Oily compositions

Abstract

Pharmaceutical compositions comprising embolic particles, that optionally comprise pharmaceutical actives, in oil or emulsion formulations that are useful in therapeutic embolization procedures, particularly for the treatment of vascularised neoplasias, such as liver carcinomas.

Claims

1. A pharmaceutical composition comprising a water in oil emulsion including an aqueous phase and an oily phase, the oily phase containing a halogenated oil and the aqueous phase containing one or more embolic particles formed from a hydrogel polymer, wherein the embolic particles are at least partially rehydrated in the aqueous phase of the emulsion.

2. A pharmaceutical composition according to claim 1 wherein the halogenated oil is an iodized ethyl-ester of the fatty acids of poppy seed oil.

3. A pharmaceutical composition according to claim 1 wherein the embolic particles comprise a pharmaceutical active.

4. A pharmaceutical composition according to claim 1 wherein the ratio of halogenated oil to aqueous phase is >1:1 (V/V).

5. A pharmaceutical composition according to claim 1 wherein the specific gravity of the aqueous phase is between 1.15 and 1.35.

6. A pharmaceutical composition according to claim 1 wherein the specific gravity of the particle is between 1.0 and 1.5.

7. A pharmaceutical composition according to claim 1 wherein the embolic particles comprise a polymer selected from polyvinyl alcohol (PVA), cross linked PVA, PVA-2-acrylamido-2-methylpropanesulfonic acid (PVA-AMPS), and PVA co-sodium acrylate.

8. A pharmaceutical composition according to claim 1 wherein the ratio of halogenated oil to embolic particles is between 100:1 and 1:1 vol/vol.

9. A process for the preparation of a pharmaceutical water in oil emulsion comprising: providing a plurality of embolic particles formed from a hydrogel polymer, an oily phase including a halogenated oil, and an aqueous phase including a pharmaceutical active; and emulsifying them to provide an emulsion, wherein the embolic particles are in the aqueous phase with the pharmaceutical active.

10. A process for the preparation of a pharmaceutical emulsion according to claim 9, comprising the steps of: a) providing a plurality of dried embolic particles; b) contacting the dried embolic particles with a halogenated oil to form a halogenated oil:embolic particle mixture; c) contacting the halogenated oil:embolic particle mixture with an aqueous solution of a pharmaceutical active; and d) emulsifying the composition of c).

11. A process for loading a pharmaceutical active into an embolic particle comprising: a) providing a dried embolic particle; b) contacting the dried embolic particle with a halogenated oil; c) contacting the composition of b) with an aqueous solution of a pharmaceutical active.

12. A process for preparing an embolic composition, comprising the steps of: a) providing a plurality of dried embolic particles; b) contacting the dried embolic particles with a halogenated oil to form a halogenated oil: embolic particle mixture; c) contacting the halogenated oil: embolic particle mixture with a sufficient amount of an aqueous solution of a pharmaceutical active to at least partially rehydrate the embolic particles; and d) allowing the embolic particles to take up the aqueous solution to provide an embolic composition.

13. A method of treatment of a patient in need of therapy by embolization of a tissue having a blood vessel, comprising: a) providing an emulsion according to claim 1; and b) delivering the emulsion to said blood vessel to embolise the tissue.

14. A pharmaceutical composition prepared by the method of claim 9.

15. An embolic particle prepared by a method according to claim 11.

16. A kit for preparing an emulsion composition according to claim 1, the kit comprising a sterilized preparation comprising a plurality of embolic particles in a sealed vessel and instructions as to how to prepare said composition.

17. A kit according to claim 16 wherein the embolic particles are dried embolic particles.

18. A kit according to claim 16 wherein the particles are dried embolic particles, which take up a packed volume of between 1 and 5 mls when fully hydrated with 1mM sterile phosphate buffered physiological saline.

19. A method of tissue embolization, comprising administering a patient in need of therapy by embolisation of a tissue a composition according to claim 1.

Description

FIGURES

(1) FIG. 1 illustrates the uptake of doxorubicin into PVA-AMPS hydrogel embolic beads in the presence of Lipiodol.

(2) FIG. 2 illustrates the elution of doxorubicin from emulsions prepared using mannitol-dried PVA-AMPS hydrogel beads (100-300 um), DC-beads, which are hydrated PVA-AMPS hydrogel beads (100-300 um) and control Lipiodol emulsions.

(3) FIG. 3. illustrates a device for preparing an oily composition.

EXAMPLES

Example 1

(4) Preparation of dried embolic beads: Commercially available PVA-AMPS hydrogel microbeads (LC Bead Biocompatibles UK Ltd, Farnham, UK2 ml beads packed volume (100-300 um) in 8 ml 1 mM physiological phosphate buffered saline (PBS)) were removed from the suspension medium and resuspended in 10% D-mannitol. After equilibration, the supernatant was removed by aspiration and the beads lyophilised. A second batch of beads were lyophilised as above, without mannitol.

Example 2

(5) Suspension of Embolic Beads in Lipiodol:

(6) Sample 1. A vial of lyophilised mannitol-dried embolic beads prepared as per example 1 was resuspended in 4 ml of Lipiodol Ultra Fluide (Guerbet (Lipiodol)) by gentle shaking and allowed to stand for a few minutes to absorb the Lipiodol.

(7) Sample 2. The packing solution was completely removed from one vial of LC-beads (100-300 um). Four millilitres of Lipiodol was added and mixed by gentle shaking. Phase separation between remaining water and Lipiodol was observed immediately, with clumps of beads.

(8) Upon microscopic examination, the lyophilised beads (sample 1) were observed to be transparent and evenly dispersed in the Lipiodol. The beads from sample 2 were found to be almost entirely present in the water phase.

Example 3

(9) Bead loading: 2 ml of a 25 mg/ml solution of doxorubicin was added to each sample from example 2 and gently agitated.

(10) The mannitol-dried beads (sample 1) rapidly absorbed almost all the doxorubicin solution and formed a slurry which separated from the Lipiodol layer. A sample of the bead phase showed bright red beads and occasional small water droplets.

(11) The preparation of sample 2 however, separated out into 3 layers, a lower oil phase, an intermediate doxorubicin bead layer and a top layer of depleted doxorubicin solution.

(12) A sample of the beads from samples one and two were then gently pipetted below the surface of a volume of de ionised water. Many of the beads of sample 2 dispersed in the water as they sank, indicating a tendency to disperse in the blood, whilst those of sample 1 (made with lyophilised beads) sank to the bottom of the water in the oil droplet and did not disperse.

Example 4

(13) Emulsion: Omnipaque 350 (GE HealthcareOmnipaque)) was mixed 50:50 with water and 4 ml of this solution was added to each vial from example 3. The contents of each vial was then transferred to a 20 ml syringe and all air removed. Emulsions were prepared by passage back and forth between two 20 ml syringes (BD Luer-Lok Tip) through a three way stainless steel stopcock until the characteristic sound of emulsification ceased and a smooth stable emulsion was formed. This took approximately 20 passages.

(14) A volume of the emulsion was gently dispensed below the surface of de ionised water through a needle. Beads began to disperse from the emulsion prepared from sample 2 (DC Bead) within one to two minutes, but not from that prepared from sample 1, prepared with mannitol-dried beads.

Example 5

(15) Observations on the effect of lipiodol on the rate of loading of PVA-AMPS Hydrogel Embolic Beads: 10 ml of Lipiodol was added to one vial of dried beads (100-300 um, both mannitol-dried and non mannitol-dried) prepared according to example 1. The vial was set aside for 10 min. Once the lipiodol was loaded into the dried beads, 2 ml of a 25 mg/ml solution of doxorubicin HCl was added to the vial and briefly gently mixed. Aliquots of 50 of aqueous phase were removed periodically and diluted to 1 ml with water. Care was taken not to remove Lipiodol. The experiment was repeated in the absence of Lipiodol.

(16) The dried bead preparations above were compared to similar preparations using hydrated beads. The packing solution was removed from a vial of DC Beads (100-300 um) by aspiration. Ten millilitres of Lipiodol was added and gently mixed with the beads and the mixture set aside for 10 minutes. Two millilitres of 25 mg/ml doxorubicin was added to the vial. Aliquots of 5l were removed and assayed as before. The experiment was repeated in the absence of Lipiodol.

(17) The absorbance of the diluted samples at 483 nm was determined and converted to % maximal absorbtion by the beads.

Example 6

(18) Preparation of Lipiodol Emulsions

(19) A. 10 ml of Lipiodol was added to one vial of dried beads (100-300 um) prepared according to example 1. Following gentle mixing and equilibration, 2 ml of 25 mg/ml doxorubicin HCl solution and 6 ml of Omnipaque 350 was added (density of aqueous phase 1.27). The composition was emulsified by rapidly passing between a 20 ml syringe and a 5 ml syringe through a three way tap, 20 times. Microscopic examination showed a water in oil emulsion with doxorubicin loaded beads in the water phase.

(20) B. The packing solution was removed from one vial of DC beads and replaced with 10 ml of Lipiodol. 2 mls of 25 mg/ml doxorubicin HCl was then added. Beads immediately began taking up the drug. After shaking, 6 ml of Omnipaque 350 was added and the composition vigorously mixed between two syringes as above. Microscopic examination showed a water in oil emulsion with doxorubicin loaded beads in the water phase.

(21) C. Beads of 40-90 um size range: PVA-AMPS embolic beads were prepared according to U.S. Pat. No. 7,442,385 example 1, High AMPS formula and sieved to provide beads between 40 and 90 um in diameter. The beads are aliquoted to provide 2 ml packed volume of the beads in 8 ml of 1 mM sterile phosphate buffered physiological saline for storage. For use, the PBS storage solution was aspirated and the beads were then either used as is, or used to prepare mannitol dried beads as per example 1.

(22) D. Emulsion using Mannitol dried beads of 40-90 um. 10 ml of Lipiodol was added to one vial of mannitol-dried beads (40-90 um) prepared according to C above and mixed to provide a uniform suspension. Following equilibration, 2 ml of 25 mg/ml doxorubicin HCl solution was added followed by 6 ml of Omnipaque 350. The beads retained almost all the doxorubicin solution. A uniform suspension was seen after mixing, which settled out after 2 mins. 2 ml additional water was added and the mixture was transferred to a 20 ml syringe. The composition was emulsified as above. The emulsion was stable for 7-8 minutes (ie separation of the phases was first noted at this point).

(23) E. Emulsion using hydrated beads of 40-90 um. This emulsion was prepared in the absence of Omnipaque. The packing solution was removed from one vial of 40-90 um beads prepared according to C above and 10 ml of Lipiodol added. The beads were mixed with the Lipiodol to form a uniform suspension and 2 ml of 25 mg/ml doxarubicin added. An emulsion was prepared as above. The beginning of phase separation was observed after 4 mins.

Example 7

(24) Comparison of Lipiodol emulsions with emulsions containing embolic particles.

(25) A lipiodol emulsion was prepared as follows: 10 ml of Lipiodol was taken up in a 20 ml syringe. 2 ml of doxorubicin HCl solution (25 mg/ml) was then taken up followed by 6 ml of Omnipaque. All the three components were mixed well (20 times) by passage through a 3 way connector (BD Connecta) back and forth into a 5 ml syringe to produce a smooth emulsion.

(26) The experiment was repeated incorporating either mannitol-dried beads prepared according to example 1 or hydrated DC-beads

(27) To a vial of dried beads (100-300 um) prepared according to example 1, 10 ml of lipiodol was added and mixed well to provide a suspension of Beads in Lipiodol. The vial was set aside for 10 min. Once the Lipiodol was loaded into the beads, 2 ml of doxorubicin HCl (25 mg/ml) was added and the vial set aside for drug loading for 5 mins. Following drug loading 6 ml Omnipaque was added to the vial. All the components of vial were then transferred to a 20 ml syringe and emulsified as before to get smooth emulsion.

(28) Following complete removal of the packing solution from a vial of DC beads (100-300 um), 10 ml of Lipiodol was added and mixed well to provide a suspension of beads in lipiodol. The vial was then set aside for 10 mins. DC beads are a hydrogel, which comprises approximately 95% water. In a vial containing 2 ml packed volume beads, the volume of water is approximately 0.9 ml, when interstitial packing solution is removed.

(29) After 10 mins, 2 ml of 25 mg/ml doxorubicin HCl solution was added. The contents of the vial was then transferred to a 20 ml syringe, 6 ml of Omnipaque was added to the syringe and the contents emulsified as before.

(30) Following emulsification, each syringe was then stood upright, with the tip pointing upwards and observed over the next 50 minutes.

(31) The Lipiodol emulsion remained stable over 50 minutes with no observed phase separation.

(32) In the syringe holding the emulsion made with the dried beads, phase separation was just visible at the top and bottom of the preparation after 15 min and clear after 20 mins, whilst in the vial made with hydrated beads, the beginning of phase separation was evident after 7 mins. Table 1 summarises the observations.

(33) Initial samples from each were introduced below the surface of a volume of phosphate buffered saline pH7.4 through a Terumo 2.4Fr catheter. The standard Lipiodol emulsion rapidly dissipated releasing the doxorubicin into the solution. Emulsion prepared using mannitol-dried beads remained as a droplet below the surface, very few beads separated from the droplet. Emulsions prepared using DC bead also remained as a droplet, however significantly more beads were dispersed in the saline.

Example 8

(34) Comparison of the Elution of Doxorubicin from Emulsion

(35) A beaker was set up containing 400 ml of phosphate buffered saline pH7.4 (PBS) at room temperature and a magnetic stirrer bar. The beaker was placed on a magnetic stirrer. Emulsions were prepared according to example 7 and the complete sample was immediately gently introduced below the surface of the saline and gentle stirring commenced. 5 ml samples of PBS were removed at intervals and replaced with fresh PBS. The samples were centrifuged to separate any Lipiodol contamination and the concentration of doxorubicin in the sample determined by absorbance at 483 nm. FIG. 2 illustrates the elution of doxorubicin over the first 2 hrs.

(36) Almost all the doxorubicin present was very rapidly eluted from the standard Lipiodol emulsion. Much less doxorubicin was eluted from the bead-containing emulsions in the same time period.

(37) TABLE-US-00001 TABLE 1 Observations on Lipiodol emulsions prepared with and without embolic particles. Volume of Separated Phase Emulsion Emulsion prepared prepared with Time Lipiodol with mannitol-dried hydrated DC (min) Emulsion beads Bead 0 None None None 2-3 None None None 5 None None None 7 None None top = 0.5 ml Bottom = 0 10 None None Top = 6-7 ml, Bottom- = 2 ml 15 None phase separation just Top = 6-7 ml, visible at top and Bottom- = 4 ml bottom 20 None top = 0.5 ml. Top = 8 ml, bottom = 0.5 ml. Bottom- = 5 ml 25 None Top = 1 ml. Top = 8 ml, Bottom = 1 ml. Bottom- = 5 ml Increase in emulsion droplet size in the middle layer. 30 None Top = 1 ml. Top = 8 ml, Bottom = 2 ml. Bottom- = 5 ml Increase in emulsion droplet size in the middle layer. 50 None Top = 1.5 ml. Bottom = 4 ml. Increase in emulsion droplet size in the middle layer.

Example 9

(38) Ten mls of Lipiodol were mixed with 2.2-2.3 mls of dried PVA-AMPS beads (no manitolsize 70-150 um) and transferred to a syringe. Doxorubicin solution (25 mg/ml) and contrast (Omnipaque 350specific gravity 1.406) were mixed with this composition to provide various ratios of lipiodol to aqueous phase and specific gravities of aqueous phase. Doxorubicin solution was added first to the bead/lipiodol composition and gently mixed until the majority of the doxorubicin was taken up into the bead (over a 40 minute period, approximately 80% of the doxorubicin had been taken up into the beads).

(39) Following vigorous mixing between two syringes as described above, the syringe was held upright to determine the time for 25% of the lipiodol phase to settle out (stability measure). Samples from each were introduced below the surface of a volume of phosphate buffered saline pH7.4 through a Terumo 2.4Fr catheter and observations on the behaviour of the emulsion were made and scored according to the scheme below.

(40) TABLE-US-00002 TABLE 2 Key to scoring of Example 9 SCORE STABILITY SALINE DROP SCORE + 1-2 min.sup. Loose beads with stream of oil. Few beads associated with the oil. ++ 2-3 mins Stream oil with some beads associated with the oil. Some loose beads +++ 3-5 mins Stream of oil with beads mainly associated with the oil. Droplet formation with beads within the droplet and migration to the aq. interface. Or significanlt on the outside Oil droplets disintegrate rapidly ++++ 5-10 mins Mainly Oil droplets formed with streams of oil with beads. Droplet formation with beads mainly within the droplet Beads within stream are visually bound within the oil steam Oil droplets sometimes hold together +++++ >10 mins Mainly Oil droplets formed with streams of oil with beads. Beads within stream are visually bound within the oil steam Oil droplets may hold together. Beads aggregate towards the oil

(41) TABLE-US-00003 TABLE 3 Observations on emulsions from Example 9 Specific gravity Lipiodol Lipiodol:aqueous of aqueous Saline (ml) ratio phase* Stabiliy drop test 10.00 10.4 1.30 +++++ +++ 10.00 10.3 1.30 +++++ +++ 10.00 10.45 1.30 +++++ ++ 10.00 10.6 1.27 ++++ ++ 10.00 10:2 1.30 +++ +++++ 10.00 10:6 1.27 ++++ ++ 10.00 10:5 1.24 +++ +++ 10.00 10:4 1.2 ++ ++++ 10.00 10:4.5 1.22 ++ +++ 10.00 10:3.5 1.17 + ++++ *excludes contribution from doxorubicin