US Pharm. 2024;49(6):59-60.
Method of Preparation: Calculate the precise amount of each ingredient needed for the desired total quantity. Calibrate the mold, accounting for roughly 10% overage to accommodate any excess mixture needed. Weigh or measure each ingredient. Secure a five-cavity, 200-mg tablet triturate mold to a clean and nonporous surface, taping one side down firmly. Coat the top of the mold lightly with nonstick food-grade spray. First, triturate the tadalafil to a fine powder; then combine it with the silica gel, acesulfame potassium (Ace-K), and acacia, mixing thoroughly for uniformity. Melt the polyethylene glycol (PEG) to 55°C and incorporate the desired flavoring. Add the powdered mixture and blend thoroughly. Once the mixture has cooled slightly, draw it into a syringe and fill each mold cavity. When the troches have cooled, remove the tape and press to release them from the mold. Sample the troche weights for consistency. Package the troches and label.1
Use: Tadalafil troches may be used to treat conditions such as erectile dysfunction (ED) and benign prostatic hyperplasia (BPH).
Packaging: Package in an airtight container. Store at controlled room temperature.
Labeling: Keep out of reach of children. Discard after ____ [time period].
Stability: The USP default beyond-use date for solid formulations is 180 days when stored at controlled room temperature.2
Quality Control: Weight/volume, pH, specific gravity, active drug assay, color, rheologic properties/pourability, physical observation, and physical stability (discoloration, foreign materials, gas formation, mold growth) are all examples of quality-control assessments.3
Discussion: Tadalafil (Cialis, C22H19N3O4, MW 389.41) is a phosphodiesterase 5 (PDE5) inhibitor used to treat ED and BPH. This drug works by competitively blocking PDE5’s hydrolysis of cyclic guanosine monophosphate (cGMP), resulting in increased cGMP levels and vascular smooth muscle relaxation. This mechanism enhances sexual stimulation–dependent smooth muscle relaxation in the penis, facilitating blood flow to the corpus cavernosum and promoting erection. Tadalafil exhibits greater selectivity for PDE5 and a longer half-life than other PDE5 inhibitors. It is available commercially as tablets of various dosages. Frequent side effects include headaches, indigestion, back pain, muscle aches, stuffy nose, flushing, and limb discomfort. Tadalafil, a crystalline solid, is insoluble in water and slightly soluble in ethanol.4
Silica gel, which is derived from silicon dioxide by insolubilizing dissolved silica in sodium silicate solution, is a fine, white, odorless, amorphous powder that readily absorbs moisture from its surroundings. Its particle size typically ranges from 2 μm to 10 μm. Silica gel is insoluble in water and organic solvents, but it can be dissolved in hot alkali hydroxide solutions. Silica gel is a versatile additive in various formulations; in addition to functioning as a desiccant, it is used as a suspending agent and a viscosity enhancer.5
Ace-K is a white, odorless, crystalline powder commonly employed as an excipient and sweetener. Ace-K is highly soluble in water and minimally soluble in ethanol, with a pH range of 5.5 to 7.5. This nonnutritive sweetener is used as an additive in various food products.6
Acacia (gum arabic) is a practically odorless substance that imparts a mucilaginous sensation on the tongue. Derived from certain acacia species, it is a complex aggregate of sugars and hemicelluloses. Acacia is used in pharmaceuticals as an emulsifying agent, pastille base, suspending agent, and tablet binder as well as in cosmetics, confectionery, and food products. Acacia is insoluble in alcohol.7
PEG (Carbowax) is an addition polymer of ethylene oxide and water that is available in various grades and has a range of applications, including pharmaceuticals. It is soluble in water and miscible with other PEGs. PEGs are chemically stable and do not support microbial growth. PEG troche base formulations may include PEG 1000, aspartame sweetener, and flavoring and coloring agents. Alternatively, commercial products are available.8
REFERENCES
1. Tadalafil 10 mg mini troches: suggested formula. New Brunswick, NJ: Spectrum Pharmacy Products.
2. U.S. Pharmacopeia/National Formulary [current revision]. Rockville, MD: U.S. Pharmacopeial Convention, Inc; September 2022.
3. Allen LV Jr. Standard operating procedure for performing physical quality assessment of suppositories, troches, lollipops and sticks. IJPC. 1999;3:56-57.
4. Cialis (tadalafil) product information. Indianapolis, IN: Eli Lilly and Co; October 2011.
5. Hapgood KP. Colloidal silicon dioxide. In: Rowe RC, Sheskey PJ, Quinn ME, eds. Handbook of Pharmaceutical Excipients. 6th ed. London, England: Pharmaceutical Press; 2009:185-188.
6. PubChem. Acesulfame potassium. https://pubchem.ncbi.nlm.nih.gov/compound/Acesulfame-potassium. Accessed May 3, 2024.
7. Kibbe AH. Acacia. In: Rowe RC, Sheskey PJ, Quinn ME, eds. Handbook of Pharmaceutical Excipients. 6th ed. London, England: Pharmaceutical Press; 2009:1-3.
8. Wallick D. Polyethylene glycol. In: Rowe RC, Sheskey PJ, Quinn ME, eds. Handbook of Pharmaceutical Excipients. 6th ed. London, England: Pharmaceutical Press; 2009:517-522.
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