Pharmaceutical Compounding: Sodium Phosphate, Ammonium Chloride, and Sulfa Drugs

Product Name (Exp. 1)

Sodium Phosphate Oral Solution

Formula of Active Ingredient (Exp. 1)

Na3PO4

Molecular Weight of Sodium Phosphate

163.94 g/mol

Physical Properties of Sodium Phosphate

Boiling Point: 373 K / Melting Point: 1856 K

Therapeutic Use (Exp. 1)

Saline Laxative for constipation & colonoscopy prep.

Mechanism of Action (Exp. 1)

Increases fluid in the small intestine.

Onset of Action (Exp. 1)

30 minutes to 6 hours.

Warning (Exp. 1)

Do not use in children younger than 5 years old.

Adverse Events (Exp. 1)

GI issues, dizziness, weakness, thirst, chest pain, headache.

Formulation - Sodium Phosphate

22.20 g

Formulation - Citric Acid (Exp. 1)

10.40 g

Formulation - Glycerin (Exp. 1)

10.00 mL

Formulation - Sodium Benzoate

0.12 g

Compounding Step 1 & 2 (Exp. 1)

Heat 60mL water to boiling, then dissolve Sodium Phosphate with Citric Acid.

Compounding Step 3, 4, 5 (Exp. 1)

Remove from heat, mix in glycerin, then dissolve sodium benzoate.

Packaging (Exp. 1)

Fill into a clean, calibrated, 60 mL amber Boston-round bottle.

Final Product Characteristics (Exp. 1)

Clear, colorless liquid with a saline taste.

Specific Gravity (Exp. 1)

1.39 @ 25 °C

Key Disadvantage of Solutions

Prone to microbial contamination and have a shorter shelf life.

Product Name (Exp. 2)

Ammonium Chloride Syrup

Formula of Active Ingredient (Exp. 2)

NH4Cl

Therapeutic Use (Exp. 2)

Expectorant

Mechanism of Action (Exp. 2)

Irritative action on bronchial mucosa causes production of respiratory fluid.

Pharmacodynamics of Ammonium Chloride

Systemic acidifier; converted to urea in the liver, liberating H+ ions.

Formulation - Ammonium Chloride

1.50 g

Formulation - Sodium Citrate (Exp. 2)

2.50 g

Formulation - Citric Acid (Exp. 2)

0.80 g

Formulation - Methyl Paraben (Exp. 2)

0.12 g

Formulation - Glycerin (Exp. 2)

7.5 mL

Formulation - Ethyl Alcohol, 95%

7.5 mL

Formulation - Lemon Oil

0.03 mL

Formulation - Simple Syrup (Exp. 2)

22.5 mL

Prepare simple syrup

Dissolve 85g of sucrose in 40mL boiling water.

Compounding Step 2 & 3 (Exp. 2)

Dissolve active ingredients in heated water; separately dissolve preservative.

Compounding Step 4, 5, 6 (Exp. 2)

Incorporate flavor/glycerin into syrup; add preservative to actives; combine mixtures.

Final Compounding Steps (Exp. 2)

Gradually add alcohol, add water to final volume, and filter.

Packaging (Exp. 2)

Fill into a clean, sterilized, light-resistant 60 mL amber Boston-round bottle.

Examples of Preservatives for Syrups

Benzoic acid, Methyl paraben, Sodium benzoate.

Role of Glycerin in Syrups

Acts as a co-solvent and humectant.

Product Name (Exp. 3)

Sulfadiazine-Sulfamerazine-Sulfamethazine Oral Suspension

Therapeutic Use (Exp. 3)

Antimicrobial.

Primary Objective (Exp. 3)

Manufacture by Dispersion method using a Homogenizer, per cGMP standards.

Physical Properties of Sulfamethazine

White/yellowish crystals, darkens on light exposure, melts at 197-200 °C.

Solubility of Sulfamethazine

Sparingly soluble in acetone.

Formulation - All 3 Sulfa Drugs

2.12 g EACH of Sulfadiazine, Sulfamerazine, and Sulfamethazine.

Formulation - Veegum

0.83 g.

Formulation - Sodium Citrate (Exp. 3)

0.67 g.

Formulation - Simple Syrup (Exp. 3)

20 mL.

Formulation - Methyl Paraben (Exp. 3)

0.17 g.

Equipment Unique to Exp. 3

Mortar and Pestle; Colloid Mill/Homogenizer.

Compounding Step 2 & 3 (Exp. 3)

Suspend Veegum in simple syrup; stir in sodium citrate and flavor.

Compounding Step 4 & 5 (Exp. 3)

Pre-mix dry sulfa powders in a mortar; gradually incorporate into syrup mixture.

Crucial Compounding Step (Exp. 3)

Pass the bulk suspension through the homogenizer several times.

Result of Homogenization

A homogenous, creamy, and viscous suspension is produced.

Packaging (Exp. 3)

Fill into a 120 mL wide-mouthed flint (clear) Boston-round bottle.

Desirable Properties of a Suspension

Pours freely, delivers homogenous doses, is easily resuspended by shaking.

Suspending Agents Used (Exp. 3)

Veegum (main agent) and Sodium Citrate (stabilizer).

Examples of Other Suspending Agents

Bentonite.