I glass (borosilicate glass) has inherently high hydrolytic resistance and typically does not require this specific test. Type III glass (soda-lime glass) has moderate hydrolytic resistance, and Type IV glass (general-purpose soda-lime glass) has the lowest hydrolytic resistance and is generally not suitable for parenteral preparations without proper treatment.