| 1. |
- Persson, Anita M., 1975-, et al.
(författare)
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Correlation of in vitro dissolution rate and apparent solubility in buffered media using a miniaturized rotating disk equipment : Part II. Comparing different buffer media
- 2009
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Ingår i: Drug Discoveries & Therapeutics. - : IACMHR and SDU-DDSC. - 1881-7831. ; 3:3, s. 114-122
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Tidskriftsartikel (refereegranskat)abstract
- A correlation of the logarithmic values of the in vitro dissolution rate, G, and apparent solubility, S, was made for seven different drug substances from all of the classes in the Biopharmaceutics Classification System (BCS), in four different phosphate buffers. The effect of inorganic salts added as sodium chloride, sodium nitrate, sodium phosphate and sodium sulfate in the buffer media was investigated for the correlation. Triethanolammonium acetate buffer was also included in the study of the correlation of logG vs. logS. The pH was 7.0 ± 0.1 in all of the buffers to mimic a pH condition in intestinal fluids. The dissolution rate was determined with a newly constructed miniaturized rotating disk equipment, which enables fast determinations and consumes only minute quantities of substance (about 5 mg). The solubility was determined by conventional shake-flask methodology, using 1.5 mL solution volumes. All quantifications were performed with reversed phase high-performance liquid chromatography (RP-HPLC) and diode array detection (DAD). The different inorganic anions seemed to affect the solubility more than the dissolution rate. The phosphate and nitrate ions decreased the solubility for amines compared to the chloride ion. The best correlations of logG and logS were however obtained with a triethanolammonium acetate buffer. The good correlation (R2 = 0.991) may be sufficient in initial screening of drug solubility, based on dissolution rates in aqueous buffer media.
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| 2. |
- Persson, Anita M., 1975-, et al.
(författare)
-
Correlation of in vitro dissolution rate and apparent solubility in buffered media using a miniaturized rotating disk equipment : Part I. Comparison with a traditional USP rotating disk apparatus
- 2009
-
Ingår i: Drug Discoveries & Therapeutics. - : IACMHR and SDU-DDSC. - 1881-7831. ; 3:3, s. 104-113
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Tidskriftsartikel (refereegranskat)abstract
- A correlation of the logarithmic values of the in vitro dissolution rate, G, and the apparent solubility, S, was evaluated in phosphate and ammonium acetate buffer at an initial pH of 7. The dissolution rates were determined with a newly designed and build miniaturized rotating disk equipment, as well as with a traditional rotating disk apparatus. The two apparatuses gave the same correlation pattern of logG and logS. Thirteen diverse drug substances from all of the classes in the Biopharmaceutics Classification System (BCS) were used for the correlation in the phosphate buffer system, with the results from the miniaturized apparatus only. A coefficient of determination, R2, of 0.982 was found if bases formulated as hydrochloride salts were excluded in the correlation. The miniaturized equipment is used for rapid screening of the dissolution rate, approximately 10 min for one run, and consumes small amounts of substance (about 5 mg) and dissolution media. All quantifications were performed by using reversed phase high-performance liquid chromatography (RPHPLC) with a diode array detector (DAD), integrated with the miniaturized rotating disk equipment.
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