There are 4 major types of glass used in modern packaging all of which vary in appearance, chemical compatibility, functional use, and price.
Types I, Type II, and Type III glass containers are all suitable for parenteral (injection or intravenous) preparations as specified by the U.S. Pharmacopoeia on the basis of chemical durability tests.
Type I Glass:
Type I glass bottles are made from borosilicate, which have has a highly resistant composition and releases the least amount of alkali. It is commonly used for pharmaceutical or fine chemical products that are sensitive to PH changes.
Type II Glass:
Type II glass containers are made from commercial soda lime glass that has been de-alkalized to obtain a great improvement in chemical resistance by treating the interior surfaces at a high temperature to eat away the alkali on or near the glass surfaces. The undesirable characteristic of Type II Glass is that the treating etches the surface, causing a frosted appearance.
Type III Glass:
Type III glass bottles and containers are made of untreated commercial soda-lime glass and has average or somewhat above average chemical resistance. It is the most common in use and is compatible with most items such as: food; beverages; common chemicals, etc.
Type NP Glass:
Untreated glass containers made of ordinary soda-lime glass. This glass cannot be used for parenteral preparations.