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Title: Delivery of
beta-blockers through an inhalation route
United States Patent: 7,048,909
Issued: May 23, 2006
Inventors: Rabinowitz;
Joshua D. (Mountain View, CA); Zaffaroni; Alejandro C. (Atherton, CA)
Assignee: Alexza
Pharmaceuticals, Inc. (Palo Alto, CA)
Appl. No.: 775586
Filed: February 9, 2004
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Outsourcing Guide
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Abstract
The present invention relates to aerosols
containing of atenolol, pindolol, esmolol, propranolol, or metoprolol that
are used in inhalation therapy. In a method aspect of the present
invention, of atenolol, pindolol, esmolol, propranolol, or metoprolol is
administered to a patient through an inhalation route. The method
comprises: a) heating a thin layer of atenolol, pindolol, esmolol,
propranolol, or metoprolol, on a solid support to form a vapor; and, b)
passing air through the heated vapor to produce aerosol particles having
less than 5% drug degradation products. In a kit aspect of the present
invention, a kit for delivering of atenolol, pindolol, esmolol,
propranolol, or metoprolol through an inhalation route is provided which
comprises: a) a thin coating of an atenolol, pindolol, esmolol,
propranolol, or metoprolol composition and b) a device for dispensing said
thin coating as a condensation aerosol.
SUMMARY OF THE
INVENTION
The present invention relates to the
delivery of beta-blockers through an inhalation route. Specifically, it
relates to aerosols containing atenolol, pindolol, esmolol, propranolol,
or metoprolol that are used in inhalation therapy. In certain cases the
beta-blockers are β1 selective.
In a composition aspect of the present invention, the aerosol comprises
particles comprising at least 5 percent by weight of atenolol, pindolol,
esmolol, propranolol, or metoprolol. Preferably, the particles comprise at
least 10 percent by weight of atenolol, pindolol, esmolol, propranolol, or
metoprolol. More preferably, the particles comprise at least 20 percent,
30 percent, 40 percent, 50 percent, 60 percent, 70 percent, 80 percent, 90
percent, 95 percent, 97 percent, 99 percent, 99.5 percent or 99.97 percent
by weight of atenolol, pindolol, esmolol, propranolol, or metoprolol.
Typically, the aerosol has a mass of at least 10 μg. Preferably, the
aerosol has a mass of at least 100 μg. More preferably, the aerosol has a
mass of at least 200μ.
Typically, the particles comprise less than 10 percent by weight of
atenolol, pindolol, esmolol, propranolol, or metoprolol degradation
products. Preferably, the particles comprise less than 5 percent by weight
of atenolol, pindolol, esmolol, propranolol, or metoprolol degradation
products. More preferably, the particles comprise less than 2.5, 1, 0.5,
0.1 or 0.03 percent by weight of atenolol, pindolol, esmolol, propranolol,
or metoprolol.
Typically, the particles comprise less than 90 percent by weight of water.
Preferably, the particles comprise less than 80 percent by weight of
water. More preferably, the particles comprise less than 70 percent, 60
percent, 50 percent, 40 percent, 30 percent, 20 percent, 10 percent, or 5
percent by weight of water.
Typically, at least 50 percent by weight of the aerosol is amorphous in
form, wherein crystalline forms make up less than 50 percent by weight of
the total aerosol weight, regardless of the nature of individual
particles. Preferably, at least 75 percent by weight of the aerosol is
amorphous in form. More preferably, at least 90 percent by weight of the
aerosol is amorphous in form.
Typically, where the aerosol comprises atenolol, the aerosol has an
inhalable aerosol drug mass density of between 0.1 mg/L and 20 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 0.2 mg/L and 10 mg/L. More preferably, the aerosol has an
inhalable aerosol drug mass density of between 0.5 mg/L and 5 mg/L.
Typically, where the aerosol comprises pindolol, the aerosol has an
inhalable aerosol drug mass density of between 0.1 mg/L and 20 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 0.2 mg/L and 10 mg/L. More preferably, the aerosol has an
inhalable aerosol drug mass density of between 0.5 mg/L and 5 mg/L.
Typically, where the aerosol comprises esmolol, the aerosol has an
inhalable aerosol drug mass density of between 4 mg/L and 100 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 8 mg/L and 75 mg/L. More preferably, the aerosol has an inhalable
aerosol drug mass density of between 12 mg/L and 50 mg/L.
Typically, where the aerosol comprises propranolol, the aerosol has an
inhalable aerosol drug mass density of between 0.2 mg/L and 50 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 0.5 mg/L and 40 mg/L. More preferably, the aerosol has an
inhalable aerosol drug mass density of between 1 mg/L and 20 mg/L.
Typically, where the aerosol comprises metoprolol, the aerosol has an
inhalable aerosol drug mass density of between 1 mg/L and 30 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 2 mg/L and 25 mg/L. More preferably, the aerosol has an inhalable
aerosol drug mass density of between 3 mg/L and 20 mg/L.
Typically, the aerosol has an inhalable aerosol particle density greater
than 106 particles/mL. Preferably, the aerosol has an inhalable
aerosol particle density greater than 107 particles/mL or 108
particles/mL.
Typically, the aerosol particles have a mass median aerodynamic diameter
of less than 5 microns. Preferably, the particles have a mass median
aerodynamic diameter of less than 3 microns. More preferably, the
particles have a mass median aerodynamic diameter of less than 2 or 1
micron(s).
Typically, the geometric standard deviation around the mass median
aerodynamic diameter of the aerosol particles is less than 3.0.
Preferably, the geometric standard deviation is less than 2.5. More
preferably, the geometric standard deviation is less than 2.2.
Typically, the aerosol is formed by heating a composition containing
atenolol, pindolol, esmolol, propranolol, or metoprolol to form a vapor
and subsequently allowing the vapor to condense into an aerosol.
In a method aspect of the present invention, one of atenolol, pindolol,
esmolol, propranolol, or metoprolol is delivered to a mammal through an
inhalation route. The method comprises: a) heating a composition, wherein
the composition comprises at least 5 percent by weight of atenolol,
pindolol, esmolol, propranolol, or metoprolol, to form a vapor; and, b)
allowing the vapor to cool, thereby forming a condensation aerosol
comprising particles, which is inhaled by the mammal. Preferably, the
composition that is heated comprises at least 10 percent by weight of
atenolol, pindolol, esmolol, propranolol, or metoprolol. More preferably,
the composition comprises at least 20 percent, 30 percent, 40 percent, 50
percent, 60 percent, 70 percent, 80 percent, 90 percent, 95 percent, 97
percent, 99 percent, 99.5 percent, 99.9 percent or 99.97 percent by weight
of atenolol, pindolol, esmolol, propranolol, or metoprolol.
Typically, the particles comprise at least 5 percent by weight of atenolol,
pindolol, esmolol, propranolol, or metoprolol. Preferably, the particles
comprise at least 10 percent by weight of atenolol, pindolol, esmolol,
propranolol, or metoprolol. More preferably, the particles comprise at
least 20 percent, 30 percent, 40 percent, 50 percent, 60 percent, 70
percent, 80 percent, 90 percent, 95 percent, 97 percent, 99 percent, 99.5
percent, 99.9 percent or 99.97 percent by weight of atenolol, pindolol,
esmolol, propranolol, or metoprolol.
Typically, the condensation aerosol has a mass of at least 10 μg.
Preferably, the aerosol has a mass of at least 100 μg. More preferably,
the aerosol has a mass of at least 200 μg.
Typically, the particles comprise less than 10 percent by weight of
atenolol, pindolol, esmolol, propranolol, or metoprolol degradation
products. Preferably, the particles comprise less than 5 percent by weight
of atenolol, pindolol, esmolol, propranolol, or metoprolol degradation
products. More preferably, the particles comprise 2.5, 1, 0.5, 0.1 or 0.03
percent by weight of atenolol, pindolol, esmolol, propranolol, or
metoprolol degradation products.
Typically, the particles comprise less than 90 percent by weight of water.
Preferably, the particles comprise less than 80 percent by weight of
water. More preferably, the particles comprise less than 70 percent, 60
percent, 50 percent, 40 percent, 30 percent, 20 percent, 10 percent, or 5
percent by weight of water.
Typically, at least 50 percent by weight of the aerosol is amorphous in
form, wherein crystalline forms make up less than 50 percent by weight of
the total aerosol weight, regardless of the nature of individual
particles. Preferably, at least 75 percent by weight of the aerosol is
amorphous in form. More preferably, at least 90 percent by weight of the
aerosol is amorphous in form.
Typically, the particles of the delivered condensation aerosol have a mass
median aerodynamic diameter of less than 5 microns. Preferably, the
particles have a mass median aerodynamic diameter of less than 3 microns.
More preferably, the particles have a mass median aerodynamic diameter of
less than 2 or 1 micron(s).
In certain embodiments the particles have an MMAD of from about 0.2 to
about 3 microns.
Typically, the geometric standard deviation around the mass median
aerodynamic diameter of the aerosol particles is less than 3.0.
Preferably, the geometric standard deviation is less than 2.5. More
preferably, the geometric standard deviation is less than 2.2.
Typically, where the aerosol comprises atenolol, the delivered aerosol has
an inhalable aerosol drug mass density of between 0.1 mg/L and 20 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 0.2 mg/L and 10 mg/L. More preferably, the aerosol has an
inhalable aerosol drug mass density of between 0.5 mg/L and 5 mg/L.
Typically, where the aerosol comprises pindolol, the delivered aerosol has
an inhalable aerosol drug mass density of between 0.1 mg/L and 20 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 0.2 mg/L and 10 mg/L. More preferably, the aerosol has an
inhalable aerosol drug mass density of between 0.5 mg/L and 5 mg/L.
Typically, where the aerosol comprises esmolol, the delivered aerosol has
an inhalable aerosol drug mass density of between 4 mg/L and 100 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 8 mg/L and 75 mg/L. More preferably, the aerosol has an inhalable
aerosol drug mass density of between 12 mg/L and 50 mg/L.
Typically, where the aerosol comprises propranolol, the delivered aerosol
has an inhalable aerosol drug mass density of between 0.2 mg/L and 50
mg/L. Preferably, the aerosol has an inhalable aerosol drug mass density
of between 0.5 mg/L and 40 mg/L. More preferably, the aerosol has an
inhalable aerosol drug mass density of between 1 mg/L and 20 mg/L.
Typically, where the aerosol comprises metoprolol, the delivered aerosol
has an inhalable aerosol drug mass density of between 1 mg/L and 30 mg/L.
Preferably, the aerosol has an inhalable aerosol drug mass density of
between 2 mg/L and 25 mg/L. More preferably, the aerosol has an inhalable
aerosol drug mass density of between 3 mg/L and 20 mg/L.
Typically, the delivered aerosol has an inhalable aerosol particle density
greater than 106 particles/mL. Preferably, the aerosol has an
inhalable aerosol particle density greater than 107 particles/mL
or 108 particles/mL.
Typically, the rate of inhalable aerosol particle formation of the
delivered condensation aerosol is greater than 108 particles
per second. Preferably, the aerosol is formed at a rate greater than 109
inhalable particles per second. More preferably, the aerosol is
formed at a rate greater than 1010 inhalable particles per
second.
Typically, the delivered condensation aerosol is formed at a rate greater
than 0.5 mg/second. Preferably, the aerosol is formed at a rate greater
than 0.75 mg/second. More preferably, the aerosol is formed at a rate
greater than 1 mg/second, 1.5 mg/second or 2 mg/second.
Typically, where the condensation aerosol comprises atenolol, between 0.1
mg and 20 mg of atenolol are delivered to the mammal in a single
inspiration. Preferably, between 0.2 mg and 10 mg of atenolol are
delivered to the mammal in a single inspiration. More preferably, between
0.5 mg and 5 mg of atenolol are delivered in a single inspiration.
Typically, where the condensation aerosol comprises pindolol, between 0.1
mg and 20 mg of pindolol are delivered to the mammal in a single
inspiration. Preferably, between 0.2 mg and 10 mg of pindolol are
delivered to the mammal in a single inspiration. More preferably, between
0.5 mg and 5 mg of pindolol are delivered in a single inspiration.
Typically, where the condensation aerosol comprises esmolol, between 4 mg
and 100 mg of esmolol are delivered to the mammal in a single inspiration.
Preferably, between 8 mg and 75 mg of esmolol are delivered to the mammal
in a single inspiration. More preferably, between 12 mg and 50 mg of
esmolol are delivered in a single inspiration.
Typically, where the condensation aerosol comprises propranolol, between
0.2 mg and 50 mg of propranolol are delivered to the mammal in a single
inspiration. Preferably, between 0.5 mg and 40 mg of propranolol are
delivered to the mammal in a single inspiration. More preferably, between
1 mg and 20 mg of propranolol are delivered in a single inspiration.
Typically, where the condensation aerosol comprises metoprolol, between 1
mg and 30 mg of metoprolol are delivered to the mammal in a single
inspiration. Preferably, between 2 mg and 25 mg of metoprolol are
delivered to the mammal in a single inspiration. More preferably, between
3 mg and 20 mg of metoprolol are delivered in a single inspiration.
Typically, the delivered condensation aerosol results in a peak plasma
concentration of atenolol, pindolol, esmolol, propranolol, or metoprolol
in the mammal in less than 1 h. Preferably, the peak plasma concentration
is reached in less than 0.5 h. More preferably, the peak plasma
concentration is reached in less than 0.2, 0.1, 0.05, 0.02, 0.01, or 0.005
h (arterial measurement).
In a kit aspect of the present invention, a kit for delivering atenolol,
pindolol, esmolol, propranolol, or metoprolol through an inhalation route
to a mammal is provided which comprises: a) a composition comprising at
least 5 percent by weight of atenolol, pindolol, esmolol, propranolol, or
metoprolol; and, b) a device that forms a atenolol, pindolol, esmolol,
propranolol, or metoprolol aerosol from the composition, for inhalation by
the mammal. Preferably, the composition comprises at least 20 percent, 30
percent, 40 percent, 50 percent, 60 percent, 70 percent, 80 percent, 90
percent, 95 percent, 97 percent, 99 percent, 99.5 percent, 99.9 percent or
99.97 percent by weight of butalbital, pindolol, esmolol, propranolol, or
metoprolol.
Typically, the device contained in the kit comprises: a) an element for
heating the atenolol, pindolol, esmolol, propranolol, or metoprolol
composition to form a vapor; b) an element allowing the vapor to cool to
form an aerosol; and, c) an element permitting the mammal to inhale the
aerosol.
DETAILED DESCRIPTION
OF THE INVENTION
ormation of Atenolol, Pindolol, Esmolol,
Propranolol, or Metoprolol Containing Aerosols
Any suitable method is used to form the aerosols of the present invention.
A preferred method, however, involves heating a composition comprising
atenolol, pindolol, esmolol, propranolol, or metoprolol to form a vapor,
followed by cooling of the vapor such that it condenses to provide an
atenolol, pindolol, esmolol, propranolol, or metoprolol comprising aerosol
(condensation aerosol). The composition is heated in one of four forms: as
pure active compound (i.e., pure atenolol, pindolol, esmolol, propranolol,
or metoprolol); as a mixture of active compound and a pharmaceutically
acceptable excipient; as a salt form of the pure active compound; and, as
a mixture of active compound salt form and a pharmaceutically acceptable
excipient.
Salt forms of atenolol, pindolol, esmolol, propranolol, or metoprolol are
either commercially available or are obtained from the corresponding free
base using well known methods in the art. A variety of pharmaceutically
acceptable salts are suitable for aerosolization. Such salts include,
without limitation, the following: hydrochloric acid, hydrobromic acid,
acetic acid, maleic acid, formic acid, and fumaric acid salts.
Pharmaceutically acceptable excipients may be volatile or nonvolatile.
Volatile excipients, when heated, are concurrently volatilized,
aerosolized and inhaled with atenolol, pindolol, esmolol, propranolol, or
metoprolol. Classes of such excipients are known in the art and include,
without limitation, gaseous, supercritical fluid, liquid and solid
solvents. The following is a list of exemplary carriers within the
classes: water; terpenes, such as menthol; alcohols, such as ethanol,
propylene glycol, glycerol and other similar alcohols; dimethylformamide;
dimethylacetamide; wax; supercritical carbon dioxide; dry ice; and
mixtures thereof.
Solid supports on which the composition is heated are of a variety of
shapes. Examples of such shapes include, without limitation, cylinders of
less than 1.0 mm in diameter, boxes of less than 1.0 mm thickness and
virtually any shape permeated by small (e.g., less than 1.0 mm-sized)
pores. Preferably, solid supports provide a large surface to volume ratio
(e.g., greater than 100 per meter) and a large surface to mass ratio
(e.g., greater than 1 cm2 per gram).
A solid support of one shape can also be transformed into another shape
with different properties. For example, a flat sheet of 0.25 mm thickness
has a surface to volume ratio of approximately 8,000 per meter. Rolling
the sheet into a hollow cylinder of 1 cm diameter produces a support that
retains the high surface to mass ratio of the original sheet but has a
lower surface to volume ratio (about 400 per meter).
A number of different materials are used to construct the solid supports.
Classes of such materials include, without limitation, metals, inorganic
materials, carbonaceous materials and polymers. The following are examples
of the material classes: aluminum, silver, gold, stainless steel, copper
and tungsten; silica, glass, silicon and alumina; graphite, porous
carbons, carbon yarns and carbon felts; polytetrafluoroethylene and
polyethylene glycol. Combinations of materials and coated variants of
materials are used as well.
Where aluminum is used as a solid support, aluminum foil is a suitable
material. Examples of silica, alumina and silicon based materials include
amphorous silica S-5631 (Sigma, St. Louis, Mo.), BCR171 (an alumina of
defined surface area greater than 2 m2/g from Aldrich, St.
Louis, Mo.) and a silicon wafer as used in the semiconductor industry.
Carbon yarns and felts are available from American Kynol, Inc., New York,
N.Y. Chromatography resins such as octadecycl silane chemically bonded to
porous silica are exemplary coated variants of silica.
The heating of the atenolol, pindolol, esmolol, propranolol, or metoprolol
compositions is performed using any suitable method. Examples of methods
by which heat can be generated include the following: passage of current
through an electrical resistance element; absorption of electromagnetic
radiation, such as microwave or laser light; and, exothermic chemical
reactions, such as exothermic solvation, hydration of pyrophoric materials
and oxidation of combustible materials.
Delivery of Atenolol, Pindolol, Esmolol, Propranolol, or Metoprolol
Containing Aerosols
Atenolol, pindolol, esmolol, propranolol, or metoprolol containing
aerosols of the present invention are delivered to a mammal using an
inhalation device. Where the aerosol is a condensation aerosol, the device
has at least three elements: an element for heating an atenolol, pindolol,
esmolol, propranolol, or metoprolol containing composition to form a
vapor; an element allowing the vapor to cool, thereby providing a
condensation aerosol; and, an element permitting the mammal to inhale the
aerosol. Various suitable heating methods are described above. The element
that allows cooling is, in it simplest form, an inert passageway linking
the heating means to the inhalation means. The element permitting
inhalation is an aerosol exit portal that forms a connection between the
cooling element and the mammal's respiratory system.
One device used to deliver the atenolol, pindolol, esmolol, propranolol,
or metoprolol containing aerosol is described in reference to FIG. 1 (see
Original Patent).
Devices, if desired, contain a variety of components to facilitate the
delivery of atenolol, pindolol, esmolol, propranolol, or metoprolol
containing aerosols. For instance, the device may include any component
known in the art to control the timing of drug aerosolization relative to
inhalation (e.g., breath-actuation), to provide feedback to patients on
the rate and/or volume of inhalation, to prevent excessive use (i.e.,
"lock-out" feature), to prevent use by unauthorized individuals, and/or to
record dosing histories.
Dosage of Atenolol, Pindolol, Esmolol, Propranolol, or Metoprolol
Containing Aerosols
Atenolol, pindolol, esmolol, propranolol, and metoprolol are given at
strengths of 5 mg, 5 mg, 35 mg, 20 mg, and 15 mg respectively for the
treatment of hypertension. As aerosols, 0.1 mg to 20 mg of atenolol, 0.1
mg to 20 mg of pindolol, 4 mg to 100 mg of esmolol, 0.2 mg to 50 mg of
propranol, and 1 mg to 30 mg of metoprolol are generally provided per
inspiration for the same indication. A typical dosage of an atenolol,
pindolol, esmolol, propranolol, or metoprolol aerosol is either
administered as a single inhalation or as a series of inhalations taken
within an hour or less (dosage equals sum of inhaled amounts). Where the
drug is administered as a series of inhalations, a different amount may be
delivered in each inhalation. The dosage amount of atenolol, pindolol,
esmolol, propranolol, or metoprolol in aerosol form is generally no
greater than twice the standard dose of the drug given orally.
One can determine the appropriate dose of atenolol, pindolol, esmolol,
propranolol, or metoprolol containing aerosols to treat a particular
condition using methods such as animal experiments and a dose-finding
(Phase I/II) clinical trial. One animal experiment involves measuring
plasma concentrations of drug in an animal after its exposure to the
aerosol. Mammals such as dogs or primates are typically used in such
studies, since their respiratory systems are similar to that of a human.
Initial dose levels for testing in humans is generally less than or equal
to the dose in the mammal model that resulted in plasma drug levels
associated with a therapeutic effect in humans. Dose escalation in humans
is then performed, until either an optimal therapeutic response is
obtained or a dose-limiting toxicity is encountered.
Analysis of Atenolol, Pindolol, Esmolol, Propranolol, or Metoprolol
Containing Aerosols
Purity of an atenolol, pindolol, esmolol, propranolol, or metoprolol
containing aerosol is determined using a number of methods, examples of
which are described in Sekine et al., Journal of Forensic Science
32:1271-1280 (1987) and Martin et al., Journal of Analytic
Toxicology 13:158-162 (1989). One method involves forming the aerosol
in a device through which a gas flow (e.g., air flow) is maintained,
generally at a rate between 0.4 and 60 L/min. The gas flow carries the
aerosol into one or more traps. After isolation from the trap, the aerosol
is subjected to an analytical technique, such as gas or liquid
chromatography, that permits a determination of composition purity.
A variety of different traps are used for aerosol collection. The
following list contains examples of such traps: filters; glass wool;
impingers; solvent traps, such as dry ice-cooled ethanol, methanol,
acetone and dichloromethane traps at various pH values; syringes that
sample the aerosol; empty, low-pressure (e.g., vacuum) containers into
which the aerosol is drawn; and, empty containers that fully surround and
enclose the aerosol generating device. Where a solid such as glass wool is
used, it is typically extracted with a solvent such as ethanol. The
solvent extract is subjected to analysis rather than the solid (i.e.,
glass wool) itself. Where a syringe or container is used, the container is
similarly extracted with a solvent.
The gas or liquid chromatograph discussed above contains a detection
system (i.e., detector). Such detection systems are well known in the art
and include, for example, flame ionization, photon absorption and mass
spectrometry detectors. An advantage of a mass spectrometry detector is
that it can be used to determine the structure of atenolol, pindolol,
esmolol, propranolol, or metoprolol degradation products.
Particle size distribution of an atenolol, pindolol, esmolol, propranolol,
or metoprolol containing aerosol is determined using any suitable method
in the art (e.g., cascade impaction). An Andersen Eight Stage Non-viable
Cascade Impactor (Andersen Instruments, Smyrna, Ga.) linked to a furnace
tube by a mock throat (USP throat, Andersen Instruments, Smyrna, Ga.) is
one system used for cascade impaction studies.
Inhalable aerosol mass density is determined, for example, by delivering a
drug-containing aerosol into a confined chamber via an inhalation device
and measuring the mass collected in the chamber. Typically, the aerosol is
drawn into the chamber by having a pressure gradient between the device
and the chamber, wherein the chamber is at lower pressure than the device.
The volume of the chamber should approximate the tidal volume of an
inhaling patient.
Inhalable aerosol drug mass density is determined, for example, by
delivering a drug-containing aerosol into a confined chamber via an
inhalation device and measuring the amount of active drug compound
collected in the chamber. Typically, the aerosol is drawn into the chamber
by having a pressure gradient between the device and the chamber, wherein
the chamber is at lower pressure than the device. The volume of the
chamber should approximate the tidal volume of an inhaling patient. The
amount of active drug compound collected in the chamber is determined by
extracting the chamber, conducting chromatographic analysis of the extract
and comparing the results of the chromatographic analysis to those of a
standard containing known amounts of drug.
Inhalable aerosol particle density is determined, for example, by
delivering aerosol phase drug into a confined chamber via an inhalation
device and measuring the number of particles of given size collected in
the chamber. The number of particles of a given size may be directly
measured based on the light-scattering properties of the particles.
Alternatively, the number of particles of a given size is determined by
measuring the mass of particles within the given size range and
calculating the number of particles based on the mass as follows: Total
number of particles=Sum (from size range 1 to size range N) of number of
particles in each size range. Number of particles in a given size
range=Mass in the size range/Mass of a typical particle in the size range.
Mass of a typical particle in a given size range=π*D3*φ/6,
where D is a typical particle diameter in the size range (generally, the
mean boundary MMADs defining the size range) in microns, φ is the particle
density (in g/mL) and mass is given in units of picograms (g-12).
Rate of inhalable aerosol particle formation is determined, for example,
by delivering aerosol phase drug into a confined chamber via an inhalation
device. The delivery is for a set period of time (e.g., 3 s), and the
number of particles of a given size collected in the chamber is determined
as outlined above. The rate of particle formation is equal to the number
of 100 nm to 5 micron particles collected divided by the duration of the
collection time.
Rate of aerosol formation is determined, for example, by delivering
aerosol phase drug into a confined chamber via an inhalation device. The
delivery is for a set period of time (e.g., 3 s), and the mass of
particulate matter collected is determined by weighing the confined
chamber before and after the delivery of the particulate matter. The rate
of aerosol formation is equal to the increase in mass in the chamber
divided by the duration of the collection time. Alternatively, where a
change in mass of the delivery device or component thereof can only occur
through release of the aerosol phase particulate matter, the mass of
particulate matter may be equated with the mass lost from the device or
component during the delivery of the aerosol. In this case, the rate of
aerosol formation is equal to the decrease in mass of the device or
component during the delivery event divided by the duration of the
delivery event.
Rate of drug aerosol formation is determined, for example, by delivering
an atenolol, pindolol, esmolol, propranolol, or metoprolol containing
aerosol into a confined chamber via an inhalation device over a set period
of time (e.g., 3 s). Where the aerosol is pure atenolol, pindolol, esmolol,
propranolol, or metoprolol, the amount of drug collected in the chamber is
measured as described above. The rate of drug aerosol formation is equal
to the amount of atenolol, pindolol, esmolol, propranolol, or metoprolol
collected in the chamber divided by the duration of the collection time.
Where the atenolol, pindolol, esmolol, propranolol, or metoprolol
containing aerosol comprises a pharmaceutically acceptable excipient,
multiplying the rate of aerosol formation by the percentage of atenolol,
pindolol, esmolol, propranolol, or metoprolol in the aerosol provides the
rate of drug aerosol formation.
Utility of Atenolol, Pindolol, Esmolol, Propranolol, or Metoprolol
Containing Aerosols
The atenolol, pindolol, esmolol, propranolol, or metoprolol containing
aerosols of the present invention are typically used for the treatment of
hypertension, acute myocardial infarction, cardiac arrhythmias, or side
effects of situational anxiety.
Claim 1 of 37 Claims
1. A condensation aerosol for
delivery of a drug selected from the group consisting of atenolol, pindolol,
esmolol, propranolol, and metoprolol
wherein the condensation aerosol is formed by heating a thin layer
containing the drug, on a solid support, to produce a vapor of the drug, and
condensing the vapor to form a condensation aerosol,
characterized by less than 10% drug degradation products by weight, and
an MMAD of less than 5 microns.
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