Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Particulate form
Patent
1996-05-01
2000-01-11
Webman, Edward J.
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Particulate form
514951, 514952, 428403, 427 214, 427212, A61K 916
Patent
active
060132841
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to new types of particles which can be used alone or as vectors for various compounds. It also relates to a process for the preparation of particulate vectors which makes possible improved control of the active principle charging.
Supramolecular biovectors or SMBVs are particles which are biomimetic of the endogenous vectors of the body and which are capable of encapsulating and of carrying a large number of active principles for, in particular, pharmaceutical, cosmetic or agribusiness use.
A first type of SMBV was described in Application EP 344,040. Their structure is very well suited to the role of vector, in particular as a result of the possibility of modifying their size and their composition according to the molecule or molecules transported and their use.
SMBVs are synthesized in three successive steps: polysaccharide, which can be derived by ionic groups and brought, in particular by ultramilling, to the desired size (between 10 nanometers and a few microns, according to the desired use) periphery of the central core, in order to confer a peripheral hydrophobic nature on the latter while retaining its internal hydrophilic nature particular of phospholipids or of ceramides, sometimes with the addition of other constituents, for example of constituents of biological membranes.
The active principles, according to their physicochemical characteristics, can be transported either in the external lipid lamellae (in the case of lipophilic or amphiphilic compounds) or within the hydrophilic core (in the case of polar compounds).
Encapsulation of active principles of polar nature can take place, according to the structure of the latter, either before formation of the fatty acid ring or between this step and stabilization of the external lamella.
Despite their suitability for many uses, the synthesis of SMBVs can sometimes cause problems and in particular: acid ring; carried out homogeneously, which requires in particular a prior drying step, under very specific conditions; acid ring, some of these molecules, localized, after their encapsulation, at the periphery of the core, can be derived by the fatty acid, leading to modification of the properties of this active principle; acid ring, the latter can be detrimental to the penetration of the active principle into the hydrophilic core.
The Applicant Company has shown that, surprisingly, in certain applications, it was possible to scale down the reaction scheme by not grafting the ring of fatty acids to the periphery of the crosslinked hydrophilic core.
The Applicant Company has shown that the polysaccharide particles thus obtained could be used as is. They are then named PS-type SMBVs, by analogy with supramolecular biovectors.
The Applicant Company has indeed shown that the polysaccharide particles, even of small size, could be used provided that suitable charging protocols are adopted.
They can also be used in combination with natural amphiphilic compounds, in particular phospholipids, and the Applicant Company has shown that the external lipid lamellae can possibly be arranged around this core in the absence of a grafted fatty acid ring as in the case of SMBVs. These particles have a supramolecular nature and are known as L-type SMBVs.
This is why the subject of the present invention is a synthetic particulate vector, characterized in that it comprises: compounds, combined with the core via hydrophobic interactions and/or ionic bonds, or by the external ring of the hydrophilic core, by using a special process which avoids encapsulation of the active principle in this ring and which concentrates the active principle in the internal part of the core.
The notion of vector must, in this instance, be understood within the broad meaning, that is to say that it comprises particles having a support role, for example when they are incorporated in a composition, either as such or for the transportation, the presentation and/or the stabilization of active compounds.
A non-liquid hydrophilic core (or matrix) can be a hydrophilic polymer.
REFERENCES:
patent: 5145684 (1992-09-01), Liversidge et al.
patent: 5188837 (1993-02-01), Domb
patent: 5607695 (1997-03-01), Ek et al.
patent: 5670172 (1997-09-01), Buxton et al.
Cervilla Monique
De Miguel Ignacio
Delrieu Pascal
Ding Li
Dirson Roselyne
Biovector Therapeutics S.A.
Webman Edward J.
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