Liquisolid systems and methods of preparing same
First Claim
1. A method of producing a free-flowing and readily compressible liquid/powder admixture of a liquid medication, which involves converting the liquid medication into a liquisolid system, comprising the steps of:
- (a) selecting a weight (W) of the liquid medication to be included in a single liquisolid compact;
(b) selecting a carrier material and a coating material to be included in the liquisolid system;
(c) determining the characteristic minimum carrier;
coating ratio, Rmin, and flowable liquid-retention potentials of the carrier (Φ
) and coating (φ
) materials using a liquisolid flowability test;
(d) determining the characteristic compressible liquid-retention potentials of the carrier (Ψ
) and coating (ψ
) materials using a liquisolid compressibility test;
(e) selecting a carrier;
coating ratio, R, where R>
Rmin, of the carrier and coating materials to be included in the liquisolid system, where R=Q/q, Q=the weight of carrier material, and q=the weight of coating material;
(f) calculating the optimum liquid load factor (Lo) of the system according to the equations;
space="preserve" listing-type="equation">L.sub.o =.sup.Φ
L.sub.f when .sup.Φ
L.sub.f <
.sup.Ψ
L.sub.for
space="preserve" listing-type="equation">L.sub.o =.sup.Ψ
L.sub.f when .sup.Φ
L.sub.f >
.sup.Ψ
L.sub.fwhere;
space="preserve" listing-type="equation">.sup.Φ
L.sub.f =Φ
+φ
(1/R)and
space="preserve" listing-type="equation">.sup.Ψ
L.sub.f =Ψ
+ψ
(1/R)(g) calculating the optimum quantities of the carrier (Qo) and coating (qo) materials according to the equations;
space="preserve" listing-type="equation">Q.sub.o =W/L.sub.o
space="preserve" listing-type="equation">q.sub.o =Q.sub.o /R(h) admixing the liquid medication with the calculated quantity of carrier material (Qo); and
(i) blending the resulting wet mixture with the calculated amount of coating material (qo) to produce a nonadherent, free-flowing and compressible liquid/powder admixture.
1 Assignment
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Accused Products
Abstract
Liquisolid systems are acceptably flowing and compressible powdered forms of liquid medications. According to the concept of liquisolid systems, liquid lipophilic drugs, or water-insoluble solid drugs dissolved in suitable non-volatile solvents, may be converted into free-flowing and readily compressible powders by a simple admixture with selected powder excipients referred to as the carrier and coating materials. Various grades of microcrystalline or amorphous cellulose may be used as carriers, whereas very fine particle size silica powders may be used as coating materials. Based on the theory that the carrier and coating materials can retain only certain amounts of liquid and at the same time maintain acceptable flow and compression properties, a new formulation-mathematical model is provided to calculate the optimum quantities of carrier and coating materials required to yield acceptably flowing and compressible liquid/powder admixtures.
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Citations
25 Claims
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1. A method of producing a free-flowing and readily compressible liquid/powder admixture of a liquid medication, which involves converting the liquid medication into a liquisolid system, comprising the steps of:
-
(a) selecting a weight (W) of the liquid medication to be included in a single liquisolid compact; (b) selecting a carrier material and a coating material to be included in the liquisolid system; (c) determining the characteristic minimum carrier;
coating ratio, Rmin, and flowable liquid-retention potentials of the carrier (Φ
) and coating (φ
) materials using a liquisolid flowability test;(d) determining the characteristic compressible liquid-retention potentials of the carrier (Ψ
) and coating (ψ
) materials using a liquisolid compressibility test;(e) selecting a carrier;
coating ratio, R, where R>
Rmin, of the carrier and coating materials to be included in the liquisolid system, where R=Q/q, Q=the weight of carrier material, and q=the weight of coating material;(f) calculating the optimum liquid load factor (Lo) of the system according to the equations;
space="preserve" listing-type="equation">L.sub.o =.sup.Φ
L.sub.f when .sup.Φ
L.sub.f <
.sup.Ψ
L.sub.for
space="preserve" listing-type="equation">L.sub.o =.sup.Ψ
L.sub.f when .sup.Φ
L.sub.f >
.sup.Ψ
L.sub.fwhere;
space="preserve" listing-type="equation">.sup.Φ
L.sub.f =Φ
+φ
(1/R)and
space="preserve" listing-type="equation">.sup.Ψ
L.sub.f =Ψ
+ψ
(1/R)(g) calculating the optimum quantities of the carrier (Qo) and coating (qo) materials according to the equations;
space="preserve" listing-type="equation">Q.sub.o =W/L.sub.o
space="preserve" listing-type="equation">q.sub.o =Q.sub.o /R(h) admixing the liquid medication with the calculated quantity of carrier material (Qo); and (i) blending the resulting wet mixture with the calculated amount of coating material (qo) to produce a nonadherent, free-flowing and compressible liquid/powder admixture. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of producing a free-flowing liquid/powder admixture of a liquid medication, which involves converting the liquid medication into a liquisolid microsystem, comprising the steps of:
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(a) selecting a weight (W) of the liquid medication to be included in a single liquisolid microsystem; (b) selecting a carrier material and a coating material to be included in the liquisolid microsystem; (c) determining the characteristic minimum carrier;
coating ratio, Rmin, and flowable liquid-retention potentials of the carrier (Φ
) and coating (φ
) materials using a liquisolid flowability test;(d) selecting a coating;
carrier ratio, R, where R>
Rmin, of the carrier and coating materials to be included in the liquisolid microsystem, where R=Q/q, Q=the weight of carrier material, and q=the weight of coating material;(e) calculating the optimum liquid load factor (Lo) of the system according to the equations;
space="preserve" listing-type="equation">L.sub.o =.sup.Φ
L.sub.f when .sup.Φ
L.sub.f <
.sup.Ψ
L.sub.for
space="preserve" listing-type="equation">L.sub.o =.sup.Ψ
L.sub.f when .sup.Φ
L.sub.f >
.sup.Ψ
L.sub.fwhere;
space="preserve" listing-type="equation">.sup.Φ
L.sub.f =Φ
+φ
(1/R)and
space="preserve" listing-type="equation">.sup.Ψ
L.sub.f =Ψ
+ψ
(1/R)(f) calculating the optimum quantities of the carrier (Qo) and coating (qo) materials according to the equations;
space="preserve" listing-type="equation">Q.sub.o =W/L.sub.o
space="preserve" listing-type="equation">q.sub.o =Q.sub.o /R(g) admixing the liquid medication with the calculated quantity of carrier material (Qo); and (h) blending the resulting wet mixture with the calculated amount of coating material (qo) to produce a nonadherent, free-flowing liquid/powder admixture. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification