Atenolol

METHOD OF PREPARATION

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

2. Accurately weigh and/or measure each ingredient.

Tablets as the source of the drug:

3. Pulverize the tablets and prepare a paste with a portion of the Ora-Plus. Add the remainder of the Ora-Plus and mix well. Add sufficient Ora-Sweet SF to volume and mix well.

Atenolol USP powder as the source of the drug:

4. Dissolve the atenolol in sufficient Ora-Sweet SF to volume and mix well.

5. Package and label.

PACKAGING

Package in tight, light-resistant containers.1

LABELING

Keep out of reach of children. Use only as directed. Shake well before taking.

STABILITY

A beyond-use date of up to 90 days can be used for this preparation.2

USE

Atenolol oral liquid is indicated in the treatment of hypertension, angina pectoris due to coronary atherosclerosis and acute myocardial infarction.3

QUALITY CONTROL

Quality-control assessment can include weight/volume, pH, specific gravity, active drug assay, color, rheological properties/pourability, physical observation and physical stability (discoloration, foreign materials, gas formation, mold growth).4

DISCUSSION

Atenolol (C^sub 14^H^sub 22^N^sub 2^O^sub 3^, MW 266.34) occurs as a white or practically white, odorless powder. It has a melting range between 152° and 156.5°C. It is slightly soluble in water (26.5 mg/mL at 37°C) and sparingly soluble in alcohol. It has a pKa of 9.6. It should be stored in well-closed containers and protected from light. Atenolol injection has a pH between 5.5 and 6.5.1

Commercial Tenormin tablets also contain magnesium stearate, microcrystalline cellulose, povidone and sodium starch glycolate.3

The most definitive stability study to date for extemporaneous compounding was done by Patel et al,2 with an evaluation of the stability of several oral liquid formulations of atenolol prepared from both powder and tablets in various vehicles, including simple syrup, Ora-Sweet, Ora-Sweet SF, Ora-Plus and methylcellulose 1% dispersion. The most stable were the OraPlus and Ora-Sweet-SF samples, with less than 10% loss in 90 days using either atenolol source. Those preparations containing sugar were not as stable.2

Ora-Plus is an oral suspending vehicle that accepts dilution of up to 50% or more with water, flavoring agents or syrups and still retains its suspending properties. It has a pH of approximately 4.2 and an osmolality of about 230 mOsm/Kg. Tt is a thixotropic vehicle with a viscosity of approximately 1000 cps at 25°C. It contains purified water, microcrystalline cellulose, sodium carboxymethylcellulose, xanthan gum, carrageenan, sodium phosphate and citric acid as buffering agents; simethiconc as an antifoaming agent; and potassium sorbatc and methylparaben as preservatives.5

Ora-Sweet SF is a flavoring vehicle for oral extemporaneous preparations. It is a sugar-free, alcohol-free syrup flavored with a citrus-berry blend. It is buffered to a pH of approximately 4.2 and may be used alone or in combination with other vehicles. It will tolerate a dilution to 50% with dissolved actives in water or suspending agents and still retain an acceptable taste. It has an osmolality of 2150 mOsm/Kg. It contains water, sodium saccharin, xanthan gum, glycerin, sorbitol, citric acid and sodium citrate as buffers; methylparaben, propylparaben and potassium sorbate as preservatives; and flavoring agents.5

REFERENCES

1. US Pharmacopeial Convention, Inc. United States Pharmacopeia 27-National Formulary22. Rockville, MD: US Pharmacopeial Convention, Inc; 2004: 183-186, 2345-2349, 2750.

2. Patel D, Doshi DH, Desai A. Short-term stability of atenolol in oral liquid formulations. IJPC 1997; 1(6): 437-439.

3. [No author listed.] Physicians' Desk Reference. 58th ed. Montvale, NJ: Thomson PDR; 2004: 689-694.

4. Allen Jr LV. Standard operating procedure for performing physical quality assessment of oral and topical liquids. IJPC 1999; 3: 146-147.

5. Ora-Plus, Ora-Sweet SF [product information]. Minneapolis, MN: Paddock Laboratories, Inc.

Copyright International Journal of Pharmaceutical Compounding May/Jun 2004
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