INTRODUCTION:

Chemically Loratadine, is Ethyl 4-(8-chloro 5, 6-dihydro-11H-benzo [5,6]cyclo hepta[1,2-b]pyridine 11-ylidene)-1-piperidine carboxylate. It is white to off white powder not soluble in water but very soluble in acetone, alcohol and chloroform. It has a molecular weight of 382.89 and empirical formula of C₂₂H₂₃ClN_202.

Analysis is an important component in the formulation development of any drug molecule. A suitable and validated method has to be available for the analysis of drug(s) in the bulk, in drug delivery systems, from release dissolution studies and in biological samples. If a suitable method, for specific need, is not available then it becomes essential to develop a simple, sensitive, accurate, precise, reproducible method for the estimation of drug samples. The estimation of Loratadine by high performance liquid chromatography [HPLC]², high performance thin layer chromatography [HPTLC]⁴ is reported in Literature.

MATERIALS AND METHOD

Instrument and materials

Instrument used were pharmaspec UV-1700 Shimadzu UV/Visible Spectrophotometer and Shimazdu AX200 analytical balance. Loratadine pure drug was obtained from Micro Labs Ltd.

Hyderabad as gift sample with 99.99% w/w assay value and was used without further purification. All chemicals and reagents used were of analytical grade.

Selection of media:

Main criteria for media selection are solubility and stability, i.e. drug should be soluble as well as stable for sufficient time in selected media. Though the official reported media for this drug is Acetone, Alcohol and Chloroform but in provided experimental condition drug is giving clear solution in Methanol, has been selected as analytical media.

Preparation of standard stock solution:

Standard drug solution of Loratadine was prepared by dissolving 10mg Loratadine in 10ml methanol to obtain stock solution of 1000μg/ml concentration. From that 1ml is transferred to 10 ml standard flask and make up to mark with methanol. So that we obtain 100 μg/ml.

Preparation of calibration curve:

Calibration curve was prepared using Methanol at max 245 nm using UV-1700 Shimazdu UV-Visible spectrophotometer. For this stock solution of 100mg/ml was prepared. Serial dilution of 0, 5, 10, 15, 20, and 25 μg /ml were prepared and absorbance was taken at λ max 245 nm. Averages of such 5 sets of values were taken for standard calibration curve, and solutions were scanned in the range of 200-400 nm against blank. The calibration curve was plotted. The optical characteristics are summarized in Table no.1

No.1 - Calibration Curve parameter.

S. No	Concentration (μg /ml)	Absorbance
1.	5	0.028
2.	10	0.051
3.	15	0.078
4.	20	0.098
5.	25	0.118

Table.2 - Validation parameters

S. No	Parameter	Result
1	Absorption maxima(nm)	245
2	Linearity range(μg/ml)	5-25
3	Standard regression equation	Y=0.0043X+0.01
4	Correlation coefficient	0.9868
5	Molar absorbtivity	13631.49
6	Accuracy	98.9%
7	Precision	99.9%(Intra day precision) &100.1%(Inter day precision)
8	Specificity	A 20μg/ml solution of candidate drug in methanol at UV detection 1 of 245nm will show an absorbance of 0.098
9	LOD	0.99
10	LOQ	3.3

Preparation of sample solution:

Ten tablets were weighed and powdered. The amount of tablet powder equivalent to 10 mg of Loratadine was weighed accurately and transfer to 25 ml methanol and kept for 15 min with frequent shaking and volume was made up to 100 ml mark with Methanol. The solution was then filtered through Whatmann filter paper # 41. This filtrate was diluted suitably with methanol to get 25 μg /ml .The absorbance was measured against blank (Methanol). The drug content of the preparation was calculated using standard calibration curve. Amount of drug estimated by this method is given in Table no.3

RESULT AND DISCUSSION:

Precision:

Assay of method precision (intra-day precision) was evaluated by carrying out three independent assays of test samples of Loratadine. The intermediate precision (Inter-day precision) of the method was also evaluated using two different analysts, systems and different days in the same laboratory. The relative standard deviation (RSD) and assay values obtained by two analysts were and respectively (Table no.4).

Figure No.2 - Determination of λ max of Loratadin by UV scanning.

Accuracy (Recovery Test):

Accuracy of the method was studied by recovery experiments. The recovery experiments were performed by adding known amounts to tablet. The recovery was performed at three levels, 80,100and 120% of Loratadine standard concentration. The recovery samples were prepared in afore mentioned procedure. Three samples were prepared for each recovery level. The solutions were then analyzed, and the percentage recoveries were calculated from the calibration curve. The recovery values for

Loratadine ranged from 99.97 ± 0.3969 (Table no.3).

Figure No.3 - Determination of linearity of Loratadine

Linearity:

The linearity of the response of the drug was verified at 0 to 50 μg /ml concentrations, but linearity was found to be between 5-25 μg /ml concentration. The calibration graphs were obtained by plotting the absorbance versus the concentration data and were treated by linear regression analysis (Table no.2). The equation of the calibrationcurve for loratadine obtained y = 0.0043X+0.01, the calibration curve was found to be linear in the afore mentioned concentrations. The correlation coefficient (r2) of determination was 0.99868.

Limit of Detection (LOD) and Limit of Quantification (LOQ):

The LOD and LOQ of loratadine were determined by using standard deviation of the response and slope approach as defined in International Conference on Harmonization (ICH) guidelines .The LOD and LOQ was found to be as in table no.2.

Determination of Active Ingredients in Tablets:

The validated method was applied to the determination of Loratadine in Tablets. five tablets were assayed and the results are shown in (Table no. 3) indicating that the

amount of drug in tablet samples met with requirements (99–102% of the label claim).

CONCLUSIONS:

The developed method was found to be simple, sensitive, accurate, precise, reproducible, and can be used for routine quality control analysis of Loratadine in bulk and pharmaceutical formulation

Sample number	Assay of loratadine as % labeled amount
Sample number	Analyst-I (Intra –day precision)	Analyst-II (Inter-day precision)
1	99.46	99.84
2	99.62	99.78
3	99.54	99.69
4	99.66	99.75
5	99.74	99.86
6	99.84	99.98
MEAN	99.64	99.81
RSD	0.074	0.0741

Table no 4: Determination of Precision

ACKNOWLEDGEMENT:

We are thankful to Micro Labs Ltd. Hyderabad for providing the gift sample of Loratadine. We would also like to thank Mr. Ishari Ganesh Chancellor, Vel’s University for providing all the facilities to complete our work successfully.

REFERENCES:

1. Reddy K.V.S.R.K.; Babu J.M.; Kumar Y.R.; Reddy S.V.V.; Kumar M.K.; Eswaraiah S.; Reddy K.R.S.; Reddy M.S.; Bhaskar B.V.; Dubey P.K.; Vyas K.¹ Impurity profile study of loratadine Journal of Pharmaceutical and Biomedical Analysis, Volume 32, Number 1, 24 April 2003, pp. 29-39(11)

2. Spectrophotometric and HPLC methods for simultaneous estimation of pseudo ephedrine hydrochloride and loratadine from tablets Indian Journal Of pharmaceutical Sciences Year 2006, Volume 68 Page no.72-75.

3. Journal Of Pharmaceutical And Biomedical Analysis

4. Jabera A.M.Y., Sherifeb H.A. Al., Omarib, M.M., J.Pharmaceut.Biomed.Anal.. 2004, 36,341–350.

5. Melanie M.T., Brian Beatoa., Weng Naidongb., Journal of Chromatography B, 2005, 814,

Received on 23.09.2009 Modified on 19.11.2009

Asian J. Research Chem. 3(2): April- June 2010; Page 302-304

Ingredients	Tablet amount(μg/ml)	Level of addition (%)	Amount added (mg)	Drug found (mg/ml)	% Recovery	Average percentage recovery
Loratadine	20	80	17.4	9.86	98.6	99.5
	20	100	20	9.98	99.8
	20	120	22.6	10.02	100.2