U.S. patent application number 11/767698 was filed with the patent office on 2007-10-11 for rapid acting drug delivery compositions.
This patent application is currently assigned to Biodel Inc.. Invention is credited to Roderike Pohl, Solomon S. Steiner.
Application Number | 20070235365 11/767698 |
Document ID | / |
Family ID | 34963134 |
Filed Date | 2007-10-11 |
United States Patent
Application |
20070235365 |
Kind Code |
A1 |
Pohl; Roderike ; et
al. |
October 11, 2007 |
Rapid Acting Drug Delivery Compositions
Abstract
Drug formulations for systemic drug delivery with improved
stability and rapid onset of action are described herein. The
formulations may be administered via buccal administration,
sublingual administration, pulmonary delivery, nasal
administration, subcutaneous administration, rectal administration,
vaginal administration, or ocular administration. In the preferred
embodiments, the formulations are administered sublingually or via
subcutaneous injection. The formulations contain an active agent
and one or more excipients, selected to increase the rate of
dissolution. In the preferred embodiment, the drug is insulin, and
the excipients include a metal chelator such as EDTA and an acid
such as citric acid. Following administration, these formulations
are rapidly absorbed by the oral mucosa when administered
sublingually and are rapidly absorbed into the blood stream when
administered by subcutaneous injection. In one embodiment, the
composition is in the form of a dry powder. In another embodiment,
the composition is in the form of a film, wafer, lozenge, capsule,
or tablet. In a third embodiment, a dry powdered insulin is mixed
with a diluent containing a pharmaceutically acceptable carrier,
such as water or saline, a metal chelator such as EDTA and an acid
such as citric acid. Devices for storing and mixing these
formulations are also described.
Inventors: |
Pohl; Roderike; (Sherman,
CT) ; Steiner; Solomon S.; (Mount Kisco, NY) |
Correspondence
Address: |
PATREA L. PABST;PABST PATENT GROUP LLP
400 COLONY SQUARE, SUITE 1200
1201 PEACHTREE STREET
ATLANTA
GA
30361
US
|
Assignee: |
Biodel Inc.
|
Family ID: |
34963134 |
Appl. No.: |
11/767698 |
Filed: |
June 25, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11077604 |
Mar 11, 2005 |
|
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11767698 |
Jun 25, 2007 |
|
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60552637 |
Mar 12, 2004 |
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60609194 |
Sep 9, 2004 |
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Current U.S.
Class: |
206/529 ;
424/443; 514/11.7; 514/11.8; 514/5.9; 514/7.7; 514/9.5 |
Current CPC
Class: |
Y10S 514/959 20130101;
Y10S 514/866 20130101; A61K 9/0056 20130101; A61K 38/28 20130101;
A61K 9/006 20130101; Y10S 514/951 20130101; A61K 9/0019 20130101;
Y10S 514/953 20130101; A61P 3/08 20180101 |
Class at
Publication: |
206/529 ;
424/443; 514/003 |
International
Class: |
A61K 38/28 20060101
A61K038/28; A61K 9/70 20060101 A61K009/70; B65D 83/06 20060101
B65D083/06 |
Claims
1. A composition comprising a biologically active agent, a
solubilizing agent and a metal chelator, in a form suitable for
sublingual or subcutaneous administration.
2. The composition of claim 1, wherein the agent is selected from
the group consisting of insulin and derivatives thereof; C-peptide;
glucagon-like peptide 1 (GLP 1) and active fragments thereof; human
amylin and synthetic forms thereof; parathyroid hormone (PTH) and
active fragments thereof (e.g. PTH.sub.1-34); calcitonin; human
growth hormone (HGH); erythropoietin (EPO); macrophage-colony
stimulating factor (M-CSF); granulocyte-macrophage-colony
stimulating factor (GM-CSF); and interleukins.
3. The composition of claim 2, wherein the agent is insulin or a
derivative thereof.
4. The composition of claim 1, wherein the chelator is selected
from the group consisting of ethylenediaminetetraacetic acid
(EDTA), dimercaprol (BAL), penicillamine, alginic acid, Chlorella,
Cilantro, Alpha Lipoic Acid, Dimercaptosuccinic Acid (DMSA),
dimercaptopropane sulfonate (DMPS), and oxalic acid.
5. The composition of claim 4, wherein the chelator is
ethylenediaminetetraacetic acid (EDTA).
6. The composition of claim 1, wherein the agent is a charged
compound and wherein the chelator and solubilizing agent are
present in effective amounts to mask charges on the agent.
7. The composition of claim 1 wherein the solubilizing agent is an
acid selected from the group consisting of acetic acid, ascorbic
acid, citric acid, and hydrochloric acid.
8. The composition of claim 1 in a form selected from the group
consisting of dry powders, tablets, wafers, films, lozenges, and
capsules.
9. The composition of claim 8, wherein the composition is in the
form of a trilayer film or wafer suitable for sublingual
delivery.
10. The composition of claim 1 in a form suitable for sublingual
delivery.
11. A kit comprising a first storage container and a second storage
container, wherein the first storage contain comprises a
pharmaceutically active agent and wherein the second storage
container comprises a solubilizing agent and a metal chelator.
12. The kit of claim 11 wherein the first container is a cap and
the second container is a vial the cap is secured to, and wherein
the two containers are separated by a barrier.
13. A method of delivering a biologically active agent to a patient
comprising administering sublingually or via subcutaneous injection
a composition comprising an effective amount of the agent, a
solubilizing agent and a metal chelator.
14. The method of claim 13, wherein the agent is selected from the
group consisting of insulin and derivatives thereof, C-peptide;
glucagon-like peptide 1 (GLP 1) and active fragments thereof; human
amylin and synthetic forms thereof; parathyroid hormone (PTH) and
active fragments thereof (e.g. PTH.sub.1-34); calcitonin; human
growth hormone (HGH); erythropoietin (EPO); macrophage-colony
stimulating factor (M-CSF); granulocyte-macrophage-colony
stimulating factor (GM-CSF); and interleukins.
15. The method of claim 14, wherein the agent is insulin or a
derivative thereof.
16. The method of claim 13, wherein the chelator is selected from
the group consisting of ethylenediaminetetraacetic acid (EDTA),
dimercaprol (BAL), penicillamine, alginic acid, Chlorella,
Cilantro, Alpha Lipoic Acid, Dimercaptosuccinic Acid (DMSA),
dimercaptopropane sulfonate (DMPS), and oxalic acid.
17. The method of claim 16, wherein the chelator is
ethylenediaminetetraacetic acid (EDTA).
18. The method of claim 13, wherein the agent is a charged compound
and wherein the chelator and solubilizing agent are present in
effective amounts to mask charges on the agent.
19. The method of claim 13, wherein the solubilizing agent is an
acid selected from the group consisting of acetic acid, ascorbic
acid, citric acid, and hydrochloric acid.
20. The method of claim 13, wherein the composition is in a form
selected from the group consisting of dry powders, tablets, wafers,
films, lozenges, and capsules.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Ser. No.
60/552,637, entitled "Sublingual Drug Delivery Compositions" to
Roderike Pohl and Solomon S. Steiner filed Mar. 12, 2004, and U.S.
Ser. No. 60/609,194, entitled "Sublingual Drug Delivery
Compositions" to Roderike Pohl and Solomon S. Steiner filed Sep. 9,
2004.
FIELD THE INVENTION
[0002] The invention is in the general field of rapid acting drug
delivery formulations.
BACKGROUND OF THE INVENTION
[0003] An effective, non-invasive oral delivery system for
peptides, in general, and insulin, in particular, has not been
developed to date, due to several limiting factors. First, tablets
or liquids containing peptides, such as insulin, are readily
digested in the harsh stomach environment, and thus require
extensive protection to survive and be absorbed. Food effects and
individual gastrointestinal (GI) transit times confound a
dependable temporal or quantitative delivery.
[0004] The lack of effective oral delivery means is further
complicated in some cases. For example, insulin is most stable in
its hexameric form (six insulin monomers assembled around zinc
ions). Therefore, it is preferable to store it in this form for
greater shelf-life stability. However, this form is too large for
rapid absorption though tissue membranes.
[0005] U.S. Pat. No. 6,676,931 to Dugger, III discloses liquid
sprays that deliver an active agent to the mouth for absorption
through the oral mucosa. U.S. Pat. No. 6,676,931 notes that the
active agent may be insulin lispro, which is a rapidly-acting human
insulin analog that contains hexameric insulin. However, such
liquid sprays are not very useful for delivering hexameric insulin
due to its poor absorption. Additionally, many active agents are
not stable in the liquid form and cannot be stored in liquid
form.
[0006] Buccal administration using sprays of insulin has been
attempted with limited bioavailability since hexameric insulin is
not readily absorbed and liquids are eventually swallowed. The
administered dose is not rapidly absorbed, and has an absorption
profile similar to subcutaneous injection. Also, due to its poor
bioavailability, a large dose is required for a useful glucose
lowering effect. Thus, it is not a cost effective or therapeutic
alternative.
[0007] Pulmonary formulations are being developed and may provide a
good alternative to injection. However, these formulations require
the use of an inhaler and may lack good patient compliance if the
delivery technique is complicated.
[0008] Therefore it is an object of the invention to provide oral
drug delivery compositions with improved stability and rapid onset
of action.
[0009] It is a further object of the invention to provide methods
for storing drugs and rapidly delivering drugs.
SUMMARY OF THE INVENTION
[0010] Drug formulations for systemic drug delivery with improved
stability and rapid onset of action are described herein. The
formulations may be administered via buccal administration,
sublingual administration, pulmonary delivery, nasal
administration, subcutaneous administration, rectal administration,
vaginal administration, or ocular administration. In the preferred
embodiments, the formulations are administered sublingually or via
subcutaneous injection. The formulations contain an active agent
and one or more excipients selected to increase the rate of
dissolution. In the preferred embodiment, the drug is insulin, and
the excipients include a metal chelator such as EDTA and an acid
such as citric acid. Following administration, these formulations
are rapidly absorbed by the oral mucosa when administered
sublingually and are rapidly absorbed into the blood stream when
administered by subcutaneous injection. In one embodiment, the
composition is in the form of a dry powder. In another embodiment,
the composition is in the form of a film, wafer, lozenge, capsule,
or tablet. In a third embodiment, a dry powdered insulin is mixed
with a diluent containing a pharmaceutically acceptable carrier,
such as water or saline, a metal chelator such as EDTA and an acid
such as citric acid. Devices for storing and mixing these
formulations are also described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1a is a schematic for the delivery of a dry powder
insulin composition: FIG. 1b is schematic for the delivery of a
lozenge composition.
[0012] FIG. 2 is a perspective view of a vial containing powdered
insulin in the cap, separated by a seal which can be broken by
rotation of the cap, to allow the insulin to mix with the citric
acid-EDTA solution in the vial.
[0013] FIG. 3 is a bar graph showing the percentage of total
insulin that was transferred through a 30,000 molecular weigh
cut-off membrane (i.e. a filter) in the presence of varying
quantities of EDTA.
[0014] FIG. 4 is a graph of the effect of EDTA alone or in
combination with citric acid, hydrochloric acid, acetic acid, and
ascorbic acid, on the percent of low molecular weight (i.e.,
monomeric) insulin.
[0015] FIGS. 5a-5d are graphs of the percent of low molecular
weight insulin in the presence of HCl (FIG. 5a), ascorbic acid
(FIG. 5b), citric acid (FIG. 5c), and acetic acid (FIG. 5d), alone
or in combination with EDTA, at either pH 3.0 or pH 7.0.
[0016] FIG. 6 is a graph of decrease in blood glucose following
subcutaneous administration of insulin in combination with citric
acid and EDTA.
[0017] FIG. 7 is a graph of the mean insulin accumulation (.mu.U)
over time (minutes) in the lower chamber of a transwell membrane
plate seeded with epithelial cells, comparing the effect of an
insulin formulation containing EDTA (.diamond-solid.) with one
without EDTA (.box-solid.), with a control, no cells
(.tangle-solidup.).
DETAILED DESCRIPTION OF THE INVENTION
I. Compositions
[0018] Formulations including an active agent, such as insulin, and
one or more excipients, such as a chelator and/or solubilizing
agent, that dissolve rapidly in aqueous media are described herein.
In the preferred embodiment, the formulations are suitable for
subcutaneous or sublingual administration. These formulations are
rapidly absorbed through mucosal surfaces (parenteral, pulmonary,
etc.) and through the fatty tissue when administered
subcutaneously. This is achieved through the addition of
excipients, especially solubilizers such as acids and metal
chelators.
[0019] Definitions
[0020] As generally used herein, a drug is considered "highly
soluble" when the highest dose strength is soluble in 250 ml or
less of aqueous media over the pH range of 1-7.5. The volume
estimate of 250 ml is derived from typical bioequivalence (BE)
study protocols that prescribe administration of a drug product to
fasting human volunteers with a glass (about 8 ounces) of water. A
drug is considered highly soluble when 90% or more of an
administered dose, based on a mass determination or in comparison
to an intravenous reference dose, is dissolved. Solubility can be
measured by the shake-flask or titration method or analysis by a
validated stability-indicating assay.
[0021] As generally used herein, an immediate release drug
formulation is considered "rapidly dissolving" when no less than
85% of the labeled amount of the drug substance dissolves within 30
minutes, using U.S. Pharmacopeia (USP) Apparatus I at 100 rpm (or
Apparatus II at 50 rpm) in a volume of 900 ml or less in each of
the following media: (1) 0.1 N HCI or Simulated Gastric Fluid USP
without enzymes; (2) a pH 4.5 buffer; and (3) a pH 6.8 buffer or
Simulated Intestinal Fluid USP without enzymes.
[0022] Pharmaceutically Active Agents
[0023] Although described with reference to insulin, the
formulations may be used with other agents, including peptides,
proteins, nucleotide molecules (RNA sequences, DNA sequences),
sugars, polysaccharides, and small organic molecules. Preferably,
the active agent is at least slightly soluble in aqueous medium
(i.e. 10,000 parts of aqueous solvent per solute), and more
preferably is highly soluble in aqueous medium. Preferably the
active agent is highly potent, so that only a small amount (e.g. in
the microgram range) is needed to provide a therapeutic effect.
Suitable peptides include but are not limited to insulin and
derivatives of insulin, such as lispro; C-peptide; glucagon-like
peptide 1 (GLP 1) and all active fragments thereof; human amylin
and synthetic forms of amylin, such as pramlintide; parathyroid
hormone (PTH) and active fragments thereof (e.g. PTH.sub.1-34);
calcitonin; human growth hormone (HGH); erythropoietin (EPO);
macrophage-colony stimulating factor (M-CSF);
granulocyte-macrophage-colony stimulating factor (GM-CSF); and
interleukins. In the preferred embodiment the active agent is
insulin. Sutiable small molecules include nitroglycerin,
sumatriptan, narcotics (e.g. fenatnyl, codeine, propoxyphene,
hydrocodone, and oxycodone), benzodiazepines (e.g. Alprazolam,
Clobazam, Clonazepam, Diazepam Flunitrazepam, Lorazepam,
Nitrazepam, Oxazepam, Temazepam, and Triazolam), phenothiazines
(Chlorpromazine, Fluphenazine, Mesoridazine, Methotrimeprazine,
Pericyazine, Perphenazine, Prochlorperazine, Thioproperazine,
Thioridazine, and Trifluoperazine), and selective serotonin
reuptake inhibitors (SSRIs) (e.g. sertraline, fluvoxamine,
fluoxetine, citalopram, and paroxetine).
[0024] In the preferred embodiment, the active agent is insulin or
an analog or derivative thereof. The insulin can be recombinant or
purified. In the preferred embodiment, the insulin is human
insulin. Recombinant human insulin is available from a number of
sources.
[0025] The dosages of the active agents depend on their
bioavailability and the disease or disorder to be treated. Insulin
is generally included in a dosage range of 12 to 2000 IU per human
dose. Thus if the insulin has a bioavailability 5-25%, the actual
systemic dose delivered to an individual ranges from 3 to 100 IU.
For insulin with only 2.5% bioavailability, an oral dose of 4,000
IU will deliver a 100 IU systemically available dose. For insulin
with a much greater bioavailability, such as a 50% bioavailability,
the delivery of a 3 IU systemically available dose requires an oral
dose of 6 IU.
[0026] Formulations
[0027] The compositions contain one or more excipients. In the
preferred embodiment, at least one of the excipients is selected to
mask any charges on the active agent. This facilitates the
transmembrane transport for the active agent and thereby increases
both the onset of action and bioavailability for the active agent.
The excipients are also selected to form compositions that dissolve
rapidly in aqueous medium. Optional pharmaceutically acceptable
excipients present in the drug-containing tablets, beads, granules
or particles include, but are not limited to, diluents, binders,
lubricants, disintegrants, colorants, stabilizers, and
surfactants.
[0028] Solubilizing Agents
[0029] In the preferred embodiment, one or more solubilizing agents
are included with the active agent to promote rapid dissolution in
aqueous media. Suitable solubilizing agents include wetting agents
such as polysorbates and poloxamers, non-ionic and ionic
surfactants, food acids and bases (e.g. sodium bicarbonate), and
alcohols, and buffer salts for pH control. Suitable acids include
acetic acid, ascorbic acid, citric acid, and hydrochloric acid. For
example, if the active agent is insulin, a preferred solubilizing
agent is citric acid.
[0030] Chelators
[0031] In the preferred embodiment, a metal chelator is mixed with
the active agent or in a coating surrounding the active agent. The
chelator may be ionic or non-ionic. Suitable chelators include
ethylenediaminetetraacetic acid (EDTA), citric acid, dimercaprol
(BAL), penicillamine, alginic acid, chlorella, cilantro, alpha
lipoic acid, dimercaptosuccinic acid (DMSA), dimercaptopropane
sulfonate (DMPS), and oxalic acid. In the preferred embodiment, the
chelator is EDTA. The chelator hydrogen bonds with the active
agent, thereby masking the charge of the active agent and
facilitating transmembrane transport of the active agent. For
example, when the active agent is insulin, in addition to charge
masking, it is believed that the chelator pulls the zinc away from
the insulin, thereby favoring the monomeric form of the insulin
over the hexameric form and facilitating absorption of the insulin
by the tissues surrounding the site of administration (e.g. mucosa,
or fatty tissue). Optionally, the chelator and solubilizing agent
are the same compound.
[0032] Ions may be part of the active agent, added to the
stabilizing agent, mixed with the chelator, and/or included in the
coating. Representative ions include zinc, calcium, iron,
manganese, magnesium, aluminum, cobalt, copper, or any di-valent
metal or transitional metal ion. Zn.sup.+2 has a stronger binding
preference for EDTA than Ca.sup.+2 .
[0033] Diluents and Fillers
[0034] Diluents, also referred to herein as fillers, are typically
necessary to increase the bulk of a solid dosage form so that a
practical size is provided for compression of tablets or formation
of beads and granules. Suitable fillers include, but are not
limited to, dicalcium phosphate dihydrate, calcium sulfate,
lactose, sucrose, mannitol, sorbitol, cellulose, microcrystalline
cellulose, powdered cellulose, kaolin, sodium chloride, dry starch,
hydrolyzed starches, pregelatinized starch, silicone dioxide,
titanium oxide, magnesium aluminum silicate, calcium carbonate,
compressible sugar, sugar spheres, powdered (confectioner's) sugar,
dextrates, dextrin, dextrose, dibasic calcium phosphate dehydrate,
glyceryl palmitostearate, magnesium carbonate, magnesium oxide,
maltodextrin, polymethacrylates, potassium chloride, talc, and
tribasic calcium phosphate.
[0035] Binders
[0036] Binders are used to impart cohesive qualities to a solid
dosage formulation, and thus ensure that a tablet, bead or granule
remains intact after the formation of the dosage forms. Suitable
binder materials include, but are not limited to, starch,
pregelatinized starch, gelatin, sugars (including sucrose, glucose,
dextrose, lactose and sorbitol), dextrin, maltodextrin, zein,
polyethylene glycol, waxes, natural and synthetic gums such as
acacia, guar gum, tragacanth, alginate, sodium alginate,
celluloses, including hydroxypropylmethylcellulose,
carboxymethylcellulose sodium, hydroxypropylcellulose,
hydroxylethylcellulose, ethylcellulose, methyl cellulose, and
veegum, hydrogenated vegetable oil, Type I, magnesium alumninum
silicate, and synthetic polymers such as acrylic acid and
methacrylic acid copolymers, carbomer, methacrylic acid copolymers,
methyl methacrylate copolymers, aminoalkyl methacrylate copolymers,
polyacrylic acid/polymethacrylic acid, and
polyvinylpyrrolidone.
[0037] Lubricants
[0038] Lubricants are used to facilitate tablet manufacture.
Examples of suitable lubricants include, but are not limited to,
magnesium stearate, calcium stearate, stearic acid, glyceryl
behenate, glyceryl monostearate, glyceryl palmitostearate,
hydrogenated castor oil, hydrogenated vegetable oil, type I, sodium
benzoate, sodium lauryl sulfate, sodium stearyl fumarate,
polyethylene glycol, talc, zinc stearate, and mineral oil and light
mineral oil.
[0039] Disintegrants
[0040] Disintegrants are used to facilitate dosage form
disintegration or "breakup" after administration, and generally
include, but are not limited to, starch, sodium starch glycolate,
sodium carboxymethyl starch, methylcellulose, calcium
carboxymethylcellulose, sodium carboxymethylcellulose,
hydroxypropyl cellulose, microcrystalline cellulose, colloidal
silicon dioxide, croscarmellose sodium, pregelatinized starch,
clays, cellulose, powdered cellulose, pregelatinized starch, sodium
starch glycolate, sodium aginate, alginic acid, guar gum, magnesium
aluminum silicate, polacrilin potassium and cross linked polymers,
such as cross-linked PVP, crospovidone (POLYPLASDONE.RTM. XL from
GAF Chemical Corp).
[0041] Stabilizers
[0042] Stabilizers are used to inhibit or retard drug decomposition
reactions which include, by way of example, oxidative reactions. A
number of stabilizers may be used. Suitable stabilizers include
polysaccharides, such as cellulose and cellulose derivatives, and
simple alcohols, such as glycerol; bacteriostatic agents such as
phenol, m-cresol and methylparaben; isotonic agents, such as sodium
chloride, glycerol, and glucose; lecithins, such as example natural
lecithins (e.g. egg yolk lecithin or soya bean lecithin) and
synthetic or semisynthetic lecithins (e.g.
dimyristoylphosphatidylcholine, dipalmitoylphosphatidylcholine or
distearoyl-phosphatidylcholine; phosphatidic acids;
phosphatidylethanolamines; phosphatidylserines such as
distearoyl-phosphatidylserine, dipalmitoylphosphatidylserine and
diarachidoylphospahtidylserine; phosphatidylglycerols;
phosphatidylinositols; cardiolipins; sphingomyelins; and synthetic
detergents, such as diosctanoylphosphatidyl choline and
polyethylene-polypropylene glycol). Other suitable stablizers
include acacia, albumin, alginic acid, bentonite,
carboxymethylcellulose calcium, carboxymethylcellulose sodium,
cyclodextrins, glyceryl monostearate, hydroxypropyl cellulose,
hydroxypropyl methylcellulose, magnesium aluminum silicate,
propylene glycol, propylene glycol alginate, sodium alginate, white
wax, xanthan gum, and yellow wax. In the preferred embodiment, the
agent is insulin and the stabilizer may be a combination of one or
more polysaccharides and glycerol, bacteriostatic agents, isotonic
agents, lecithins, or synthetic detergents.
[0043] Surfactants
[0044] Surfactants may be anionic, cationic, amphoteric or nonionic
surface active agents. Suitable anionic surfactants include, but
are not limited to, those containing carboxylate, sulfonate and
sulfate ions. Examples of anionic surfactants include sodium,
potassium, ammonium of long chain alkyl sulfonates and alkyl aryl
sulfonates such as sodium dodecylbenzene sulfonate; dialkyl sodium
sulfosuccinates, such as sodium dodecylbenzene sulfonate; dialkyl
sodium sulfosuccinates, such as sodium
bis-(2-ethylthioxyl)-sulfosuccinate; and alkyl sulfates such as
sodium lauryl sulfate. Cationic surfactants include, but are not
limited to, quaternary ammonium compounds such as benzalkonium
chloride, benzethonium chloride, cetrimonium bromide, stearyl
dimethylbenzyl ammonium chloride, polyoxyethylene and coconut
amine. Examples of nonionic surfactants include ethylene glycol
monostearate, propylene glycol myristate, glyceryl monostearate,
glyceryl stearate, polyglyceryl-4-oleate, sorbitan acylate, sucrose
acylate, PEG-150 laurate, PEG-400 monolaurate, polyoxyethylene
monolaurate, polysorbates, polyoxyethylene octylphenylether,
PEG-1000 cetyl ether, polyoxyethylene tridecyl ether, polypropylene
glycol butyl ether, Poloxamer.RTM. 401, stearoyl
monoisopropanolamide, and polyoxyethylene hydrogenated tallow
amide. Examples of amphoteric surfactants include sodium
N-dodecyl-.beta.-alanine, sodium N-lauryl-.beta.-iminodipropionate,
myristoamphoacetate, lauryl betaine and lauryl sulfobetaine.
[0045] If desired, the tablets, wafers, films, lozenges, beads,
granules, or particles may also contain minor amount of nontoxic
auxiliary substances such as dyes, sweeteners, coloring and
flavoring agents, pH buffering agents, or preservatives.
[0046] Polymers
[0047] Blending or copolymerization sufficient to provide a certain
amount of hydrophilic character can be useful to improve
wettability of the materials. For example, about 5% to about 20% of
monomers may be hydrophilic monomers. Hydrophilic polymers such as
hydroxylpropylcellulose (HPC), hydroxpropylmethylcellulose (HPMC),
carboxymethylcellulose (CMC) are commonly used for this purpose.
Also suitable are hydrophobic polymers such as polyesters and
polyimides. It is known to those skilled in the art that these
polymers may be blended with polyanhydrides to achieve compositions
with different drug release profiles and mechanical strengths.
Preferably, the polymers are bioerodable, with preferred molecular
weights ranging from 1000 to 15,000 Da, and most preferably 2000 to
5000 Da.
[0048] Formulations
[0049] The active compounds (or pharmaceutically acceptable salts
thereof) may be administered in the form of a pharmaceutical
composition wherein the active compound(s) is in admixture or
mixture with one or more pharmaceutically acceptable carriers,
excipients or diluents. Suitable dosage forms include powders,
films, wafers, lozenges, capsules, and tablets. The compositions
may be administered in a variety of manners, including buccal
administration, nasal administration, pulmonary administration,
sublingual administration, and subcutaneous administration.
Following administration, the dosage form dissolves quickly
releasing the drug or forming small particles containing drug,
optionally containing one or more excipients.
[0050] The formulation may dissolve in a time period ranging from 1
second to 3 minutes, 3 to 5 minutes, 5 to 8 minutes, or 8 to 12
minutes. The preferred dissolution time is less than 30 seconds.
Preferably the drug is absorbed and transported to the plasma
quickly, resulting in a rapid onset of action (preferably beginning
within about 5 minutes following administration and peaking at
about 15-30 minutes following administration).
[0051] In one preferred embodiment, the formulation is a sublingual
solid formulation that contains an active agent, and at least one
solubilizing agent, along with other standard excipients, such as
poly(vinyl alcohol), glycerin, carboxymethyl cellulose (CMC), and
optionally poly(ethylene glycol) and water. In the preferred
embodiment the active agent is insulin and the solubilizing agents
are ethylenediamintetraacetic acid (EDTA), and citric acid. The
sublingual composition may be in the form of a dry powder,
monolayer, bilayer, or trilayer film, a lyophilized wafer, lozenge,
capsule, or a tablet.
[0052] In a second preferred embodiment, the formulation is in a
form sutiable for subcutaneous injection. In this embodiment, the
formulation is formed by mixing a powdered active agent with a
liquid diluent that contains a pharmaceutically acceptable liquid
carrier and one or more solubilizing agents. In the preferred
embodiment, the active agent is insulin, and the diluent contains
saline, EDTA and citric acid. Prior to administration the powder
and diluent are mixed together to form an injectable
composition.
[0053] Dry Powder
[0054] The composition may be in the form of a dry powder
containing the pharmaceutically active agent and one or more
excipient(s). Typically the dry powder composition is in a form
suitable for oral, nasal or pulmonary administration. Typical
routes for oral administration include buccal delivery and
sublingual delivery. Preferably the composition is delivered
sublingually. The active agent and excipient may be stored together
or separately. The active agent and excipients may be stored
together if the active agent is stable in the presence of the
excipients. Alternatively, they may be stored separately, and then
mixed before, during or after they are dispensed to the oral
cavity. The powder rapidly dissolves upon mixing with saliva and
effectively delivers the active agent to the systemic circulation
via absorption through the sublingual epithelium.
[0055] The active agents and excipients may be in the form of
particles having the same or different sizes. In one embodiment,
the excipient particles are larger than the particles of agent.
This will allow the small particles of agent to coat the larger
particle so that both particles are administered simultaneously.
Typically, the average particle diameter for the agent particles is
less than or equal to one-tenth of the average particle diameter
for the excipient particles. For sublingual delivery, the large
particles generally have diameters greater than 8 .mu.m, preferably
greater than 20 .mu.m. The average diameters for the large
particles typically range from 8 .mu.m to 500 .mu.m, preferably
from 50 .mu.m to 150 .mu.m. The small particles generally have a
diameter ranging from 1 nm to 9 .mu.m, preferably from 100 nm to
400 nm. For buccal and nasal administration, the particles
generally have similar size ranges to those described from
sublingual administration. For pulmonary administration, the large
particles typically have an average diameter ranging from 1 .mu.m
to 10 .mu.m, preferably from 2 .mu.m to 5 .mu.m; and the small
particles typically have an average diameter ranging from 10 nm to
1 .mu.m.
[0056] If the particles of excipient have generally the same size,
the average diameters will generally be greater than 8 .mu.m,
preferably greater than 20 .mu.m, with typical size ranges from 8
.mu.m to 500 .mu.m, and preferably from 50 .mu.m to 150 .mu.m (for
sublingual, buccal and nasal administration); and from 1 .mu.m to
10 .mu.m, preferably from 2 .mu.m to 5 .mu.m (for pulmonary
administration).
[0057] Optionally, the particles are oppositely charged, so that
the excipient particles contain one charge and the agent particles
contain the opposite charge so that the particles are administered
simultaneously. The particles may be charged by blowing them into a
chamber formed of plastic surfaces, which impart charge to the
particles. Two oppositely charged chambers may be used. The charged
particles may be formed by using an acidic solution to make one of
the particles, and a basic solution to form the other particles.
Alternatively, charge can be transferred through ion discharge
(e.g. using a staticizer or destaticizer). If the particles of
agent and excipient are oppositely charged, they may have the same
average diameter or different average diameters.
[0058] In one embodiment, the components are stored separately,
either in separate containers, a blister pack or capsules, which
are combined at the time of administration. In one embodiment,
shown in FIG. 2, the container is an ampoule 20 wherein the insulin
is present in powdered form in the cap 22, separated from a
solution 24 containing citric acid and EDTA. At the time of
administration, the insulin is added to the solution 24 and
administered. This may be accomplished by breaking a seal located
at the bottom 26 of the cap 22, for example, made of a
polyethylene, which is ruptured by rotating the cap 22.
[0059] Film
[0060] The composition may be in the form of a film. The film is a
clear or opaque, flexible, thin material. Typical thicknesses range
from 0.01 to 2 mm. The film may have any suitable shape, including
round, oval, rectangle, or square. The film may be a monolayer,
bilayer or trilayer film. In the preferred embodiment, the film is
designed to be suitable for sublingual administration. The
monolayer film contains an active agent and one or more excipients.
The bilayer film contains one or more excipients, such as a
solubilizing agent and/or a metal chelator, in a first layer, and
an active agent in the second layer. This configuration allows the
active agent to be stored separated from the excipients, and may
increase the stability of the active agent, and optionally
increases the shelf life of the composition compared to if the
excipients and active agent were contained in a single layer. The
trilayer film contains three layers of film. Each of the layers may
be different, or two of the layers, such as the bottom and top
layers, may have substantially the same composition. In one
embodiment, the bottom and top layers surround a core layer
containing the active agent. The bottom and top layers may contain
one or more excipients, such as a solubilizing agent and a metal
chelator. Perferably the bottom and top layers have the same
composition. Alternatively, the bottom and top layers may contain
different excipient(s), or different amounts of the same
excipient(s). The core layer typically contains the active agent,
optionally with one or more excipients.
[0061] In the preferred embodiment, the film is a bilayer film that
contains EDTA and citric acid in one layer and insulin in the
second layer. Each layer may contain additional excipients, such as
glycerin, polyvinyl alcohol, carboxymethyl cellulose, and
optionally PEG (such as PEG 400 or PEG 1600). In one embodiment, a
third layer can be located between the active agent layer and the
layer containing the other ingredients to further protect the
active agent from degradative ingredients located in the other
layer during storage. Suitable materials for the protective layer
include carboxymethylcellulose sodium, camauba wax, cellulose
acetate phthalate, cetyl alcohol, confectioner's sugar,
ethylcellulose, gelatin, hydroxyethyl cellulose, hydroxypropyl
methylcellulose, liquid glucose, maltodextrin, methylcellulose,
microcrystalline wax, polymethacrylates, polyvinyl alcohol,
shellac, sucrose, talc, titanium dioxide, and zein.
[0062] By altering the composition of the excipients, the film can
be designed to dissolve rapidly (less than 30 seconds) or slowly
(up to 15 minutes) in order to achieve the desired absorption
profile and subsequent effect. The film may dissolve in a time
period ranging from 3 to 5 minutes, 5 to 8 minutes, or 8 to 12
minutes. Preferably, the film dissolves in a time period ranging
from 15 seconds to 2 minutes.
[0063] Lozenge, Tablet, Capsule, or Wafer
[0064] In another embodiment, the composition is in the form of a
lozenge, tablet, capsule, or wafer containing the active agent and
one or more excipients, such as chelators, stabilizing agents,
solubilizing agents.
[0065] Lozenge
[0066] The lozenge core is composed of a solid gel or a lyophilized
wafer, containing an active agent in the core. Optionally, the core
also contains a stabilizing agent, optionally with one or more
additional excipients. Optionally, the upper and lower surfaces of
the lozenge core are coated with a chelator, such as sodium EDTA.
Alternatively, the chelator may be mixed with the active agent in
the core. In the preferred embodiment, the core contains alginate
(preferably calcium stabilized alginate), citric acid, EDTA, and
insulin. The lozenge covers a large surface area with a thin layer,
and can be made in any convenient shape. Typically it has a round
or oval shape. Generally, the lozenge has a diameter and thickness
that is approximately the same as the diameter and thickness of a
dime. In one embodiment, the lozenge contains glycerine.
[0067] Tablet
[0068] In one embodiment, the tablet is a compressed homogenous
powder of all of the ingredients. In another embodiment, inactive
ingredients, such as the filler and binding agent, and one or more
excipients, including the solubilizing agents, are formed into one
tablet. The active agent along with filler, binding agent, and
other excipients are formed into another tablet. Then the two
tablets are placed together and coated to form a single tablet.
Optionally, the tablet is coated with an enteric coating.
[0069] Wafer
[0070] The composition may be in the form of a wafer. The wafer is
a flat, solid dosage form. Typical thicknesses range from 0.1 mm to
1.5 cm. Typical diameters range from 0.2 to 5 cm. The wafer may be
in any suitable shape, including round, oval, rectangular, or
square. The wafer may be a monolayer, bilayer or trilayer. In the
preferred embodiment, the wafer is designed to be suitable for
sublingual administration. The monolayer wafer contains an active
agent and one or more excipients. The bilayer wafer contains one or
more excipients, such as a solubilizing agent and/or a metal
chelator, in a first layer and an active agent in the second layer.
This configuration allows the active agent to be stored separated
from the excipients, and may increase the stability of the active
agent, and optionally increases the shelf life of the composition
compared to if the excipients and active agent were contained in a
single layer. The trilayer wafer contains three layers. Each of the
layers may be different, or two of the layers, such as the bottom
and top layers may have substantially the same composition. In one
embodiment, the bottom, and top layers surround a core layer
containing the active agent. The bottom and top layers may contain
one or more excipients, such as a solubilizing agent and a metal
chelator. Preferably the bottom and top layers have the same
composition. Alternatively, the bottom and top layers may contain
different excipient(s), or different amounts of the same
excipient(s). The core layer typically contains the active agent,
optionally with one or more excipients.
[0071] Capsules
[0072] Another suitable dosage form is a capsule. The capsule
contains a rapidly dissolving outer shell, which is typically
composed of sugars, starches, polymers (and other suitable
pharmaceutical materials). The capsule contains powders or granules
of agent and excipient. The capsule is designed rapidly release
powders or small rapidly dissolving granules into the oral cavity
following administration.
[0073] Formulations for Subcutaneous Injection
[0074] The formulation may be an injectable formulation that is
suitable for subcutaneous injection. The injectable formulation
contains the active agent, a chelator, a solubilizing agent, and
saline. In a preferred embodiment the injectable formulation
contains insulin, EDTA, citric acid, and saline.
II. Methods of Making the Formulations
[0075] Pharmaceutical compositions may be formulated in a
conventional manner using one or more physiologically acceptable
carriers comprising excipients and auxiliaries which facilitate
processing of the active compounds into preparations which can be
used pharmaceutically. Formulation of drugs is discussed in, for
example, Hoover, John E., Remington's Pharmaceutical Sciences, Mack
Publishing Co., Easton, Pa. (1975), and Liberman, H. A. and
Lachman, L., Eds., Pharmaceutical Dosage Forms, Marcel Decker, New
York, N.Y. (1980). Proper formulation is dependent upon the route
of administration chosen.
[0076] The compounds may be complexed with other agents when they
are formulated into the desired dosage form. If water-soluble, such
formulated complex then may be formulated in an appropriate buffer,
for example, phosphate buffered saline or other physiologically
compatible solutions. Alternatively, if the resulting complex has
poor solubility in aqueous solvents, then it may be formulated with
a non-ionic surfactant such as TWEEN.TM., or polyethylene
glycol.
[0077] Preferred methods for making the films, tablets, wafers, and
subcutaneous injectible formulations are described below.
[0078] Films
[0079] The monolayer film is typically formed by first suspending
inactive ingredients and the active agent in water. The suspension
is transferred, such as by pouring or pipetting, to a sheet or
mold. Then the suspension is dried by lyophilization to remove the
water and form a film. Films may be made as one large sheet and cut
to a desired size, based on the desired dosage. Alternatively
formulations containing a single dose may be manufactured by
forming the film using a mold. The bilayer and trilayer films are
generally formed in the same manner as the monolayer film with the
exception that each layer contains only certain ingredients (e.g.
one layer contains the active agent and the other layer contains
one ore more excipients).
[0080] Tablets
[0081] Tablets are made using a traditional compression machine
with flat punches. Dry active ingredients are combined with an
appropriate amount of an inert filler excipient such as a binding
agent excipient, along with other suitable excipients. After mixing
thoroughly, a predetermined amount of the mixture is placed into a
tablet press and a tablet is formed. The depth of the tablet is
determined by the quantity of ingredients. Compression should be
sufficient to hold the ingredients together during dose
administration, while allowing water penetration into the tablet
for easy dissolution in the mouth.
[0082] Wafers
[0083] The wafer may be formed by compressing a powder,
lyophilizing a cake, or evaporating a suspension, emulsion or gel
(e.g. a hydrogel). A compression machine may also be used to make
wafers using a larger, flatter punch. Alternatively, the mixed dry
materials could be flattened or compressed between rollers to form
the powder into a sheet that may be cut to an appropriate size that
can be inserted in the mouth, preferably under the tongue. Dosing
of the wafers can be determined by standard methods, such as
altering the concentration of the active agent in the powder and
keeping the wafer size uniform. Alternatively, the concentration of
the powder can be maintained, and the surface area of the wafer can
be increased to achieve higher doses, or decreased to lower the
dosage. In one embodiment, the wafer is formed by suspending the
active agent, solubilizing agents, binding agent or other
excipients in a solvent such as water. A predetermined amount of
the suspension is placed in wells in a plastic mold and lyophilized
in the wells to remove the water and form a wafer. Alternatively, a
bilayer wafer may be formed with the one or more excipients (e.g.
solubilizing agent and/or binding agent) in one layer and the
active agent along with the binding agent or other inert components
in the second layer
[0084] Wafers can also be made by combining the dry powders into
aqueous solution, pipetting the appropriate amount of solution into
molds, flash freezing and lyophilizing the material. This forms a
very light wafer that dissolves very rapidly and requires little
fill and binding material.
[0085] Formulations for Subcutaneous Injection
[0086] In the preferred embodiment, the subcutaneous injectable
formulation is produced by mixing saline, citric acid and EDTA to
form a solution and sterilizing the solution (referred to as the
"diluent"). The insulin is separately added to sterile water to
form a solution, filtered, and a designated amount is placed into
each of a number of separate sterile injection bottles. The insulin
solution is lyophilized to form a powder and should be stored
separately from the diluent to retain its stability. Prior to
administration, the diluent is added to the insulin injection
bottle. After the predetermined amount of insulin is subcutaneously
injected into the patient, the remaining insulin solution may be
stored, preferably by refrigeration. The insulin solution should
remain stable for at least one week.
III. Methods of Using Formulations
[0087] The formulations may be administered in a variety of
manners, including buccal administration, nasal administration,
pulmonary administration, sublingual administration, subcutaneous
administration, rectal administration, vaginal administration, or
ocular administration. Following administration, the dosage form
dissolves quickly releasing the drug or forming small particles
containing drug, optionally containing one or more excipients. The
formulation is designed to be rapidly absorbed and transported to
the plasma for systemic delivery.
[0088] Formulations containing insulin as the active agent may be
administered to a type 1 or type 2 diabetic patient before or
during a meal. The formulation is typically administered
sublingually, or by subcutaneous injection. The formulation may
also be administered by buccal, nasal or pulmonary administration.
Due to the rapid absorption, the compositions can shut off the
conversion of glycogen to glucose in the liver, thereby preventing
hyperglycemia, the main cause of complications from diabetes and
the first symptom of type 2 diabetes. As seen in Example 2, the
sublingual insulin formulations deliver insulin to the blood stream
of the patient quickly, resulting in a rapid onset of action
(beginning at about 5 minutes following administration and peaking
at about 15-30 minutes following administration). In contrast,
currently available, standard, subcutaneous injections of human
insulin must be administered about one hour prior to eating to
provide a less than desired effect, because the insulin is absorbed
too slowly to shut off the production of glucose in the liver.
Additionally, if given early enough in the progression of the
disease, the sublingual or subcutaneous insulin compositions may be
able to slow or stop the progression of type 2 diabetes.
[0089] FIG. 1A is a schematic for administering the preferred dry
powder composition, i.e. insulin, alginate, citric acid, and EDTA
powder. As shown in FIG. 1A, the powder is composed of a solid, dry
powder of citric acid, insulin, and EDTA powder. A device is used
to dispense a single dose of dry powder under the tongue, so that
the dose is evenly dispersed throughout the sublingual region of
the oral cavity. The disodium EDTA rapidly dissolves in the saliva.
The citric acid solubilizes the insulin, allowing it to be in
solution in close proximity with the EDTA. The EDTA then chelates
the zinc in the insulin, thereby releasing its sodium ions and
pulling the zinc away from the insulin. This causes the insulin to
take on its dimeric and monomeric form and prevents reassembly into
hexamers. The monomeric form has a molecular weight that is less
than one-sixth the molecular weight of the hexameric form, thereby
markedly increasing both the speed and quantity of insulin
absorption. The dimers and monomers are in equilibrium. Thus, as
insulin monomers are absorbed through the epithelial membrane,
additional dimers dissemble to form more monomers.
[0090] A similar process occurs if a bulking agent is included in
the drug powder, For example, if alginate is used as a bulking
agent for the insulin, the calcium embedded in the alginate is
chelated by the EDTA, removing it from the gel matrix. This
de-stabilizes the matrix, which releases the insulin into the local
saliva, where insulin is now in close proximity to the EDTA. The
EDTA identifies the zinc-insulin in close proximity, and exchanges
its calcium for the zinc, for which it has a higher affinity. This
releases the hexameric insulin into its dimeric form, of which a
portion splits into monomers. Since these two forms exist in a
concentration-driven equilibrium, as the monomers are absorbed,
more monomers are created.
[0091] These small polypeptides of .about.5,800 Da are now ready
for epithelial absorption. Since the epithelium is relatively thin
in the sublingual region, and blood vessels are readily available,
the systemic absorption is fast and efficient. To the extent that
the EDTA and/or citric acid hydrogen bond with the insulin, it
masks the charge on the insulin, facilitating its transmembrane
transport and thereby increases both the onset of action and
bioavailability for insulin. Since the epithelium is relatively
thin in the sublingual region, and blood vessels are readily
available, the systemic absorption is fast and efficient, taking
from 1 second to 15 minutes following administration. The powder
may dissolve in a time period ranging from 1 second to 3 minutes, 3
to 5 minutes, 5 to 8 minutes, or 8 to 12 minutes. The preferred
dissolution time is less than 5 minutes.
[0092] As described in FIG. 1B, before a meal, a lozenge is
inserted under the tongue, and tongue is relaxed on top of the
lozenge 10. The lozenge could be replaced with a film, wafer,
tablet, or capsule. The sodium EDTA is dissolved from the surfaces
12 and into the local saliva. The surface 12 of the lozenge is
wetted by the removal of the EDTA layer, providing the embedded
calcium in the gel 10 with access to the surface 12. EDTA is a
calcium chelator, and removes the calcium from the gel matrix,
removing its supporting structure. With the calcium removed, the
alginate liquefies, and releases the hexameric zinc insulin into
the saliva. The EDTA is attracted to the zinc in close proximity,
and removes the zinc from the insulin (for which it has a higher
affinity), releasing the hexameric insulin into its dimeric form,
of which a portion splits into monomers. Since the monomers and
dimers exist in a concentration-driven equilibrium, as the monomers
are absorbed, more monomers are created.
IV. Kits
[0093] The active agent can be stored in one container and the
excipients can be stored in a second container. Immediately prior
to administration the contents of both containers are mixed.
[0094] As illustrated in FIG. 2, the kit may contain a vial
containing powdered insulin in the cap (22), separated by a seal
(26) which can be broken by rotation of the cap, to allow the
insulin to mix with the excipient, e.g. citric acid-EDTA, solution
in the vial (24).
[0095] The methods and compositions described above will be further
understood with reference to the following non-limiting
examples.
EXAMPLES
Example 1
Effect of Insulin Solutions Containing Different Concentrations of
EDTA on Conversion of Insulin from a Hexameric Form to
Monomer/Dimers
[0096] Materials
[0097] Human recombinant Insulin (Akzo-Nobel), Citric acid and
disodium EDTA were used in this experiment in distilled water.
Nanosep microtubes with 30,000 MW cutoff (Pall Scientific) were
used to separate the hexamers (36,000 MW) from the dimers/monomers
(6-12,000 MW) in the insulin solutions. Analysis was performed by
HPLC using a waters 2695 separations module fitted with a symmetry
300.TM. C.sub.4 5 um column (Waters Corp, Milford, Mass.,
#186000285) and a photodiode array detector (at 220 nm absorbance).
A gradient method (25-32% ACN in water, 0.05% TFA) was used to
separate the insulin from the other ingredients.
[0098] Methods
[0099] Human recombinant Insulin was dissolved in 2 mg/mL Citric
acid to from a 1 mg/ml solution and 1.5 mL of this solution was
subsequently pipetted into test tubes. EDTA was added to each tube
in order to achieve a concentration of 0, 1, 2, 3, or 4 mg EDTA/mL.
0.5 mL of the combined ingredients were added to the top of the
Nanosep microtubes and tubes were spun at 10,000 rpm for 10 minutes
in a microcentrifuge (Fisher Scientific). Insulin was assayed
before and after the spin, and the percent recovered in the
filtrate was determined by dividing the amount of the insulin that
filtered through the filter by the initial quantity placed on
top.
[0100] Setup TABLE-US-00001 TABLE 1 Four experimental conditions
and control Formulation Insulin EDTA Citric acid No. (mg/ml)
(mg/mL) (mg/mL) 0 1 0 2 1 1 1 2 2 1 2 2 3 1 3 2 4 1 4 2
[0101] Results
[0102] As shown in FIG. 3, increasing amounts of EDTA resulted in
greater concentrations monomers/dimers relative to hexamer in the
insulin solution. About 8% of the total insulin was filtered
through the filter when no EDTA was present (control "0"). The
quantity of monomer/dimers recovered in the filtrate increased to
over 20% after the addition of EDTA, with a maximal effect at 2
mg/mL. Further addition of EDTA did not enhance the effect. Thus,
the addition of EDTA to an insulin solution (in the presence of
citric acid) increases the concentration of monomers/dimers.
Example 2
Effect of Administration of Sublingual Dry Powder Insulin
Formulation on a Patient's Insulin and Glucose Levels
[0103] The insulin and blood glucose levels following a single
sublingual administration of a dry powder insulin formulation were
measured in one male, 35-year old, Type 1 diabetic patient. The
dose administered to the patient contained 6 mg insulin, 4 mg
citric acid and 4 mg EDTA. The insulin in the formulation was
approximately 28 IU/mg.
[0104] The patient fasted overnight and arrived at the clinic in
the early morning. An IV line with a saline drip was attached to
the patient. The patient was instructed to open his mouth and touch
his upper palette with his tongue and the dry powder formulation
was sprinkled under his tongue. He was then instructed to lower his
tongue, close his mouth and not swallow for one minute.
[0105] Blood glucose was measured at five minutes prior to the
application of the sublingual insulin formulation. Following
administration of the insulin formulation, blood glucose was
monitored in real time by the use of glucose strips and samples of
blood were taken according to the times listed in Tables 2 and 3
for a laboratory determination of blood glucose concentration by
the glucose oxidase method and of blood insulin concentration by a
LINKO enzyme linked immunosorbent assay (ELISA).
[0106] Results and Discussion
[0107] Data obtained using the glucose strip method and glucose
oxidase method are listed in Table 2. TABLE-US-00002 TABLE 2
Glucose Concentrations over Time Strip Method Oxidase Method Time
Glucose concentration Glucose concentration (minutes) (mg/DL)
(mg/DL) -5 N/A 99.5 3 84 96.3 7 83 87.0 10 75 90.1 15 70 83.2 20 73
78.3 30 63 75.5 45 59 68.0 60 46 61.8 61 42 60.2 62 42 57.7 80 33
53.7 (glucose ingestion) 90 136 143 120 97 122.0 145 N/A 122.0 180
N/A 80.5
[0108] By the real-time glucose strip method, the blood glucose
concentration dropped rapidly and precipitously, starting within
10-15 minutes after administration. By one hour post
administration, blood glucose appeared to be dangerously low (46
mg/DL by the strip method). The initial protocol was modified at
this time, and the blood glucose readings were taken more
frequently. At 80 minutes post administration, the patient's blood
glucose was 33 mg/DL by the strip method, and a liquid formulation
of glucose was orally administerd to the patent. This intervening
administration of glucose was effective at raising the patient's
blood glucose levels to the normal range (95-140 mg/DL by the strip
method. In contrast to this oral dosage, a subcutaneous injection
of human insulin typically begins to lower blood glucose about 30
minutes after administration and produces a peak effect between 90
minutes and 3 hours after administration.
[0109] As seen based on the data in Table 2, the data obtained
using the more accurate test for blood gluclose, the oxidase
method, mirrored the real time strip method, but was higher by
about 12-20 mg/DL on an absolute basis.
[0110] Table 3 lists the blood insulin concentrations over time
obtained by the LINKO ELISA test. TABLE-US-00003 TABLE 3 Insulin
concentrations over time Time Insulin concentration (minutes)
(.mu.U/mL) -5 16.9 3 13.9 7 22.7 10 21 15 22.95 20 23.4 30 19.7 45
21.2 60 21.9 80 21.1 (glucose ingestion) 120 18.9 180 13.9
[0111] As seen in based on the data listed in Table 3, the blood
insulin concentration rose very rapidly, beginning at 7 minutes
after administration and reached a peak effect between 15 and 20
minutes after administration. In contrast, a subcutaneous injection
of human insulin achieves maximum blood concentration about two
hours after administration. Thus the dry powder sublingual
formulation is about 6 to 8 times faster than a subcutaneous
injection of human insulin.
Example 3
Determination of Effect of EDTA and Various Acids on Insulin
Particle Size
[0112] A study was conducted to determine the effect of EDTA, a
chelator, in combination with various acids: acetic acid,
hydrochloric acid, ascorbic acid and citric acid, on insulin
particle size. Controls included insulin with EDTA and no acid, and
insulin with acid and no EDTA.
[0113] Using the same techniques described in example 1, insulin (1
mg/ml) was dissolved in a food acid, EDTA added, and the mixture on
top of a 30,000 mw cutoff filer in a microtube, and then spun for
10 minutes at 10,000 rpm. Each mixture was tested at pH 3 (without
buffer) and pH 7.0 (with phosphate buffer). The results were
calculated as a percent of insulin recovered in the filtrate,
compared to the starting quantity (percent).
[0114] The results are depicted graphically in FIGS. 4 and 5a-d.
The results show that the combination of EDTA and citric acid
produces a significantly greater amount of lower weight (i.e.,
monomeric rather than hexameric) insulin.
Example 4
Subcutaneous Administration of EDTA Insulin to Pigs
[0115] The EDTA-citric acid insulin formulation was administered by
subcutaneous injection to pigs to compare the effect of EDTA and
citric acid on insulin administered by subcutaneous administration
with normal (hexameric) human insulin. The insulin was administered
in a dosage of 25 U/ml, 2 mg EDTA/ml, 2 mg citric acid/ml. An
insulin dose of 0.125 U/kg was administered. The effect on blood
glucose was compared to the effect of 100 units regular human
insulin, dose 0.125 U/kg.
[0116] Normal human insulin normally produces its lowest glucose
level at about 120 minutes after administration, with levels
returning to baseline over a period of six hours. In contrast, as
shown by the results in FIG. 6, the EDTA-citric acid insulin
formulation produces a more rapid and significantly greater
decrease in blood glucose.
Example 5
Determination of Effect of EDTA on Insulin Absorption through a
Membrane overlayed with an Epithelial Cell Monolayer
[0117] A study was conducted to demonstrate the effect of EDTA on
absorption through a membrane overlayed with an epithelial cell
monolayer.
[0118] Two saline solutions were mixed containing 1 mg/ml insulin,
2 mg/ml EDTA and 2 mg/ml citric acid ("solution 1") or 1 mg/ml
insulin and 2 mg/ml citric acid ("solution 2"). The control
solution contained only EDTA and citric acid. Immortalized
epithelial cell line cultures were seeded on transwell membranes.
When the cells were grown to confluence, at time zero, the fluid in
the top chambers of the transwell plates was replaced with 0.5 ml
of insulin solution (i.e. solution 1 or solution 2). Two plates
with solution 1, two plates with solution 2 and one plate with the
control solution (no cells) were tested simultaneously. The lower
chamber of each plate contained 1.5 mL of saline solution. At each
time point, 100 .mu.L of fluid from the lower chamber was removed
and analyzed with Enzyme-Linked Immunosorbent Assay (ELISA). 100
.mu.L of saline was added to the lower chamber to maintain a
constant volume of 1.5 mL throughout the study.
[0119] The amount of insulin removed from the lower chamber at each
time point was added to the amount removed in the previous time
point(s) to determine the cumulative amount of insulin recovered in
the lower chamber. This data is presented in FIG. 7.
[0120] Cells were stained to check for viability before and after
the experiment. There was no statistical difference in the cell
viability for each of the plates.
[0121] The mean insulin accumulated in the lower chamber (receiver
chamber) over time is shown in FIG. 7. As shown in FIG. 7, solution
1, which contained EDTA, moved through the monolayer of epithelial
cells and through the membrane more effectively than solution 2,
which did not contain EDTA.
[0122] Those skilled in the art will recognize, or be able to
ascertain using no more than routine experimentation, many
equivalents to the specific embodiments of the invention described
herein. Such equivalents are intended to be encompassed by the
following claims.
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