PASER (aminosalicylic acid) granules are a delayed release granule preparation of aminosalicylic acid (p-aminosalicylic acid: 4-aminosalicylic acid) for use with other anti-tuberculosis drugs for the treatment of all forms of active tuberculosis due to susceptible strains of tubercle bacilli. The granules are designed for gradual release to avoid high peak levels not useful (and perhaps toxic) with bacteriostatic drugs. Aminosalicylic acid is rapidly degraded in acid media; the protective acid-resistant outer coating is rapidly dissolved in neutral media so a mildly acidic food such as orange, apple or tomato juice, yogurt or apple sauce should be used.

Aminosalicylic acid (p-aminosalicylic acid) is 4-Amino-2-hydroxybenzoic acid. PASER granules are the free base of aminosalicylic acid and do NOT contain sodium or a sugar. The molecular formula is C 7 H 7 NO 3 with a molecular weight of 153.14. With heat p-aminosalicylic acid is decarboxylated to produce CO 2 and m-aminophenol. If the airtight packets are swollen, storage has been improper. DO NOT USE if packets are swollen or the granules have lost their tan color and are dark brown or purple.

The structural formula is:

PASAR granules are supplied as off-white tan colored granules with an average diameter of 1.5 mm and an average content of 60% aminosalicylic acid by weight. The acid resistant outer coating will be completely removed by a few minutes at a neutral pH. The inert ingredients are:

colloidal silicon dioxide

dibutyl sebacate

hydroxypropyl methyl cellulose

methacrylic acid copolymer

microcystalline cellulose


The packets contain 4 grams of aminosalicylic acid for oral administration three times a day by sprinkling an apple sauce or yogurt to be eaten without chewing. Suspension in an acidic fruit drink such as orange juice or tomato juice will protect the coating for at least 2 hours. Swirling the juice in the glass will help resuspend the granules if they sink.


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