Pharmaceutical Compounding Introduction

Introduction to Pharmaceutical Compounding

• The primary goal of dosage forms is to deliver the right amount of a drug to the correct site for optimal therapeutic effects and minimal side effects.
• Dosage forms encompass various types and administration routes to achieve either systemic or local effects.
• Cleanliness, hygiene, and sterility (if required) are essential in all dosage forms.
• Pharmaceutical practice utilizes basic principles of dosage forms and compounding medicinal products on a small laboratory scale.
• The lab introduces drug formulation basics including patient administration methods, preparation skills and formulation principles.
• Key considerations include selection of ingredients, packaging, labeling, and storage for the finished product.

Lab Guidelines

• Always wear a clean, white lab coat fully buttoned.
• Keep personal items away from the work area.
• Tie back long hair and scarves.
• Use surgical gloves at all times due to potential skin irritation from materials.
• Come prepared by reviewing experiments beforehand and researching any necessary calculations, labels, containers, shelf lives, incompatibilities, and storage conditions.
• Keep your bench organized with a clean towel and sponge.
• Clean balances and sinks after use to prevent contamination.
• Work near the sink when handling liquids to minimize spillage risks.
• Return all materials to their original sealed containers.
• Avoid cross-contamination while using spatulas or pipettes.
• Work independently, even in groups.

Weighing and Measurement

• Electronic balances with different sensitivities and capacities are used for weighing.
• Use the appropriate balance and read instructions beforehand to avoid errors.
• Ensure the balance is level and free from drafts.
• Approximation is discouraged during weighing.
• To avoid spoilage, use a clean sheet of paper on the balance.
• Select a suitable labeled weighing vessel/paper, folding appropriately to avoid loss/contamination.
• Ensure the balance is at zero, review labels for batch numbers, expiry dates, and warnings, and select an appropriate spatula.
• Record the weight in your lab notebook.
• Clean up after weighing.
• Use appropriate liquid measures based on amount/viscosity.
• Volumes under 5 mL should be measured using regular or volumetric pipettes.
• Graduated cylinders can be used for volumes as low as 1ml.
• Beakers are suitable for large volumes, as they are easy to fill, empty, rinse, and clean.
• Volumetric flasks have a sharply marked meniscus and come in various sizes.
• Burettes may be employed in analytical procedures, with maximum burette capacity being 50 mL.

Volume Taking Technique

• Always select the smallest measure suitable for the required volume.
• Ensure the measure is clean and dry before usage.
• Check label information and batch number before taking a liquid.
• Always hold the bottle in the right hand.
• Pour liquid carefully and realign volume at eye level.
• Close container and return stock after use.

Labeling Dispensed Medicines

• Labels must have all information required for the patient to take or use the medication correctly.
• Labels must list the patient, contents, quantity and strength of the medicine and storage conditions/shelf life.
• Must be accurate, legible, intelligible, adequate and relevant.

Compounding Calculations

• Calculations for compounding/dispensing are typically simple arithmetic but must be accurate due to risks to patient welfare.
• Errors are less likely with a disciplined approach.

Working from Master Formulas

• Start with a quantities list for all ingredients.
• Adjust master formulas, as appropriate.

Dealing With Percentage Concentrations

• Pharmaceutical preps containing solids in liquids consist of liquids, or admixtures of liquids in solids; proportions are expressed as "percentage".
• Use w/v, w/w or v/v solution weight to indicate percentage.
• Percentage weight by volume (% w/v) measures the number of grams of ingredient per 100 mL of product.

Percentage Weight Examples

• To prepare 100ml of 0.9% Sodium Chloride BP 1988, use 900 mg sodium chloride, and bring to 100ml volume, at 20°C.
• Weigh by weight (% w/w) indicates grams per 100 grams of product.
• To prep 100g of syrup, use 66.7 grams of sucrose plus purified water until 100 grams of with and at 20°C.

Liquid Dosage Forms: Solutions

• A solution involves one phase and two or more substances for internal, external or parenteral use.
• There are oral dosage forms, elixirs, suspensions and linctuses.
• Use of solutions to instill into the body cavities, vaginal douches, enemas, ear drops, nasal drops.
• Use of solutions topically on body surfaces, liniments, paints, lotions.
• Solutions can be injectables.

Aromatic Waters

• Saturated water solutions of volatile principles, consisting of volatile oils that evaporate at room temperature: anise, lemon, peppermint, and orange oils, and volatile solids/liquids that evaporate at room temperature like camphor, menthol, and chloroform.
• Freshly boiled and cooled, purified water is utilized as gases and microbes are expelled by boiling and impurities are eliminated by purification.
• Cooling avoids the degradation or evaporation of principles.

Spirits

• Spirits are alcohol solutions of volatile principle prepared through mixing with alcohol, and must be prepared with dry equipment due to separation of principles.
• Volatile substance contents vary, but they are generally higher.
• Alcohol content ranges from 62% to 68% in spirit, and 80-87% in camphor spirit.

Containers and Storage

• Both aromatic waters and spirits must be stored in cool places in light-resistant and screw-capped containers to avoid the chance of evaporation.

Aromatic Water and Spirit Uses

• Aromatic water uses are carminatives, rubefacients, counter-irritants, flavorings, and preservatives.
• Spirit uses include flavoring, carminatives, and expectorants.

Aromatic Water vs Spirit Comparison

• Spirits have high and aromatic water has low volatile principle content.
• Spirits can have alcohol or water as the vehicle, and aromatic water uses water with or without alcohol.
• Spirits are relatively stable and aromatic water is not.
• Spirits have physical and aromatic water has chemical stability.

Aromatic Water Formula

• To prepare 100ml Concerated Camphor Water, 40 g of Camphor and 600ml alchohol.
• Dissolve camphor using alcohol.
• Add water in small portions, and shake vigorously after every addition.

Spirit Formula

• Lemon Spirit is 10 % lemon oil and alchohol.
• Add lemoil using alcohol.
• Then, shake.

Syrups

• Sweet, viscous aqueous liquids
• Can be medicated or non-medicated.
• Used in formulations like antibiotics, antihistamines, anti-tussives, sedatives and vitamins.
• Three types are simple, flavored and medicated syrups.

Simple Syrups

• Simple syrup is a saturated sugar solution (66.70, 85% w/v) as a sweetening or vehicle agent for water soluble drugs.

Flavored Syrups

• Flavored syrups contain a flavoring agent like aromatic water, volatile oils, or spirits and simple syrup as a vehicle with disagreeable odor.

Medicated Syrups

• Active drugs get therapeutic value from syrup or flavor through flavored syrup or active drugs.

Sample Syrup Formula

• For a 200g simple syrup, use 66.7% or alternatively 85% sucrose mixed in water.
• To produce gentle heat will dissolve sucrose in water.

Elixirs

• Sweetened hydro-alcoholic solutions with flavoring and a medicament. Primary solvents are alcohol (4% to 40%) for drug dissolution and water.
• Elixirs must be easily recognized and distinguished from other liquid dosage via sugar content and alcohol.
• Sugar may even be replaced by saccharin.
• Glycerin acts as a co-solvent and sub.
• Three options are simple, flavoring, and medicated elixirs.

Simple Elixirs

• This is a sweetened hydro-alcoholic solution. It is used as a vehicle for bitter and/or water-insoluble drugs consisting of sugar.

Flavoring Elixirs

• A solution containing a flavoring.

Medicated Elixirs

• Consist of a flavored elixir and active drugs.
• Water-insoluble elixirs give the preparation therapeutic activity, such as Vitamin-elixirs.
• 400 ml syrup, and 1000 ml of varying percentages of Alchohol are the components.
• First alcohol and water are added to create mixture and then it is diluted.

Suspensions

• Preparations featuring finely separated drug partictles equally divided throughout a vehicle with drug exhibiting solubility degrees. A-Ready to Use refers to drugs spread with stabilizers across liquid or pharmaceutical additives.
• Intended intended suspension with liquid at use, from powder, such as antibiotics.

Ideal Suspensions Showcase

• Consistent, Uniform Partical size
• No particle clumping
• Drug particals evenly spread
• And easily evenly pours from container.
• External preps shouln't have gritting particles.
• Some Powders insoluble by nature, called disperable, such light kaolin, magnesium and carbonate.
• On the other hands, powers such as Chalk, Zinc oxide, and Calamine are insoluble, and require slow sedimentation of particle size or higher solubility of sedimentation.
• Surfactants as electrolytes, cellulose starch are added to acerre flocculation, as agents, they act by coating the interfaces with liquids to to acerre multilayering controlled flocculated high visoosity.

Kaolin Formula

• Mix 200g kaolin and 50 gm with a peptin emulsion, and then add chloform water and water.
• The result is a antidiarrheal mix.

Emulsions

• Disperse systems that consist of oily and aqueoeus.
• Emulsions will not be stable without an agent.

Aqueous Emulsions

• Oil dispersed in continuous phases for better masking of bodily taste.
• Examples are bacteria, methycillose.

Oily Emulsions

• This is useful for lotions and cerams.

Surface Agents

• Agents are emulsifiers that reduce tension, and lead to stabled stable.
• Vegetables include Acacia, Traganath, and Agar
• Animals include gelatin, egg yolk, wool fat.
• Methyl and sodiun methyl are semi synthetics.

Emulsion Method

• Wet-Gum method
• Bottle Method

Ointments

• Greasy preps mixed with drugs.
• Four major groups for bases: Mix paraffin, Parafin ointment, wool fat

Formulation Notes (Ointment)

• For insoluble solid drugs, triturate them by mixing them to form fine mixtures for best result.
• Usually packaged into plastic containers and amber jars.
• Sulphar- hard paraffin, alcohol are used.