Nifedipine 0.2% Ointment

US Pharm. 2023;48(11):59-60.



Method of Preparation: Calculate the amount of each ingredient required for the total amount to be prepared. Accurately weigh out the appropriate amount of each ingredient. Transfer the nifedipine USP powder into a mortar and triturate until it is a fine, homogenous powder. Geometrically, incorporate the white petrolatum and mix until a uniform paste forms. Transfer the final product to an appropriate container, and label.

Use: Nifedipine 0.2% ointment is suitable for treating anal fissures, including in patients with diabetes.

Packaging: Package in a tight, light-resistant container. Store at controlled room temperature.

Labeling: Keep out of reach of children. For external use only. Protect from light. Discard after ____ [time period].

Stability: The USP default beyond-use date for this preparation is 180 days when stored at controlled room temperature.^1,2

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: Anal fissures (small tears in the anal lining) can be painful and cause bleeding during bowel movements. As a topical preparation, nifedipine exerts its therapeutic effect by facilitating relaxation of the smooth muscles encircling the anal sphincter and augmenting blood flow to the afflicted area. This mechanism is predicated on the dilation of blood vessels, which is accomplished through the inhibition of calcium ion entry via the blockade of L-type calcium channels in vascular smooth muscles and myocardial cells.⁴ The preparation presented here is suitable for treating anal fissures, including in patients with diabetes.

Nifedipine (C₁₇H₁₈N₂O₆, MW 346.3) is a yellow, odorless, crystalline powder that is insoluble in water but soluble in ethanol. This dihydropyridine calcium channel blocker is FDA approved to treat chronic stable angina and hypertension. Potential side effects of the ointment preparation include flushing, headache, lightheadedness, and perianal itching. Importantly, gradual withdrawal from nifedipine is advised because stopping suddenly could result in rebound hypertension or angina in patients with these conditions. Nifedipine is available commercially in immediate-release and extended-release formulations, adding to its adaptability in clinical settings. When considering the use of nifedipine ointment for anal fissures in diabetic patients, healthcare professionals must use caution and discretion while ensuring adherence to established therapeutic protocols and guidelines.⁵

White petrolatum (white petroleum jelly, white soft paraffin) is an inert, odorless, and tasteless semisolid composed of saturated hydrocarbons derived from petroleum. This translucent substance is primarily used in topical pharmaceutical formulations such as emollient creams, topical emulsions, and ointments. White petrolatum has a specific gravity ranging from approximately 0.815 to 0.880, and it exhibits a melting point between 38°C and 60°C. It is practically insoluble in ethanol, glycerin, and water. White petrolatum readily dissolves in chloroform as well as in most fixed and volatile oils. Although it maintains stability, white petrolatum may undergo discoloration upon exposure to light owing to the oxidation of certain impurities within the product. To mitigate this circumstance, the incorporation of suitable antioxidants, such as butylated hydroxyanisole, butylated hydroxytoluene, or alpha-tocopherol, is advisable. It is important to avoid subjecting white petrolatum to prolonged heating above its melting range—typically around 70°C—in order to prevent undesirable alterations. White petrolatum plays a key role in dermatology by facilitating the healing of skin injuries. This ingredient is recommended by the American Academy of Dermatology for its scar-reduction properties; it also serves as a protective skin barrier, as it prevents moisture loss.⁶

REFERENCES

1. U.S. Pharmacopeia/National Formulary [current revision]. Rockville, MD: U.S. Pharmacopeial Convention, Inc; September 2022.
2. Teimouri A, Yeung P, Agu RU. Stability of compounded topical nifedipine in cream, gel, and ointment bases. Int J Pharm Compd. 2021;25(4):344-351.
3. Allen LV Jr. Standard operating procedure for performing physical quality assessment of ointments/creams/gels. IJPC. 1998;2:308-309.
4. Golfam F, Golfam P, Golfam B, Pahlevani P. Comparison of topical nifedipine with oral nifedipine for treatment of anal fissure: a randomized controlled trial. Iran Red Crescent Med J. 2014;16(8):e13592.
5. Khan KM, Patel JB, Schaefer TJ. Nifedipine. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2023 Jan-.
6. Lambert WJ. Petrolatum. In: Rowe RC, Sheskey PJ, Cook WG, Fenton ME, eds. Handbook of Pharmaceutical Excipients. 7th ed. Washington, DC: American Pharmaceutical Association; 2012:547-549.

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