FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
PROVISIONAL SPECIFICATION / COMPLETE SPECIFICATION (See section 10 and rule 13)

1. TITLE OF THE INVENTION
PHARMACEUTICAL COMPOSITION OF RIFAMPICIN
2. APPLICANT(S)
(a) NAME
(b) NATIONALITY
(c) ADDRESS
CADILA PHARMACEUTICALS LIMITED
An INDIAN Company
"Cadila Corporate Campus", Sarkhej - Dholka Road, Bhat, Ahmedabad -382210, Gujarat, India
3. PREAMBLE TO THE DESCRITION

PROVISIONAL SPECIFICATION
The following specification describes the invention.
4. DESCRIPTION

The following specification particularly describes the invention and the manner in which it is to be performed

(Description starts from next page)


FIELD OF THE INVENTION
The present invention relates to a pharmaceutical composition comprising rifampicin and piperine with optimal enhancement in bioavailability of rifampicin by piperine. The present invention further relates to process for preparing pharmaceutical composition comprising rifampicin and piperine.
BACKGROUND OF THE INVENTION
Tuberculosis (abbreviated as TB for tubercle bacillus or Tuberculosis) is a common and often deadly infectious disease caused by mycobacteria. Tuberculosis usually attacks the lungs (as pulmonary TB) but can also affect the central nervous system, the lymphatic system, the circulatory system, the genitourinary system, the gastrointestinal system, bones, joints, and even the skin. Other mycobacteria such as Mycobactenum bovis, Mycobacterium africanum, Mycobacterium canetti, and Mycobacterium microti also cause tuberculosis, but these species are less common in humans.
US Patent No. 5,439,891 discloses about pharmaceutical composition for the treatment of tuberculosis and leprosy, said composition comprising piperine in combination with known antituberculosis drugs. However, when such pharmaceutical composition are made having rifampicin, these formulations showed different pharmacokinetic properties.
It was surprisingly found that the mere admixture of piperine with rifampicin containing formulation doesn't result in optimum enhancement in bioavailability of rifampicin. Thus, there is a need to develop a pharmaceutical composition comprising rifampicin and piperine with optimal enhancement in the bioavailability of rifampicin by piperine
According to present invention, It is found that bioenhancement property of piperine with rifampicin containing formulation depends on type of rifampicin, selection of excipients and manufacturing process.
SUMMARY OF THE INVENTION:
The main object of the present invention is to provide a pharmaceutical composition comprising rifampicin and piperine with optimal enhancement in bioavailability of rifampicin by piperine.
Another object of the present invention is to provide excipients for manufacturing of pharmaceutical composition comprising rifampicin and piperine with optimal enhancement in bioavailability of rifampicin by piperine.
Another object of the present invention is to provide process for manufacturing of pharmaceutical composition comprising rifampicin and piperine with optimal enhancement in bioavailability of rifampicin by piperine.
Applicants have surprisingly found that use of compacted rifampicin resulted in reduction of bioavailability of rifampicin, whereas powdered rifampicin resulted in enhanced

bioavailability of rifampicin, but further micronization doesn't improve the bioavailability of' rifampicin.
It was surprisingly found that the mere admixture of piperine doesn't show the enhancement in bioavailability of rifampicin. It was found that bioenhancement property of piperine depends on grade or type of rifampicin, selection of excipients and manufacturing process.
It was observed that blending of rifampicin powder, starch and magnesium stearate with piperine tablets or powder or granules provided higher bioavailability of rifampicin as compared to other excipients.
The piperine part can be formulated by wet granulation or compaction or direct blending. The rifampicin part is preferably formulated by direct blending process using starch and magnesium stearate.
Similarly, the present invention can be useful to prepare pharmaceutical composition in hard gelatin capsule or tablets.
DETAILED DESCRIPTION OF THE INVENTION:
The present invention relates to a pharmaceutical composition comprising rifampicin and piperine with optimal enhancement in bioavailability of rifampicin by piperine.
The composition of some of the marketed samples of rifampicin is provided as below:
a) Rimactan® Capsules from Sandoz contains Lactose monohydrate, Soya-bean lecithin, Gelatin, Dimeticone, Shellac, Calcium stearate, Titanium dioxide, Iron oxide
b) Rifadin® Capsules from Ab Ferrosan contains Indigo carmine, Titanium dioxide, Starch, Magnesium stearate, Gelatin and Cochineal Red A
c) Rifampin Capsule from Actavis Totowa contains Lactose monohydrate, Magnesium stearate, Methylparaben, Propylparaben, Silicon dioxide, Sodium lauryl sulfate, Corn starch, Talc, and Titanium dioxide.
d) Rifampin Capsule from Lannett Company contains Pregelatinized starch, Colloidal silicon dioxide, Talc, Magnesium stearate, and Titanium dioxide.
e) Rifampin Capsule from VersaPharm Incorporated contains Lactose monohydrate, Magnesium stearate, Sodium lauryl sulfate, Talc, and Titanium dioxide.
The present invention relates to a pharmaceutical composition comprising rifampicin • and piperine with optimal enhancement in bioavailability of rifampicin by piperine wherein the said composition has desired stability, bioavailability and which is easy to swallow.
The pharmaceutical^ acceptable excipient include any of diluent, binder, disintegrant, lubricant, glidant, stabilizer, surfactant, organic solvent, water, film forming polymer, opacifier, plasticizer, modified release polymer and the like.
The pharmaceutical composition of the present invention may contain one or more diluents added to increase mass and, hence, make a dosage form easier for the patient and caregiver to handle. Common diluents are microcrystalline cellulose, directly compressible

grade microcrystalline cellulose, lactose, starch, pregelatinized starch, calcium carbonate, calcium sulfate, sugar, dextrates, dextrin, dextrose, dibasic calcium phosphate dihydrate, tribasic calcium phosphate, magnesium carbonate, magnesium oxide, maltodextrin, mannitoi and the like. The preferred diluent used in the instant invention is starch.
Binders also can be included in the pharmaceutical composition. Some typical binders are acacia, alginic acid, carbomer (e.g. carbopol), carboxymethylcellulose sodium, dextrin, ethyl cellulose, gelatin, guar gum, hydrogenated vegetable oil, hydroxyethyl cellulose, hydroxypropyl cellulose (e.g. Klucel®), Hydroxypropyl methyl cellulose (e.g. Methocel®), liquid glucose, magnesium aluminum silicate, maltodextrin, methylcellulose, polymethacrylates, povidone (e.g. Kollidon®, Plasdone®), pregelatinized starch, sodium alginate and starch.
The surfactant like polysorbate, anionic surfactant, nonionic surfactant improves the effect of piperine on bioavailability of rifampicin. Examples of the above-mentioned nonionic surfactant are, for instance, polyoxyethylamine oxides, alkylamine oxides, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, sorbitan . fatty acid esters, polyoxyethylene sorbitan fatty acid esters, glycerine esters, polyoxyethylene alkylamine, the derivatives thereof, and the like, anionic surfactant, there can be used known ones, for example, higher fatty acid and its salt, alkyl sulfate, alkyl sulfonate, alkyl aryl sulfonate, alkyl phosphoric acid ester and the like.
The preferred surfactant used in the instant invention is Sodium lauryl sulphate. The stabilizer like citric acid may also be useful in instant invention.
The lubricant like Magnesium stearate, Sodium stearyl fumarate, Stearic acid, Talc, Colloidal silicon dioxide and the like known to skilled person in the art.
The disintegrant can be used to accelerate disintegration of the tablet or granules or capsules in the patient's stomach. Disintegrants include alginic acid, croscarmellose sodium, sodium starch glycolate, crospovidone, polacrilin potassium, powdered cellulose, pregelatinized starch, sodium alginate and starch. The preferred disintegrant used in the instant invention is croscarmellose sodium. The disintegrant is used in the instant invention in the range of 0.1% to 10% of total weight of dosage form. It was surprisingly found that use of croscarmellose sodium in piperine granules or tablets resulted in better bioavailability of rifampicin.
The solvents specify herein but are not limited to purified water, alcohols, ketones, esters, ethers, halogenated solvents, hydrocarbons, nitriles, or mixtures thereof. Lower alkanols are useful and can be any alcohol such as for example one or more of the primary, secondary or tertiary alcohols having from one to about six carbon atoms. The lower alkanol can be for example one or more of methanol, ethanol, denatured spirits, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol and the like. The ketones can be any solvent from this class such as for example one or more of acetone, propanone, 2-butanone and the

like. The halogenated solvent can be any solvent from this class such as for example one or more of chloroform, dichloromethane, 1, 2-dichloroethane, carbon tetrachloride and the like. The following examples will further illustrate certain aspects of the present invention in greater detail and are not intended to limit the scope of the invention.
Example I: The following are the examples of pharmaceutical composition to demonstrate the effect of quality of rifampicin on rifampicin bioavailability

Sr. No. Ingredients Mg / Capsule

Formulation 1 Formulation 2 Formulation 3
1. Rifampicin #200.00 *200.00 #200.00
2. Piperine - 10.00 10.00
3. Citric Acid 5.00 5.00 5.00
4. Lactose 20.00 20.00 20.00
5. Starch 10.00 10.00 10.00
6. Sodium Starch Glycolate 5.00 5.00 5.00
7. Magnesium Stearate 2.00 2.00 2.00
8. Sodium Lauryl Sulphate 4.00 4.00 4.00
9. Colloidal Silicon Dioxide 2.00 2.00 2.00
# powdered grade rifampicin
* Compacted grade rifampicin
Process description:
1. Rifampicin was sifted through 16 # s.s screen.
2. Piperine (Except Formulation 1), Citric acid, Lactose, Starch, Sodium starch glycolate, Magnesium stearate, Sodium lauryl stearate and Colloidal silicon dioxide were sifted through 40 # s.s screen.
3. Rifampicin and blend from step 2 were mixed thoroughly.
4. The blend from step 3 was filled in hard gelatin capsule shell.
These batches were subjected to in-vivo studies in human volunteers. The observation based on the study can be summarized as follows:
a) The pharmacokinetic parameters Cmax (ug/ml), AUC (0-1) (hr X ug/ml) and AUC(0-1) (hr X ug/ml) of formulation 1 was lowest as expected and highest with formulation 3. The parameters were higher with formulation 2 compared to formulation .1 but were surprisingly significantly lower than formulation 3. The said pharmacokinetic parameters of Formulation 2 were in the range of 80% -125% as compared to Formulation 1.

The above results demonstrate that piperine enhances the bioavailability of rifampicin. The powdered grade of rifampicin provides better bioavailability than compacted grade rifampicin.
Example II: The following examples shows the effect of excipients on bioenhancement of Rifampicin by piperine

Sr. No. Ingredients Mg / Capsule

Formulation 4 Formulation 5 Formulation 6
A. Rifampicin Blend
1. Rifampicin* 200.00 200.00 200.00
2. Citric Acid 5.00 5.00 -
3. Lactose 20.00 20.00 -
4. Starch 10.00 10.00 56.00
5. Sodium Starch Glycoiate 5.00 5.00 -
6. Magnesium Stearate 2.00 2.00 2.00
7. Sodium Lauryl Sulphate 4.00 4.00 -
8. Colloidal Silicondioxide 2.00 2.00 -
B. Piperine Tablets
1. Piperine 10.00 10.00 10.00
a. Base Granules
1. Lactose 41.43 - 41.83
2. Starch 22.00 - 21.27
3. Sodium Lauryl Sulphate - - 0.38
4. Starch (Paste) 2.57 - 2.57
5. Purified Water q.s q.s
b. Pre Lubrication Stage
1. Croscarmellose Sodium 2.40 - 2.40
2. Sodium Lauryl Sulphate - - 0.35
3. Colloidal Silicondioxide 0.40 - 0.30
4. Magnesium Stearate 0.40 - 0.30
c. Final Lubrication
1. Colloidal Silicondioxide 0.40 - 0.30
2. Magnesium Stearate 0.40 - 0.30
# powdered grade rifampicin
Process description:
A. Rifampicin Blend for Formulation 4 and Formulation 5
1. Rifampicin was sifted through 16 # s.s screen.
2. Citric acid, Lactose, Starch, Sodium starch glycoiate, Magnesium stearate, Sodium lauryl stearate and Colloidal silicon dioxide were sifted through 40 # s.s screen.

3. Rifampicin and blend from step 2 was mixed thoroughly. A'. Rifampicin Blend for Formulation 6
1. Rifampicin was sifted through 16 # s.s screen.
2. Starch and Magnesium stearate were sifted through 40 # s.s screen and mixed with Rifampicin.
B. Piperine Tablet for Formulation 4 and Formulation 6 1. Piperine was sifted through 60 # s.s screen.
a. Base granules:
1. Lactose, Starch and Sodium lauryl sulphate (For Formulation 6) were sifted
through 40 # s.s screen.
2. Above blend was granulated with starch paste prepared in purified water.
3. The wet mass was dried in tray dryer.
4. Dried granules were sifted through 30 # s.s screen.
b. Pre Lubrication:
1. The base granules and piperine were mixed geometrically.
2. Sodium lauryl sulphate (For Formulation 6), Croscarmellose sodium, Colloidal silicondioxide and Magnesium stearate were sifted through 40 # s.s screen.
3. The blend from step 1 and step 2 were mixed thoroughly.
Slugging:
1. The above blend was slugged and was sifted through 30 # s.s screen.
c. Final Lubrication.
1. Colloidal silicon dioxide and Magnesium stearate were sifted through 40 # s.s screen. The slugged granules and lubricants were mixed and compressed into tablets
For Formulation 4 and Formulation 6, the rifampicin blend and piperine tablet were filled in hard gelatin capsule. For Formulation 5, the rifampicin blend and powdered piperine were added in hard gelatin capsule.
The capsules from Formulation 4, Formulation 5 and Formulation 6 were subjected to pharmacokinetic studies in human volunteers for evaluating bioavailability of Rifampicin.
In case of Formulation 5 the Cmax was higher than 28%, AUC(0-t)) was higher than 20% and AUC (0-1) was higher than 23% as compared to Formulation 4.
In case of Formulation 6 the Cmax was higher than 42%, AUC(0-t) was higher than 24% and AUC (0-t) was higher than 15.31% as compared to Formulation 4.

Example III: Examples of formulation with improved bioavailability
Formulation 6:

Sr. No. Ingredients Mg / Capsule

Formulation 6
A. Rifampicin Blend
1. Rifampicin* 200.00
2. Starch 56.00
3. Magnesium Stearate 2.00
B. Piperine Tablets
1. Piperine 10.00
a. Base Granules
1. Lactose 41.83
2. Starch 21.27
3. Sodium Lauryl Sulphate 0.38
4. Starch (Paste) 2.57
5. Purified Water q.s
b. Pre Lubrication Stage
1. Sodium Lauryl Sulphate 0.35
2. Croscarmellose Sodium 2.40
3. Colloidal Silicondioxide 0.30
4. Magnesium Stearate 0.30
c. Final Lubrication
1. Colloidal Silicondioxide 0.30
2. Magnesium Stearate 0.30
# powdered grade rifampicin
Process description:
A. Rifampicin Blend
1. Rifampicin was sifted through 16 # s.s screen.
2. Starch and Magnesium stearate were sifted through 40# s.s screen.
3. Rifampicin and blend from step 2 was mixed thoroughly.
B. Piperine Tablet
1. Piperine was sifted through 60 # s.s screen. a. Base granules:
1. Lactose, Starch and Sodium lauryl sulphate were sifted through 40 # s.s screen.
2. Above blend was granulated with starch paste prepared in purified water.
3. The wet mass was dried in tray dryer.
4. Dried granules were sifted through 30 # s.s screen.

b. Pre Lubrication.
1. The base granules and piperine were mixed geometrically.
2. Sodium lauryl sulphate, Croscarmellose sodium, Colloidal silicondioxide and Magnesium stearate were sifted through 40 # s.s screen.
3. The blend from step 1 and step 2 were mixed thoroughly.
Slugging:
1. The above blend was slugged and was sifted through 30 # s.s screen.
c. Final Lubrication:
1. Colloidal Silicondioxide and Magnesium Stearate were sifted through 40 # s.s screen. The slugged granules and lubricants were mixed and compressed into tablets These batches were subjected to in-vivo studies in human volunteers. The data of the same for rifampicin is summarized as follows:
The pharmacokinetic parameters Cmax (ug/ml), AUC (0-t)(hr X ug/ml) and AUC(0-)) (hr X ug/ml) of of Formulation 6 was showing enhanced bioavailability as compared to Formulation 1.
The above results demonstrate the preferred composition having enhanced bioavailability of rifampicin. The above results also demonstrate that the bioenhancing property of piperine with respect to rifampicin is dependent on selection of excipients and grade of rifampicin and process of manufacturing of rifampicin composition.
For Cadila Pharmaceuticals Ltd.,
Dr. B. M. Khamar
Executive director - Research