HOMEOPATHIC TOPICAL GEL FOR TRANSDERMAL DELIVERY OF COLCHICINE FORMULATIONS AND METHOD OF USE

Abstract

A homeopathic topical gel for transdermal delivery of colchicine formulations is disclosed. The colchicine formulations are effective in the treatment of constantly recurring acute gout flares. The homeopathic topical gels deliver an attenuated colchicine which has been produced using a degree of succussion and a level of water purity in excess of the guidelines for manufacturing homeopathic medicines set forth in the Homeopathic Pharmacopoeia of the United States.

Claims

1. A homeopathic transdermal colchicine gel formulation, useful in the treatment of acute gout flares, comprising: about 12.6 weight percent of a de-oiled, powdered soybean lecithin enriched with about 30% phosphatidylcholine; about 8.9 weight percent of docusate sodium; about 17.8 weight percent of attenuated colchicine, wherein said attenuated colchicine is Colchicinum 4X, whereby the total amount of colchicinum in the formulation is about 0.00178%; about 12.6 percent isopropyl myristate; about 9.6 weight percent urea; and about 38.5 weight percent purified water.

2. The homeopathic transdermal colchicine gel formulation of claim 1, wherein said purified water contains a level of total organic carbon (TOC) of about 300 ppb.

3. A process for forming a homeopathic transdermal colchicine gel formulation comprising: 1. adding about 12.60 kg isopropyl myristate to a first mixing vessel; 2. adding about 12.60 kg of a de-oiled, powdered soybean lecithin enriched with about 30% phosphatidylcholine to said first mixing vessel, and continuing to mix until dissolved; 3. adding about 8.90 kg docusate sodium to said first mixing vessel and continuing to mix until dissolved; 4. separately, placing purified water, in an amount of about 38.5 kg into a second mixing vessel and initiating mixing with an air mixer; 5. adding about 9.60 kg urea to said second mixing vessel and continuing to mix until dissolved; 6. adding about 17.8 kg attenuated colchicine, wherein said attenuated colchicine is Colchicinum 4X, to said second mixing vessel and continuing to mix until dissolved; and 7. charging all of the ingredients from said first mixing vessel to said second mixing vessel, and mixing for 30 minutes; whereby the total amount of colchicinum in said homeopathic transdermal colchicine gel formulation is about 0.00178%.

4. The process of claim 3, wherein said purified water contains a level of total organic carbon (TOC) of about 300 ppb.

5. A method for the treatment of an acute gout flare comprising: administration of a homeopathic transdermal colchicine gel formulation at a site of a gout flare, wherein said homeopathic transdermal colchicine gel formulation comprises about 12.6 weight percent of a de-oiled, powdered soybean lecithin enriched with about 30% phosphatidylcholine, about 8.9 weight percent of docusate sodium, about 17.8 weight percent of attenuated colchicine, wherein said attenuated colchicine is Colchicinum 4X, thereby providing a total amount of colchicinum in said formulation of about 0.00178%, about 12.6 percent isopropyl myristate, about 9.6 weight percent urea and about 38.5 weight percent purified water; whereby symptomatic relief of said acute gout flare is provided without significant systemic absorption.

6. The method for the treatment of an acute gout flare in accordance with claim 5, wherein said purified water contains a level of total organic carbon (TOC) of about 300 ppb.

7. The method in accordance with claim 5, wherein said homeopathic transdermal colchicine gel formulation is administered by serial administration of an effective amount of a homeopathic transdermal colchicine gel formulation, utilizing a 3 hour repetitive dosage regimen, whereby said dosage regimen is effective to maintain blood levels of about 15-20 picograms/ml of colchicinum.

8. The method of claim 7, wherein said effective amount of said homeopathic transdermal colchicine gel formulation is about a 375 microliter dosage form.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 illustrates the results of 24 hour dosing over days 0-4;

[0026] FIG. 2A, 2B illustrate single dose kinetics results 1, 3, and 5 hours post dosing;

[0027] FIG. 3A, 3B and 3C illustrate results for repeated dosing 7 hours and 24 hours after the last dose;

[0028] FIG. 4 illustrates colchicine plasma concentrations at 1, 3 and 5 hours post dosing;

[0029] FIG. 5 illustrates the kinetics of colchicine plasma levels for Experiment 2;

[0030] FIG. 6 illustrates colchicine plasma concentrations at 1 hour and 24 hours post dosing;

[0031] FIG. 7 illustrates the kinetics of colchicine multi-dosing for Experiment.

DETAILED DESCRIPTION

[0032] It is understood by the skilled artisan, that a definition of the term about normally acceptable in the pharmaceutical industry includes the range as stated, plus or minus amounts that are considered unlikely to have any detectable impact on formulation quality and performance. For example, the US Pharmacopeia allows a plus and minus range of 10% in the assay for the active ingredient in most solid dosage forms.

[0033] In an embodiment, the homeopathic transdermal colchicine gel formulation of the present invention contains about 12.6 weight percent of EPIKURON 130 P, about 8.9 weight percent of docusate sodium, about 17.8 weight percent of an attenuated colchicine supplied as Colchicinum 4X, about 12.6 percent isopropyl myristate, about 9.6 weight percent urea and about 38.5 weight percent purified water.

[0034] Colchicinum is defined as a Class B 1/100Liquid class colchicine composition, containing 70% Alcohol (ethanol)as designated by the HPUS. It is dissolved in 70% alcohol based on its solubility characteristics.

[0035] In accordance with established guideline for manufacture of Homeopathic medicines, an attenuation procedure is performed on the Colchicinum. The attenuation process includes serial dilutions with defined periods of succession, which involve vigorous mechanical agitation and blending of the liquid for a defined period of time, between each dilution. The minimum successive requirement of the HPUS is 10 repetitions.

[0036] The attenuation process carried out follows the methodology of homeopathic dilution. This is a process in which a substance is diluted with either alcohol or distilled water and then vigorously mixed. Homeopaths developed a decimal scale (D or X), diluting the substance to ten times its original volume for each stage. Therefore, a 1X solution is a 1:10 dilution of the base solution; 2X is a 1:100 dilution; 3X is a 1;1000 dilution; and a 4X (the base concentration for Colchicinum used in COLCIGEL) is a 1:10,000 dilution. So, if the original base solution was at a concentration of 1 gm/1 ml, a 1:10,000 dilution would yield a 0.0001 gm/1 ml or in different units, 100 mcg/1 ml solution.

[0037] In the case of COLCIGEL the total amount of Colchicinum 4X used is 17.8% of the base, therefore COLCIGEL contains 17.8 mcg/1 gram of total product or 0.00178% of the total weight of the product.

[0038] The specific procedure for forming the attenuated Colchicinum of the present invention is as follows:

[0039] One part (by weight) of Colchicinum is dissolved in a sufficient quantity of 70% alcohol (the alcohol is ethyl alcohol) to produce 10 parts by volume and repeatedly succussed, in excess of the HPUS minimum requirements, producing a formation equivalent to Colchicinum 2X.

[0040] Subsequently, one volume of the Colchicinum 2X is added to 9 volumes of 70% alcohol and repeatedly succussed, in excess of the HPUS minimum requirements, yielding Colchicinum 3X.

[0041] Lastly, one volume of the Colchicinum 3X is added to 9 volumes of 70% alcohol and repeatedly succussed, in excess of the HPUS minimum requirements, yielding the attenuated Colchicinum 4X used in the topical gel.

[0042] Definitions

[0043] In accordance with the present invention, the term transdermal colchicine gel formulation is directed toward a formulation which does not contain colchicine, per se, but rather, it is the homeopathic version, colchicinum, which is a natural, diluted form of colchicine.

[0044] In accordance with the present invention, the term de-oiled, powdered soybean lecithin enriched with about 30% phosphatidylcholine refers to a product such as EPIKURON 130 P, available from Cargill Corporation.

[0045] In accordance with the present invention, Dioctyl sodium sulfosuccinate or docusate sodium is an ionic surfactant, and is used as an emulsifying, wetting, and dispersing agent.

[0046] In accordance with the present invention, Isopropyl myristate (Propan-2-yl tetradecanoate) is the ester of isopropanol and myristic acid. Isopropyl myristate is used in cosmetic and topical medicinal preparations where good absorption through the skin is desired.

[0047] In accordance with the present invention, Urea or carbamide is an organic compound with the chemical formula CO(NH2)2. The molecule has two NH2 groups joined by a carbonyl (CO) functional group.

[0048] In accordance with the present invention, the purified water used in the preparation of the formulation has a level of total organic carbon (TOC) of about 300 ppb, which is substantially higher in purity than the 500 ppb required by the HPUS.

[0049] In an embodiment, the transdermal colchicine gel formulation is formed in accordance with the following steps: [0050] 1. Add about 12.60 kg isopropyl myristate to a 40 gallon stainless steel tank, and begin operation of a Lightnin Air Mixer; [0051] 2. Slowly add about 12.60 kg of Epikuron 130 P to the 40 gallon stainless steel tank from Step #1, and continue to mix until dissolved; [0052] 3. Add about 8.90 kg docusate sodium to the container of step #1 and continue to mix until dissolved; [0053] 4. Separately, place purified water, in an amount of about 38.5 kg into a 55 gallon plastic drum and begin mixing with a Gast air mixer; [0054] 5. Add about 9.60 kg urea to the 55 gallon plastic drum of step #4 and continue to mix until dissolved; [0055] 6. Add about 17.8 kg Colchicinum 4X into the 55 gallon plastic drum and mix until dissolved; [0056] 7. Charge all of the ingredients in the 40 gallon stainless steel tank to the 55 gallon plastic drum, and mix for 30 minutes.

[0057] The resulting topical gel contains approximately 20 g/ml, and is identified herein as Gensco Colchicine topical gel (COLCIGEL)

[0058] Experimental Protocol

[0059] The objective of this experiment was to measure the serum level of a homeopathic transdermal colchicine gel formulation as described herein when applied as a gel to the skin using rabbit models for study. The approved drug colchicine is used to treat disease states such as gout and dermatitis. The transdermal application of colchicine provides a localized treatment for such disease states. There is no currently approved or marketed topical formulation for gout available in the US. It would be desirable to demonstrate that very low doses of colchicine administered transdermally at the site of a gout flare could provide symptomatic relief without significant systemic absorption and, therefore, the associated drug interactions, adverse effects, and toxicities seen with traditional oral dosing of colchicine. This experiment will result in a controlled measurement of the level of colchicine that enters the circulation via this novel transdermal delivery system. In rabbits, we have performed two types of studies to ascertain 1) the steady-state levels of drug in the serum with repeated application, and 2) the single-dose kinetics of serum drug levels over time. Simultaneously, we have assessed the skin for irritation.

[0060] Methodology

[0061] New Zealand White (Oryctolagus cuniculus) rabbits were chosen. The relative diffusion of drug agents across the rabbit skin and the sensitivity of the rabbit skin to topical agents has been calibrated relative to the human after extensive use of this model for transdermal drug delivery. Further, blood collection is relatively simple in this model and the species requires no specialized care. The rabbits in the 2.5-3 kg range have 150-180 ml of whole blood. All experiments and handling of the rabbits were performed with oversight and approval by the University of Alabama

[0062] Institutional Animal Care and Use Committee.

[0063] Dosing: Gensco Colchicine topical gel (COLCIGEL): 20 g/ml (0.002%). One pump=approximately 125 l (2.5 g). Sodium Lauryl Sulfate: 0.1% in water. Sodium Lauryl Sulfate is a known positive control, is used as a control agent in human clinical trials, and will not cause more than slight skin irritation or discomfort (CDER Guidance for Industry # 2887FNL)

[0064] Experiment 1 (24 h Repeat Dosing; Single Pump Colchicine Gel and Skin Irritation Assessment):

[0065] After animal adaptation, the first experiment was a repeated daily dose experiment for 4 days. The total n for this experiment is 3. All rabbits were sedated for shaving and application of a chemical depilatory cream (Veet) to remove the hair from the mid-dorsum. After application of the cream for 60-120 seconds, the cream and hair were removed with moist gauze. All animals received 1 pump (125 l) of colchicine gel (COLCIGEL) on one side of the midline, and 200 l of a control irritant, 0.1% sodium lauryl sulfate, on the other side, each within a 2.5 cm2.5 cm region. The treatments were applied on day 0, 1, 2, 3. Arterial blood was collected daily prior to treatment on day 1, 2, 3, 4. FIG. 1 illustrates photographic images of the application sites on days 0-4.

[0066] Experiment 2 (Single-Dose Kinetics):

[0067] Due to the low levels of colchicine measured in the blood of the rabbits each day in Experiment 1, the single-dose kinetics were measured 1 h, 3 h, and 5 h after a single 375 l A dose of colchicine gel were applied to a 2.5 cm2.5 cm patch on opposite sides of the shaved rabbit dorsum. Six anesthetized rabbits had the hair on the dorsum clipped and a pre-treatment arterial blood draw. Six rabbits then received the test gel at time 0 and two rabbits had blood drawn after 1 h, two others had blood drawn after 3 h, and the last 2 rabbits had blood drawn after 5 h. FIGS. 2A-2B are photographic images made of each site at each time point when arterial blood was collected.

[0068] Experiment 3:

[0069] Four anesthetized rabbits had the hair on the dorsum clipped and a pre-treatment arterial blood drawn. All rabbits were treated at time 0 with a 375 l dose of colchicine gel applied to a 2.5 cm2.5 cm patch on opposite sides of the shaved rabbit dorsum. The application of the gel was repeated after 3 hours and again after 3 additional hours. One hour following the last gel application, arterial blood was collected from the 4 rabbits sequentially during the next 50 minutes and the treatment sites were photographed. After 24 h, arterial blood was again collected and the sites were photographed. The results are illustrated in FIGS. 3A-3C.

[0070] Assay:

[0071] All arterial blood samples were approximately 1 ml and were collected in syringes coated with sodium heparin and stored in tubes containing 20 l sodium heparin. All blood samples were centrifuged at 2,000g for 17 minutes and the plasma was removed to a fresh tube and immediately frozen at 80 C. Plasma samples were kept frozen until preparation for assay. A protocol was devised using tandem HPLC/MS separation and quantification to measure colchicine in a sample.

[0072] Samples were analyzed by a mass spectrometry/HPLC combination method that determined plasma concentration relative to standard curves. Samples were assayed in each batch with freshly prepared calibration samples of 5 concentrations in duplicate and quality control samples in duplicate at the high, mid, and low expected ranges. Acceptable analytical runs had standard curves where at least 6 of 10 individual standards from each curve met method criteria. Deviations of the back-calculated standards were required to be within T1/2a 25% of the nominal concentration. The calculated concentrations of acceptable analytical quality control samples were also required to be within 25% of the nominal concentration.

[0073] Skin Irritation:

[0074] Photographs of the test and control sites were made under standardized lighting, focal length, and magnification. Photographic images were made just prior to application of a subsequent dose. Pre-treatment images were compared to post-treatment images of experimental sites and, in Experiment 1, control sites where the irritant 0.1% SLS was placed. The dermal response was scored as follows for each image.

[0075] I. Dermal Response: [0076] 0=no evidence of irritation [0077] 1=minimal erythema, barely perceptible [0078] 2=definite erythema, readily visible; minimal edema or minimal popular response [0079] 3=erythema and papules [0080] 4=definite edema [0081] 5=erythema, edema, and papules [0082] 6=vesicular eruption [0083] 7=strong reaction spreading beyond test site

[0084] II. Other Effects: [0085] A=slight glazed appearance [0086] B=marked glazing [0087] C=glazing with peeling and cracking [0088] F=glazing with fissures [0089] G=film of dried serous exudate covering all or part of the delivery site [0090] H=small petechial erosions and/or scabs

[0091] Results

[0092] Experiment 1 (24 h Dosing of Colchicine Gel)

[0093] No detectable colchicine was measured after daily single dose application in any of the 3 experimental rabbits (data not shown). These results suggested that either none of the 2.5 g is per pump was absorbed into the circulation, or that more of the drug was absorbed but metabolized within the 24 h period.

[0094] There was minimal skin irritation caused by the colchicine gel from day 1-4 of application (mean dermal score 0.40.5) as illustrated in FIG. 1.

[0095] Experiment 2 (Single-Dose Kinetics Colchicine Gel)

[0096] The colchicine was rapidly absorbed (T1/2a=30 min), almost all (90%) of the 7.5 g dose entered the bloodstream reaching a maximal concentration of 0.26 ng/ml0.09, and it was rapidly eliminated (T1/2e=65 min) with none detectable 5 h after application.

[0097] No skin irritation was detected over the 5 h application period, as illustrated in FIGS. 2A-2B. Colchicine plasma concentrations at 1, 3 and 5 hours post dosing are illustrated in FIG. 4.

[0098] The kinetics of colchicine plasma levels are illustrated in FIG. 5: [0099] T1/2a=30 min [0100] Absorption rate constant (ka)=0.693/0.5 h=1.4/h [0101] T1/2e=65 min [0102] Elimination rate constant (ke)=0.693/1.1 h=0.64/h [0103] Total plasma absorbance=90% (AUC) [0104] Cmax=0.26 ng/ml0.09 ng/ml [0105] Tmax=60 min

[0106] In an adult human, this same amount of gel (375 l) would result in a maximal concentration of 9 pg/ml colchicine in the blood due to the larger blood volume.

[0107] Experiment 3: Drug Accumulation by Multi-dosing

[0108] Following three dosing events administered every 3 hours using 375 l of gel per dose, colchicine plasma levels were measured at peak levels 1 hour following the third dose and were less than 0.45 ng/ml in all 4 rabbits. As it took an additional 15, 35, and 55 minutes to collect blood from rabbits J-L, the measured plasma levels of colchicine dropped progressively from 0.42 ng/ml to 0.2 ng/ml within the hour, as expected from the single-dose elimination kinetics.

[0109] No skin irritation was measured after 3 doses over 7 h of colchicine gel application to the skin (rabbits I-L). No erythema was detected 24 h after dosing (rabbits I and K). Results are illustrated in FIGS. 3A, 3B and 3C. Colchicine plasma concentrations at 1 hour and 24 hours post dosing are illustrated in FIG. 6.

[0110] Kinetics of colchicine multi-dosing are illustrated in FIG. 7 wherein Arrows indicate dosing events. Double arrow indicates final dose. Single-dosing kinetic curves overlay the data, and the bold line is logarithmic progression prediction built to data:

[0111] With elimination exponentially progressing over a 5 h period, 3 h repeated dosing led to some accumulation of colchicine in the blood with repeated dosing. From the logarithmic progression analysis of these data it appears that 3 h dosing would approximate a steady state level of 0.5 ng/ml after 5 sequential administrations. After the third and final dose administration at 360 min (double arrow) the plasma levels fell quickly during the animal handling time, as expected from the single dose data. Given the kinetics of the single dose, it appears that 3 h repeated dosing of the colchicine gel provides a proper and safe maintenance dose regime.

[0112] Summary Statement

[0113] These data demonstrate that the colchicine from the Gensco COLCIGEL topical colchicine gel formulation is absorbed relatively rapidly, within 60 minutes, almost completely (90%), and safely. The elimination of these drugs once absorbed is relatively rapid, within 6 hours.

[0114] These data suggest that the Gensco COLCIGEL topical colchicine gel may be applied safely in a repeated fashion every 3 hours where blood levels of the drug would remain at safe levels and the skin would be expected to experience no irritation or, at most, mild erythema, in association with the lidocaine gel.

[0115] Study Highlights

[0116] In this study of the colchicine topical gel (COLCIGEL) the gel was found to be safe and suitable for repeated application to the skin. The COLCIGEL was 90% absorbed into the bloodstream, reaching peak blood levels of 260 picograms per milliliter in a rapid 60 minutes after a single 375 microliter dose (3 pumps). The colchicine was rapidly eliminated from the blood within 5 hours, but dosing every 3 hours was able to sustain the blood levels allowing a predicted 500 picograms per milliliter to be maintained. There was little to no skin irritation resulting from prolonged application of the colchicine gel over a period of 4 days.

[0117] The safety demonstrated in these rabbits translates to safety in humans for the COLCIGEL. The measured blood levels would be lower (approximately 28 fold) in the human. Further, because the rabbit skin is slightly more delicate than the human, the acceptability for repeated application of the COLCIGEL in humans was fully validated.

[0118] In an embodiment, the present invention contemplates a method for the treatment of an acute gout flare, in a human, whereby serial administration of an effective amount of a homeopathic transdermal colchicine gel formulation, e.g. about a 375 microliter dosage form, is administered at the site of the gout flare, utilizing a 3 hour repetitive dosage regimen, whereby this dosage regimen is effective to maintain blood levels of about 15-20 picograms/ml of colchicinum.

[0119] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.

[0120] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.

[0121] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.