Visible Spectrophotometric Methods for Determination of Olanzapine from Tablet Formulation

 

Indrajeet Singhvi*

Pacific College of Pharmacy, Pacific Hills, Pratap Nagar Ext., Airport Road, Debari, Udaipur (Rajasthan) -313003.

*Corresponding Author E-mail: indrajeetsinghvi@yahoo.com

ABSTRACT:

Two simple and sensitive visible spectrophotometric methods have been developed for the determination of Olanzapine form Pharmaceutical tablet dosage form.  Developed methods are based on formation of chloroform extractable ion pair colored complex of drug with Cosneasie Brilliant Blue R (Method A) and Methyl orange (Method B). The extracted complex formed in method A and B showed absorbance maxima at 596.0 nm and 411.0 nm and linearity was observed in concentration range of 25-150 µgm/ml and 0-250 µgm/ml of olanzapine respectively. The results of analysis were validated statistically and by recovery studies.

 

 

 

INTRODUCTION:

Olanzapine, Chimically 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno [2,3-b] [1,5] benzodiazepine, is an antipsychotic drug used in the treatment of schizophrenia and other psychotic syndromes¹. Several HPLC methods^2-4 have been reported for the estimation of olanzapine in pharmaceutical formulations. Various other techniques including HPTLC⁵, non-aqueous titrimetry and UV spestrophotometry⁶, colorimetry^7-9 have been reported for assay of Olanzapine in pharmaceuticals. An attempt has been made in present study to develop two simple visible spectrophotometric methods for determination of Olanzapine in Pharmaceutical tablet dosage form.

 

MATERIALS AND METHODS:

Apparatus: A Shimadzu UV/Visible double beam spectrophotometer (Model 1700) with 1 cm matched quartz cells were used in present study for spectral and absorbance measurements.

 

Reagents and Materials: All reagents used were of analytical grade. Doubled distilled water was used.

Cosneasie Brilliant Blue R reagent: Dye solution (0.1% w/v) was prepared in phosphate buffer pH 6.8 and was extracted several times with chloroform  to remove soluble impurities.

 

Methyl Orange reagent: Dye solution (0.1% w/v) was prepared in double distilled water and was extracted several times with chloroform to remove soluble impurities.

 

Standard Stock Solution: Stock solution of drug Olanzapine was prepared in chloroform so as to give a concentration of 500µgm/ml of drug.

 

Methods:

Using Cosneasie Brilliant Blue R (Method A): Standard stock solution of Olanzapine (500µgm/ml) was further diluted with chloroform so as to give several dilutions in concentration range of 25-150µgm/ml of drug. To 10 ml of each dilution taken in separating funnel, 10 ml of Cosneasie Brilliant Blur R reagent was added, Reaction mixture was shaken gently for 5 min and allowed to stand so as to separate the aqueous and chloroform layer. Colored chloroform layer was separated out and absorbance was measured at 596.0 nm against reagent blank. Calibration curve was prepared from absorbance values obtained. A representative spectra of extracted complex is presented in fig 1.

 

 

Using Methyl Orange (Method B): Standard stock solution of Olanzapine (500µgm/ml) was further diluted with chloroform so as to give several dilutions in concentration range of 0-250µgm/ml of drug. To 10 ml of each dilution taken in separating funnel, 10 ml of Methyl Orange reagent was added, Reaction mixture was shaken gently for 5 min and allowed to stand so as to separate the aqueous and chloroform layer. Colored chloroform layer was separated out and absorbance was measured at 411.0 nm against reagent blank. Calibration curve was prepared from absorbance values obtained.  A representative spectra of extracted complex is presented in fig 2.

 

 

Table 1: Results of Analysis of Tablet Formulation and Recovery Studies

Method	Brand	Label claim (mg/tablet)	% Label Claim Estimated*	S.D	%  Recovery**
Using Cosneasie Brilliant Blue R	A B C	5 10 20	99.92 101.05 98.95	0.32 0.48 0.98	100.68
Using  Methyl orange	A B C	5 10 20	98.95 98.62 99.05	1.04 0.98 0.67	99.68

*Average of five determinations

** Average of Recovery Studies at three different concentration level.

 

 

Fig.1: Representative spectra of ion pair complex of Olanzapine and Cosneasie Brilliant Blur R in Chloroform

 

Fig.2: Representative spectra of ion pair complex of Olanzapine and Methyl Orange in Chloroform

 

Analysis of Tablet Formulation: For analysis of sample solution, twenty tablets were accurately weighed and average weight per tablet was determined. The tablets were powered and powder equivalent to 20 mg of Olanzapine was accurately weighed and extracted four times with 20 ml portions of chloroform. Combined chloroform extract was filtered through Whatman filter paper No. 41 into 100 ml volumetric flask. The residue was washed with 10 ml chloroform and the washings were added to the filtrate. Final volume was made up to the mark with chloroform.  Filtrate (5 ml) was diluted to 10 ml with chloroform. This final dilution was treated as per the procedure for respective calibration curve. Absorbance was measured at respective wavelength maxima and the concentration of the drug in sample solution was determined from calibration curve. Results of analysis are presented in Table 1.

Recovery Studies:  Recovery studies were carried out by addition of pure drug to previously analysed tablet sample at three different concentration level. The results of recovery studies are reported in Table 1. The results of recovery studies reflect that there is no interference of excipients in the analysis of Olanzapine from tablet formulation.

 

RESULT AND DISCUSSION:

Two visible spectrophotometric methods have been reported for the quantative estimation of Olanzapine from tablet formulation. The developed methods are based on formation of chloroform extractable ion pair complex of drug with Cosneasie Brilliant Blue R and Methyl orange because of protonated tertiary amino group in Olanzapine. The results of analysis from tablet formulation were within the permissible limits and the result of recovery studies reflects nil interference from excipients. The developed methods were found to be simple, accurate and economical hence can be used for routine analysis of Olanzapine from pharmaceuticals.

 

REFERENCES:

1.        Shen, W. W. 1999. The metabolism of atypical antipsychoticdrugs: an update. Ann. Clin. Psychiatry 11:145-158.

2.        Raggi, M. A., Casamenti, G., Mandrioli, R., Izzo, G.and Kenndler, E. 2000. Quantitation of olanzapine intablets by HPLC, CZE, derivative spectrometry and linear voltammetry. J. Pharm. Biomed. Anal. 23:973-981.

3.        Xuejun, X. and Zhonghua, T. 2004. Determination of olanzapine and its tablets by HPLC.  Zhongguo YiyaoGongye Zazhi 35: 46-48.

4.        Biryol, I. and Erk, N. 2003. Voltammetric, spectrophotometric,and high performance liquid chromatographic analysis of olanzapine. Anal. Lett. 36: 2497-2513.

5.        Shah, C. R., Shah, N. J., Suhagia, B. N. and Patel, N.M. 2007. Simultaneous assay of anzapine and fluoxetinein tablets by column high-performance liquid chromatography and high-performance thin-layer chromatography. J. AOAC Int. 90: 1573-1578.

6.        Firdous, S., Aman, T. and Nisa, A. 2005. Determination    of olanzapine by UV spectrophotometry   and non aqueous titration. J. Chem. Soc. Pak. 27: 163-167.

7.        Kanakapura, B., et.al., Simple and Sensitive spectrophotometric Determination of Olanzapine in Pharmaceutical Formulations Using Two Sulphonphthalein Acid Dyes, J. of Food and Drug Analysis, 2009, 17, 434-442.

8.        Jasinska, A. and Nalewajko, E. 2004. Batch and flowinjection methods for the spectrophotometric determination of olanzapine. Anal. Chim. Acta 508: 165-170.

9.        Krebs, A., Starczewska, B., Puzanowsha-Tarasiewicz, H. and Sledz, J. 2006. Spectrophotometric determination of olanzapine by its oxidation with N-bromosuccinimide and cerium (IV) sulfate. Anal. Sci. 22:829-833.

 

 

 

 

Received on 13.05.2011          Modified on 23.05.2011

Accepted on 07.06.2011         © RJPT All right reserved