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Placing parameters obtained from nonlinear regression analysis of the plasma profile (Eqn. 1) into the fractional system response profile (Eqn. 2) transforms the data into a data set similar to the fraction released from dissolution profile. |
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STEP 3: Compute the fractional response-time profile. |
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Simply making the independent variable the dependent variable and vice versa and adding limits to the now implicit variable T allows for the solution of T at various F, thus: |
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F = I×K×/AUC×KA/(KA-K)×((1-EXP(-K×T)/K)-(1-EXP(-KA×T)/KA)) |
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where TMAX is the maximum time of that profile. |
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By simulating the data set with the parameters obtained from Eqn. 1, Eqn. 2 will yield as many F versus T pairs for the profiles as needed. In general, 10 pairs are sufficient for most straight lines. |
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2. Treatment of Dissolution-Time Data |
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STEP 4: Curve-fit the dissolution-time data to the equation in MINSQ format |
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T = (SQRT(TIME)-SQRT(A))×UNIT(SQRT(TIME)-SQRT(A)) |
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F = (3×K×T-3×SQR(K×T)+(K×T)^3) (3) |
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where A is the lag time and K is the Higuchi release-rate constant for single face planar release. |
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STEP 5: Compute the fractional response-time profile. |
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Again, making the independent variable the dependent variable and vice versa and adding limits to the now implicit variable TIME allows for the solution of TIME at various F, thus: |
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T = (SQRT(TIME)-SQRT(A))×UNIT(SQRT(TIME)-SQRT(A)) |
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F = (3×K×T-3×SQR(K×T)+(K×T)^3) |
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