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2.
Pharmazie ; 61(9): 789-92, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17020157

RESUMO

Applicability of a solution model for calculating solubility of amino acids in binary aqueous-organic solvent mixtures at various temperatures was shown. The accuracy of the proposed model was evaluated by computing mean percentage deviation (MPD) employing available solubility data of amino acids in binary solvents at various temperatures from the literature. The overall MPD (+/- SD) for correlation of solubility data was 16.5 +/- 8.8%. In addition, the equations calculating solubility of amino acids in binary solvent mixtures at a fixed temperature was revisited.


Assuntos
Aminoácidos/química , Algoritmos , Fenômenos Químicos , Físico-Química , Modelos Estatísticos , Reprodutibilidade dos Testes , Solubilidade , Solventes , Temperatura
3.
Pharmazie ; 61(4): 318-21, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16649546

RESUMO

To show the applicability of a solution model, i.e. the Jouyban-Acree model, for predicting the solubility of a solute in ternary solvent systems based on model constants computed using solubility data of the solute in binary solvent systems, the solubility of salicylic acid in water-ethanol, water-propylene glycol, ethanol-propylene glycol mixtures was determined. A minimum number of three data points from each binary system was used to calculate the binary interaction parameters of the model. Then the solubility in other binary solvent compositions and also in a number of ternary solvents was predicted, and the mean percentage deviation (MPD) was calculated as an accuracy criterion. The overall MPD (+/-SD) was 7.3 (+/-7.3)% and those of a similar predictive model was 15.7 (+/-11.5)%. The mean difference between the proposed and a previous model was statistically significant (paired t-test, p < 0.004).


Assuntos
Ácido Salicílico/química , Algoritmos , Etanol , Modelos Químicos , Modelos Estatísticos , Veículos Farmacêuticos , Valor Preditivo dos Testes , Propilenoglicol , Solubilidade , Solventes , Água
4.
Pharmazie ; 60(7): 527-9, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16076080

RESUMO

Applicability of a solution model for calculating the solute solubility in binary mixtures of supercritical fluids at different SCF compositions and pressures was shown using phenanthrene solubility data in supercritical carbon dioxide and supercritical ethane at 313 K and a pressure range of 100-350 bar. The correlation ability of the proposed model was evaluated by fitting all data points and computing error term employing back-calculated solubilities. The prediction capability of the model was assessed by dividing each data set to two subsets, namely training and test subsets. The predicted solubilities using trained models were used to calculate the prediction error term. The results show that both correlative and predictive error terms were less than the experimentally obtained RSD values.


Assuntos
Modelos Estatísticos , Solubilidade , Algoritmos , Fenômenos Químicos , Físico-Química , Fenantrenos/química , Solventes
5.
Pharmazie ; 59(2): 117-20, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15025179

RESUMO

The solubility of nalidixic acid in water-ethanol mixtures has been determined at 25 degrees C. The generated solubility data sets have been used to assess the accuracy of different numerical analyses for the excess free energy model and a new numerical method for solubility prediction in water-ethanol mixtures based on four experimental determinations is proposed. The accuracy of a previously presented numerical method to fit all data points is compared with that of a proposed analysis using average percentage deviation (APD). The APD obtained are 14.6 (+/- 8.0) and 8.4 (+/- 4.1), respectively for previous and proposed methods. A minimum number of three and four data points employed to train the original forms of the excess free energy model and the solubility at other solvent compositions were predicted. The APDs obtained were 61.4 and 23.0%, respectively. The APD produced for the proposed numerical method was 16.1%.


Assuntos
Química Farmacêutica/estatística & dados numéricos , Etanol/química , Água/química , Algoritmos , Fenômenos Químicos , Físico-Química , Ácido Nalidíxico/química , Valor Preditivo dos Testes , Solubilidade , Solventes
6.
Farmaco ; 58(10): 1039-44, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14505736

RESUMO

The electrophoretic mobilities of alprenolol have been determined in a mixed solvent background electrolyte system containing sodium acetate (40 mM)+acetic acid (40 mM) as buffering agent and different volume fractions of water, methanol and ethanol using capillary electrophoresis. The mobility of alprenolol has been used to test the prediction capability of a model trained by previously reported mobility data of five beta-blocker drugs at the same electrophoretic conditions. The average percentage mean deviations (APMD) between experimental and predicted values were used as an accuracy criterion. The APMD (+/-SD) obtained for alprenolol data in binary/ternary solvent electrolyte system employing the mobility values in mono-solvent buffers was 4.37 (+/-3.50)% and the corresponding value for an ab initio prediction method was 7.65 (+/-4.30)%.


Assuntos
Antagonistas Adrenérgicos beta/análise , Alprenolol/análise , Alprenolol/química , Soluções Tampão , Eletrólitos/química , Eletroforese Capilar/métodos , Etanol , Metanol , Valor Preditivo dos Testes , Solventes/química , Água
7.
J Pharm Biomed Anal ; 32(2): 203-8, 2003 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-12763529

RESUMO

Electrophoretic mobility of salmeterol and phenylpropanolamine in capillary electrophoresis has been determined using acetate buffer containing different concentrations of water, methanol and acetonitrile. Maximum electrophoretic mobilities for salmeterol and phenylpropanolamine have been observed at water-methanol-acetonitrile (5:50:45, v/v) and (3:60:37, v/v), respectively, while minimum mobilities of both compounds occurred at methanol-acetonitrile (30:70, v/v). The generated experimental data have been used to evaluate a mathematical model to compute the electrophoretic mobility of the analytes. The proposed model reproduced the mobility data with mean percentage deviations within 1-4%.


Assuntos
Eletrólitos/análise , Eletroforese Capilar/métodos , Solventes/análise
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