INTRODUCTION:
Ziprasidone1,2 (5-[2-[4-(1, 2-benzothiazol-3-yl) piperazin-1-yl] ethyl]-6-Chloro-1, 3- dihydroindol-2- One) is the atypical antipsychotic (or second generation) approved for treatment of schizophrenia. Ziprasidone3 is indicated for the treatment of schizophrenia. Ziprasidone is indicated for the treatment of acute manic or mixed episodes associated with bipolar disorder, with or without psychotic features .Literature survey reveals individual determination and validation of Ziprasidone by, Zone electrophoresis4, spectrophotometry5, RPHPLC, LC-MSMS, LC-MS methods has been developed. To our Knowledge no article related to HPTLC method has been reported in literature.
Ziprasidone
The aim of present work is to develop an accurate, specific, repeatable, simple method foe determination of Ziprasidone in capsule dosage form as well as pure drug.6The proposed method was validated as per ICH guidelines.
MATERIALS AND METHODS:
Instrument: CAMAG HPTLC instrument was used in this method. CAMAG HPTLC is equipped with CAMAG TLC scanner-3, Linomate V Automatic sample applicator controlled by WIN CATS software (1.4.3 version). Aluminum packed silica Gel 60 F254 HPTLC plates (20 X 10cm, layer thickness 0.2mm, E.MERCK).
Reagent and chemicals:
Ziprasidone was received as gift samples from Zydus Cadila, Ahmadabad, India .All chemicals and reagents used were purchased form Merck chemicals Corporation Ltd. Mumbai, India. The drug sample in tablet dosage form, were procured from the market. [Zypsydone (Sun Pharma)]. Label claim for Ziprasidone were 20 mg. All other reagents used were of analytical grade for chromatographic method.
Optimized chromatographic condition:
Stationary phase: Pre-coated silica gel 60 F254 Aluminum plates (20x10cm)
Mobile phase: Toluene :methanol (80:20) (v/v)
Chamber saturation: 20 minutes
Development distance: 75mm
Development time: 15 minutes
Relative temperature: 25 ±2˚C
Relative Humidity: 44-49%
Detection wavelength (mm): 190-360nm
Distance between two tracks: 10 mm
Preparation of calibration curve:
To construct calibration curve 4, 8, 10, 12, 16, 20 and 22 µL of ziprasidone working solution (100 µg/mL) (Equivalent to 400, 800, 1000, 1600, and 2000, 2200 ng / band) were applied to three plates. The plates were developed and scanned at 190 and 360 nm. and peak areas were recorded for ziprasidone. Linear regression data for the calibration plots (n= 3) are illustrated in fig. no1 and 2, table no 1.
Fig 1. Chromatogram of Ziprasidone
Fig.2
Calibration curve of Ziprasidone
Table 1: Linear regression data for the calibration curve for Ziprazidone.
|
Parameter |
Observation |
|
Linearity range |
400-2200ng/Band |
|
Correlation coefficient ® |
0.99988 |
|
Slope |
4.0173 |
|
Intercept |
2648.6 |
Analysis of Commercial Formulation:
Twenty capsules were weighed and the average weight was calculated. A quantity of mixed contents of 20 capsules equivalent to 25 mg of ziprasidone was accurately weighed and transferred in to 25 ml volumetric flask. 1 mL of formic acid was added to dissolve the content and then 10 mL for methanol was added to the solution and was sonicated for 15 min at room temperature. The solution was diluted up to the mark with methanol to furnish the sample stock solution (1 mg/mL).The solution was filtered through Whatman filter paper and 10 mL was transferred to a 100 mL volumetric flask and diluted up to the mark with methanol to furnish sample stock dilution (100 µg/mL). Sample solution 10 µL was applied to the plate with standard solutions. The plate was developed and scanned under the optimized conditions described above. Peak areas were recorded and the amount of ziprasidone in the formulation was determined by use of the Calibration curve as shown in table 2.
Table 2: Recovery data of Ziprazidone
|
Concentration (ng/band) |
Intra-day precision |
Inter-day precision |
||
|
Mean area (AU) |
RSD (%) |
Mean area (AU) |
RSD (%) |
|
|
400 |
4251.17 |
0.18 |
4250.59 |
0.20 |
|
1000 |
6665.50 |
0.09 |
6665.21 |
0.09 |
|
2200 |
11434.43 |
0.07 |
11435.27 |
0.07 |
Application of sample:
The TLC plates were pre-washed with methanol and activated by keeping at 115°C for about 30 minutes. Aliquots were applied on the precoated silica gel G60 F254 TLC plate. Samples were spotted in the form of bands of width 10 mm with Hamilton microlitre syringe on the pre-coated silica gel 60 F254 plate (20X10 cm). Slit dimension was kept at 6 x 0.45mm. The distance between bands was 10mm. From the peak area the amount of ziprasidone in formulation was calculated using the calibration graph.
RESULT AND DISCUSSION:
The method was validated by establishing linearity, accuracy, inter day and intra day precision of measurement of sample application. The limit of detection and limit of quantification were also determined.
Linearity calibration curve:
Calibration curve was found to be linear in the range of 400 – 2200 ng / band for Ziprasidone. Five concentration points were assayed in triplicate. Ziprasidone showed good linearity in the tested range. The regression co-efficient (R2) value for Ziprasidone was found to be 0.9988 .
Accuracy:
Recovery study was carried out for the accuracy parameter. The study was carried out at three levels. To the powdered formulation, the standard drug Ziprasidone were added 80%, 100%, 120% levels, dilutions were made, and analyzed by the method. The % recovery and % RSD were calculated, and found to be within the limit as shown in table no.2