ADVERSE REACTIONS SECTION.

6 ADVERSE REACTIONS. Most common adverse reactions in adults (incidence >=3% are headache, abdominal pain, diarrhea, nausea, vomiting, respiratory infection, and arthralgia. Adverse reactions in children were similar. (6.1)To report SUSPECTED ADVERSE REACTIONS, contact Roxane Laboratories, Inc. at 1-800-962-8364 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.. 6.1 Clinical Studies Experience. Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.. Adult Ulcerative Colitis. During clinical development, 259 adult patients with active ulcerative colitis were exposed to 6.75 g/day balsalazide in controlled trials. In the controlled clinical trials patients receiving balsalazide dose of 6.75 g/day most frequently reported the following adverse reactions: headache (8%), abdominal pain (6%), diarrhea (5%), nausea (5%), vomiting (4%), respiratory infection (4%), and arthralgia (4%). Withdrawal from therapy due to adverse reactions was comparable among patients on balsalazide and placebo. Adverse reactions reported by 1% or more of patients who participated in the well-controlled, Phase trials are presented by treatment group (Table 1).The number of placebo patients (35), however, is too small for valid comparisons. Some adverse reactions, such as abdominal pain, fatigue, and nausea were reported more frequently in women than in men. Abdominal pain, rectal bleeding, and anemia can be part of the clinical presentation of ulcerative colitis.Table 1: Adverse Reactions Occurring In >= 1% of Adult Balsalazide Patients In Controlled Trials Adverse ReactionBalsalazide 6.75 g/day (N=259)Placebo (N=35)Abdominal Pain16 (6%)1 (3%)Diarrhea14 (5%)1 (3%)Arthralgia9 (4%)0%Rhinitis6 (2%)0%Insomnia6 (2%)0%Fatigue6 (2%)0%Flatulence5 (2%)0%Fever5 (2%)0%Dyspepsia5 (2%)0%Pharyngitis4 (2%)0%Coughing4 (2%)0%Anorexia4 (2%)0%Urinary Tract Infection3 (1%)0%Myalgia3 (1%)0%Flu-Like Disorder3 (1%)0%Dry Mouth3 (1%)0%Cramps3 (1%)0%Constipation3 (1%)0%. 6.2 Postmarketing Experience. The following adverse reactions have been identified during post-approval use of balsalazide in clinical practice: myocarditis, pericarditis, vasculitis, pruritus, pleural effusion, pneumonia (with and without eosinophilia), alveolitis, renal failure,interstitial nephritis, pancreatitis, and alopecia.Because these reactions are reported voluntarily from population of unknown size, it is not always possible to reliably estimate their frequency or establish causal relationship to drug exposure. These adverse reactions have been chosen for inclusion due to combination of seriousness, frequency of reporting, or potential causal connection to balsalazide.. Hepatic. Postmarketing adverse reactions of hepatotoxicity have been reported for products which contain (or are metabolized to) mesalamine, including elevated liver function tests (SGOT/AST, SGPT/ALT, GGT, LDH, alkaline phosphatase, bilirubin), jaundice, cholestatic jaundice, cirrhosis, hepatocellular damage including liver necrosis and liver failure. Some of these cases were fatal; however, no fatalities associated with these adverse reactions were reported in balsalazide clinical trials. One case of Kawasaki-like syndrome which included hepatic function changes was also reported, however, this adverse reaction was not reported in balsalazide clinical trials.

ANIMAL PHARMACOLOGY & OR TOXICOLOGY SECTION.

13.2 Animal Toxicology and/or Pharmacology. Renal Toxicity. In animal studies conducted at doses up to 2000 mg/kg (approximately 21 times the recommended 6.75 g/day dose on mg/kg basis for 70 kg person), balsalazide demonstrated no nephrotoxic effects in rats or dogs.. Overdosage. single oral dose of balsalazide disodium at g/kg or 4-aminobenzoyl-ss-alanine, metabolite of balsalazide disodium, at g/kg was non-lethal in mice and rats. No symptoms of acute toxicity were seen at these doses.

CARCINOGENESIS & MUTAGENESIS & IMPAIRMENT OF FERTILITY SECTION.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility. In 24-month rat (Sprague Dawley) carcinogenicity study, oral (dietary) balsalazide disodium at doses up to g/kg/day was not tumorigenic. For 50 kg person of average height this dose represents 2.4 times the recommended human dose on body surface area basis. Balsalazide disodium was not genotoxic in the following in vitro or in vivo tests: Ames test, human lymphocyte chromosomal aberration test, and mouse lymphoma cell (L5178Y/TK+/-) forward mutation test, or mouse micronucleus test. However, it was genotoxic in the in vitro Chinese hamster lung cell (CH V79/HGPRT) forward mutation test.4-aminobenzoyl-ss-alanine, metabolite of balsalazide disodium, was not genotoxic in the Ames test and the mouse lymphoma cell (L5178Y/TK+/-) forward mutation test but was positive in the human lymphocyte chromosomal aberration test. N-acetyl-4-aminobenzoyl-ss-alanine, conjugated metabolite of balsalazide disodium, was not genotoxic in Ames test, the mouse lymphoma cell (L5178Y/TK+/-) forward mutation test, or the human lymphocyte chromosomal aberration test. Balsalazide disodium at oral doses up to g/kg/day, 2.4 times the recommended human dose based on body surface area, was found to have no effect on fertility and reproductive performance in rats.

CLINICAL PHARMACOLOGY SECTION.

12 CLINICAL PHARMACOLOGY. 12.1 Mechanism of Action. Balsalazide disodium is delivered intact to the colon where it is cleaved by bacterial azoreduction to release equimolar quantities of mesalamine, which is the therapeutically active portion of the molecule, and the 4-aminobenzoyl-ss-alanine carrier moiety. The carrier moiety released when balsalazide disodium is cleaved is only minimally absorbed and is largely inert.The mechanism of action of 5-ASA is unknown, but appears to be local to the colonic mucosa rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that 5-ASA diminishes inflammation by blocking production of arachidonic acid metabolites in the colon.. 12.3 Pharmacokinetics. Balsalazide capsules contain powder of balsalazide disodium that is insoluble in acid and designed to be delivered to the colon as the intact prodrug. Upon reaching the colon, bacterial azoreductases cleave the compound to release 5-ASA, the therapeutically active portion of the molecule, and 4-aminobenzoyl-ss-alanine. The 5-ASA is further metabolized to yield N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA), second key metabolite.. Absorption. The plasma pharmacokinetics of balsalazide and its key metabolites from crossover study in healthy volunteers are summarized in Table 2. In this study, single oral dose of balsalazide 2.25 was administered to healthy volunteers as intact capsules (3 750 mg) under fasting conditions, as intact capsules (3 750 mg) after high-fat meal, and unencapuslated (3 750 mg) as sprinkles on applesauce.Table 2: Plasma Pharmacokinetics for Balsalazide and Key Metabolites (5-ASA and N-Ac-5-ASA) with Administration of Balsalazide Following Fast, High-Fat Meal, and Drug Contents Sprinkled on Applesauce (Mean +- SD)Fasting (N=17)High-Fat Meal (N=17)Sprinkled (N=17)Cmax (mcg/mL) Balsalazide0.51 +- 0.320.45 +- 0.390.21 +- 0.12 5-ASA0.22 +- 0.120.11 +- 0.1360.29 +- 0.17 N-Ac-5-ASA0.88 +- 0.390.64 +- 0.5341.04 +- 0.57AUClast (mcg.hr/mL) Balsalazide1.35 +- 0.731.52 +- 1.010.87 +- 0.48 5-ASA2.59 +- 1.462.1 +- 2.582.99 +- 1.7 N-Ac-5-ASA17.8 +- 8.1417.7 +- 13.720 +- 11.4Tmax (h) Balsalazide0.8 +- 0.851.2 +- 1.111.6 +- 0.44 5-ASA8.2 +- 1.9822 +- 8.238.7 +- 1.99 N-Ac-5-ASA9.9 +- 2.4920.2 +- 8.9410.8 +- 5.39A relatively low systemic exposure was observed under all three administered conditions (fasting, fed with high-fat meal, sprinkled on applesauce), which reflects the variable, but minimal absorption of balsalazide disodium and its metabolites. The data indicate that both Cmax and AUClast were lower, while Tmax was markedly prolonged, under fed (high-fat meal) compared to fasted conditions. Moreover, the data suggest that dosing balsalazide disodium as sprinkle or as capsule provides highly variable, but relatively similar mean pharmacokinetic parameter values. No inference can be made as to how the systemic exposure differences of balsalazide and its metabolites in this study might predict the clinical efficacy under different dosing conditions (i.e., fasted, fed with high-fat meal, or sprinkled on applesauce) since clinical efficacy after balsalazide disodium administration is presumed to be primarily due to the local effects of 5-ASA on the colonic mucosa.In separate study of adult patients with ulcerative colitis, who received balsalazide, 1.5 twice daily, for over year, systemic drug exposure, based on mean AUC values, was up to 60 times greater (0.008 mcg.hr/mL to 0.48 mcg.hr/mL) when compared to that obtained in healthy subjects who received the same dose.. Distribution. The binding of balsalazide to human plasma proteins was >=99%.. Metabolism. The products of the azoreduction of this compound, 5-ASA and 4-aminobenzoyl-ss-alanine, and their N-acetylated metabolites have been identified in plasma, urine and feces.. Elimination. Following single-dose administration of 2.25 balsalazide (three 750 mg capsules) under fasting conditions in healthy subjects, mean urinary recovery of balsalazide, 5-ASA, and N-Ac-5-ASA was 0.2%, 0.22% and 10.2%, respectively.In multiple-dose study in healthy subjects receiving balsalazide dose of two 750 mg capsules twice daily (3 g/day) for 10 days, mean urinary recovery of balsalazide, 5-ASA, and N-Ac-5-ASA was 0.1%, 0%, and 11.3%, respectively. During this study, subjects received their morning dose 0.5 hours after being fed standard meal, and subjects received their evening dose hours after being fed standard meal.In study with 10 healthy volunteers, 65% of single 2.25 dose of balsalazide was recovered as 5-ASA, 4-aminobenzoyl-ss-alanine, and the N-acetylated metabolites in feces, while <1% of the dose was recovered as parent compound.In study that examined the disposition of balsalazide in patients who were taking to g of balsalazide daily for more than year and who were in remission from ulcerative colitis, less than 1% of an oral dose was recovered as intact balsalazide in the urine. Less than 4% of the dose was recovered as 5-ASA, while virtually no 4-aminobenzoyl-ss-alanine was detected in urine. The mean urinary recovery of N-Ac-5-ASA and N-acetyl-4-aminobenzoyl-ss-alanine comprised <16% and <12% of the balsalazide dose, respectively. No fecal recovery studies were performed in this population.All pharmacokinetic studies with balsalazide are characterized by large variability in the plasma concentration versus time profiles for balsalazide and its metabolites, thus half-life estimates of these analytes are indeterminate.

CLINICAL STUDIES SECTION.

14 CLINICAL STUDIES. 14.1 Adult Studies. Two randomized, double-blind studies were conducted in adults. In the first trial, 103 patients with active mild-to-moderate ulcerative colitis with sigmoidoscopy findings of friable or spontaneously bleeding mucosa were randomized and treated with balsalazide 6.75 g/day or balsalazide 2.25 g/day. The primary efficacy endpoint was reduction of rectal bleeding and improvement of at least one of the other assessed symptoms (stool frequency, patient functional assessment, abdominal pain, sigmoidoscopic grade, and physicians global assessment [PGA]). Outcome assessment for rectal bleeding at each interim period (week 2, 4, and 8) encompassed 4-day period (96 hours). Results demonstrated statistically significant difference between high and low doses of balsalazide (Figure 1). Figure 1: Percentage of Patients Improved at WeeksA second study, conducted in Europe, confirmed findings of symptomatic improvement.. figure 1.

CONTRAINDICATIONS SECTION.

4 CONTRAINDICATIONS. Patients with hypersensitivity to salicylates or to any of the components of Balsalazide Disodium Capsules or balsalazide metabolites. Hypersensitivity reactions may include, but are not limited to the following: anaphylaxis, bronchospasm, and skin reaction.. Patients with hypersensitivity to salicylates or to any of the components of Balsalazide Disodium Capsules or balsalazide metabolites. Hypersensitivity reactions may include, but are not limited to the following: anaphylaxis, bronchospasm, and skin reaction. (4).

DESCRIPTION SECTION.

11 DESCRIPTION. Each Balsalazide Disodium Capsule contains 750 mg of balsalazide disodium, prodrug that is enzymatically cleaved in the colon to produce mesalamine (5-aminosalicylic acid or 5-ASA), an anti-inflammatory drug. Each capsule of balsalazide (750 mg) is equivalent to 267 mg of mesalamine. Balsalazide disodium has the chemical name (E)-5-[[-4-[[(2-carboxyethyl) amino]carbonyl] phenyl]azo]-2-hydroxybenzoic acid, disodium salt, dihydrate. Its structural formula is:Molecular Weight: 437.32Molecular Formula: C17H13N3O6Na2o2H2OBalsalazide disodium is stable, odorless orange to yellow microcrystalline powder. It is freely soluble in water and isotonic saline, sparingly soluble in methanol and ethanol, and practically insoluble in all other organic solvents.Inactive Ingredients: Each hard gelatin capsule contains ammonium hydroxide, colloidal silicon dioxide, FD&C Blue 1, FD&C Red 40, FD&C Yellow 6, gelatin, iron oxide black, isopropyl alcohol, magnesium stearate, n-butyl alcohol, propylene glycol, shellac, and titanium dioxide. The sodium content of each capsule is approximately 79 mg.. structural formula.

DOSAGE & ADMINISTRATION SECTION.

2 DOSAGE AND ADMINISTRATION. Adult dose is three 750 mg balsalazide capsules times day (6.75 g/day) with or without food for weeks. Some adult patients required treatment for up to 12 weeks. (2.1)Capsules may be swallowed whole or may be opened and sprinkled on applesauce, then chewed or swallowed immediately. (2.2, 12.3). Adult dose is three 750 mg balsalazide capsules times day (6.75 g/day) with or without food for weeks. Some adult patients required treatment for up to 12 weeks. (2.1). Capsules may be swallowed whole or may be opened and sprinkled on applesauce, then chewed or swallowed immediately. (2.2, 12.3). 2.1 Adult Dose. For treatment of active ulcerative colitis in adult patients, the usual dose is three 750 mg balsalazide capsules to be taken times day (6.75 per day) for up to weeks. Some patients in the adult clinical trials required treatment for up to 12 weeks.. 2.2 Administration Alternatives. Balsalazide capsules may also be administered by carefully opening the capsule and sprinkling the capsule contents on applesauce. The entire drug/applesauce mixture should be swallowed immediately; the contents may be chewed, if necessary, since contents of balsalazide are NOT coated beads/granules. Patients should be instructed not to store any drug/applesauce mixture for future use.If the capsules are opened for sprinkling, color variation of the powder inside the capsules ranges from orange to yellow and is expected due to color variation of the active pharmaceutical ingredient.Teeth and/or tongue staining may occur in some patients who use balsalazide in sprinkle form with food.

DOSAGE FORMS & STRENGTHS SECTION.

3 DOSAGE FORMS AND STRENGTHS. Balsalazide Disodium Capsules are available as light orange opaque capsules containing 750 mg balsalazide disodium and 54 795 imprinted in black ink on the cap and body, containing yellow-orange powder.. Capsules: 750 mg (3).

DRUG INTERACTIONS SECTION.

7 DRUG INTERACTIONS. In an in vitro study using human liver microsomes, balsalazide and its metabolites [5-aminosalicylic acid (5-ASA), N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA), 4-aminobenzoyl-ss-alanine (4-ABA) and N-acetyl-4-aminobenzoyl-ss-alanine (N-Ac-4-ABA)] were not shown to inhibit the major CYP enzymes evaluated (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4/5). Therefore, balsalazide and its metabolites are not expected to inhibit the metabolism of other drugs which are substrates of CYP1A2, CYP2C9, CYP2C19, CYP2D6, or CYP3A4/5.. In an in vitro study using human liver microsomes, balsalazide and its metabolites were not shown to inhibit the major CYP enzymes evaluated (CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4/5). (7).

HOW SUPPLIED SECTION.

16 HOW SUPPLIED/STORAGE AND HANDLING. Balsalazide Disodium Capsules are supplied as light orange opaque capsules containing 750 mg balsalazide disodium and 54 795 printed in black ink on the cap and body, containing yellow-orange powder.Bottles of 280 NDC 54868-6137-0 Storage Store at 20 to 25C (68 to 77F); excursions permitted between 15 to 30C (59 to 86F). [See USP Controlled Room Temperature.] Roxane Laboratories, Inc.Relabeling of Additional barcode label by:Physicians Total Care, Inc.Tulsa, OK 74146.

INDICATIONS & USAGE SECTION.

1 INDICATIONS AND USAGE. Balsalazide Disodium Capsules are indicated for the treatment of mildly to moderately active ulcerative colitis in adults. Safety and effectiveness of Balsalazide Disodium Capsules beyond 12 weeks in adults have not been established.. Balsalazide Disodium Capsules are locally acting aminosalicylate indicated for the treatment of mildly to moderately active ulcerative colitis in adults. (1)Safety and effectiveness of Balsalazide Disodium Capsules beyond 12 weeks in adults have not been established. (1). Balsalazide Disodium Capsules are locally acting aminosalicylate indicated for the treatment of mildly to moderately active ulcerative colitis in adults. (1). Safety and effectiveness of Balsalazide Disodium Capsules beyond 12 weeks in adults have not been established. (1).

INFORMATION FOR PATIENTS SECTION.

17 PATIENT COUNSELING INFORMATION. 17.1 Important Precautions Regarding Balsalazide. Instruct patients not to take balsalazide if they have hypersensitivity to salicylates (e.g., aspirin).Patients should be instructed to contact their health care provider under the following circumstances:If they experience worsening of their ulcerative colitis symptoms.If they are diagnosed with pyloric stenosis, because balsalazide capsules may be slow to pass through their digestive tract.If they are diagnosed with renal dysfunction. Damage to the kidney has been observed in people given medications similar to balsalazide. Instruct patients not to take balsalazide if they have hypersensitivity to salicylates (e.g., aspirin).. Patients should be instructed to contact their health care provider under the following circumstances:If they experience worsening of their ulcerative colitis symptoms.If they are diagnosed with pyloric stenosis, because balsalazide capsules may be slow to pass through their digestive tract.If they are diagnosed with renal dysfunction. Damage to the kidney has been observed in people given medications similar to balsalazide. If they experience worsening of their ulcerative colitis symptoms.. If they are diagnosed with pyloric stenosis, because balsalazide capsules may be slow to pass through their digestive tract.. If they are diagnosed with renal dysfunction. Damage to the kidney has been observed in people given medications similar to balsalazide.. 17.2 What Patients Should Know About Adverse Reactions. In adult clinical trials the most common adverse reactions were headache, abdominal pain, diarrhea, nausea, vomiting, respiratory infection, and arthralgia.Inform patients that this listing of adverse reactions is not complete and not all adverse reactions can be anticipated. If appropriate, more comprehensive list of adverse reactions can be discussed with patients.. In adult clinical trials the most common adverse reactions were headache, abdominal pain, diarrhea, nausea, vomiting, respiratory infection, and arthralgia.. Inform patients that this listing of adverse reactions is not complete and not all adverse reactions can be anticipated. If appropriate, more comprehensive list of adverse reactions can be discussed with patients.. 17.3 What Patients Should Know About Taking Balsalazide with Other Medication. Based upon limited studies conducted in test tube, balsalazide is not believed to interfere with other drugs by preventing how the liver functions. However, as the studies were limited in scope, you should always consult your doctor and discuss potential interactions prior to initiating any new drug. 10003708/04 Revised October 2010 (C)RLI, 2010. Based upon limited studies conducted in test tube, balsalazide is not believed to interfere with other drugs by preventing how the liver functions. However, as the studies were limited in scope, you should always consult your doctor and discuss potential interactions prior to initiating any new drug.

MECHANISM OF ACTION SECTION.

12.1 Mechanism of Action. Balsalazide disodium is delivered intact to the colon where it is cleaved by bacterial azoreduction to release equimolar quantities of mesalamine, which is the therapeutically active portion of the molecule, and the 4-aminobenzoyl-ss-alanine carrier moiety. The carrier moiety released when balsalazide disodium is cleaved is only minimally absorbed and is largely inert.The mechanism of action of 5-ASA is unknown, but appears to be local to the colonic mucosa rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that 5-ASA diminishes inflammation by blocking production of arachidonic acid metabolites in the colon.

NONCLINICAL TOXICOLOGY SECTION.

13 NONCLINICAL TOXICOLOGY. 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility. In 24-month rat (Sprague Dawley) carcinogenicity study, oral (dietary) balsalazide disodium at doses up to g/kg/day was not tumorigenic. For 50 kg person of average height this dose represents 2.4 times the recommended human dose on body surface area basis. Balsalazide disodium was not genotoxic in the following in vitro or in vivo tests: Ames test, human lymphocyte chromosomal aberration test, and mouse lymphoma cell (L5178Y/TK+/-) forward mutation test, or mouse micronucleus test. However, it was genotoxic in the in vitro Chinese hamster lung cell (CH V79/HGPRT) forward mutation test.4-aminobenzoyl-ss-alanine, metabolite of balsalazide disodium, was not genotoxic in the Ames test and the mouse lymphoma cell (L5178Y/TK+/-) forward mutation test but was positive in the human lymphocyte chromosomal aberration test. N-acetyl-4-aminobenzoyl-ss-alanine, conjugated metabolite of balsalazide disodium, was not genotoxic in Ames test, the mouse lymphoma cell (L5178Y/TK+/-) forward mutation test, or the human lymphocyte chromosomal aberration test. Balsalazide disodium at oral doses up to g/kg/day, 2.4 times the recommended human dose based on body surface area, was found to have no effect on fertility and reproductive performance in rats.. 13.2 Animal Toxicology and/or Pharmacology. Renal Toxicity. In animal studies conducted at doses up to 2000 mg/kg (approximately 21 times the recommended 6.75 g/day dose on mg/kg basis for 70 kg person), balsalazide demonstrated no nephrotoxic effects in rats or dogs.. Overdosage. single oral dose of balsalazide disodium at g/kg or 4-aminobenzoyl-ss-alanine, metabolite of balsalazide disodium, at g/kg was non-lethal in mice and rats. No symptoms of acute toxicity were seen at these doses.

NURSING MOTHERS SECTION.

8.3 Nursing Mothers. It is not known whether balsalazide disodium is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when balsalazide is administered to nursing woman.

OVERDOSAGE SECTION.

10 OVERDOSAGE. No case of overdose has occurred with balsalazide. 3-year-old boy is reported to have ingested g of another mesalamine product. He was treated with ipecac and activated charcoal with no adverse reactions.If an overdose occurs with balsalazide, treatment should be supportive, with particular attention to correction of electrolyte abnormalities.

PACKAGE LABEL.PRINCIPAL DISPLAY PANEL.

PRINCIPAL DISPLAY PANEL. Balsalazide Disodium Capsules, 750 mgNDC 54868-6137-0. image of package label.

PEDIATRIC USE SECTION.

8.4 Pediatric Use. Pediatric use information is protected by marketing exclusivity.

PHARMACOKINETICS SECTION.

12.3 Pharmacokinetics. Balsalazide capsules contain powder of balsalazide disodium that is insoluble in acid and designed to be delivered to the colon as the intact prodrug. Upon reaching the colon, bacterial azoreductases cleave the compound to release 5-ASA, the therapeutically active portion of the molecule, and 4-aminobenzoyl-ss-alanine. The 5-ASA is further metabolized to yield N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA), second key metabolite.. Absorption. The plasma pharmacokinetics of balsalazide and its key metabolites from crossover study in healthy volunteers are summarized in Table 2. In this study, single oral dose of balsalazide 2.25 was administered to healthy volunteers as intact capsules (3 750 mg) under fasting conditions, as intact capsules (3 750 mg) after high-fat meal, and unencapuslated (3 750 mg) as sprinkles on applesauce.Table 2: Plasma Pharmacokinetics for Balsalazide and Key Metabolites (5-ASA and N-Ac-5-ASA) with Administration of Balsalazide Following Fast, High-Fat Meal, and Drug Contents Sprinkled on Applesauce (Mean +- SD)Fasting (N=17)High-Fat Meal (N=17)Sprinkled (N=17)Cmax (mcg/mL) Balsalazide0.51 +- 0.320.45 +- 0.390.21 +- 0.12 5-ASA0.22 +- 0.120.11 +- 0.1360.29 +- 0.17 N-Ac-5-ASA0.88 +- 0.390.64 +- 0.5341.04 +- 0.57AUClast (mcg.hr/mL) Balsalazide1.35 +- 0.731.52 +- 1.010.87 +- 0.48 5-ASA2.59 +- 1.462.1 +- 2.582.99 +- 1.7 N-Ac-5-ASA17.8 +- 8.1417.7 +- 13.720 +- 11.4Tmax (h) Balsalazide0.8 +- 0.851.2 +- 1.111.6 +- 0.44 5-ASA8.2 +- 1.9822 +- 8.238.7 +- 1.99 N-Ac-5-ASA9.9 +- 2.4920.2 +- 8.9410.8 +- 5.39A relatively low systemic exposure was observed under all three administered conditions (fasting, fed with high-fat meal, sprinkled on applesauce), which reflects the variable, but minimal absorption of balsalazide disodium and its metabolites. The data indicate that both Cmax and AUClast were lower, while Tmax was markedly prolonged, under fed (high-fat meal) compared to fasted conditions. Moreover, the data suggest that dosing balsalazide disodium as sprinkle or as capsule provides highly variable, but relatively similar mean pharmacokinetic parameter values. No inference can be made as to how the systemic exposure differences of balsalazide and its metabolites in this study might predict the clinical efficacy under different dosing conditions (i.e., fasted, fed with high-fat meal, or sprinkled on applesauce) since clinical efficacy after balsalazide disodium administration is presumed to be primarily due to the local effects of 5-ASA on the colonic mucosa.In separate study of adult patients with ulcerative colitis, who received balsalazide, 1.5 twice daily, for over year, systemic drug exposure, based on mean AUC values, was up to 60 times greater (0.008 mcg.hr/mL to 0.48 mcg.hr/mL) when compared to that obtained in healthy subjects who received the same dose.. Distribution. The binding of balsalazide to human plasma proteins was >=99%.. Metabolism. The products of the azoreduction of this compound, 5-ASA and 4-aminobenzoyl-ss-alanine, and their N-acetylated metabolites have been identified in plasma, urine and feces.. Elimination. Following single-dose administration of 2.25 balsalazide (three 750 mg capsules) under fasting conditions in healthy subjects, mean urinary recovery of balsalazide, 5-ASA, and N-Ac-5-ASA was 0.2%, 0.22% and 10.2%, respectively.In multiple-dose study in healthy subjects receiving balsalazide dose of two 750 mg capsules twice daily (3 g/day) for 10 days, mean urinary recovery of balsalazide, 5-ASA, and N-Ac-5-ASA was 0.1%, 0%, and 11.3%, respectively. During this study, subjects received their morning dose 0.5 hours after being fed standard meal, and subjects received their evening dose hours after being fed standard meal.In study with 10 healthy volunteers, 65% of single 2.25 dose of balsalazide was recovered as 5-ASA, 4-aminobenzoyl-ss-alanine, and the N-acetylated metabolites in feces, while <1% of the dose was recovered as parent compound.In study that examined the disposition of balsalazide in patients who were taking to g of balsalazide daily for more than year and who were in remission from ulcerative colitis, less than 1% of an oral dose was recovered as intact balsalazide in the urine. Less than 4% of the dose was recovered as 5-ASA, while virtually no 4-aminobenzoyl-ss-alanine was detected in urine. The mean urinary recovery of N-Ac-5-ASA and N-acetyl-4-aminobenzoyl-ss-alanine comprised <16% and <12% of the balsalazide dose, respectively. No fecal recovery studies were performed in this population.All pharmacokinetic studies with balsalazide are characterized by large variability in the plasma concentration versus time profiles for balsalazide and its metabolites, thus half-life estimates of these analytes are indeterminate.

PREGNANCY SECTION.

8.1 Pregnancy. Pregnancy Category B. Reproduction studies were performed in rats and rabbits at oral doses up to g/kg/day, 2.4 and 4.7 times the recommended human dose based on body surface area for the rat and rabbit, respectively, and revealed no evidence of impaired fertility or harm to the fetus due to balsalazide disodium. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

RECENT MAJOR CHANGES SECTION.

Drug Interactions (7) 2/2007Postmarketing Experience (6.2) 5/2008.

SPL UNCLASSIFIED SECTION.

2.1 Adult Dose. For treatment of active ulcerative colitis in adult patients, the usual dose is three 750 mg balsalazide capsules to be taken times day (6.75 per day) for up to weeks. Some patients in the adult clinical trials required treatment for up to 12 weeks.

USE IN SPECIFIC POPULATIONS SECTION.

8 USE IN SPECIFIC POPULATIONS. Renal Impairment: Use balsalazide with caution in patients with history of renal disease. (5.3)Pediatric: Pediatric use information is protected by marketing exclusivity. (8.4). 8.1 Pregnancy. Pregnancy Category B. Reproduction studies were performed in rats and rabbits at oral doses up to g/kg/day, 2.4 and 4.7 times the recommended human dose based on body surface area for the rat and rabbit, respectively, and revealed no evidence of impaired fertility or harm to the fetus due to balsalazide disodium. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.. 8.3 Nursing Mothers. It is not known whether balsalazide disodium is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when balsalazide is administered to nursing woman.. 8.4 Pediatric Use. Pediatric use information is protected by marketing exclusivity.

WARNINGS AND PRECAUTIONS SECTION.

5 WARNINGS AND PRECAUTIONS. Exacerbation of the symptoms of ulcerative colitis was reported in adult patients. Observe patients closely for worsening of these symptoms while on treatment. (5.1)Prolonged gastric retention of balsalazide may occur in patients with pyloric stenosis. (5.2). Exacerbation of the symptoms of ulcerative colitis was reported in adult patients. Observe patients closely for worsening of these symptoms while on treatment. (5.1). Prolonged gastric retention of balsalazide may occur in patients with pyloric stenosis. (5.2). 5.1 Exacerbations of Ulcerative Colitis. In the adult clinical trials, out of 259 patients reported exacerbation of the symptoms of ulcerative colitis. Observe patients closely for worsening of these symptoms while on treatment.. 5.2 Pyloric Stenosis. Patients with pyloric stenosis may have prolonged gastric retention of balsalazide capsules.. 5.3 Renal. Renal toxicity has been observed in animals and patients given other mesalamine products. Therefore, caution should be exercised when administering balsalazide to patients with known renal dysfunction or history of renal disease. [See 13 NONCLINICAL TOXICOLOGY (13.2)].