Compounding Chapter 9

Compounding Extemporaneous Compounding is the on-demand preparation of a drug product according to a physician’s prescription, formula or recipe.

EQUIPMENT FOR WEIGHING, MEASURING, AND COMPOUNDING Terms Balances: Balance measurements using a counterbalance are made using sets of standardized pharmaceutical weights. An electronic balance is easier to learn and use and is more accurate than other types of balances. Forceps and Spatulas: Forceps should be used when picking up weights so that moisture and oils are not transferred to the weights. Spatulas are used in compounding tasks such as preparing ointments and creams or loosening material from the surfaces of a mortar and pestle.

Terms Compounding Slab: This is an ideal surface for mixing compounds because of its nonabsorbent surface. Mortar and Pestle: The coarser the surface of the mortar and pestle, the finer the triturating, or grinding, that can be done. Graduates and Pipettes: Graduates come in two varieties: conical and cylindrical. A pipette is used for measuring liquids with a volume less than 1.5 mL

Small volumetric equipment Syringe Calibrated pipette Single volume pipettes Measure volume to edge of stopper.

Types of Equipment Molding Measuring Hot plates, suppository molds, capsule shells, ointment slabs. Packaging Prescription bottles, capsule vials, suppository boxes, ointment jars. Measuring Balance, weights, weighing containers, volumetric glassware (graduates, pipets, flasks, syringes). Mixing Beakers, Erlenmeyer flasks, spatulas, funnels, sieves, mortar and pestle.

Terms Master Formula Sheet: Prepared by the pharmacist, this sheet indicates the amount of each ingredient needed, lists the procedures to follow, and provides the labeling instructions.

Terms Trituration – is the fine grinding of a powder. Levigation - the trituration of a powder drug with a solvent in which the drug is insoluble. (ie: usually making a suspension or cream) Both techniques reduce the particle size of the drug.

Mortar and Pestle Mortar and Pestle The coarser the surface of the mortar and pestle, the finer the triturating, or grinding, that can be done. Types Glass Wedgwood Porcelain

Mixing Powders When mixing powders of unequal size, the smaller amount is mixed (triturated) with an equal amount of the other. That mixture is then mixed with an equal amount of the larger amount powder. This process is repeated until the mixture is completed

TECHNIQUE FOR WEIGHING PHARMACEUTICAL INGREDIENTS Weighing of the product is one of the most essential parts of the compounding process. Weighing the exact amount prescribed is essential in compounds for several reasons: the product cannot be “checked” for content once mixed, the quantities weighed out are often very small.

4 Step Process of Compounding Measure: use balance, weights, weighing containers, volumetric glassware Mix: use beakers, flasks, spatulas, mortar & pestle Mold: use suppository molds, capsule shells, ointment slabs Package: use prescription bottles, vials, suppository boxes, jars.

Compounding Slab This is an ideal surface for mixing compounds because of its nonabsorbent surface. Levigation Technique used to reduce the particle size of a powder drug by triturating it with a solvent in which the drug is insoluble.

Ointments Used for many different purposes, e.g., as protect ants, antiseptics, emollients, antipruritics, kerotolytics, and astrigents. Transferring ointment into an ointment jar. Ointments are generally compounded on an ointment slab.

Spatulation Mixes powders using a spatula. Mixing can be done in a mortar, on an ointment slab, or in a plastic bag.

Suppositories Mold Suppository box Three types of bases: Water soluble: containing glycerinated gelatin or polethylene glycols (PEGs). Hydrophyllic: mixtures of oleaginous and water soluble bases. Mold Suppository box

Capsules Hard gelatin capsules consist of a body and a cap which fits firmly over the body of the capsule. For human use, eight sizes of capsules are available. Sizes Volume ml 000 1.37 00 0.95 0 0.68 1 0.50 2 0.37 3 0.30 4 0.20 5 0.13 Bring in different sizes of capsules

Punch Method Used when filling a small number of capsules. Have students make a capsule using the punch method Give students a compound problem to solve using their calculation ability

Volumetric Equipment Graduated cylinders, pipettes & syringes Always use the smallest device that will accommodate the desired volume. Read volumetric equipment at eye level Measure at the bottom of the meniscus – the bottom of the “U”.

Mixing Powdered Drugs with Water When mixing water into a dry powder to reconstitute (pediatric antibiotics): Measure the total amount of liquid needed in a graduated cylinder. Add about half the water to dry powder (enough to saturate) and shake well. Add remaining water and shake well again.

Suspension

Stability Stability Expiration date Beyond-use dates Shelf life The extent to which a dosage form retains the same properties and characteristics that it possessed at the time of its manufacture. Expiration date The date until which the manufacturer can guarantee of the safety and full potency of a drug- usually determined after extensive study of the product’s stability. Beyond-use dates Used for compounded preparations only and are generally in the order of “days” or “months.” Shelf life Length of time a packaged drug will last without deteriorating

Guidelines Good Compounding Practices Applicable to State Licensed Pharmacies Model Rules for Sterile Pharmaceuticals Technical Assistance Bulletin on Compounding Non-sterile Products in Pharmacies Technical Assistance Bulletin on Quality Assurance for Pharmacy- Prepared Sterile Products Remington: The Science and Practice of Pharmacy

Compounding Read Chapter 9 Review Key Concepts Take Self Test Have a great week!