Order Entry and Processing Study Guide for the PTCB Exam

Page 1

The PTCB® exam underwent some slight changes in January 2020, so we have revised our study materials to reflect those changes. Basically the same concepts are covered in four sections of study instead of the old nine sections. The new material also adds a few new concepts that we have included in our test preparation.

General Information

Order Entry and Processing questions on the newest version (2020) of the PTCB® Exam take up 21.25% of the test—so, a little under one-fourth. Be sure to be well-versed in the content covered in this study guide.

The content assessed by these questions comes from four different sections of the old test: Sterile and Non-Sterile Compounding, Order Entry and Fill Process, Information Systems, and Inventory Management. These questions cover a lot of ground.

Non-Sterile Compounding

Non-sterile compounding refers to any preparation that does not meet the standards for sterile compounding and must follow USP 795 regulations. This includes wearing the proper PPE and ensuring a clean work area before beginning any preparations. Because of the diversity in types of compounds, the procedures can vary drastically but follow some general steps:

  1. Using the prescription, create a formula for the intended product including any calculations and specific amounts of ingredients needed.
  2. Wash hands and put on all required PPE.
  3. Obtain any hardware supplies such as a balance or graduated cylinder.
  4. Weigh/measure out all ingredients using the proper measurement tools.
  5. Following the recipe, combine the ingredients in the correct ratios and in the proper order.
  6. Document the exact amounts used and label the final product including final strengths of ingredients.

Ointments

Ointments are medication preparations used topically to treat dermatologic conditions. Some ophthalmic medications come in an ointment preparation as well, such as erythromycin. Ointments are oil-based and considered preparations of water in oil. With that being said, ointments differ from creams since creams are water-based and considered preparations of oil in water.

The process of spatulation is used, which is the mixing of semi-solids and powders on an oil slab by use of a spatula. The mixing during this process must be geometric, meaning small equal parts of each ingredient are mixed at a time to obtain a uniform mixture until all ingredients are integrated into the mixture. An ointment once compounded can be stored in a tube but more than likely will be stored in a jar, as mixing may be necessary prior to administration.

Mixtures

In pharmacy compounding, a mixture can be categorized as a variety of formulations. A mixture can consist of numerous active and inactive ingredients to formulate a compound. Simple mixing can include a solid and a liquid, two liquids, or two solids.

As mentioned above in the ointments subsection, it is important that the physical mixing of two substances is done geometrically. If not, inconsistencies may be present in your mixture. An example of a liquid mixture is a magic mouthwash used to treat mouth pain and mucositis. This mixture has many different formulations; however, a simple formula includes a 1:1:1 ratio of lidocaine 2% viscous, liquid antacid, and diphenhydramine. All three are mixed into a uniform solution mixture used to coat a patient’s mouth and/or throat. If 300mL of mouthwash were to be made for dispensing, each ingredient would equate to 100 mL (100 mL lidocaine + 100 mL antacid + 100 mL diphenhydramine = 300 mL).

A suspension is also a simple pharmacy mixture that is composed of a medication in powder form that is suspended in a liquid vehicle, typically sterile water. Compatible flavoring agents may be added to a suspension to mask any unpleasant taste the medication may have. Suspensions are also mentioned briefly under the next header, Liquids.

Liquids

Many medications come commercially available in a liquid dosage form, while others must be compounded. A liquid is composed of a solute and solvent. In simple terms, the solute can be the active drug component that is evenly (homogeneously) dispersed through a liquid component, which is the solvent. The solvent is a compatible substance used as a liquid vehicle to administer the active ingredient (medication) to the body.

When compounding, the solute must be completely dissolved in the solvent, resulting in a homogenous product at the desired concentration. Some liquid formulations, like a suspension, must be mixed thoroughly prior to use as some parts of the formulation might settle and need resuspending to make the liquid a uniform concentration.

Emulsions

An emulsion consists of two liquid substances that are immiscible, meaning they do not mix together. In an emulsion, one liquid is dispersed (discontinuous phase) throughout another liquid (continuous phase). The classic example for an emulsion is an oil in water solution. We all know that oil and water do not mix. Once shaken, oil is dispersed as small droplets throughout the water. Emulsions are typically used as topical formulations as creams and as bases in ointments or lotions.

Suppositories

Suppositories are a solid formulation that are used mostly rectally but some vaginally. These are solids that consist of medication suspended in a base, such as cocoa butter. This type of preparation can be used for both local conditions as well as systemic. Once inserted rectally, a suppository will melt at body temperature and dissipate the medication. Suppositories are housed and stored in a thick plastic or foil wrapper to prevent melting prior to use.

Suppositories can be prepared by hand rolling, fusion molding, or compression molding. Hand rolling is the simplest method and each includes mixing suppository base with medication and forming it into a uniform cone-shaped mold. This type of formulation is beneficial to treat conditions involving one’s bowels but also for those who have trouble swallowing or are unable to take medication orally.

Enemas

Enemas are solution formulations used rectally to treat a variety of conditions. Enemas are formulated to treat and manage conditions like constipation, irritable bowel syndrome, ulcerative colitis, etc. Also, enemas may be used for bowel prep and cleansing. They work at the site of action of the colon lining and are not systemically absorbed.

Necessary Calculations

It is important to note that preparing non-sterile products also requires calculations to determine the exact amounts needed of each ingredient to make the final product in the correct strength. Many prescriptions are written in percentage strengths, which can sometimes be confusing, depending on what type of preparation it is. There are three main types of percentage strengths:

Weight/weight (w/w%)—measured in grams of the ingredient/100 grams of the total product

Volume/volume (v/v%)—measured in mL of the ingredient/100 mL of the total product

Weight/volume (w/v%)—measured in grams of the ingredient/100 mL of the total product

Example:

If 20 mg of aspirin powder is dissolved in 50 mL of water, what is the final weight/volume percentage strength?

Answer:

\[20 \ mg = 0.020 \ gm\] \[\dfrac{0.020 \ gm}{50 \ mL} \times \dfrac{2}{2} = \dfrac{0.040 gm}{100 mL} = 0.040\% \;\text{aspirin in water}\]
Next

All Study Guides for the PTCB Exam are now available as downloadable PDFs