Abstract:
The invention relates to the isolation of an extract and/ or its fraction from the plant  Carum carvi,  its standardization with its intended use as drug bioavailability and/or bioefficacy enhancer for the drugs belonging to therapeutic categories such as but not limited to antimicrobial, antifungal, anti-viral, antitubercular, antileprosy, antiinflammatory/anti-arthritic, cardiovascular, antihistaminics, respiratory distress relieving drugs, immunosuppressants, anti-ulcers, nutraceuticals in compositions to be administered orally/parenterally, topically, inhalations (including nebulizers), rectally, vaginally in human beings and/or veterinary conditions.

Description:
BACKGROUND OF THE INVENTION  
       FIELD OF THE INVENTION  
         [0001]    The present invention relates to the use of bioavailability and/or bioefficacy enhancers—also termed as bioenhancers or BE and methods of their preparation which include their isolation from a natural source and obtaining the final products in their chemically characterized or fingerprint—profiled form.  
           [0002]    The present invention is directed to preparation of active extracts/fraction from the plant  Carum carvi  which include their chemical characterisation, fingerprint profiling and methods of using such products to enhance bioavailability and/or bioefficacy of drugs, natural products and essential nutraceuticals. The present invention is directed to preparation of composite bioenhancers comprising polar and non-polar extracts of parts of  Zingiber officinale  and/or piperine (Ex:  Piper nigrum  and  Piper longum ) which increased significantly (50-180%) , the bioavailability of a number of classes of drugs, for example, but not limited to, antibiotics, antifungals, anti-virals, anticancer, cardiovascular, CNS, anti-inflammatory/anti-arthritic, anti-TB/antileprosy, anti-histaminic/respiratory dosorders, corticosteroids, immunosppressants, anti-ulcer. Such extracts/fractions of Carum carvi either in presence or absence of  Zingiber officinale  and/or piperine (Ex:  Piper nigrum  and  Piper longum ) have been found to be highly selective in their bioavailability/bioefficacy enhancing action.  
           [0003]    There is a great interest and medical need for the improvement of bioavailability of a large number of drugs which are (a) poorly bioavailable, (b) given for long periods, and are (c) toxic and expensive. Maximizing oral bioavailability is therapeutically important because the extent of bioavailability directly influences plasma concentrations and consequently therapeutic efficacy and dose related toxic effects resulting after oral drug administration. Poorly bioavailable drugs remain sub-therapeutic because a major portion of a dose never reaches the plasma or exerts its pharmacological effect unless and until very large doses are given which may lead to serious side effects. Any significant improvement in bioavailability will result in lowering the dose or the dose frequency of that particular drug. Besides, inter-subject variability is inversely correlated with the extent of bioavailability. Therefore, low oral bioavailability leads to high variability and poor control of plasma concentration and pharmacodynamic effects. Inter-subject variability is particularly of concern for a drug with a narrow safety margin.  
           [0004]    Incomplete oral bioavailability has various causes. These include poor dissolution or low aqueous solubility, poor intestinal membrane permeation, degradation of the drug in gastric or intestinal fluids and pre-systemic intestinal or hepatic metabolism. The normal practice to offset some of these problems has been to increase the dosage as stated earlier which has the concerns of toxicity patients&#39; non-compliance.  
           [0005]    Many therapeutic treatments are also accompanied by loss of essential nutraceuticals in the course of therapy. The present invention improves nutritional status by increasing bioavailability/bioefficacy of various nutraceuticals also which include metals and vitamins. The bioenhancers of the invention also have the potential to enhance the bioefficacy of a drug without influencing its plasma concentrations for various reasons, some of which, but not limited to, are described later in this invention under Section on ‘Bioavailability/Bioenhancing activity’.  
         DESCRIPTION OF RELATED ART  
         [0006]    Several approaches have been adopted in the past to maximize oral bioavailability, such as (a) particle size reduction (micronization, nanonization, etc.,) (b) polymorphic or crystal size and form selection, (c) solubilization of lesser soluble drugs by way of chemical modifications, complexation and use of co-solvents/surfactants, (d) targeted delivery of drug at the site of action, (e) controlled drug delivery by film coating or use of polymeric matrices for sustained release of drugs, (f) prodrug approach, and (g) microencapsulation using liposomes.  
           [0007]    However, based on clues from Ayurvedic literature, a new approach of increasing the bioavailability of drugs including poorly bioavailable drugs had been conceptualized at RRL, Jammu. One of the groups of herbals which has been documented very frequently as essential part of about 70% of Ayurvedic prescriptions, was noted to be ‘Trikatu’, that comprises three acrids viz. long pepper, black pepper and dry ginger in equal proportions. A single major alkaloidal constituent from peppers (piperine) was found to be responsible for bioavailability enhancing effect. The role of ginger is to regulate intestinal function to to facilitate absorption. Influence of piperine was extensively studied on anti-TB drugs. It was determined that in combination with piperine the dose of rifampicin can be reduced by about 50% while retaining the therapeutic efficacy of this anti-TB drug at par with the standard dose (450 mg). Based on these findings several other reputed plants were evaluated for bioavailability/bioefficacy enhancing activity. Polar and non-polar extracts of parts of a few plants viz.,  Zingiber officinale,  and  Cuminum cyminum  increased significantly (25-300%), the bioavailability of a number of classes of drugs, for example, but not limited to, antibiotics, antifungals, anti-virals, anticancer, cardiovascular, CNS, anti-inflammatory/anti-arthritic, anti-TB/antileprosy, anti-histaminic/respiratory disorders, corticosteroids, immunosuppressants, anti-ulcer. Such extracts either in presence or absence of piperine have been found to be highly selective in their bioavailability/bioefficacy enhancing action.  
         DESCRIPTION OF THE PREFERRED EMBODIMENTS  
         [0008]    [0008] Carum carvi    
           [0009]    It is one of the most prized culinary herb which is used extensively in India. The herb finds very frequent mention in Ayurved and other Indian Systems of Medicine prescriptions used against a wide variety of ailments. It remained a scientific curiosity that a single plant can have biological activities for such a large variety of ailments or diseases for which these prescriptions are employed.  
           [0010]    Chemistry of  Carum carvi    
           [0011]    [0011] Carum carvi  Linn seeds are known as Jira (Beng.), Shahjiru (Guj.), Kala jira, Shiajira (Hindi), Shalajira (Mar.)  Carum carvi  is an annual or biennial glabrous herb, 30-100 cm in height, native to Europe and West Asia, found growing wild in Himachal Pradesh and cultivated in the hills and plains of North India and in the hills of South India for its aromatic seeds.  
           [0012]    Its seeds are widely used as a spice for culinary purposes and for flavouring bread, biscuits, cakes, candies, cheese, curries, pickles, sausages, meat products, confectionery and liqueurs of kummel type. They are also used as a flavouring constituent in cordials and in certain preparations of Cannabis. In medicine, they are used as carminative, mild stomachic, aromatic and diuretic. Both the seeds and the essential oils (caraway oil) are prescribed in flatulent colic and stomach derangements. In patients suffering from lumbago and rheumatism, exposing the affected parts to the vapours from the seeds gives relief from the disease. The alcoholic extract of the fruits show dose-dependent antispasmodic effect. Its water finds use as a vehicle for paediatric medicines. Hexane extract of the fruits was found to have excellent larvicidal activity against the mosquito  Culex pipiens fatigans  Wiedm. [ Marketing of Minor Spices in India,  1968, 119; Krishna &amp; Badhwar,  J. Sci. Industr. Res.,  1952, 11A, suppl., 259; Sharma and Kapil, Loc. cit.; Embong et al  Canad J Pl Sci.,  1977, 57, 543; I.P., 1966, 104; I PC., 55; Gharat,  Pharmaceutist,  1958-59, 4 (2), 21; Cappelletti et al.,  J. Ethnopharmacol,  1982, 6, 178; Forster et al,  Planta Med,  1980, 40, 309; Deshmukh et al,  Pesticides,  1982, 16 (12), 7]. The dried crushed seeds, on steam distillation, gave a pale yellow to light brown essential oil (known as caraway oil) with a strong aromatic odour. The oil content of the seeds varies according to the degree of maturity of the seeds. Storage affects the oil content of seeds up to 2.8 per cent per annum. All Indian samples of the seeds contained 5.8-8.1 per cent of caraway oil. Carvone and the limonene are the chief constituents of the oils and its odour and flavour are mainly attributed to them. Other constituents present in the oil are α- and β-pinene and ρ-cymene. Besides the above constituents, camphene, Δ 3 -carene, dihydrocarvone, β-fenchene, myrcene, α- and β-phellandrene, sabinene, α and γ-terpinene, α-thujene, terpinolene, tricyclene, d- and 1-dihydropinol, 1-neodihydrocarveol, 1-isodihydrocarveol, carveol, d-dihydrocarveol, acetaldehyde, methyl alcohol, furfural have also been isolated from European caraway oil ( Arctander,  124; Dijkstra and Speckmann, loc. cit.; Atal &amp; Sood,  Indian J Pharm,  1967, 29, 42; I.P., 1966, 105; Padha et al  Parfum u Kosmetik,  1969, 50, 296;  Chem Abstr.  1980, 93, 191892; Salveson &amp; Svendsen,  Planta Med.  1976, 30, 93, Guenther, IV, 582).  
           [0013]    Caraway oil is primarily used like caraway seeds in flavouring several food products, and in medicine as carminative. It is the main ingredient in the scandinavian “snaps” and the German “kummel”. It is employed in gargle preparations, toothpaste flavours, chewing gum, candy and as a masking agent in bad tasting pharmaceutical preparations and obnoxius insecticides. It also exhibits neurotropic anti-spasmodic activity. In mixture with alcohol and castor oil, it is used for the treatment of scabies. The essential oil shows moderate anti-bacterial and anti-fungal property against several bacteria and fungi. Decarvonised oil is sold in the market for scenting cheap soaps, in jasmine bases and tabac perfumes (IPC., 54;  Arctander,  125; Chopra et al, 1958, 92;  Chem Abstr,  1968, 68, 48218; Narayan et al  Indian Drugs,  1979-80, 17, 394; El-keltawi et al,  Herba pol,  1980, 26, 245).  
           [0014]    The seeds also contain 3-glucosides and 3-galactosides of kaempferol, quercetin and isorhamnetin, and a hydrocarbon (m p, 62-63°). Presence of 5-methoxy-, and 8-methoxy psoralens, sterol, umbelligerone, scopoletin and herniarin is also reported. The fatty acid composition of the oil is: palmitic, 3.6; oleic, 60.7; linoleic, 19.6 and petroselinic, 17.0% ( Food technol Abstr.,  1974, No. 93, 470; Harborne &amp; Williams, Phytochemistry, 1972, 11, 1741; Ceska et al., ibid, 1987, 26, 165; Chakraborti, Trans Bose Res Inst, 1956-58, 21, 61; Chem. Abstr., 1969, 71, 57561; Hilditch &amp; Williams, 287).  
           [0015]    Bioavailability/Bioefficacy Enhancing Activity  
           [0016]    The aqueous, aqueous—alcoholic, ketonic, ethereal, halogenated solvents extracts of the plant parts were evaluated with different therapeutic categories of drugs and nutraceutical (vital amino acids, metals, antioxidants, vitamins) and herbal drugs. The bioavailability/bioefficacy enhancing (BE) activity of  Carum carvi  extracts was found to be consistent from 5 mg to 100 mg irrespective of the amount of the drug(s) present in the formulation. Sub-fractions of the active extracts were also evaluated, with the same categories of drugs. The doses of the fraction(s) responsible for the BE activity ranged from 1.0 to 55 mg. The parent extract as well as the active fraction(s) were found to be active individually as well as in combination with each other with different categories of drugs.  
           [0017]    The individual extract or its fractions were found to be 20-110% more active when used in combination with bioenhancer products developed from  Zingiber officinale.  The effective range for  Zingiber officinale.  BEs was 10-150 mg. Besides both the parent extracts as well as their fractions from  Carum carvi  in different combinations showed pronounced activity ranging from 25-95% in presence of piperine. The amount of piperine in these formulations ranged from 3-15 mg. The extracts or its fractions either in presence or absence of BEs from  Zingiber officinale.  and/or piperine have been found to be highly selective in their bioavailability and/ or bioefficacy enhancing activity. This is apparent from the degree of bioavailibility and/or bioefficacy enhancement caused by these extracts/fractions as exmeplified in accompanying examples. The reasons for this selective pattern may be attributable to one or more than one of the following reasons: (a) Promoting the absorption of drugs from GIT, (b) Inhibiting or reducing the rate of biotransformation of drugs in the liver or intestines, (c) Modifying the immune system in a way that the overall requirement of the drug is reduced substantially, (d) Increasing the penetration or the entry into the pathogens even where they become persistors within the macrophages such as for  Mycobacterium tuberculosis  and such others. This eventually ensures the enhanced killing of these organisms well secured within the places otherwise inaccessible to the active drug, (e) Inhibiting the capability of pathogens or abnormal tissue to reject the drug e.g., efflux mechanisms frequently encountered with anti-malarial, anti-cancer and anti-microbial drugs, (f) Modifying the signalling process between host and pathogen ensuring increased accessibility of the drugs to the pathogens, (g) Enhancing the binding of the drug with the receptors like proteins, DNA, RNA, etc., in the pathogen, thus potentiating and prolonging its effect leading to enhanced antibiotic activity against pathogens, (h) Besides above plausible modes of action, the bioenhancer agents may also be useful for promoting the transport of nutrients and the drugs across the blood brain barrier, which could be of immense help in the control of diseases like cerebral infections, epilepsy and other CNS problems.  
           [0018]    Primarily, but not exclusively, the invention enhances the carrier mediated entry of drugs and also the passive diffusion and the active transport pathways in the tissue which are responsible for transporting physiological substances such as nutraceuticals to their target sites. As applicable to any mechanism of action the products of this invention contribute in a synergistic and/or additive manner so that most drugs and nutraceuticals in presence of the products described in the present art are more bioavailable or bioefficaceous as a result of one or more of these mechanisms. The bioavailability and/or bioefficacy of drugs and nutraceuticals is also relevent to animal health besides being important for humans. The invention therefore is also intended to be used in veterinary preparations. 
       
    
    
     EXAMPLES  
       [0019]    The following examples are intended to demonstrate some of the preferred embodiments and in no way should be construed so as to limit the scope of the invention. Any person skilled in the art can design more formulations, which may be considered as part of the present invention.  
         [0020]    Example 1 Preparation of colourless, non-pungent piperine by a novel process as already claimed (Indian Patent No 1726890)  
         [0021]    Example 2. Preparation of fully characterized BEs from  Zingiber officinale  as already claimed in a copending patent.  
         [0022]    Example 3. List of drugs cited below as some of the examples for the purpose of the present invention.  
                                                                 Categories   Drugs                                    I.   Antibiotics   Fluoroquinolones: Cipro-, nor-, P-, and O-floxacins               Macrolides: Erythro-, roxythro-, and Azithromycin               Cephalosporins: Cefixime, Cefalexin, Cefadroxil and               Cefatrioxone, cefidinir               Penicillins: Amoxycillin Cloxacillin               Aminoglycosides: Amikacin, Kanamycin       II.   Antifungal   Fluconazole, Amphotericin B, Ketoconazole       III.   Anti-viral   Acyclovir, Zidovudine       IV.   Anti-cancer   Methotrexate, 5-Fluorouracil, Dauxorubicin, Cisplatin,               Adriamycin       V.   CVS drugs   Amlodipine, Lisinopril, Atenolol       VI.   CNS drugs   Alprazolam Haloperidol       VII.   Anti-inflammatory   Diclofenac, Piroxicam, Nimesulide, Rofecoxib           Antiarthritic       VIII.   Anti-TB/Antileproxy   Rifampicin, Isoniazid, Pyrazinamide, Ethambutol, Dapsone           drugs       IX.   Anti histamines/   Salbutamol, Theophylline, Bromhexine, Loretidine           respiratory disorders       X.   Carticosteroids   Prednisolone, dexamethsone, betamethasone       XI.   Immunosuppressants   Cyclosporins, Tacrolimus, Mycophenolate mofetil       XII.   Anti-ulcer   Ranitidine, Cimetidine, Omeprazole                  
 
       EXAMPLE 3  
       [0023]    (i): Antibiotics:  
         [0024]    (a) Fluroquinolones  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Ciprofloxacin   78   55   110   68   133       P-floxacin   Nil   61   70   53   75       O-floxacin   65   52   167   49   170       Norfloxacin   55   nil   65   nil   60                  
 
         [0025]    (b) Macrolides  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Erythromycin   70   95   100   68   105       Roxythromycin   65   110   95   72   98       Azithromycin   55   89   90   78   86                  
 
         [0026]    (c) Cephalosporins  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Cefalexin   Nil   90   90   75   79       Cefadroxil   67   70   95   68   85       Cefatrioxone   72   Nil   78   Nil   75       Cefixime   80   nil   79   nil   82       Cefidinir   89   60   95   35   130                  
 
         [0027]    (d) Penicillins  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Amoxycillin   75   120   115   80   100       Cloxacillin   110   87   95   76   110                  
 
         [0028]    (e) Aminoglycosides  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Amikacin   85   nil   100   nil   92       Kanamycin   Nil   72   87   65   68                  
 
         [0029]    (ii) Antifungal  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Fluconazole   65   87   98   120   110       Amphotericin   78   nil   90   nil   80       B       Ketoconazole   55   105   100   125   96                  
 
         [0030]    (iii) Anti-Cancer  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Methotrexate   76   65   89   87   102       5-Fluorouracil   90   87   110   110   100       Dauxorubicin   Nil   68   70   72   69       Cisplatin   Nil   nil   nil   56   55                  
 
         [0031]    (iv) Cardiovascular  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Amlodipine   Nil   43   50   68   65       Lisinopril   79   85   95   76   90       Atenolol   100   nil   93   nil   97       Propranolol   68   84   90   76   75                  
 
         [0032]    (v) Anti-Viral  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Acyclovir   78   96   100   82   90       Zidovudine   92   140   95   105   87                  
 
         [0033]    (vi) CNS Drugs:  
                                                                                                   % Enhancement in bioavailability                BE from         Carun     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Alprazolam   Nil   65   70   76   80       Haloperidol   95   nil   90   nil   85                  
 
         [0034]    (vii) Anti-Inflammatory/Antiarthritic:  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Diclofenac   Nil   120   100   90   95       Piroxicam   Nil   110   98   86   76       Nimesulide   100   132   140   144   145       Rofecoxib   75   nil   70   nil   80                  
 
         [0035]    (viii) Anti-TB/Antileprosy Drugs:  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Rifampicin   110   45   170   65   140       Isoniazid   Nil   nil   nil   nil   nil       Pyrazinamide   45   nil   50   nil   55       Ethambutol   Nil   nil   nil   nil   nil       Dapsone   56   34   67   46   68       Ethionamide   68   45   65   56   70       Cycloserine   70   67   80   71   75                  
 
         [0036]    (ix). Anti-Histamines/Respiratory Disorders:  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Salbutamol   75   60   89   78   80       Theophylline   70   65   79   76   89       Bromhexine   Nil   67   70   67   71       Loratidine   76   nil   70   nil   80                  
 
         [0037]    (X) Corticosteroids:  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Prednisolone   65   nil   67   nil   60       Dexamethasone   72   66   77   76   73       Betamethasone   80   72   89   75   77                  
 
         [0038]    (xi) Immunosuppressants:  
                                                                                                   % Enhancement in bioavaiiability                BE from       Carum   BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Cyclosporin A   100   nil   105   116   120       Tacrolimus   90   105   95   75   114       Mycophenolate   Nil   nil   nil   nil   nil       Mofeit                  
 
         [0039]    (xii) Anti-Ulcer  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                          Ranitidine   67   21   70   147   150       Cimetidine   72   nil   84   98   100       Omeprazole   76   nil   70   nil   75                  
 
         [0040]    D. Herbal Formulations  
                                                                                                   % Enhancement in bioavailability                BE from         Carum     BE from     Carum carvi               Carum     Piperine     carvi +       Zingiber     +  Zingiber               carvi     as BE   Piperine     officinale       officinale                            Echinacea     Nil   75   76   66   65         augustifolia           Tinospora     76   85   90   67   71         cordifolia           Picrorrhiza     80   78   110   56   76         kurroa           Aegles     65   Nil   65   Nil   60         marmelos           Andrographis     68   63   72   55   54         paniculata           Emblica ribes     Nil   Nil   nil   65   68         Asparagus     Nil   58   55   44   45         racemosus           Terminalia     92   Nil   87   Nil   91         chebula           Withania     76   55   70   64   76         somnifera           Centella     68   nil   65   nil   62         asiatica                    
 
         [0041]    B. Nutraceutical  
                                                       Category                           I.   Vitamins               Vitamin A               Vitamin E               Vit. B1               Vit. B6               Vit. B12               Vit. C               Folic acid           II.   Antioxidants               β-Carotene               Silymarin               Selenium           III.   Natural herbal products               Curcumin               Boswellic acid               Rutin               Piperine           IV.   Essential nutritional components               Methionine               Lysine               Leucine               Valine               Isolencine               Zinc               Calcium               Glucose               Potassium               Copper               Iron