Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Particulate form
Patent
1995-06-16
1998-08-11
Phelan, D. Gabrielle
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Particulate form
242470, 242490, 242449, 242458, 242491, A61K 914
Patent
active
057924740
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/EP93/01289 filed May 21, 1993.
FIELD OF THE INVENTION
The present invention is concerned with a process for the production of pharmaceutical compositions with retarded liberation of active materials. More specifically, a mixture of an active material, and a low and high melting lipid or lipoid components are introduced by means of an extruder screw conveyor into a preheated extruder and brought to a temperature which is at most 4.degree. C. above the melting temperature of the low melting component at a pressure of 200 to 600 kPa (N/m.sup.2). The mass is extruded through a nozzle plate with a nozzle diameter of 1.2 to 4 mm and subsequently cooled and, if desired, granulated.
BACKGROUND
From EP0 043,254 is a known process for the production of pharmaceutical compositions with a retarded release of active materials which is based upon a selective melting process of at least two lipid or lipoid components which have a retarding action for pharmaceutically active materials mixed with these components. Retarded release, or a more commonly referred to as sustained release, concerns the timed control of the liberation of active materials from active-material containing compositions and especially from pharmaceutical compositions. Retarded release compositions, therefore, achieve a prolongation of the period of action and avoid too quick and/or too concentrated a release of the active materials in the compositions, and too high of peaks of the blood or tissue levels, which can lead to undesirable side effects.
The process is characterized in that finely divided, high melting lipid or lipoid component but also with a finely divided, low melting lipid or lipoid component, the weight ratio of the two lipid or lipoid components thereby being in the range of from 1:5 to 5:1; is brought to a temperature which lies above the melting point of the low melting component but below the melting point of the high melting component, the active material and the high melting lipid or lipoid component thereby being uniformly dispersed in the molten low melting lipid or lipoid component; is allowed to cool below the melting point thereof; and the statements "low melting" and "high melting" thereby being used with reference to the relationship to one another without including any particular melting points.
Although it has already proved to be technically useful, the said process has certain disadvantages which, in particular, impede a continuous and automatically controlled production process. Thus, hitherto, it has not been possible to carry out the melting process continuously. In the Patent Specification, it is admittedly suggested, inter alia, to bring about the melting of the low melting component solely by means of the frictional heat of an extruder and, in this way, to omit a separate heating of the mixture. However, experiments recently carried out have shown that the frictional heat of an extrusion process is not sufficient completely to melt the low melting component. Therefore, the extrudate obtained is inhomogeneous and cannot be used for the granulation or other working up to give a medicament. Consequently, hitherto it has not been possible homogeneously to extrude the partly melted product. If, now, an attempt is made to increase the frictional heat by increasing the speed of rotation of the screw conveyor, then, without the working temperature increasing substantially, surprisingly a demixing takes place and, due to an extreme pressure increase in front of the nozzle plate, the extruder is sometimes stressed as far as a material destruction (breakage of the screw conveyor) without it having been possible to achieve the desired effect. Consequently, according to EP0 043,254, as previously, each batch must itself be mixed in appropriately dimensioned vessels, heated and again cooled within a previously determined period of time scheme. This is not only time-consuming but is automatically involved with many empty runs for cleaning and resupplying between the actual production batche
REFERENCES:
patent: 4483847 (1984-11-01), Augart
patent: 4540602 (1985-09-01), Motoyama et al.
patent: 5518730 (1996-05-01), Fuisz
Atkins Michael J.
Benston, Jr. William E.
Goedecke Aktiengesellschaft
Phelan D. Gabrielle
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