Determinação de minoxidil em formulações farmacêuticas usando permanganometria

Sousa, Rogério Adelino de; Cavalheiro, Éder Tadeu Gomes

doi:10.1590/s0100-46702009000300005

Cited by 4 publications

(5 citation statements)

References 8 publications

(9 reference statements)

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“…Regarding the industrial sample, odor of propylene glycol and ethanol were noticed. Such solution, since it is composed of minoxidil base, supposedly requires a greater amount of propylene glycol for active solubilization, when compared to the magistral formulations that use minoxidil sulfate [15]. Also, a higher viscosity of the industrial solution was observed compared to the magistral samples, which indicates a higher amount of propylene glycol, since such substance is a slightly viscous raw material.…”

Section: Evaluation Of Physicochemical Characteristicsmentioning

confidence: 95%

“…The active minoxidil in base form is chemically presented as 3-hydroxy-2-imino-6-piperidin-1ylpyrimidin-4-amine (C9H15N5O), with a molecular weight of 209.5 g/mol, CAS of 38304-91-5 and DCB number of 05980. It is a crystalline, off-white solid, soluble in acid and propylene glycol solutions, poorly soluble in alcohols and insoluble in water, acetone and alkaline solutions [14,15].…”

Section: Composition Of Formulationsmentioning

confidence: 99%

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Quality evaluation of minoxidil topical solutions obtained from magistral pharmacies

Dartora¹,

Bona²,

Santos³

et al. 2019

Drug Anal. Res.

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The objective of this study was to evaluate quality parameters of magistral topical solutions containing minoxidil (A, B and C), comparing the results with the ones obtained for the industrial formulation. Organoleptic tests, evaluation of the pH and density, centrifuge test, drug content determination, comparison of indicated dosages and in vitro follicular penetration of minoxidil were performed. Regarding the organoleptic properties, differences in color and viscosity were observed between the magistral (composed of minoxidil sulfate) and the industrial formulations (composed of minoxidil base). For pH values, the magistral solutions presented considerably more acidic pH, compared to the industrial sample. For the density test, the samples with the highest ethanol percentages (B and C) presented lower density. In the centrifuge test, none of the samples showed changes. Considering the drug content test, only the industrial sample and the magistral sample C showed drug percentage within the expected (90-110%), indicating lack of correction factor determination by the magistral pharmacies. Furthermore, it was observed that the dosage indicated by the magistral pharmacies do not correspond to the dose indicated by the industry, being significantly lower. All topical solutions tested presented hair follicle penetration of minoxildil, without statistical difference. The results indicate that there is a failure in the magistral pharmacies regarding the production and the indication of dosage of minoxidil topical solutions.

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Section: Evaluation Of Physicochemical Characteristicsmentioning

confidence: 95%

Section: Composition Of Formulationsmentioning

confidence: 99%

Quality evaluation of minoxidil topical solutions obtained from magistral pharmacies

Dartora¹,

Bona²,

Santos³

et al. 2019

Drug Anal. Res.

View full text Add to dashboard Cite

show abstract

“…In order to check the accuracy of the proposed procedure the results were compared with those from a chromatographic procedure describe by Zarghi et al [8], using a HPLC LC-6AD Shimadzu chromatographic system with a SPD-10A VP Shimadzu spectrophotometric detector, Supelco C-18 (150 x 3.9 mm, 4 mm) column, detection at 254 nm, mobile phase methanol / water (80 /20) flowing at 1.3 mL min -1 .…”

Section: Comparison Methodsmentioning

confidence: 99%

“…Concerning analytical methods, MnO 4 has been proposed for the oxidimetric titration of minoxidil [2,[7][8]. In addition, several instrumental techniques have been described for minoxidil determination in matrixes such as serum and pharmaceutical products.…”

Section: Introductionmentioning

confidence: 99%

Potentiometric determination of Minoxidil in topical use pharmaceutical samples

Sousa

Cavalheiro

2009

Eclet. Quím.

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A potentiometric titration method for the determination of minoxidil based on its redox reaction with K2Cr2O7 is described. The best results were observed using 1.00 x 10-3 mol L-1 K2Cr2O7 and 1.00 x 10-2 mol L-1 minoxidil solutions, and the minoxidil as titrant in 2.00 mol L-1 H2SO4 medium. The method was applied to commercial samples and compared with the results from a chromatographic procedure. Recoveries from 97.4 to 98.7 % were observed depending on the sample. Comparison with the chromatographic procedure reveled agreement within 90% confidence level.

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“…Few reports showed some interesting applications of volumetric titration on pharmaceutical analysis, being them based on different reactions [5,6] and ways of detection. In this sense a special role is played by spectrophotometric [5,7], potentiometry [8,9] and conductimetry [10].…”

Section: Introduction Thmentioning

confidence: 99%

Potentiometric and conductimetric studies of chemical equilibria for pyridoxine hydrochloride in aqueous solutions: simple experimental determination of pKa values and analytical applications to pharmaceutical analysis

et al. 2010

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The combination of two low-cost classical procedures based on titrimetric techniques is presented for the determination of pyridoxine hydrochloride in pharmaceuticals samples. Initially some experiments were carried out aiming to determine both pKa1 and pKa2 values, being those compared to values of literature and theoretical procedures. Commercial samples containing pyridoxine hydrochloride were electrochemically analysed by exploiting their acid-base and precipitation reactions. Potentiometric titrations accomplished the reaction between the ionizable hydrogens present in pyridoxine hydrochloride, being NaOH used as titrant; while the conductimetric method was based on the chemical precipitation between the chloride of pyridoxine hydrochloride molecule and Ag+ ions from de silver nitrate, changing the conductivity of the solution. Both methods were applied to the same commercial samples leading to concordant results when compared by statistical tests (95 and 98% confidence levels). Recoveries ranging from 99.0 to 108.1% were observed, showing no significant interference on the results.

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Determinação de minoxidil em formulações farmacêuticas usando permanganometria

Cited by 4 publications

References 8 publications

Quality evaluation of minoxidil topical solutions obtained from magistral pharmacies

Quality evaluation of minoxidil topical solutions obtained from magistral pharmacies

Potentiometric determination of Minoxidil in topical use pharmaceutical samples

Potentiometric and conductimetric studies of chemical equilibria for pyridoxine hydrochloride in aqueous solutions: simple experimental determination of pKa values and analytical applications to pharmaceutical analysis

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