Claims for Patent: 5,662,933

Summary for Patent: 5,662,933

Title:	Controlled release formulation (albuterol)
Abstract:	A sustained release pharmaceutical formulation and methods of making and using the same are provided. The sustained release pharmaceutical formulation includes a sustained release excipient including a gelling agent, an inert pharmaceutical diluent, an optional hydrophobic material and/or hydrophobic coating, and a medicament for sustained oral administration.
Inventor(s):	Baichwal; Anand (Wappingers Falls, NY), McCall; Troy W. (New Milford, CT)
Assignee:	Edward Mendell Co., Inc. (Patterson, NY)
Application Number:	08/553,008
Patent Claims:	1. A controlled release solid dosage form for oral administration of a therapeutically active medicament to a patient in need thereof, comprising: a pharmaceutically effective amount of a medicament to be administered to a patient in need of said medicament; a sustained release excipient comprising a gelling agent comprising a heteropolysaccharide gum and a homopolysaccharide gum capable of reciprocally cross-linking when exposed to an environmental fluid, the ratio of said heteropolysaccharide gum to said homopolysaccharide gum being from about 1:3 to about 3:1; an inert pharmaceutical diluent selected from the group consisting of a pharmaceutically acceptable saccharide, polyhydric alcohol, a pre-manufactured direct compression diluent, and mixtures of any of the foregoing, the ratio of said inert diluent to said gelling agent being from about 1:8 to about 8:1, said dosage form providing a sustained release of said medicament when exposed to an environmental fluid and a pharmaceutically acceptable hydrophobic material. 2. The controlled release solid dosage form according to claim 1 wherein said diluent is a saccharide selected from the group consisting of sucrose, dextrose, lactose, microcrystalline cellulose, fructose, xylitol, sorbitol, a starch, and mixtures thereof. 3. The controlled release solid dosage form according claim 1, wherein said heteropolysaccharide gum comprises xanthan gum and said homopolysaccharide gum comprises locust bean gum. 4. The controlled release solid dosage form according claim 2, wherein said xanthan gum and said locust bean gum are present in about a 1:1 ratio, respectively, by weight. 5. The controlled release solid dosage form according to claim 1, wherein said hydrophobic material is selected from the group consisting of a cellulose ether, a cellulose ester and an alkylcellulose. 6. The controlled release solid dosage form according claim 1, wherein said hydrophobic material is selected from the group consisting of ethylcellulose, carboxymethylcellulose, cellulose acetate phthalate, hydroxypropylmethylcellulose phthalate and a polyvinyl acetate polymer. 7. The controlled release solid dosage form according claim 1, wherein said hydrophobic material is present in an amount ranging from about 1 through about 90%, by weight, of the solid dosage form. 8. The controlled release solid dosage form according claim 1, wherein said hydrophobic material is present in an amount ranging from about 25% through about 50%, by weight, of the solid dosage form. 9. The controlled release solid dosage form according to claim 1 wherein said medicament is a pharmaceutically effective amount of albuterol or a salt or derivative thereof. 10. The controlled release solid dosage form according to claim 1 which is a tablet. 11. The controlled release solid dosage form according to claim 1 which is in granular form. 12. The controlled release solid dosage form according to claim 11, which comprises a gelatin capsule containing a sufficient amount of said granules to provide an effective dose of said therapeutically active medicament. 13. The controlled release solid dosage form according to claim 9, wherein said hydrophobic material is selected from the group consisting of carboxymethylcellulose, cellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropylmethylcellulose phthalate, ethylcellulose, a copolymer of acrylic and methacrylic and esters, waxes, shellac, zein, and mixtures of any of the foregoing, prior to incorporation of said medicament, said hydrophobic material being included in said dosage form in an amount effective to slow the hydration of said gelling agent when exposed to an environmental fluid. 14. The controlled release solid dosage form according to claim 12 which is a tablet, at least part of a surface of said tablet being coated with a hydrophobic material to a weight gain from about 1 to about 20 percent, by weight. 15. The controlled release solid dosage form according to claim 1 which comprises a granulation which is coated with a hydrophobic material to a weight gain from about 1% to about 20%. 16. The controlled release solid dosage form according to claim 14, wherein said hydrophobic material is selected from the group consisting of a cellulose ether, a cellulose ester and an alkylcellulose. 17. The controlled release solid dosage form according to claim 16 which is a tablet, at least part of a surface of said tablet being coated with a hydrophobic material to a weight gain from about 1 to about 20 percent, by weight. 18. The controlled release solid dosage form according to claim 17, wherein said mixture of sustained release excipient and medicament are coated with a hydrophobic material prior to tableting. 19. The controlled release solid dosage form according to claim 1 which is a tablet, said tablet further comprising a coating containing from about 10 to about 40 percent of the total amount of said medicament included in said dosage form. 20. The controlled release solid dosage form according to claim 1 wherein the amount of albuterol is an amount equivalent to about 4 mg to about 16 mg of albuterol free base. 21. A method of preparing a controlled release solid dosage form comprising a medicament for oral administration, the method comprising preparing a sustained release excipient comprising from about 10 to about 99 percent by weight of a gelling agent comprising a heteropolysaccharide gum and a homopolysaccharide gum capable of cross-linking said heteropolysaccharide gum when exposed to an environmental fluid, the ratio of said heteropolysaccharide gum to said homopolysaccharide gum being from about 1:3 to about 3:1, and from about 0 to about 89 percent by weight of an inert pharmaceutical diluent, and from about 1 to 90% by weight of a pharmaceutically acceptable hydrophobic material; and adding an effective amount of a medicament thereto, such that a final product is obtained having a ratio of said medicament to said gelling agent from about 1:3 to about 1:8, such that a gel matrix is created when said formulation is exposed to environmental fluid and said formulation provides therapeutically effective blood levels of said medicament for at least 12 hours. 22. The method of claim 21, further comprising tableting said mixture of said sustained release excipient and said medicament. 23. The method of claim 21, further comprising coating said tablets with a hydrophobic coating to a weight gain from about 1% to about 20%. 24. The method of claim 21, further comprising granulating said sustained release excipient with a hydrophobic material. 25. The method of claim 21, wherein said medicament is albuterol or a salt or derivative thereof. 26. The method of claim 21, wherein said hydrophobic coating comprises ethylcellulose. 27. The method of claim 25, wherein the amount of albuterol is an amount equivalent to about 4 mg to about 16 mg of albuterol free base. 28. The method of claim 21, wherein said sustained release excipient comprises from about 10 to about 75 percent gelling agent, from about 0 to about 90% hydrophobic material and from about 30 to about 75 percent inert diluent. 29. The method of claim 21, wherein said formulation provides therapeutically effective blood levels of said medicament for at least 24 hours. 30. The method of claim 21, further comprising compressing the mixture of said sustained release excipient and said tablet into tablets. 31. The method of claim 21, wherein said medicament comprises a therapeutically effective dose of albuterol or salts and derivatives of the same. 32. A method of treating a patient with albuterol comprising, preparing a sustained release excipient comprising from about 10 to about 99 percent by weight of a gelling agent comprising a heteropolysaccharide gum and a homopolysaccharide gum capable of cross-linking said heteropolysaccharide gum when exposed to an environmental fluid, the ratio of said heteropolysaccharide gum to said homopolysaccharide gum being from about 1:3 to about 3:1, and from about 0 to about 89 percent by weight of an inert pharmaceutical diluent, and from about 1 to 90% by weight of a pharmaceutically acceptable hydrophobic material; and adding an effective amount of a albuterol, or a salt or derivative thereof, to said sustained release excipient, such that a final product is obtained having a ratio of albuterol to said gelling agent from about 1:3 to about 1:8, such that a gel matrix is created when said formulation is exposed to environmental fluid and said formulation provides therapeutically effective blood levels of albuterol for at least 12 hours. adding an amount of albuterol effective to render a desired therapeutic effect; tableting the resultant mixture such that a final product is obtained having a ratio of albuterol to said gelling agent from about 1:3 to about 1:8, such that a gel matrix is created when said tablet is exposed to gastrointestinal fluid and said tablet provides therapeutically effective blood levels of albuterol; and administering said tablet to a patient at a predetermined dosage interval from about 12 to about 24 hours. 33. The method of claim 32, further comprising coating said tablets with a hydrophobic material to a weight gain from about 1% to about 20%. 34. The method of claim 32, further comprising preparing said formulation such that it provides therapeutically effective blood levels of said medicament for at least 24 hours. 35. The controlled release solid dosage form of claim 1 which, when orally administered to a patient, provides a medicament plasma concentration-time curve with an area under the curve, to infinity, ranging from about 89 to about 150 (ng-hours/ml). 36. The controlled release solid dosage form of claim 1 which, when orally administered to a fasting patient, provides a medicament plasma concentration-time curve with an area under the curve, to infinity, ranging from about 57 to about 157 (ng-hours/ml). 37. The controlled release solid dossage form of claim 1 which, when orally administered to a fed patient, provides a medicament plasma concentration-time curve with an area under the curve, to infinity, ranging from about 75 to about 162 (ng-hour s/ml). 38. The controlled release solid dosage form of claim 1 which, when orally administered to a patient, provides a mean peak plasma concentration ranging from about 7 to about 12 ng/ml. 39. The controlled release solid dossage form of claim 1 which, when orally administered to a fasting patient, provides a mean peak plasma concentration ranging from about 4.5 to about 19 ng/ml. 40. The controlled release solid dosage form of claim 1 which, when orally administered to a fed patient, provides a mean peak plasma concentration ranging from about 6 to about 16 ng/ml. 41. The controlled release solid dosage form of claim 1 which, when orally administered to a patient, provides a time to mean peak plasma concentration ranging from about 3 to about 10 hours. 42. The controlled release solid dosage form of claim 1 which, when orally administered to a fasting patient, provides a time to mean peak plasma concentration ranging from about 3 to about 6 hours. 43. The controlled release solid dosage form of claim 1 which, when orally administered to a fed patient, provides a time to mean peak plasma concentration ranging from about 3 to about 8 hours. 44. The controlled release solid dosage form of claim 35 wherein the area under the plasma concentration curve, to infinity, ranges from about 112 to about 129 (ng-hours/ml). 45. The controlled release solid dosage form of claim 38 wherein the mean peak plasma concentration ranges from about, 9.5 to about 12 ng. 46. The controlled release solid dosage form of claim 42 wherein the time to mean peak plasma concentration ranges from about 3.5 to about 8 hours. 47. The controlled release solid dosage form of claim 1 which, when orally administered to a patient, provides a medicament plasma concentration-time curve wherein time to peak plasma concentration in a fasted patient divided by a time to peak plasma concentration in a fed patient ranges from about 0.50 to about 0.70. 48. The controlled release solid dosage form of claim 1 which, when orally administered to a patient, provides a medicament plasma concentration-time curve wherein peak plasma concentration in a fasted patient divided by peak plasma concentration in a fed patient ranges from about 0.90 to about 1.10.