Intraventricular drug delivery system for improving outcome after a brain injury affecting cerebral blood flow

1. A method of treating a delayed complication of a brain injury that deposits blood in a subarachnoid space of the brain, wherein the brain injury is mediated by decreased cerebral perfusion, comprising:

a) providing a microparticulate composition comprising

(i) a microparticulate suspension comprising a therapeutic amount of at least one therapeutic agent selected from the group consisting of a calcium channel antagonist, an endothelin (ET) receptor antagonist, and a transient receptor potential (TRP) channel antagonist, wherein the microparticulate formulation comprises a plurality of microparticles of a uniform distribution of microparticle size, and wherein each microparticle comprises a matrix,

(ii) and a pharmaceutical carrier comprising an agent that affects viscosity of the suspension,

the composition being characterized by

1) dispersal of the at least one therapeutic amount of the therapeutic agent throughout each microparticle,

2) the therapeutic amount is effective to improve cerebral perfusion and to treat the delayed complication comprising a delayed cerebral ischemia (DCI) comprising an angiographic vasospasm, formation of a plurality of microthromboemboli, a cortical spreading ischemia, or a combination thereof;

3) gradual release of the therapeutic agent from the composition over an extended period of time, and

4) its flowability around at least one cerebral artery in the subarachnoid space; and

b) administering the composition locally into a cerebral ventricle so that the microparticulate suspension flows from the cerebrospinal fluid (CSF) in the cerebral ventricle into the cerebrospinal fluid (CSF) in the subarachnoid space before releasing the therapeutic agent in the subarachnoid space without entering systemic circulation in an amount to cause unwanted side effects.

2. The method according to claim 1 , wherein the at least one therapeutic agent is a calcium channel antagonist selected from the group consisting of an L-type voltage dependent calcium channel inhibitor, an R-type voltage dependent calcium channel inhibitor, an N-type voltage dependent calcium channel inhibitor, a P/Q-type voltage dependent calcium channel inhibitor, a T-type voltage dependent calcium channel inhibitor, or a combination thereof.

3. The method according to claim 2 , wherein the L-type voltage dependent calcium channel inhibitor is a dihydropyridine, selected from the group consisting of amlodipine, aranidipine, azelnidipine, bamidipine, benidipine, cinaldipine, efonidipine, felodipine, isradipine, lacidipine, lemildipine, lercanidipine, nicardipine, nifedipine, nilvadipine, nimodipine, nisoldipine, nitrendipine, manidipine, pranidipine, or a combination thereof.

4. The method according to claim 3 , wherein the dihydropyridine is nimodipine.

5. The method according to claim 1 , wherein the microparticulate suspension comprises a powder suspension of microparticles.

6. The method according to claim 1 , wherein the microparticulate suspension further comprises a slow-release compound.

7. The method according to claim 6 , wherein the slow release compound is a biodegradable polymer.

8. The method according to claim 7 , wherein the biodegradable polymer is selected from the group consisting of polylactide-polyglycolide, poly(orthoester), and poly(anhydride).

9. The method according to claim 1 , wherein administering occurs via an injection apparatus.

10. The method according to claim 9 , wherein the injection apparatus is a needle, a cannula, a catheter, or a combination thereof.

11. The method according to claim 1 , wherein one-half of the therapeutic amount of the therapeutic agent is released within 1 day to 30 days from delivery of the composition to the cerebral ventricle.

12. The method according to claim 1 , wherein the cerebral ventricle is at least 0.001 mm from the cerebral artery in the subarachnoid space.

13. The method according to claim 12 , wherein the cerebral ventricle is a lateral ventricle, a third ventricle, a fourth ventricle, or a combination thereof.

14. The method according to claim 1 , wherein the flowable sustained release microparticulate composition produces a predominantly localized effect around a cerebral artery in the subarachnoid space.

15. The method according to claim 1 , wherein the therapeutic amount of the therapeutic agent is effective to increase the internal diameter of a cerebral artery in the subarachnoid space.

16. The method according to claim 1 , wherein the pharmaceutical carrier comprises a buffer solution.

17. The method according to claim 1 , wherein the brain injury comprises a subarachnoid hemorrhage.

18. The method according to claim 1 , wherein the agent that affects viscosity of the suspension is hyaluronic acid.

19. The method according to claim 1 , wherein the microparticles have a diameter ranging from about 25 μm to about 100 μm.