Pharmaceutical Excipients- Review of USP Water Grades (Pro Version)

Hello and welcome to a quick review on use of
water in dosage forms. This is an important topic not only for your
licensing exams but also for when you start your practice.
Now, just so you know, this video is part 1 of lesson covering pharmaceutical
excipients. When the second video on pharmaceutical excipients is ready, you
will see the link for that video here, on the top, as well as down below in the
description of the video. In this video we will briefly review types
or grades of water as defined by United States Pharmacopeia that are commonly
used in pharmaceutical processes as well as in preparation of dosage forms. We
will also compare preparation and packaging requirements for these waters.
At the end of the video, we’ll also go over sample question to check your
knowledge. So, let’s jump right in! United States Pharmacopeia specifies
uses, packaging, methods of preparation, and quality attributes of waters that are
commonly used for pharmaceutical purposes. These nine types of waters are
also known as monographed waters. All other waters, such as drinking water or
distilled water, fall under the category of non-monographed waters. Remember that all
non-monographed waters are bulk waters that are typically used for
manufacturing or analytical purposes. For those of you who are interested in
knowing more about non-monographed waters, you can follow the link included in the
description of this video. For this video, we will primarily focus on monographed
waters. Based on the packaging, monographed waters
can be of two general types. First one is- bulk waters. That is those that are
produced on-site and are distributed from an internal water system. Second
type is – packaged waters. That is those which are produced elsewhere and
packaged for transportation. These are also sterilized to preserve microbial
quality throughout the shelf-life of the package. As shown in the figure, there are four types of
bulk waters and five types of packaged waters. Here is an interesting fact- all
packaged monographed waters are packaged form of either the Purified Water or
Water for Injection, that has been sterilized to preserve the microbiological
properties. We will go over all these waters beginning with purified water.
The first kind of bulk water is Purified Water.It is prepared by treatment of a
source water such as drinking water or potable water.
Depending on the need, typical treatment steps include combination of processes
such as – pre-filtration, softening dechlorination, deammonification,
deionization, reverse osmosis, distillation, ultrafiltration, and UV
light treatment. According to USP specifications, Purified
Water cannot contain more than ten parts per million of total solid and the pH of
Purified Water should be between five to seven.
Now… remember it is a bulk product and is used as an excipient for production of
non-parenterals as well as for cleaning of certain equipments. Purified Water
should not be used in parental or ophthalmic products. Next type of bulk water is, Water for
Injection. Water for injection is usually obtained by treatment or drinking water
using superior treatment processes like distillation or reverse osmosis. Water
for Injection is also expected to meet bacterial endotoxins specifications. In
simple words, it conforms to the standards of Purified Water and is also
expected to be free of pyrogens, however, unlike Purified Water, Water for
Injection is commonly used in the production of parenterals. The two other
types of bulk water include pure steam and water for hemodialysis. Let’s talk
about pure steam. First, similar to purified water, pure steam is also
prepared from pretreated source of water such as drinking water. It is
vaporized using a suitable mist elimination process and is distributed
under pressure. Pure steam is primarily used in steam sterilization of
equipments as well as in cleaning of official articles or containers.
Regarding water for hemodialysis, this type of water is specifically used for
hemodialysis applications – mainly the dilution of hemodialysis concentrate
solutions. Like other bulk waters, it is also produced and used on-site. As
mentioned earlier, purified water and water for injection can be packaged and
sterilized to form packaged waters. As shown on your screen, purified water
serves as the source of sterile water for inhalation and sterile purified water.
Similarly, water for injection can be used for manufacturing sterile water for
irrigation and sterile water for injection. Let’s go over these waters. As
the name indicates, sterile water for inhalation is typically used in
preparation of inhalation solutions. In general, sterile water for inhalation
contains no antimicrobial agents except when it is used in humidifiers or other
similar devices where it is liable to contamination over a period of time.
Sterile purified water is simply sterilized and packaged form of purified
water. This water also does not contain any antimicrobial agents
as this water does not meet the pyrogen specification specified by the
pharmacopoeia. It is not intended to be used in parenteral preparations.
Now… let’s discuss waters that are obtained from water for injection. First
one is sterile water for irrigation. Sterile water for irrigation is often
packaged in containers that are typically greater than 500 millilitres
in size. It is commonly used when sterile water is required but when the
application does not have particulate matter specification. This water is
hypertonic and has lower refractive index. Therefore this water provides
excellent visibility during endoscopy urological procedures. Now, let’s talk
about sterile water for injection. Sterile water for injection is packaged
in single-dose containers of type 1 or type 2 glass. The containers for
sterilized water for injection can vary in capacity, but they cannot exceed a
capacity of one liter. Therefore, limitations of total solid
depends on the size of container. This water is used for processing of sterile
products that are intended to be used intravenously. It can also be used for
compounding. Another kind of water that is related to
sterile water for injection is bacteriostatic water for injection.
Addition of one or more antimicrobials to sterile water for injection produces
bacteriostatic water for injection. Similar to sterile water for injection,
it is also packaged in containers of type 1 or type 2 glass but the capacity
of containers cannot exceed 30 milliliters. You should note that among
all the monographed water grades that can be used for parental administration, only
bacteriostatic water for injection contains antimicrobials. Another
advantage of adding antimicrobials is that these waters are safe for multiple
uses after container has been opened. Therefore, the containers used for
packaging of bacteriostatic waters are often multi-dose containers. In previous
slides we covered some facts and specifications that can be hard to
remember over a period of long time. Therefore, I strongly recommend using
these cheat sheets and the mind map a few days before your pharmacy or other
licensing exam. Let’s find out how much information you were able to retain
through this particular question. You should pause the video now to review
your choices. Note that the question is asking for a
water that is used in manufacturing, meaning you should recall a bulk water.
Also, it should be okay for parenteral use. As you can see on the cheat sheet as
well as the mind map, the only non -pyrogenic bulk water type is water for
injection. Therefore, the correct answer is C.
You can download these slides, cheat sheet, as well as the mind map by going
to our website or at the link given below. Thank you for your time!


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