Tolazoline

METHOD OF PREPARATION

Note: This preparation should be prepared in a laminar airflow hood in a deanroom or via isolation barrier technology by a validated aseptic compounding pharmacist using strict aseptic technique. This is a high-risk preparation.

1. Calculate the required quantity of each ingredient for the total amount to be prepared.

2. Accurately weigh and/or measure each ingredient.

3. Dissolve the tolazoline hydrochloride, tartaric acid and sodium citrate in about 90 mL of sterile water for injection.

4. Adjust the pH to the range of 3 to 4.

5. Add sufficient sterile water for injection to volume and mix well.

6. Filter through a sterile 0.220 -µm filter into sterile vials.

7. Package and label.

PACKAGING

Package in tight, light-resistant containers.2

LABELING

Keep out of reach of children. Use only as directed. Store at controlled room temperature and protected from light.

STABILITY

If not sterility tested: A beyond-use date of up to 24 hours at room temperature, up to 3 days at refrigerated temperature (2 to 8°C), or up to 45 days if frozen can be used for this preparation.2

If sterility tested: A beyond-usc date of up to 6 months can be used for this preparation, because this formulation was formerly commercially available.2

USE

Tolazoline injection has been used as an α-adrenergic blocking agent in the treatment of persistent pulmonary vasoconstriction and hypertension of the newborn and in peripheral vasospastic disorders.

QUALITY CONTROL

Quality-control assessment can include weight/volume, physical observation, pH, specific gravity, osmolality, assay, color, clarity, paniculate matter, sterility and pyrogenicity.3,4

DISCUSSION

Tolazoline hydrochloride (C^sub 10^H^sub 12^N^sub 2^.HCl, MW 196.68, Priscoline hydrochloride) occurs as a white to off-white, crystalline powder. Its solutions are slightly acid to litmus. It is freely soluble in water and in alcohol. It melts at between 172.0 and 176.0°C. It should be stored in well-closed containers. Tolazoline Hydrochloride Injection USP is a sterile solution of tolazoline hydrochloride in water for injection, containing not less than 95.0% and not more than 105.0% of the labeled amount of tolazoline hydrochloride. The pH is between 3.0 and 4.0. The osmolality of tolazoline HCl at a concentration of 25 mg/mL is about 402 mOsm/kg by freezing-point depression and 353 mOsm/kg by vapor pressure. It contains not more than 0.8 USP Endotoxin Units per milligram of tolazoline hydrochloride.2

Tartaric acid (C^sub 4^H^sub 6^O^sub 6^, MW 150.09) occurs as colorless or translucent crystals or white, fine to granular, crystalline powder. It is odorless with an acid taste and is stable in air. It is very soluble in water (l g in 0.8 mL; 0.5 mL of boiling water) and freely soluble in alcohol (l g in 3 mL). It is used as an acidifying agent.2

Sodium citrate (C^sub 6^H^sub 5^Na^sub 3^O^sub 7^, MW 258.07, anhydrous; C^sub 6^H^sub 5^Na^sub 3^O^sub 7^-ZH2O, MW 294.10, dehydrate) occurs as colorless crystals, or as a white, crystalline powder. The hydrous form is freely soluble in water and very soluble in boiling water but insoluble in alcohol. It should be preserved in tight containers and labeled as to the anhydrous or hydrous form.2

Hydrochloric acid (HCl, MW 36.46) occurs as a clear, colorless, fuming aqueous solution of hydrogen chloride that has a pungent odor. It is miscible with water and is soluble in ethanol.1

Sodium hydroxide (NaOH, MW 40.00, caustic soda, soda lye) occurs as dry, very deliquescent, white or almost white sticks, pellets or fused masses that are hard and brittle. It is soluble l g in 1 mL of water and is freely soluble in alcohol. It should be stored in airtight, nonmetallic containers.6

REFERENCES

1. Trissel LA. Handbook of Injectable Drugs. 12th ed. Bethesda MD: American Society of Health-System Pharmacists; 2003:1327-1328.

2. United States Pharmacopeial Convention, Inc. United States Pharmacopeia 27-National Formulary22. Rockville, MD: US Pharmacopeial Convention, Inc.; 2004: 1702,1863-1864,1950, 2345-2349, 2782, 2784, 2786, 2795, 2946.

3. Alien LV Jr. Standard operating procedure for particulate testing for sterile products. IJPC1998; 2(1): 78.

4. Alien LV Jr. Standard operating procedure: Quality assessment for injectable solutions. IJPC1999; 3(5): 406-407.

5. Owen SC. Hydrochloric acid. In: Rowe RC, Sheskey PJ, Weller PJ, eds. Handbook of Pharmaceutical Excipients. 2003: 281-282.

6. Kibbe AH. Sodium hydroxide. In: Rowe RC, Sheskey PJ, Weller PJ, eds. Handbook of Pharmaceutical Excipients. 4th ed. Washington, DC: American Pharmaceutical Association; 2003: 566-567.

Copyright International Journal of Pharmaceutical Compounding Jan/Feb 2005
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