Capsule formulation of pirfenidone and pharmaceutically acceptable excipients

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ABSTRACT:A capsule formulation of pirfenidone is provided that includes pharmaceutically acceptable excipients. In one embodiment, this capsule formulation is capable of sustaining desirable pharmacokinetic study responses in a patient. Further provided are methods of treating fibrotic conditions and other cytokine-mediated disorders by administering pirfenidone capsules of such formulation to a patient in need.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present disclosure relates in general to pirfenidone, a small drug molecule whose chemical name is 5-methyl-1-phenyl-2-(1H)-pyridone. Specifically, the present disclosure relates to a capsule formulation of pirfenidone including pharmaceutically acceptable excipients. Further provided are methods of using such capsule formulation in the treatment of fibrotic conditions and other disorders mediated by cytokines.

2. Description of the Related Art

Pirfenidone is a non-peptide synthetic molecule with a molecular weight of 185.23 daltons. Its chemical elements are expressed as C12H11NO, and its structure is known. The synthesis of pirfenidone has been worked out. Pirfenidone is manufactured and being evaluated clinically as a broad-spectrum anti-fibrotic drug. Pirfenidone has anti-fibrotic properties via: decreased TNF-α expression, decreased PDGF expression, and decreased collagen expression. Several pirfenidone Investigational New Drug Applications (INDs) are currently on file with the U.S. Food and Drug Administration. Phase II human investigations are ongoing or have recently been completed for pulmonary fibrosis, renal glomerulosclerosis, and liver cirrhosis. There have been other Phase II studies that used pirfenidone to treat benign prostate hypertrophy, hypertrophic scarring (keloids), and rheumatoid arthritis.

One important use of pirfenidone is known to be providing therapeutic benefits to patients suffering from fibrosis conditions such as Hermansky-Pudlak Syndrome (HPS) associated pulmonary fibrosis and idiopathic pulmonary fibrosis (IPF). Pirfenidone demonstrates a pharmacologic ability to prevent or remove excessive scar tissue found in fibrosis associated with injured tissues including that of lungs, skin, joints, kidneys, prostate glands, and livers. Published and unpublished basic and clinical research suggests that pirfenidone may safely slow or inhibit the progressive enlargement of fibrotic lesions, remove pre-existing fibrotic lesions, and prevent formation of new fibrotic lesions following tissue injuries.

It is understood that one mechanism by which pirfenidone exerts its therapeutic effects is modulating cytokine actions. Pirfenidone is a potent inhibitor of fibrogenic cytokines and TNF-α. It is well documented that pirfenidone inhibits excessive biosynthesis or release of various fibrogenic cytokines such as TGF-β1, bFGF, PDGF, and EGF. Zhang S et al., Australian and New England Journal Ophthalmology, 26; S74-S76, 1998. Experimental reports also show that pirfenidone blocks the synthesis and release of excessive amounts of TNF-α from macrophages and other cells. Cain et al., International Journal Immunopharmacology, 20:685-695 (1998).

As an investigational drug, pirfenidone is provided in tablet and capsule forms principally for oral administration. Various formulations have been tested and adopted in clinical trials and other research and experiments. The effectiveness of a formulation may be determined by a plurality of factors, including the amount of pirfenidone it contains, the kinds and relative amounts of pharmacologically acceptable excipients used, and the target patient profile (e.g., the physiological and genetic conditions, disease prognosis, and demographic characteristics of the patient). Changes in these factors cause changes in pharmacokinetic (PK) responses in the patient. Thus, there is a need in general for effective pharmaceutical formulations that elicit desirable pharmacokinetic study responses in patients thereby optimizing therapeutic actions of pirfenidone.

SUMMARY OF THE VARIOUS EMBODIMENTS

It is therefore an object of this disclosure to provide pharmaceutical formulations of pirfenidone capable of advantageous therapeutic actions. It is a related object to provide pharmaceutical formulations of pirfenidone capable of eliciting and sustaining desirable pharmacokinetic responses in the patient in need thereof. It is another object of this disclosure to provide methods for treating fibrotic conditions and other cytokine-mediated disorders using such formulations.

In accordance with this disclosure, there is provided, in one embodiment, a capsule having a pharmaceutical formulation of 5-methyl-1-phenyl-2-(1H)-pyridone (pirfenidone), which includes 5-30% of pharmaceutically acceptable excipients and 70-95% of pirfenidone by weight.

According to another embodiment, the excipients include disintegrators, binders, fillers, and lubricants. Examples of disintegrators include agar-agar, algins, calcium carbonate, carboxmethylcellulose, cellulose, clays, colloid silicon dioxide, croscarmellose sodium, crospovidone, gums, magnesium aluminium silicate, methylcellulose, polacrilin potassium, sodium alginate, low substituted hydroxypropylcellulose, and cross-linked polyvinylpyrrolidone hydroxypropylcellulose, sodium starch glycolate, and starch. Examples of binders include microcrystalline cellulose, hydroxymethyl cellulose, hydroxypropylcellulose, and polyvinylpyrrolidone. Examples of fillers include calcium carbonate, calcium phosphate, dibasic calcium phosphate, tribasic calcium sulfate, calcium carboxymethylcellulose, cellulose, dextrin derivatives, dextrin, dextrose, fructose, lactitol, lactose, magnesium carbonate, magnesium oxide, maltitol, maltodextrins, maltose, sorbitol, starch, sucrose, sugar, and xylitol. Examples of lubricants include agar, calcium stearate, ethyl oleate, ethyl laureate, glycerin, glyceryl palmitostearate, hydrogenated vegetable oil, magnesium oxide, magnesium stearate, mannitol, poloxamer, glycols, sodium benzoate, sodium lauryl sulfate, sodium stearyl, sorbitol, stearic acid, talc, and zinc stearate.

According to yet another embodiment, by weight 2-10% of the capsule is disintegrator, 2-30% is binder, 2-30% is filler, and 0.3-0.8% is lubricant. In another embodiment, by weight 2-10% of the capsule is disintegrator, 2-25% is binder, 2-25% is filler, and 0.3-0.8% is lubricant. According to still another embodiment, the excipients further include povidone. In a further embodiment, by weight 1-4% of the capsule is povidone. According to another embodiment, the capsule includes 100-400 mg Pirfenidone.