Details for Patent: 5,330,764
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| Title: | Methods of preparing bulk delivery matrices by solid-state dissolution |
| Abstract: | A method is disclosed for preparing pharmaceutical and other matrix systems that comprises solidifying a matrix composition dissolved or dispersed in a first solvent and subsequently contacting the solidified matrix with a second solvent that is substantially miscible with the first solvent at a temperature lower than the solidification point of the first solvent, the matrix components being substantially insoluble in the second solvent, whereby the first solvent is substantially removed resulting in a usable matrix. |
| Inventor(s): | Gole; Dilip J. (Ann Arbor, MI), Levinson; R. Saul (Saline, MI), Carbone; James (Belleville, MI), Davies; J. Desmond (Grosse Pointe Farms, MI) |
| Assignee: | Janssen Pharmaceutica Inc. (Piscataway, NJ) |
| Filing Date: | Jul 23, 1991 |
| Application Number: | 07/734,635 |
| Claims: | 1. A method for preparing a porous delivery matrix comprising the steps of: (a) solidifying a dispersion or solution of a matrix forming agent in a first solvent; (b) contacting the solidified dispersion or solution with a second solvent, the first solvent in the solidified dispersion or solution being substantially miscible with the second solvent, the solidification point of the first solvent being higher than the solidification point of the second solvent, the second solvent being at a temperature at or higher than the solidification point of the second solvent and at a temperature at or lower than the solidification point of the first solvent, the matrix forming agent being substantially insoluble in the second solvent, the contacting being sufficient to substantially remove the first solvent from the solidifed disperison or solution thereby yielding a delivery matrix that is substantially free of the solvent; and (c) recovering the delivery matrix. 2. The method according to claim 1, comprising the additional step of: (d) evaporating residual second solvent from the delivery matrix. 3. The method according to claim 1, comprising the additional step of: (d) removing residual second solvent from the delivery matrix by contacting the matrix with one or more additional solvents having greater volatility than the second solvent. PG,56 4. The method according to claim 1, wherein the matrix forming agent is selected from the group consisting of gelatins, dextrins, soy proteins, wheat proteins, psyllium seed proteins, gums, alginates, polysaccharides, carboxymethylcellulose, carrageenans, dextrans, pectins, polyvinylpyrrolidone, gelatin-acacia complexes, mannitol, dextrose, lactose, galactose, cyclodextrin, konjac flour, cellulose, sodium starch glycolate, polydextrose, hydroxyethylcellulose, amino acids having 2 to 12 carbon atoms, corn syrup solids, chitosan, rice flour, wheat gluten, soy fiber proteins, potato proteins, papain, horse radish peroxidase and mixtures thereof. 5. The method according to claim 4, wherein at least one of the matrix forming agents is selected from the group consisting of gelatin, pectin, mannitol and glycine. 6. The method according to claim 4, wherein the matrix forming agent is present in a concentration of about 0.1 to 15% by weight of the dispersion or solution. 7. The method according to claim 1, wherein the second solvent is at a temperature from about 1.degree. to 100.degree. C. lower than solidification point of the first solvent. 8. The method according to claim 1, wherein the second solvent to total delivery matrix weight ratio is from about 2:1 to about 40:1. 9. The method according to claim 1, wherein the dispersion or solution also contains an active agent to be delivered, the active agent being substantially insoluble in the second solvent. 10. The method according to claim 1, comprising the additional step of: (c) contacting the delivery matrix with an active agent to be delivered such that the active agent is dispersed through the matrix. 11. A method for preparing a porous foam dosage form comprising the steps of: (a) forming a dispersion of a gas and a matrix forming agent in a first solvent; (b) maintaining the gas in a dispersed state within said dispersion; (c) solidifying the dispersion; (d) contacting the solidified dispersion with a second solvent, the first solvent in the solidified dispersion being substantially miscible with the second solvent, the solidification point of the first solvent being higher than the solidification point of the second solvent, the second solvent being at a temperature at or higher than the solidification point of the second solvent and at a temperature at or lower than the solidification point of the first solvent, the matrix forming agent being substantially insoluble in the second solvent, the contacting being sufficient to substantially remove the first solvent from the solidified dispersion thereby yielding a foam dosage form; and (e) recovering the foam dosage form. 12. The method according to claim 11, comprising the additional step of: (f) contacting the foam dosage form with an active agent, such that the active agent is dispersed through the dosage form. 13. The method according to claim 11 wherein the dispersion further comprises an active agent. 14. The method according to claim 1 wherein the delivery matrix additionally comprises an active agent. 15. The method according to claim 11 wherein the foam dosage form additionally comprises an active agent. |
