(12) United States Patent
`Colombo et al.
`
`USOO6495534B2
`(10) Patent No.:
`US 6,495,534 B2
`(45) Date of Patent:
`Dec. 17, 2002
`
`(54) STABILIZED AQUEOUS SUSPENSIONS FOR
`PARENTERALUSE
`(75) Inventors: Giuseppe Colombo, Milan (IT);
`Alessandro Martini, Milan (IT); Lloyd
`E. Fox, Richland, MI (US)
`(73) Assignees: Pharmacia & Upjohn SpA, Milan
`(IT); Pharmacia & Upjohn Company,
`Kalamazoo, MI (US)
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(*) Notice:
`
`CA
`E.
`JP
`JP
`JP
`JP
`WO
`WO
`WO
`WO
`WO
`WO
`
`FOREIGN PATENT DOCUMENTS
`2304808
`4/1999
`o'E'S A 181991
`/1998
`63. 146829. A 6/1988
`O5 097671. A
`4/1993
`08 245421 A 9/1996
`10-212303
`8/1998
`WO 98 11912 A 3/1998
`98/14476
`* 4/1998
`WO 98/14476
`4/1998
`WO99 15193. A 4/1999
`WO99/51237
`10/1999
`WOO1 24814 A 4/2001
`OTHER PUBLICATIONS
`
`(21) Appl. No.: 09/571,395
`(22) Filed:
`May 15, 2000
`(65)
`Prior Publication Data
`US 2002/0115645 A1 Aug. 22, 2002
`7
`(51) Int. Cl." ................................................ A61K 31/56
`(52) U.S. Cl. ........................ 514/169; 514/178; 514/182
`(58) Field of Search ................................. 514/169, 178,
`514/182
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`4,154,820 A
`5/1979 Simoons ..................... 424/175
`5,569.464 A 10/1996 Endo et al.
`5,773,432 A
`6/1998 Kauser et al. .............. 514/182
`5,846,962 A 12/1998 Suzuki et all
`... 514/177
`5,880,116 A * 3/1999 Vigo-Pelfrey ............... 514/178
`5,916,550 A 6/1999 Inada et al.
`5,972.921. A * 10/1999 Santti et al. ................ 514/177
`6,040,301 A 3/2000 Skrabanja et al.
`6,114,324 A 9/2000 Skrabanja et al.
`
`
`
`Merck Index, ninth edition, 1976, 3629 & 5618, 1976.*
`The Merck Index, 12th Edition, 1996, p. 1023.
`* cited by examiner
`Primary Examiner Barbara P. Badio
`(74) Attorney, Agent, Of Firm-Oblon, Spivak, McClelland,
`Maier & Neustadt, P.C.
`(57)
`ABSTRACT
`A pharmaceutical aqueous suspension formulation for
`parenteral administration having Substantially Stabilized pH,
`comprising a biologically active compound and a pH con
`trolling effective concentration of L-Methionine.
`-
`Preferably, the biologically active compound is a Steroidal
`compound, for instance eXemeStane, medroxyprogesterone
`acetate and estradiol cypionate or a combination of medroX
`yprogesterone acetate and estradiol cypionate.
`
`21 Claims, No Drawings
`
`Mylan v. Janssen (IPR2020-00440) Ex. 1008 p. 001
`
`

`

`1
`STABILIZED AQUEOUS SUSPENSIONS FOR
`PARENTERALUSE
`
`US 6,495,534 B2
`
`SUMMARY OF THE INVENTION
`The present invention is in the field of galenic prepara
`tions. It concerns in particular a pharmaceutical aqueous
`Suspension of a biologically active compound, e.g. a Steroi
`dal compound, having Stabilized pH, particularly Suitable for
`parenteral administration.
`The inventors of the present invention have found that the
`pH of a pharmaceutical aqueous Suspension of a biologically
`active compound can be controlled by adding a pH control
`ling effective concentration of L-Methionine thereto.
`Moreover, when a pH controlling effective concentration
`of L-Methionine is used, it strengthens the buffering capac
`ity of low concentrations of conventional buffering agents
`with a Super-additive (Synergistic) effect. In this way the use
`of conventional buffering agents can be eliminated or
`limited, thus improving the re-Suspendability and controlled
`flocculation of the pharmaceutical preparation.
`
`BACKGROUND OF THE INVENTION
`A pharmaceutical Suspension is a coarse dispersion in
`which insoluble Solid particles are dispersed in a liquid
`medium.
`Suspensions contribute to pharmacy and medicine by
`Supplying insoluble and often distasteful Substances in a
`form that is pleasant to the taste, by providing a Suitable
`form for the application of dermatological materials to the
`skin and Sometimes to the mucous membranes, and for the
`parenteral administration of insoluble drugs. Therefore phar
`maceutical Suspensions may be classified into three groups:
`orally administered mixtures, externally applied lotions and
`injectable preparations.
`An acceptable Suspension possesses certain desirable
`qualities, including the followings:
`i) the Suspended material should not settle rapidly;
`ii) the particles that do settle to the bottom of the container
`must not form a hard cake but should be readily
`re-dispersed into a uniform mixture when the container
`is Shaken;
`iii) the Suspension must not be too viscous to pour freely
`from the orifice of the bottle or to flow through a
`Syringe needle.
`It is important that the characteristics of the dispersed
`phase are chosen with care So to as to produce a Suspension
`having optimum physical, chemical and pharmacological
`properties. Particle Size distribution, Specific Surface area,
`inhibition of crystal growth, and changes in the polymorphic
`form are of Special significance and the formulator must
`ensure that these and other properties do not change Suffi
`ciently during Storage to adversely affect the performance of
`the Suspensions with aging.
`In the field of injectable preparations, aqueous Suspen
`Sions for parenteral administration have already been
`described in Scientific and patent literature and have been
`known for a long time. Parenteral Suspensions are often
`prepared with the so called “controlled flocculation”
`approach, i.e. by the application of known principles of
`formulation chemistry to produce vehicles which permits
`drug flocs to form and Settle, but which they are easily
`re-Suspended with slight agitation and remain uniformly
`dispersed or Suspended during the period required for thera
`peutic administration. Specifically, it is well known that one
`
`2
`of the main difficulty in formulating parenteral aqueous
`Suspensions of Steroids is the overcome of their
`hydrophobicity, that significantly reduce the wettability,
`Suspendability or re-Suspendibility of the active in aqueous
`media. Both wetting and Suspending agents are needed in
`order to gain the proper formulation of the active compound
`Such as the concomitant use of preservatives. This is
`described, for example, by Nash and coworkers in the U.S.
`Pat. No. 3,457,348 where non-ionic surfactants (such as
`polySorbates) and Suspending agents (like polyethylene
`glycols) are the basic excipients to gain the proper stability
`of the formulation.
`Sometimes, even in the presence of the proper Suspending
`and wetting agents, the Suspension is not stable for a long
`time, but it is necessary to form it just before the adminis
`tration (while it is stored as lyophilized formulation). This is
`described, for example, in the case described by Geller and
`coworkers in the U.S. Pat. No. 5,002,940 and greatly
`impacts on the cost of the manufacturing process, Since an
`additional freeze-drying proceSS is mandatory.
`Even if an improved physical Stability of Steroidal drug
`Suspensions in water can be gained, as above mentioned, by
`the use of polyethylene glycols and non-ionic Surfactants,
`Some chemical Stability issues, Such as a relevant pH
`reduction, are likely to be faced during development.
`In fact, for instance, both polyethylene glycols and
`polySorbates, when in Solution, may undergo degradation,
`leading to the formation of acid Species Such as formic and
`acetic acid.
`An example of this pH reduction effect is given in Table
`1.
`
`15
`
`25
`
`TABLE 1.
`
`35
`
`pH of a typical vehicle for parenteral aqueous suspensions formulations
`Vehicle composition (batch 13169/12-1A): Methylparaben 0.2%,
`propylparaben 0.02%, sodium chloride 0.9%, PEG 4000 3%,
`polysorbate 80 0.3%, sodium hydroxide C.S. to pH 6.5, WH C.S to 100 ml.
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`Storage condition
`
`Time zero
`10 days at 65 C.
`15 days at 65° C.
`1 month at 65° C.
`3 months at 40 C.
`6 months at 40 C.
`6 months at 25 C.
`
`PH
`
`6.46
`3.43
`3.16
`3.32
`3.24
`3.15
`4.93
`
`This pH reduction occurs both at accelerated testing
`conditions and at room temperature. Considering that after
`only 6 months at room temperature a relevant decrease of
`approximately 1.5 pH unit is experimented, very low pH
`values (close or below 3) are anticipated after long-term
`Storage (1–2 years). This fact necessarily causes the reduced
`Shelf life of parenteral Suspension, being the progressive
`acidification of the formulation linked to the impossibility to
`administer the formulation, e.g. by intramuscular or Subcu
`taneous injection, without generating Significant pain on
`patients (it is advisable that the pH value is maintained
`above 3 for administering a painless formulation).
`This pH variation during Storage can be minimized by
`appropriately buffering the formulation. The most obvious
`approach, in order to maintain the pH within Specific and
`predetermined limits, is the use of buffering agents, Such as
`inorganic acid Salts, in appropriate concentrations in order
`not only to exert but also to maintain their buffering capacity.
`An example of buffering agents commonly used in
`parenteral formulations and of their usual concentrations can
`be found in Pharmaceutical Dosage Form: Parenteral
`
`Mylan v. Janssen (IPR2020-00440) Ex. 1008 p. 002
`
`

`

`3
`Medications, Volume 1, 2" Edition, Chapter 5, p. 194, De
`Luca and Boylan, “Formulation of Small Volume
`Parenterals”, Table 5: Commonly used additives in
`Parenteral Products
`The use of inorganic acid Salts as buffering agents offers
`to the formulator both advantages and disadvantages. In fact,
`if a careful control of pH of formulations could be gained,
`
`5
`
`US 6,495,534 B2
`
`4
`buffered Suspension cannot be re-Suspended at all by manual
`wrist Shaking and, as a consequence, cannot be adminis
`tered. On the other hand, when a lower and unusual con
`centration (approx. 0.1%) of phosphate buffer is used, no
`relevant effect on Suspension re-Suspendability is experi
`mented but, at the Same time, no Substantial pH control is
`obtained.
`
`TABLE 2
`
`pH, re-suspendability and syringeability study of “buffered vs. “as is 20%
`Medroxy ProgesteroneAcetate parenteral aqueous suspension formulations
`Suspension composition (batch 13451/01-1): Medroxyprogesterone acetate 20%,
`MyristylGammaPicoliniumChloride 0.2%, sodium sulphate 1.1%,
`PEG 3350 2.03%, sodium hydroxide q.s. to pH 6.5, WFI q.s to 100 ml.
`
`13451/O1-1
`
`B: + Phosphate buffer
`-0.1%
`
`A: as is
`
`C: Phosphate buffer ~1%
`
`Syring. pH
`
`Resusp.
`
`Syring. PH
`
`Resusp.
`
`Syring.
`
`R
`(T = 7s)
`R
`(T = 18s)
`R
`(T = 33 s)
`R
`(T = 31 s)
`
`MT 6.71
`
`MT 3.67
`
`MT 3.28
`
`MT 3.15
`
`R
`(T = 8s)
`R
`(T = 29s)
`R
`(T = 24s)
`R
`(T = 32 s)
`
`MT 6.30
`
`MT 5.94
`
`MT 5.93
`
`R
`(T = 10s)
`R
`(T = 40s)
`NR
`
`MT 5.81
`
`NR
`
`MT
`
`MT
`
`NP
`
`NP
`
`Batch
`
`Time zero
`
`pH
`
`6.35
`
`1 month at 55° C. 3.12
`
`2 months
`at 55° C.
`3 months
`at 55° C.
`
`2.92
`
`2.83
`
`Phosphate Buffers (M = molar)
`
`Concentration -0.1%
`
`Concentration ~1%
`
`Monobasic Sodium Phosphate.1 H2O (MW 137.99)
`
`Dibasic Sodium Phosphate.12 H2O (MW 358.14)
`
`mg 69.4/100 ml
`(0.005M)
`mg 58.8/100 ml
`(0.0016M)
`
`mg 694/100 ml
`(0.05M)
`mg 588/100 ml
`(0.016M)
`
`Resuspendability
`R = RESUSPENDABLE by manual wrist shaking. In brackets: T = time of manual wrist shaking
`requested in order to obtain a homogeneous suspension (s = seconds).
`NR = NOT RESUSPENDABLE
`Syringeability
`MT = meets test
`NP = not performed as product cannot be resuspended and therefore cannot be homogeneously with
`drawed and syringed
`
`on the contrary, when Suspension formulations are
`concerned, ionic species tend to destabilize the formulations
`with detrimental effects on the re-suspendability and on the
`controlled flocculation of the formulation. This means that
`the use of inorganic acid Salt based buffering Systems into
`the formulations has to be minimized.
`In fact, when talking about parenteral Suspension, accord
`ing to Nash (Parenteral Suspensions, Bulletin of Parenteral
`Drug Association, March-April 1972, Vol. 26, No. 2), “...
`indiscriminate use of Salts and bufferS is normally avoided,
`provided chemical Stability is not a problem Since changes
`in electrolyte concentration often have a profound effect on
`the absorbed Surface charge of Suspension particles'.
`An example of the relevant pH decrease occurring in a
`medroxyprogesterone acetate parenteral aqueous Suspension
`is showed in Table 2. This accelerated stability study shows
`that the pH of an unbuffered formulation significantly
`decrease from an initial pH value of approx. 6.5 to pH values
`of 3 or lower than 3. It also demonstrates that, when a usual
`concentration (approx.1%) of phosphate buffer is added to
`control the pH, a detrimental effect on the Suspension
`re-Suspendability and Syringeability is experimented. In fact
`an increased time of manual wrist shaking is needed to
`re-suspend the buffered suspension after 1 month at 55 C.
`vs. the unbuffered one. Besides, after 2 month at 55 C. the
`
`45
`
`50
`
`55
`
`60
`
`65
`
`DESCRIPTION OF THE INVENTION
`The inventors of the present invention have Surprisingly
`found out that Suitable concentrations of L-Methionine are
`able both to control the pH of a pharmaceutical aqueous
`Suspension of a biologically active compound, in particular
`a Steroidal compound, by minimizing its pH decrease and to
`Strengthen the pH controlling capacity of lower and unusual
`concentrations of conventional buffering agents, with a
`Super-additive (synergistic) effect.
`In fact the gist of the present invention is based on the
`finding that an oxygen Scavenger Such as L-Methionine not
`only shows antioxidant properties per se, like known anti
`oxidant thiol-derivatives, but Surprisingly itself takes part in
`pH controlling activity.
`A first object of the present invention is thus to provide the
`use of L-Methionine as pH controlling agent in a pharma
`ceutical aqueous Suspension formulation having Substan
`tially stabilized pH, for parenteral administration of a bio
`logically active compound.
`A further object of the present invention is to provide a
`pharmaceutical aqueous Suspension formulation for
`parenteral administration having Substantially Stabilized pH
`comprising a biologically active compound and a pH con
`trolling effective concentration of L-Methionine.
`
`Mylan v. Janssen (IPR2020-00440) Ex. 1008 p. 003
`
`

`

`S
`Object of the invention is also the use of L-Methionine, in
`a pH controlling effective concentration, in the preparation
`of a pharmaceutical aqueous Suspension formulation having
`Substantially Stabilized pH, for parenteral administration of
`a biologically active compound.
`A further object is a method for preparing a pharmaceu
`tical aqueous Suspension formulation for parenteral admin
`istration of a biologically active compound having Substan
`tially Stabilized pH, characterized in that a pH controlling
`effective concentration of L-Methionine is added thereto.
`The inventors have also found that L-Methionine, besides
`exercising a pH controlling activity per Se, also strengthens
`the pH controlling capacity of a conventional buffer with a
`(Super-additive) Synergistic effect.
`A Super-additive (synergistic) effect is a pH controlling
`effect that is greater than the one which is expected to be
`obtainable by Summing up the experimentally verified pH
`controlling effects of the Single agents.
`This means that low unusual concentrations of conven
`tional buffering agents can be included into the formulations,
`without any risk of loosing in buffering capacity and, at the
`Same time, to deteriorate the physico-technological quality
`of parenteral Suspensions.
`A further advantage is given by the fact that as no relevant
`concentrations of buffers are needed, the formulation has
`low or no buffering capacity per Se and therefore, once
`administered, the pH of the formulation will be easily
`adjusted to the physiological value by the buffering capacity
`of body fluids.
`AS Stated above, the reduction in the quantity of conven
`tional buffering agents, Such as inorganic acid Salts,
`improves the physical stability of the formulation, since
`ionic Species tend to destabilize the formulations with det
`rimental effects on the re-Suspendibility and on the con
`trolled flocculation of the formulation.
`A further object of the invention is therefore to provide a
`pharmaceutical aqueous Suspension formulation for
`parenteral administration having Substantially Stabilized pH
`comprising a biologically active compound, a buffering
`agent and L-Methionine in concentrations effective to pro
`duce a pH controlling Super-additive effect.
`The present invention also provides the combined use of
`L-Methionine and a conventional buffering agent in con
`centrations effective to produce a pH controlling Super
`additive effect, in the preparation of a pharmaceutical aque
`ous Suspension formulation having Substantially Stabilized
`pH, for parenteral administration of a biologically active
`compound.
`The term “a buffering agent' is herein meant to comprise
`(unless otherwise specified) both a single buffering agent
`and a mixture of two or more thereof.
`The term “substantially pH stabilized” means that the pH
`of the formulation remains within acceptable limits for
`parenteral administration over the time, according to well
`known practice in the art. It also means that the pH of the
`formulation containing L-Methionine, or the combination of
`L-Methionine and a buffering agent in concentrations effec
`tive to provide a pH controlling Super-additive effect, is
`maintained over the time closer to the initial value than the
`pH of the “as is” formulation (i.e. the formulation without
`L-Methionine or the combination of L-Methionine and a
`buffering agent).
`The pH range for the suspension formulation of the
`invention is from about pH 3.0 to about pH 8.0, preferably
`pH 3.0 to pH 7.5, and most preferably pH 4.0 to pH 7.0.
`
`5
`
`15
`
`25
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`US 6,495,534 B2
`
`6
`A pH controlling effective concentration of L-Methionine,
`when used as a single pH controlling agent, may vary from
`about 0.005% w/v to about 5% w/v., preferably from about
`0.01% w/v to about 1.0% w/v.
`The pH controlling effective concentration of
`L-Methionine, when used as a combined pH controlling
`agent, may be Substantially the same as above.
`Thanks to the pH controlling properties of L-Methionine
`and the Superadditive pH controlling effect, which is obtain
`able by using L-Methionine in combination with a conven
`tional buffering agent, the concentration of the latter can be
`reduced by about 50% to about 95%. Namely the concen
`tration of the buffering agent can thus range from about 5%
`to about 50% of the usual buffering concentration thereof,
`preferably from about 5% to about 25%.
`The usual concentrations of conventional buffering agents
`employed in parenteral formulations can be found in: Phar
`maceutical Dosage Form: Parenteral Medications, Volume
`1, 2" Edition, Chapter 5, p. 194, De Luca and Boylan,
`“Formulation of Small Volume Parenterals', Table 5: Com
`monly used additives in Parenteral Products.
`According to Said literature, the usual buffering concen
`tration for phosphoric acid salts range from about 0.8% to
`about 2.0% w/v or w/w. On the contrary, thanks to the newly
`found Super-additive effect, the concentration of phosphoric
`acid Salts according to the formulation of the invention are
`lower than 0.4% w/w or w/v., preferably lower than 0.2%
`w/w or w/v.
`Re-suspendibility and controlled flocculation of the phar
`maceutical aqueous Suspension are thus improved.
`The pharmaceutical aqueous Suspension, according to the
`invention, may in addition also include one or more
`Surfactants, Suspending agents and/or thickening agents.
`Suitable Surfactants are for instance phospholipids (e.g.
`lecithin), cationic Surfactants (e.g. myristylgammapi
`colinium chloride), anionic Surfactants and non-ionic Sur
`factants (e.g. polySorbate 80).
`Suitable Suspending and/or density adjusting agents are
`for instance polyvinylpyrrolidone compounds and polyeth
`ylene glycols. Preferred examples of polyethylene glycols
`are those having a molecular weight from about 300 to about
`6000, e.g. polyethylene glycol 3350 and polyethylene glycol
`4000. Preferred polyvinylpyrrolidone (PVP) compounds
`according to the invention are those having a molecular
`weight from about 7000 to about 54000, for instance PVP
`K12, K17, K25 and K30, in particular K12 and K17, PVP
`K17 being the most preferred. According to a preferred
`embodiment of the invention, the pharmaceutical aqueous
`Suspension formulation of the invention in addition contain
`a suitable amount of a PVP compound, in particular K12 or
`K17, especially K17.
`Suitable thickening or Viscosity agents are for instance
`well known cellulose derivatives (e.g. methylcellulose,
`carboxymethylcellulose, hydroxyethylcellulose and
`hydroxypropylmethylcellulose), gelatin and acacia, in par
`ticular methylcellulose.
`In addition, the formulations of the present invention may
`also include metal chelating agents, antioxidants or thiol
`containing compounds and preservatives.
`Suitable metal chelating agents are for instance
`ethylenediamine-tetracetic acid salts (e.g. edetate disodium).
`Suitable antioxidants are for instance ascorbic acid
`derivatives (e.g. ascorbic acid, erythorbic acid, Sodium
`ascorbate), thiol derivatives (e.g. thioglycerol, cysteine,
`acetylcysteine, cystine, dithioerythreitol, dithiothreitol,
`
`Mylan v. Janssen (IPR2020-00440) Ex. 1008 p. 004
`
`

`

`US 6,495,534 B2
`
`8
`EXAMPLE 1.
`pH Stabilization of a parenteral aqueous Suspension of
`Exemestane (CAS: 6-Methylenandrosta-1,4-diene-3,17
`dione; other name: Androsta-1,4-diene-3,17-dione-6-
`methylene) by means of L-Methionine.
`Exemestane is an irreversible aromatase inhibitor, Struc
`turally related to the natural Steroid androstenedione and it
`is a molecule prone to oxidation. When performing an
`experimental Study, by adding different antioxidants to a
`10% Exemestane parenteral aqueous Suspension we have
`Surprisingly found out that L-Methionine can Stabilize the
`pH of the Suspension. In fact, the experimental data provided
`in Table 3 clearly demonstrate that in the suspension for
`mulation containing L-Methionine the pH reduction is mini
`mized in comparison with the “as is and that by adding
`L-Methionine, the pH of the suspension is stabilized at
`values above pH 4.5 even after 2 months storage at 55 C.
`What is outmost Surprising is that among the added
`antioxidants, only Methionine is effective in substantially
`controlling/stabilizing the pH of the Suspension (after 2
`months storage at 55 C. the pH decrease of the formulations
`containing ascorbic acid, and Sodium metabisulfite is in fact
`comparable or worse than the one experimented in the “as
`is” formulation).
`Therefore a simple antioxidant effect cannot explain the
`result obtained and the presence of a specific Stabilizer, Such
`as L-Methionine, is needed in order to prevent a dramatic pH
`decrease and Stabilize the parenteral aqueous Suspension.
`The present invention, however, is not intended to be
`limited to any particular theory of the exact mechanism of
`this substantial pH stabilization but relates to the fact that a
`substantial pH stabilization is obtained, to the unconven
`tional way through which this substantial pH stabilization is
`obtained and to its possible advantages.
`It is an advantage of the present invention that the pH of
`these Stabilized parenteral aqueous Suspensions does not
`dramatically decrease during Storage but, on the contrary, is
`maintained closer to the initial value (i.e. closer to
`neutrality) and therefore these stabilized Suspensions can be
`Safely administered without generating Significant pain on
`patients.
`
`7
`gluthathione), tocopherols, butylated hydroxyanisole, buty
`lated hydroxytoluene, Sulfurous acid Salts (e.g. Sodium
`Sulfate, Sodium bisulfite, acetone Sodium bisulfite, Sodium
`metabisulfite, sodium sulfite, sodium formaldehyde
`Sulfoxylate, Sodium thiosulfate) and nordihydroguaiareti
`cacid.
`Suitable preservatives are for instance phenol,
`chlorobutanol, benzylalcohol, methyl paraben, propyl
`paraben, benzalkonium chloride and cetylpyridinium chlo
`ride.
`In addition, the formulations of the present invention may
`also include tonicity-adjusting agents. Suitable tonicity
`adjusting agents are for instance Sodium chloride, Sodium
`Sulfate, dextrose, mannitol and glycerol.
`The formulations of the present invention may also have
`a nitrogen blanket overlay on the head-space of the Vial.
`Additionally, the formulations of the present invention may
`include purging the formulation buffer with helium, argon,
`or nitrogen.
`When the formulation of the invention, besides
`L-Methionine, contains also buffering agents, useful buffers
`include e.g. those derived from acetic, aconitic, citric,
`glutaric, lactic, malic, Succinic, phosphate and carbonic
`acids, as known in the art. Typically employed is an alkali
`or alkaline earth Salt of one of the aforementioned acids.
`Phosphate and citrate buffers, Such as phosphoric acid or a
`pharmaceutically acceptable Salt thereof, or citric acid or a
`pharmaceutically acceptable Salt thereof, are preferred.
`Sodium phosphate or sodium citrate is the preferred buff
`ering agents, with Sodium phosphate being most preferred.
`The pharmaceutical aqueous Suspension according to the
`invention is e.g. for intramuscular, Subcutaneous and intra
`dermal administration, preferably for intramuscular and
`Subcutaneous administration.
`A biological active compound according to the invention
`is any compound that after administration to a mammal,
`including humans, provides a therapeutic effect. Preferably
`it is a Steroidal biologically active compound.
`Asteroidal biologically active compound according to the
`invention is the Steroidal compound itself or, when
`appropriate, a pharmaceutically acceptable Salt thereof as
`known in the art, e.g. medroxyprogesterone acetate,
`exemestane, estradiol cypionate, methylprednisolone
`acetate, Oxabolone cypionate, clostebol acetate, testosterone
`cypionate; preferably medroxyprogesterone acetate, estra
`diol cypionate and exemestane, or a combination of two or
`more thereof according to the art.
`Concentrations of medroxyprogesterone acetate in the
`formulation can range from about 1% w/v to about 40% w/v,
`preferably from about 3% w/v to about 30% w/v.
`Concentrations of estradiol cypionate in the formulation
`can range from about 0.1% w/v to about 5% w/v., preferably
`from about 0.25% w/v to about 2.5% w/v.
`When a combination of estradiol cypionate and medroX
`yprogesterone acetate is the active ingredient of the phar
`maceutical preparation of the invention, the amounts of Such
`compounds present in the pharmaceutical preparation are
`Substantially as here above.
`Concentrations of exemestane in the formulation can
`range from about 1% w/v to about 25% w/v., preferably from
`about 5% w/v to about 20% w/v.
`The Steroidal biologically active compound is preferably
`in milled or micronized form according to the common
`practice.
`The pH controlling activity of L-Methionine either alone
`or in combination with a conventional buffer is shown for
`instance by the following examples.
`
`15
`
`25
`
`35
`
`40
`
`45
`
`50
`
`TABLE 3
`
`pH study of a 10% Exemestane parenteral aqueous suspension
`formulation containing different antioxidants.
`Suspension composition (batch 13833/11): Exemestane 10%,
`methylparaben 0.18%, propylparaben 0.02%, sodium chloride 0.9%,
`PEG 4000 3.0%, polysorbate 80 0.2%, sodium hydroxide
`9.S. to pH 6.0–6.5 , WFI q.S to 100 ml.
`
`A: as is
`
`6.02
`4.28
`
`4.03
`
`55
`
`Time zero
`1 month at
`55° C.
`2 months at
`55° C.
`
`B: +
`Ascorbic
`Acid
`
`D: +
`Sodium
`Metabisulfite
`
`E: +
`L-Methionine
`
`6.40
`4.20
`
`4.18
`
`6.47
`2.30
`
`2.50
`
`6.OO
`4.86
`
`4.74
`
`60
`
`65
`
`EXAMPLE 2
`pH and technological quality (re-Suspendability,
`Syringeability) Stabilization of a medroxyprogesterone
`acetate parenteral aqueous Suspension by means of
`L-Methionine used alone or in combination with low and
`unconventional concentrations of phosphate buffer.
`
`Mylan v. Janssen (IPR2020-00440) Ex. 1008 p. 005
`
`

`

`9
`AS previously shown in Table 2, the use of a conventional
`buffering agent, Such as Phosphate buffer, in usual effective
`concentrations (approx. 1%) in order to stabilize the pH of
`a medroxyprogesterone acetate aqueous Suspension has a
`detrimental effect on the Suspension technological quality,
`i.e. resuspendability and Syringeability.
`In this example, outlined in Table 4 (Tables 4a and 4b), it
`is evident that the pH of the Same type of Suspension can be
`controlled/stabilized by using L-Methionine alone or by a
`combination of L-Methionine with a lower and unusual
`concentration of phosphate buffer (approx. 0.1%). In fact,
`when L-Methionine is used alone, as in the case of batch
`13451/47-I, a substantially stabilized pH is obtained.
`Besides, when L-Methionine is used in combination with
`a low unusual concentration of Phosphate buffer (approx.
`0.1%) a synergistic effect is obtained.
`In fact, as clearly shown in the case of batch 13451/47-C,
`when an unusually low concentration of phosphate buffer
`(approx. 0.1%) is used, no significant pH stabilization is
`obtained vs. the “as is' formulation.
`On the contrary, when the same low unusual concentra
`tion of phosphate buffer (approx. 0.1%) is used in combi
`nation with L-Methionine, as in the case of batch 13451/
`84-D, a Surprising Super-additive effect is obtained in
`controlling/stabilizing the pH of the formulation.
`Besides, when L-Methionine is used alone or in combi
`nation with a low unusual amount of phosphate buffer, no
`negative effect is produced on the Suspension's technologi
`cal quality, thus allowing the achievement of a pH Stabilized
`medroxyprogesterone acetate Suspension with good
`re-Suspendability and Syringeability properties that are
`maintained during Storage.
`On the contrary, when a usual effective concentration of
`phosphate buffer (approx. 1%) is used in order to stabilize
`the pH, as in the case of batch 13451/47-G, a detrimental
`effect on the physical stability of the formulation is obtained.
`It is an advantage of this invention that the pH of
`parenteral aqueous Suspensions can be Substantially Stabi
`lized without using effective usual concentrations of con
`ventional buffering agents, i.e. typically inorganic or organic
`acid Salts, thus avoiding Some Substantial drawbacks, Such
`as the profound effects caused by ionic Species, and espe
`cially by polyvalent ions, on the nature and the Stability of
`flocculated Suspensions, with detrimental effects on Suspen
`Sion re-Suspendability and Syringeability.
`
`TABLE 4
`pH, resuspendability and syringeability study of a 20%
`Medroxyprogesterone Acetate (MPA) parenteral aqueous suspension
`formulated with different amounts of L-Methionine and Phosphate buffers.
`Suspension composition:
`
`Medroxyprogesterone Acetate 20%, MyristylGammaPicoliniumChloride
`0.1% (batch 13451/84) or 0.2% (batch 13451f47), sodium sulphate 1.1%,
`PEG 3350 2.03%, sodium hydroxide q.s. to pH 6.5, WFI q.s to 100 ml.
`
`13451f47-C 13451f47-G
`Phosphate ~ Phosphate ~
`O.1%
`1%
`(0.0066 M) (0.066 M)
`
`13451f47-I
`L
`Methionine
`0.5%
`
`13451f47-A
`as is
`
`pH
`
`Time zero
`65° C.: 10 days
`65° C.: 15 days
`65° C.: 1
`month
`
`6.O7
`2.85
`2.82
`2.88
`
`6.35
`3.03
`2.97
`3.06
`
`6.33
`:
`:
`5.13*
`
`6.11
`5.29
`5.13
`4.76
`
`US 6,495,534 B2
`
`TABLE 4-continued
`
`13451f84-B 13451f84-C
`L-
`L-
`13451f84-A Methionine
`Methionine
`as is
`O.1%
`0.25%
`
`13451f84-D
`L
`Methionine
`O.1%
`--
`Phosphate ~
`O.1%
`(0.0066 M)
`
`6.10
`3.OO
`2.89
`3.01
`
`6.04
`4.49
`4.30
`3.83
`
`5.94
`5.28
`4.88
`4.55
`
`6.31
`5.92
`6.25
`6.2O
`
`resuspend-
`able
`(15s)
`
`resuspend-
`able
`(13s)
`
`resuspend-
`able
`(15s)
`
`Resuspend
`able (14s)
`
`meets test
`
`meets test
`
`meets test
`
`Meets test
`
`15
`
`PH
`
`Time zero
`65° C.: 10 days
`65° C.: 15 days
`65° C.: 1
`month
`Resuspend
`ability
`
`65° C.: 1
`month
`
`Syringeability
`
`65° C.: 1
`month
`
`25
`
`Phosphate Buffers (M = molar) approx. 0.1%
`
`approx. 1%
`
`mg 694/100 ml
`Monobasic Sodium Phosphate mg 69.4/100 ml
`(0.05 M)
`1 H2O (MW 137.99)
`(0.005 M)
`mg 588/100 ml
`Dibasic Sodium Phosphate
`mg 58.8/100 ml
`(0.016 M)
`12 H2O (MW 358.14)
`(0.0016 M)
`* not resuspendable by manual wrist shaking, pH measured after mixing
`the suspension with a spatula
`Resuspendability: In brackets the time of manual wrist shaking requested
`in order to obtain a homogeneous suspension (s = seconds).
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`EXAMPLE 3
`
`pH Stabilization of a medroxyprogesterone acetate and
`estradiol cypionate pare