extractive spectrophotometric determination of quetiapine fumarate in ...

2 downloads 0 Views 274KB Size Report
Feb 22, 2011 - served from common pharmaceutical adjuvants in tablets. Statistical com ..... absorbance, b is slope, a is intercept and x is the con- centration of ...
Available on line at Association of the Chemical Engineers of Serbia AChE www.ache.org.rs/CICEQ

CI&CEQ

Chem. Ind. Chem. Eng. Q. 17 (3) 259−267 (2011)

NAGARAJU RAJENDRAPRASAD KANAKAPURA BASAVAIAH KANAKAPURA BASAVAIAH VINAY Department of Chemistry, University of Mysore, Manasagangothri, Mysore, India SCIENTIFIC PAPER UDC 661.12:615.2:543 DOI 10.2298/CICEQ101124010R

EXTRACTIVE SPECTROPHOTOMETRIC DETERMINATION OF QUETIAPINE FUMARATE IN PHARMACEUTICALS AND HUMAN URINE USING CALMAGITE AS AN ION-PAIR REAGENT Quetiapine fumarate (QTF) is an antipsychotic drug belonging to the benzisoxazole derivatives indicated for the treatment of schizophrenia. A sensitive and selective method based on dichloromethane-extractable ion-pair of QTF with calmagite (CGT), which exhibited an absorption maximum at 490 nm, is described. At this wavelength, Beer’s law is obeyed over the concentration range of 3.0–30.0 µg ml-1. The apparent molar absorptivity, limit of detection (LOD) and quantitation (LOQ) values are 1.32×104 l mol-1 cm-1, 0.27 and 0.81 µg ml-1, respectively. The reaction is extremely rapid at room temperature and the absorbance values remain unchanged up to 19 h. The precision results, expressed as intra-day and inter-day relative standard deviation values, are satisfactory (RSD ≤ 2.2%). The accuracy is satisfactory as well (RE ≤ 2.44%). The method was successfully applied to the determination of QTF in pharmaceuticals and spiked human urine with satisfactory results. No interference was observed from common pharmaceutical adjuvants in tablets. Statistical comparison of the results with the official method showed an excellent agreement and indicated no significant difference in precision. Key words: quetiapine fumarate; spectrophotometry; calmagite; spiked human urine; ion-pair complex.

Quetiapine fumarate (QTF) is one of the most recent “atypical” antipsychotic drugs [1]. QTF is a selective monoaminergic antagonist with high affinity for the serotonin Type 2 (5HT2), and dopamine type 2 (D2) receptors. It is used alone or in combination with other medications to treat schizophrenia and bipolar disorder [2, 3]. QTF is chemically designated as 2-(2(4-dibenzo[b,f] [1,4]thiazepine-11-yl-1-piperazinyl)ethoxy)ethanol, fumaric acid (1:2 salt) (Figure 1) and its molecular weight is 615.66 g mol-1. Several analytical methods have been reported for the determination of QTF in biological fluids and pharmaceuticals. QTF was determined in biological materials by HPLC with UV [4-11], chemiluminescence [12], electrospray ionization MS [13-16], tandem MS/MS detection [17-20], UPLC with tandem MS

detection [21,22], GC [23,24] and voltammetry [25]. Different techniques such as polarography [26], potentiometry [27], capillary zone electrophoresis [28,29], HPTLC [30-32], HPLC [33-36] and spectrophotometry [28,37-39] have earlier been used for the determination of QTF in pharmaceuticals. O

S HO N N N O

OH O O

HO

OH O

OH

Correspondening author: K. Basavaiah, Department of Chemistry, University of Mysore, Manasagangothri, Mysore 570 006, India. E-mail: [email protected] Paper received: 24 November, 2010 Paper revised: 22 February, 2011

Figure 1. Chemical structure of QTF.

Pucci et al. [28] have reported a UV spectrophotometric method for the determination of QTF after converting the drug into its free base by using 50 mM

259

N. RAJENDRAPRASAD, K. BASAVAIAH, K.B. VINAY: EXTRACTIVE SPECTROPHOTOMETRIC…

phosphate buffer (pH 2.5) as diluent. The assay was carried out by measuring the absorbance of quetiapine free base solution at 246 nm. The linearity was observed in the range of 5-25 µg ml-1 QTF. Another UV spectrophotometric method developed by Fursule et al [37] involves the measurement of QTF at 290 nm in water and Beer’s law is obeyed in the range, 6-54 µg ml-1. The only reported visible spectrophotometric method [38] based on the measurement of absorbance of chloroform extractable ion-pair complex of QTF with bromocresol green at 415 nm and Beer’s law was obeyed over the linear range of 5.0-25.0 μg ml-1. Present authors have also reported two extraction-free spectrophotometric methods [39] based on the same reaction protocol using two sulphonthalein dyes, namely, bromophenol blue (BPB) and thymol blue (TB). The ion-pair complexes were quantified in 1,4-dioxane–acetone solvent system and by measuring the absorbance at 410 and 380 nm for BPB and TB methods, respectively. The reported UV methods have some demerits such as use of buffer solution to convert QTF into its free base [28], poor sensitivity and narrow linear dynamic range [37]. Though the reported visible spectrophotometric methods [38,39] seem to be more sensitive, they are applicable only for pharmaceuticals and not applied to urine samples. Extractive spectrophotometric procedures are popular for their selectivity and sensitivity, and hence, have received considerable attention in the quantitative determination of many pharmaceutical compounds [40-43]. The present study deals with development and validation of a visible extractive spectrophotometric method for the determination of QTF in bulk drug, tablets and spiked human urine sample using calmagite as an ion-pair reagent. The method is based on the formation of orange red coloured ion-pair complex between QTF and calmagite in acidic medium. The absorbance measurements were made at 490 nm after extracting the complex into dichloromethane. The method is more sensitive than all the reported spectrophotometric methods and is featured by a wide linear dynamic range. The proposed method was successfully applied to the determination of QTF in bulk drug, tablets and spiked human urine. The results of recovery studies were satisfactory. EXPERIMENTAL Apparatus Absorbance measurements were made on a Systronics model 106 digital spectrophotometer (Sys-

260

CI&CEQ 17 (3) 259−267 (2011)

tronics India Ltd, Ahmedabad, India) with 1 cm path length quartz cells. Reagents and solutions All chemicals used were of analytical reagent grade and solutions were prepared with distilled water. Dichloromethane (spectroscopic grade) was purchased from Merck, Mumbai, India. Pharmaceutical grade QTF was kindly gifted by Cipla Ltd, Bangalore, India, and is certified to be 99.5% pure. It was used without further purification. Qutipin-200 and Qutipin-100 (both from Sun Pharmaceuticals Ltd, India) tablets were purchased from local market. Drug-free human urine was obtained from a healthy male aged about 28 years. Sulphuric acid (0.1 M). Concentrated acid (S.D. Fine Chem, Mumbai, India, Sp. gr. 1.84) was appropriately diluted with water to get 0.1 M. Sodium acetate (1 M). A 1 M solution was prepared by dissolving an accurately weighed amount of 13.6 g of pure sodium acetate trihydrate (S.D. Fine Chem Ltd, Mumbai, India) in 100 ml of water in a volumetric flask. Calmagite (CGT) solution (0.05% w/v). A 0.05% solution was prepared by dissolving 0.05 g of CGT (S.D. Fine, Mumbai) in 100 ml of water in a volumetric flask. QTF solution (100 and 60 µg ml-1). A standard stock solution of QTF was prepared by dissolving an accurately weighed 10 mg of pure drug in 0.1 M H2SO4 and the volume was made up to 100 ml in a volumetric flask with the same acid to get 100 µg ml-1 QTF. This solution was diluted appropriately with 0.1 M H2SO4 to get 60 µg ml-1 QTF and used for the assay. Procedure for calibration curve Into a series of 125 ml separating funnels, 0.5-5.0 ml aliquots of 60 µg ml-1 QTF solutions were transferred by means of a microburette. The total volume in each separating funnel was adjusted to 5 ml by adding 0.1 M H2SO4. To each funnel, 10 ml of water and 5 ml of dye solution were added. The contents were mixed thoroughly, and after 5 min, the ionpair complex was extracted with 10 ml of dichloromethane by shaking for 30 s and the layers were allowed to separate. The organic layer was then passed over anhydrous sodium sulphate and absorbance was measured at 490 nm against the reagent blank prepared in the absence of QTF. The procedure was repeated three times and standard graph was prepared by plotting the absorbance vs. drug concentration. The concentration of the unknown was read from the calibretion graph or computed from the regression equation derived using the absorbance-concentration data.

N. RAJENDRAPRASAD, K. BASAVAIAH, K.B. VINAY: EXTRACTIVE SPECTROPHOTOMETRIC…

Procedure for tablets Twenty tablets were weighed and ground into a fine powder. An amount of tablet powder equivalent to 6 mg of QTF was weighed and transferred into a clean 100 ml volumetric flask containing 65-70 ml of 0.1 M H2SO4. After shaking the content for 20 min, the volume was brought up to the mark with the same acid and filtered through Whatman No. 42 filter paper. A suitable aliquot (say 3 ml) of the resulted solution (60 µg ml-1 QTF) was subjected to analysis by using the general procedure described earlier.

CI&CEQ 17 (3) 259−267 (2011)

possible reaction path way for the formation of ionpair complex is suggested in the scheme 1.

A

B

Procedure for spiked human urine A 15 ml aliquot of 100 μg ml-1 QTF solution was mixed with 3 ml of urine and 2 ml of acetonitrile in a 25 ml volumetric flask and the volume was made up to mark with 0.1 M H2SO4. The resulting solution was filtered through Whatman No. 42 filter paper and three different aliquots were subjected to analysis by following the general procedure. The concentration of QTF in urine was found from the standard graph or from the regression equation. Procedure for the analysis of placebo blank and synthetic mixture A placebo blank containing starch (10 mg), acacia (15 mg), hydroxyl cellulose (10 mg), sodium citrate (10 mg), talc (20 mg), magnesium stearate (15 mg) and sodium alginate (10 mg) was made and its solution was prepared as described for tablets and then subjected to analysis. The absorbance of the placebo solution was almost equal to the absorbance of the blank which revealed no interference from the excipients added to pure drug. A synthetic mixture was prepared by adding pure QTF (100 mg) to the placebo blank and the content was homogenised. Synthetic mixture containing 6 mg of QTF was weighed and its solution in a 100 ml volumetric flask was prepared as described for tablets. Three different aliquots were subjected to analysis by the general procedure and the percentage recovery of QTF was evaluated. RESULTS AND DISCUSSION QTF, when reacted with CGT and extracted into dichloromethane in acidic medium, was found to yield a clear orange-red coloured ion-pair complex which showed an absorption maximum at 490 nm (Figure 2). The coloured product is due to the sulphonate anionic group present in the dye, CGT, which has a strong tendency to form dichloromethane soluble ion-pair complex with the protonated QTF (QTF⋅2H++). The

Figure 2. Absorption spectra of A: QTF–CGT ion-pair complex (30 µg ml-1 QTF) and B: blank.

Optimization of variables Preliminary investigations were carried out to establish the most favourable conditions to give a highly intense colour which could be used for the quantitative determination of the drug. Optimum conditions were fixed by varying one parameter at a time while keeping other parameters constant and observing its effect on the absorbance at 490 nm against respective blank. The influence of each of the following variables on the reaction was tested. Effect of ratio of aqueous to organic phase. The effect of ratio of aqueous to organic phase was examined by adding 5-30 ml of water to 5 ml of QTF solution before the addition of dye solution. Maximum and constant absorbance values were obtained with quick separation of the two phases with 10-25 ml of water. Therefore, aqueous to organic phase ratio of 2:1 was used in the investigation. Effect of extraction solvent. Dichloromethane was preferred to other solvents (chloroform, carbontetrachloride, 1,2-dichloroethane, hexane, ether, ethyl acetate and benzene) for its selective and quantitative extraction. Effect of CGT concentration. The influence of dye concentration on the absorbance was investigated by adding different volumes of 0.05% CGT solution (2-8 ml) in to 3 ml of 60 µg ml-1 QTF solution. With volumes less than 4 ml, lower absorbance values were obtained and when the volumes greater than 6 ml, the absorbance values were reduced and there was no clear separation of the two phases. A constant and maximum absorbance was obtained in the range of 4-6 ml of CGT (Figure 3). Therefore, a 5 ml of 0.05% CGT solution in a total volume of 20 ml aqueous phase was chosen as optimal for complete complexation.

261

N. RAJENDRAPRASAD, K. BASAVAIAH, K.B. VINAY: EXTRACTIVE SPECTROPHOTOMETRIC…

S

N N

O

N

O

O

2H+

O

NH

OH

HO

OH

S

OH

HO

HN

O

+

QTF

+

O

O

O OH

HO

OH

O

QTF.2H++

Protonated quetiapine fumarate

O S

OH

HO

N

O

Quetiapine fumarate

HO

CI&CEQ 17 (3) 259−267 (2011)

OH

O N H

H N

O OH

O S

OH

O N H

H N

OH +

+ H

CGT -

CGT Calmagite

Anionic form of CGT

QTF.2H+++ 2CGT -

[QTF.2H] ++ [2CGT] -Ion-pair complex of QTF-CGT (1:2)

Scheme 1. Probable reaction pathway showing the formation of QTF-CGT ion-pair complex.

Number of extractions. To obtain complete ex-

Absorbance

0.33 0.31 0.29 0.27 0.25 2

4

6

8

10

Volum e of 0.05% CGT

Figure 3. Effect of dye concentration on the absorbance of QTF-CGT ion-pair complex (QTF. 18 µg ml-1).

Reaction time. After the addition of dye, the effect of standing time on the complex formation was studied from 5 to 30 min before extraction. A contact time of 5 min was found adequate for the complex formation. Effect of shaking time. The effect of the shaking time on the extraction of QTF-CGT ion-pair was studied by shaking the separating funnel for different times ranging from 30 to 180 s after adding dichloromethane. Constant absorbance readings were obtained from 30 s and onwards and hence, a 30 s shaking time was fixed.

262

traction of the QTF-CGT ion-pair complex under optimum conditions, the drug-dye complex in the aqueous phase was extracted with three 10 ml portions of dichloromethane separately and absorbance was measured each time against the respective blank. In the second and third extraction, the absorbance of the organic layer was negligibly small. Hence, a single extraction with 10 ml of dichloromethane was found adequate to remove the drug-dye ion-pair completely from the aqueous layer.

Equilibration time and stability of the coloured complexes. The organic and aqueous phases were clearly separated in less than 1 min. The drug-dye ion-pair complex was stable for more than 19 h at laboratory temperature (30±2 °C). Effect of order of addition of reactants. The sequence of order of addition of the reactants prior to extraction had very little effect on the absorbance, so the order of addition of reactants should be in the described manner. Composition of ion-pair complex. The composition of the ion-pair complex was determined by Job’s continuous variations method [44]. Aqueous QTF and dye solutions of 5.59×10-4 M each were mixed in various molar ratios (with a total volume of 5 ml) in a

N. RAJENDRAPRASAD, K. BASAVAIAH, K.B. VINAY: EXTRACTIVE SPECTROPHOTOMETRIC…

series of separating funnels. The volumes in all funnels were diluted to 20 ml with water. The extraction was performed using 10 ml of dichloromethane and the absorbance was measured at 490 nm. Graph of the results obtained (Figure 4) gave a maximum at molar ratio of xmax = 0.333 which indicated the formation of 1:2 (QTF:CGT) ion-pair complex.

Figure 4. Job’s continuous variations plot of QTF-CGT on-pair complex (5.59×10-4 M).

Conditional stability constant (Kf) of the ion-pair complex. The conditional stability constant (Kf) of the ion-pair formed by QTF with CGT was calculated from the continuous variation data using the following equation [45]:

Kf =

A Am  A  1 −   Am 

n +2

n

cM (n )

where A is the maximum observed absorbance and Am is the absorbance value when whole amount of drug is associated. cM is the molar concentration of drug at the maximum absorbance and n is the combination ratio of the ion-pair considered. The log Kf value obtained for QTF-CGT ion-pair, based on five determinations, is 7.08±0.26.

Optimisation of conditions for spiked human urine Different experiments were performed with different organic solvents such as chloroform, dichloromethane, 1,2-dichloroethane, ethyl acetate, ether, benzene, acetonitrile and 1,4-dioxane by following extraction and extraction-free steps to obtain better extraction of QTF from spiked urine. Acetonitrile yielded excellent results without any pre-extraction procedure and without interference of urinary matrices in the complex formation. The volume of acetonitrile was found critical for the formation of matrix-free QTF-CGT ion-pair complex. It was necessary to maintain 1.8–2.5 ml of acetonitrile in a total volume of 25 ml. At the vo-

CI&CEQ 17 (3) 259−267 (2011)

lumes less than 1.8 ml and greater than 2.5 ml of acetonitrile, higher and lower absorbance values were obtained. Therefore, a 3 ml of urine was mixed with 2 ml of acetonitrile to prepare 60 µg ml-1 QTF in a total volume of 25 ml. Method validation

Linearity, sensitivity, limits of detection and quantification. Beer’s law limits, molar absorptivity, Sandell’s sensitivity, linear regression equation, correlation coefficient and detection limit were determined and are given in Table 1. A linear relationship was found between the absorbance at λmax and concentration of the drug in the range 3.0-30 µg ml-1. The graph showed negligible intercept and is described by the regression equation, A = bx + a (where A is the absorbance, b is slope, a is intercept and x is the concentration of drug in µg ml-1) and the correlation coefficient value close to unity (r = 0.9988). The calculated molar absorptivity and Sandell’s sensitivity values are summarized in Table 1. The limits of detection (LOD) and quantification (LOQ) were calculated according to ICH guidelines [46] using the formulae: LOD = 3.3S/b and LOQ = 10S/b, (where S is the standard deviation of five blank absorbance values, and b is the slope of the calibration plot) are also summarized in Table 1. The high values of ε and low values of Sandell’s sensitivity and LOD indicate the high sensitivity of the proposed method. Table 1. Sensitivity and regression parameters Parameter

Value

λmax / nm

490 -1

Linear range, µg ml

3.0-30 -1

Molar absorptivity (ε), L mol cm a

Sandell’s sensitivity , µg cm

-1

1.32×10

-2

0.0467 -1

Limit of detection (LOD), μg ml

0.27 -1

Limit of quantification (LOQ), μg ml

Regression equation, y Intercept (a)

4

0.81 b

-0.0220

Slope (b)

0.0230

Standard deviation of a (Sa)

0.0121

Standard deviation of b (Sb) 2

Variance (Sa ) Regression coefficient (r)

0.0006 1.46×10

-4

0.9988

a

Limit of determination as the weight in μg per ml of solution, which corresponds to an absorbance of A = 0.001 measured in a cuvette of crossb section area 1 cm2 and l = 1 cm; y = bx + a, where y is the absorbance, x is concentration in µg ml-1, a is intercept, b is slope

Precision and accuracy. In order to determine the accuracy and precision of the proposed method,

263

N. RAJENDRAPRASAD, K. BASAVAIAH, K.B. VINAY: EXTRACTIVE SPECTROPHOTOMETRIC…

Robustness and ruggedness. The robustness of the method was evaluated by making small incremental changes in the volume of dye and contact time, and the effect of these changes on the absorbance of the coloured systems was studied. The changes had negligible influence on the results as revealed by small intermediate precision values expressed as % RSD (≤ 1.88%). Method ruggedness was demonstrated by having the analysis done by four analysts, and also by a single analyst performing analysis on four different instruments in the same laboratory. Intermediate precision values (%RSD) in this study were in the range 1.78-2.64% indicating acceptable ruggedness. The results are presented in Table 3. Application to tablets. The proposed method was applied for the quantification of QTF in commercial tablets. The results obtained were compared with those obtained using a conventional UV spectrophotometric method [28], where the absorbance of the methanolic solution of QTF was measured at 246 nm. Statistical analysis of the results did not detect any significant difference in the performance of the proposed method to the reference method with respect to accuracy and precision as revealed by the Student’s t-value and variance ratio F-value. The results of this study are given in Table 4. Application to spiked human urine. As an additional application, the developed method was applied to determine QTF in spiked urine sample. The recovery of QTF from spiked human urine sample was carried out on three different concentrations (12, 18 and 24 µg ml-1). As shown in Table 5, the percentage recovery values in the range 95.63-106.1 with standard deviation values of less than 3% proved that the accuracy and reproducibility of the proposed method

the assay described under “Procedure for calibration curve” was repeated seven times on the same day to determine the repeatability (intra-day accuracy and precision) and five times on different days to determine the intermediate precision (inter-day accuracy and precision). These assays were performed for three levels of analyte. The results of this study are summarized in Table 2. The percentage relative standard deviation (%RSD) values were ≤ 2.01% (intra-day) and ≤ 2.2% (inter-day) indicating high precision of the method. The accuracy of the method was determined by the percent mean deviation from known concentration, by using the formula: %RE =

CI&CEQ 17 (3) 259−267 (2011)

Found − Taken  QTF × 100 TakenQTF

and the obtained results are presented in Table 2. Percent relative error (%RE) values ≤ 2.44% demonstrate the high accuracy of the proposed method. Selectivity. The results obtained from placebo blank and synthetic mixture analyses revealed that the inactive ingredients used in the preparation did not interfere in the assay of active ingredient. The absorbance values obtained from the placebo blank solution were almost equal to the absorbance of the blank which revealed no interference from the adjuvants. To study the role of additives added to the synthetic sample, 5 ml of the resulting solution prepared by using synthetic mixture containing 6 mg of QTF was assayed (n = 4). The percentage recoveries of 98.36–102.65 with %RSD values in the range 0.92– -3.53 demonstrated the accuracy as well as the precision of the proposed method and complement the findings of the placebo blank analysis with respect to selectivity.

Table 2. Evaluation of intra-day and inter-day accuracy and precision (%RE – percent relative error, %RSD – relative standard deviation and CL – confidence limits were calculated from: CL = ±tS/√n; the tabulated values of t are 2.45 and 2.77 for six and four degrees of freedom respectively, at the 95% confidence level; S – standard deviation and n – number of measurements) QTF taken, µg ml

-1

Intra-day accuracy and precision (n = 7) -1

6.0 18.0 24.0

Inter-day accuracy and precision (n = 5) -1

QTF found±CL, µg ml

%RE

%RSD

QTF found±CL, µg ml

%RE

%RSD

5.92±0.09 18.22±0.25 24.26±0.56

1.33 1.22 1.08

1.58 1.50 2.01

6.08±0.17 17.56±0.37 24.39±0.73

1.33 2.44 1.63

2.20 1.69 2.00

Table 3. Method robustness and ruggedness expressed as intermediate precision (% RSD) Robustness QTF taken, µg ml

-1

Ruggedness

Parameters altered Volume of dye

a

b

Reaction time

Inter-analysts (%RSD, n = 4)

Inter-instruments (%RSD, n = 4)

12

1.88

0.96

2.64

2.58

18

1.84

1.03

1.78

1.86

24

1.78

1.03

2.35

2.14

a

b

The volumes of dye used were 4, 5 and 6 ml; the reaction times were 4, 5 and 6 min

264

N. RAJENDRAPRASAD, K. BASAVAIAH, K.B. VINAY: EXTRACTIVE SPECTROPHOTOMETRIC…

CI&CEQ 17 (3) 259−267 (2011)

Table 4. Results of analysis of tablets by the proposed methods and statistical comparison of the results with the reference method b

a

Tablet brand name

Found (percent of label claim±SD)

Nominal amount (mg/tablet)

Reference method

Proposed method

Qutipin-200

200

100.6±1.34

102.1±0.89 t = 2.12 F = 2.27

Qutipin-100

100

98.76±1.42

97.8±0.569 t = 1.53 F = 6.22

a

b

Marketed by: Sun Pharmaceuticals Ltd., India; mean value of 5 determinations; tabulated t-value at the 95 % confidence level and for four degrees of freedom is 2.77; tabulated F-value at the 95 % confidence level and for four degrees of freedom is 6.39

phic techniques [4-11,21,22,30-36] have several disadvantages such as expensive instrumental setup, multiple steps, longer analysis time, stringent experimental conditions to be maintained, and several clean-up steps. The proposed method makes use of an inexpensive reagent, and low-cost instrument which can be afforded in any ordinary laboratory. The method is sufficiently sensitive to permit determination even down to 0.27 µg ml-1. The proposed method has the advantages of simplicity and reproducibility, and satisfies the need for a rapid procedure for the assay of QTF in bulk drug and in tablets in quality control laboratories. The hall-mark of proposed method is its application to the determination of QTF in spiked human urine without any prior-extraction procedure. Therefore, the method allows determination of QTF in human urine samples in the physiological concentration range obtained after the usual therapeutic dose of QTF has been administered.

are satisfactory for the determination of QTF in spiked human urine and non-interferences from matrices present in urine. Table 5. Application of the proposed method to QTF concentration measurements in spiked human urine -1

QTF added, µg ml 12.0 18.0 24.0 a

QTF found -1 µg ml

a

Recovery of QTF (percent±SD)

11.48 18.58 25.46

95.63±1.89 103.2±2.89 106.1±1.23

Mean value of three determinations

Recovery study. To further assess the accuracy of the method, recovery experiment was performed by following the standard-addition technique. The recovery was assessed by determining the agreement between the measured standard concentration and added known concentration to the sample. The test was done by spiking the pre-analyzed tablet powder with pure QTF at three different levels (50, 100 and 150 % of the content present in the tablet powder (taken)) and the total was found by the proposed method. Each test was repeated three times. The percentage recovery values ranged between 97.8 and 105.9 with standard deviation in the range 1.06-2.55%. Closeness of the results to 100% showed the good accuracy of the method. The results of this study are shown in Table 6.

Acknowledgement Authors are thankful to Cipla Ltd., Bangalore, India, for providing pure QTF sample. Authors also thank the University of Mysore, Mysore, India, for providing facilities to carry out this work. One of the authors (NRP) is grateful to the University Grants Commission, New Delhi, India, for giving meritorious research fellowship. REFERENCES

CONCLUSION A sensitive extractive spectrophotometric method for the determination of quetiapine fumarate in pharmaceutical preparations and spiked human urine was developed and validated. The reported chromatogra-

[1]

J. Arnt, T. Skarsfeldt, Neuropsychopharmacol. 18 (1998) 63-101

[2]

Matrindale: The complete Drug Reference, Electronic Version; S. Sweetman, Ed.; Pharmaceutical Press; London, 2006.

Table 6. Results of recovery study via standard-addition method (mean value of three determinations); QTF in tablet: 12.0 μg ml-1 Tablets studied Qutipin-200

-1

-1

Pure QTF added, µg ml

Total found, µg ml

Pure QTF recovered (percent±SD)

6.0 12.0 18.0

17.87 24.67 31.06

97.8±1.89 105.6±1.06 105.9±2.55

265

N. RAJENDRAPRASAD, K. BASAVAIAH, K.B. VINAY: EXTRACTIVE SPECTROPHOTOMETRIC…

CI&CEQ 17 (3) 259−267 (2011)

[3]

S.M. Cheer, A.J. Wagstaff, CNS Drugs 18 (2004) 173-199

[26]

[4]

F. Belal, A. Elbrashy, M. Eid, J.J. Nasr, J. Liquid Chromatogr. Rel. Technol. 31 (2008) 1283–1298

N. El-Enany, A. El-Brashy, F. Belal, N. El-Bahay, Portugaliae Electrochim. Acta 27 (2009) 113-125

[27]

[5]

P.C. Davis, A.J. Wonga, O. Gefvertb, J. Pharma. Biomed. Anal. 20 (1999) 271–282

N. Rajendraprasad, K. Basavaiah, K.B. Vinay, Portugaliae Electrochim. Acta 28 (2010) 299-308

[28]

[6]

J. Sachse, J. Köller, S. Härtter, C. Hiemke, J. Chromatogr., B 830 (2006) 342-348

V. Pucci, R. Mandrioli, A. Ferranti, S. Furlanetto, M.A. Raggi, J. Pharm. Biomed. Anal. 32 (2003) 1037-1044

[29]

[7]

M.A. Saracino, L. Mercolini, G. Flotta, L.J. Albers, R. Merli, M.A. Raggi, J. Chromatogr., B 843 (2006) 227-233

S. Hillaert, L. Snoeck, W. van den Bossche, J. Chromatogr. 1033 (2004) 357-362

[30]

[8]

R. Mandrioli, S. Fanali, A. Ferranti, M.A. Raggi, J. Pharm. Biomed. Anal. 30 (2002) 969-977

B. Dhandapani, A. Somasundaram, S. H. Raseed, M. Raja, K. Dhanabal, Int. J. PharmTech Res. 1 (2009) 139-141

[31]

[9]

C. Frahnert, M.L. Rao, K. Grasmader, J. Chromatogr., B 794 (2003) 35-47

R. Skibiński, Ł. Komsta, I. Kosztyła, J. Chromatogr. Modern TLC 21 (2008) 289-294

[32]

[10]

J. Hasselstroem, K. Linnet, J. Chromatogr., B 798 (2003) 9-16

S.R. Dhaneshwar, N.G. Patre, M.V. Mahadik, Acta Chromatographia 21 (2009) 83-93

[33]

[11]

W.B. Li, Y.Z. Xue, Y.M. Zhai, J. Zhang, G.X. Guo, C.Y. Wang, Z.J. Cai, Yaowu Fenxi Zazhi 23 (2003) 247-251 (in Chinese)

S. Radha Krishna, B.M. Rao, N. Someswara Rao, Rasayan J. Chem. 1 (2008) 466-474

[34]

C.H. Bharathi, K.J. Prabahar, C.H.S. Prasad, M. Srinivasa Rao, G.N. Trinadhachary, V.K. Handa, R. Dandala, A. Naidu, Pharmazie 63 (2008) 14-19

Planar

[12]

S.A. Bellomarino, A.J. Brown, X.A. Conlan, N.W. Barnett, Talanta 77 (2009) 1873-1876

[35]

[13]

K. Y. Li , Z. N. Cheng , X. Li , X. L. Bai , B. K. Zhang, F. Wang, H. D. Li, Acta Pharmacol. Sin. 25 (2004) 110-114

C.M. Fu, R.Z. Wang, Zhongguo Xinyao Zazhi 11 (2002) 144-146 (in Chinese)

[36]

[14]

Z.L. Zhou, X. Li, K.Y. Li, Z.H. Xie, Z.N. Cheng, W.X. Peng, F. Wang, R.H. Zhu, H.D. Li, J. Chromatogr., B 802 (2004) 257-262

I.V.S. Raju, P. Raghuram, J. Sriramulu, Chromatographia 70 (2009) 545-550

[37]

R.A. Fursule, D.K. Rupala, M.D. Mujeeb Gulzar Khan, A. A. Shirkhedkar, S.J. Surana, Biosci. Biotechnol. Res. Asia 05 (2008), http://www.biotech-asia.org/ display.asp?id=429.

[38]

R.X. Arulappa, M. Sundarapandian, S. Venkataraman, M. Boopathi, M. Kaurav, Res. J. Pharm. Tech. 2 (2009) 884-885

[39]

N. Rajendraprasad, K. Basavaiah, K. B. Vinay, J. PreClin. Clin. Res. 4 (2010) 24-31

[40]

O.H. Abdelmageed, P.Y. Khasaba, Talanta 40 (1993) 1289-1294

[15]

Z. Li, Z. R. Tan, D.S. Ouyang, G. Wang, L.S. Wang, G. Zhou, D. Guo, Y. Chen, H.H. Zhou, Yaowu Fenxi Zazhi 28 (2008) 706-708 (in Chinese)

[16]

S.N. Lin, Y. Chang, D.E. Moody, R.L. Foltz, J. Anal. Tox. 28 (2004) 443-448

[17]

B. Barrett, M. Holcapek, J. Huclova, V. Borek-Dohalsky, P. Fejt, B. Nemec, I. Jelinek, J. Pharm. Biomed. Anal. 44 (2007) 498-505

[18]

R. Nirogi , G. Bhyrapuneni , V. Kandikere, K. Mudigonda, D. Ajjala, K. Mukkanti, Biomed. Chromatogr. 22 (2008) 1043–1055

[19]

A. Tan, B. Pellerin, J. Couture, F. Vallée, SFBC Anafarm, http://www.aapsj.org/abstracts/AM_2006/staged/ /AAPS2006-000989.PDF

[20]

M.L. Kundlik, S. Kambli, V. Shah, Y. Patel, S. Gupta, R. Sharma, B. Zaware, S.R. Kuchekar, Chromatographia 70 (2009) 1587-1592

[21]

K.-Y. Li, Y.-G. Zhou, H.-Y. Ren, F. Wang, B.-K. Zhang, H.-D. Li, J. Chromatogr., B 850 (2007) 581-585

[22]

J.Y. Tu, P. Xu, D.H. Xu, H.D. Li, Chromatographia 68 (2008) 525-532

[23]

M.M. McMullin, Ther. Drug Monit. 21 (1999) 459-459

[24]

V.N. Atanasov, K.P. Kanev, M.I. Mitewa, Central Europ. J. Med. 3 (2008) 327-331

[25]

S.A. Ozkan, B. Dogan, B. Uslu, Microchim. Acta 153 (2006) 27-35

266

[41]

S. Ashour, R. Alkhalil, Farmaco 60 (2005) 771-775

[42]

J.C. Botello, G. Perez-Caballero, Talanta 42 (1995) 105-108

[43]

C.S.P. Sastry, K. Rama Rao, D. Siva Prasad, Talanta 42 (1995) 311-316

[44]

W.C. Vocburgh, G.R. Cooper, J. Amer. Chem. Soc. 63 (1941) 437-442

[45]

A.E. Harvey, D.L. Manning, J. Amer. Chem. Soc. 72 (1950) 4488-4493

[46]

International Conference on Hormonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, ICH Harmonised Tripartite Guideline, Validation of Analytical Procedures: Text and Methodology Q2(R1), Complementary Guideline on Methodology dated 06 November 1996, incorporated in November 2005, London.

N. RAJENDRAPRASAD, K. BASAVAIAH, K.B. VINAY: EXTRACTIVE SPECTROPHOTOMETRIC…

NAGARAJU RAJENDRAPRASAD KANAKAPURA BASAVAIAH KANAKAPURA BASAVAIAH VINAY Department of Chemistry, University of Mysore, Manasagangothri, Mysore, India NAUČNI RAD

CI&CEQ 17 (3) 259−267 (2011)

EKSTRAKTIVNO SPEKTROFOTOMETRIJSKO ODREĐIVANJE KUETIAPIN FUMARATA U FARMACEUTSKIM PREPARATIMA U LJUDSKOM URINU POMOĆU KALMAGITA KAO JONSKOG PARA Kuetiapin fumarat (QTF) je antipsihotik koji pripada derivatima benzisoksazola, koji se koristi u lečenju šizofrenije. U radu je opisana osetljiva i selektivna spektrofotometrijska metoda zasnovana na ekstrakciji jonskog para QTF-kalmagit (CGT) sa dihlormetanom, koji pokazuje apsorpcioni maksimum na 490 nm. Na ovoj talasnoj dužini, Berov zakon važi u opsegu koncentracije od 3,0 do 30,0 μg ml-1. Vrednosti molarne apsorpsione konstante, limita detekcije i limita kvantifikacije su 1,32×104 l mol-1 cm-1, 0,27 i 0,81 μg ml-1, redom. Ova reakcija je jako brza na sobnoj temperaturi, a vrednost apsorbance ostaje nepromenjene u toku 19 sati. Preciznost metode, izražene preko vrednosti standardne devijacije intra- i inter-dnevne preciznosti, je zadovoljavajuća (RSD ≤ 2,2%). Tačnost je, takođe, zadovoljavajuća (RE ≤ 2,44%). Ova metoda je uspešno primenjena za određivanje QTF u farmaceutskim preparatima i ljudskom urinu sa zadovoljavajućim rezultatima. Nije uočena interferencija sa uobičajenim pomoćmim lekovima u tabletama. Statističko poređenje rezultata sa oficijelnom metodom je pokazalo odlično slaganje i nije ukazalo na značajne razlike u preciznosti. Ključne reči: kuetiapin fumarat, spektrometrija, kalmagit, ljudski urin, kompleks jonskog para.

267