INTRODUCTION:

All drugs in this class have analgesic, antipyretic and anti-inflammatory actions in different measures. In contrast to morphine they do not depress CNS, do not produce physical dependence, have no abuse liability and are weaker analgesics (except for inflammatory pain). They are also called non-narcotic, nonopioid or aspirin-like analgesics. They act primarily on peripheral pain mechanisms, but also in the CNS to raise pain threshold. They are more commonly employed and many are over-the-counter drugs¹².

Figure 1: Structure of Lornoxicam

INSTRUMENTATION:

Double beam UV- visible spectrophotometer, Make: JASCO spectrophotometer, model Jasco V630 connected to a computer loaded with spectra manager software was used for all the spectrophotometric measurements in all proposed spectrophotometric methods. It consists of pair of 10 mm matched quartz cells was used for experiments. The absorption spectra of reference and test solution were carried out in a 1 cm quartz cell over the range 200-400 nm.

Reagents and Chemicals :

All the reagents used were of analytical reagent grade. Lornoxicam was a gifted sample obtained from Abbott Pharma Ltd., Mumbai, India.

Preparation of Stock Solution of Lornoxicam :

Standard Lornoxicam of 10mg was accurately weighed and transferred into a 100 ml volumetric flask. Add small quantity of methanol in volumetric flask and dissolve the drug into it and then adjust the volume upto 100 ml this solution form 100 ppm of concentration and then prepared further dilutions.

Selection of Analytical Concentration Ranges:

From the standard stock solutions of Lornoxicam (100 ug/ml), appropriate aliquots of 2 ppm, 4 ppm, 6 ppm, upto 24ppm.

Determination of Absorption Maxima(λmax):

10ug/ml solution of Lornoxicam was prepared and scanned in UV range of 200-400nm and spectrum was obtained. The λmax was found to be at 375nm wavelength where absorbance was maximum at this wavelength.

Validation Parameters for Lornoxicam:

Accuracy:

Accuracy is the closeness of the results obtained by the method to the true value. This study can be done with the help of preparing three concentrations of 14, 16 and 18 ppm each respectively.

Precision:

The precision of an analytical method is the degree of agreement among individual test results, when the method is applied repeatedly to multiple sampling of homogeneous samples. It provides an indication of random error results and is expressed as relative standard deviations [% RSD].

Robustness:

The solution were prepared and analysed with change in the analytical conditions like change in wavelength, change in solvent etc. This can be studied with the help of using minimum six concentrations. Absorbance can be calculated using UV spectrophotometer.

Limit of Detection [LOD] and Limit of Quantitation [LOQ]:

The sensitivity of the proposed method for the measurement of Lornoxicam was estimated in terms of limit of detection [LOD] and limit of quantitation [LOQ]. The LOD and LOQ were calculated by using the slope and SD of response [intercept]. The mean slope value and the SD of response were obtained from the calibration curve. The LOD and LOQ calculations were done and reported.

Linearity, Range and Calibration:

The method can be validated by using ICH guidelines. The linearity of analytical method is its ability to elicit test results that are directly proportional to the concentration of analyte in the sample within the range. The range of the analytical method is the interval between the upper and the lower levels that have been demonstrated to be determined within a suitable level of precision, accuracy and linearity.

Application of the Proposed Method for Pharmaceutical Dosage Form:

The solution was filtered through whatmann filter paper 0.5 ml of this solution was transferred to 10 ml volumetric flask and final volume made with the help of solvent. It was scanned on a spectrophotometer in the UV range 200-400 nm. The spectrum was recorded at 375 nm against blank solution. Determine the amount of % Lornoxicam in solid SMEDDS according to the following formula.

AT× WS× Sample D.F. × Average weight × PR

% Assay = ----------------------------------------------------------

AR× Standard D.F. × WT×LA

Where,

WS= weight of standard; WT= weight of sample, AT= absorbance of Lornoxicam solid SMEDDS in the test solution, AR=absorbance of Lornoxicam solid SMEDDS in the standard solution, Standard D.F. = Standard dilution factor, Sample D. F. = Sample dilution factor, PR= Purity of working standard [%], LA= Labeled amount of Lornoxicam.

RESULT AND DISCUSSION:

The method was validated according to ICH guidelines in order to determine the linearity, precision, accuracy and ruggedness of the method.

The standard stock solution of Lornoxicam 10 ug/ml concentration was scanned from 200-400 nm and the absorption spectra’s were recorded at 375 nm wavelength in UV spectrophotometer.

Linearity:

The absorbance of the solution of Lornoxicam solid SMEDDS was determined at a wavelength of 375 nm. The correlation coefficient was found to be 0.9967 and the regression equation was found to be Y= 0.0252x+ 0.0718. The calibration curves and overlay spectra’s of Lornoxicam solid SMEDDS was shown in fig.

Intermediate Precision [Reproducibility]:

The precision of the developed method was expressed in terms of percent relative standard deviation [%RSD]. These results show reproducibility of the assay. The % RSD values were found to be less than 2 that indicate this method precise for the determination of the pure form. The interday and intraday precision results were mentioned in table 3.

Accuracy:

Accuracy is determined by performing recovery studies at 3 levels in which known amount of analyte shall be added and recovery shall be carried out in three replicates of each concentration level and the % recovery was calculated. The accuracy results are shown in table.5.

Ruggedness:

Ruggedness studies was performed by two different analysts and two different analyst and the results of the study and % RSD obtained was less than 2 which is within the acceptance limits. And % RSD were found to be 0.34was reported in table.6.

Limit of Detection and Limit of Quantification:

The parameters LOD and LOQ were determined on the basis of response and slope the regression equation LOD and LOQ values are 0.0868 and 0.2632 respectively.

Application of the Proposed Method for Pharmaceutical Formulation:

The result of % purity was found to be 98.70 which were shown in table.7.

Table no.1: Data for Calibration curve.

Sr. no.	Concentration	Bulk form	Solid SMEDDS
Sr. no.	Concentration	Absorbance
1	5	0.2081	0.2166
2	10	0.3193	0.3181
3	15	0.4469	0.4513
4	20	0.5619	0.5609
5	25	0.6912	0.6910
6	30	0.8412	0.8429

Table No.2: Repeatability Studies of Lornoxicam Solid SMEDDS.

Sr. no.	Concentration	Absorbance	S. D.	R.S.D.
1	10	0.3219
2	10	0.3211
3	10	0.3228	0.5243	0.5279
4	10	0.3201
5	10	0.3237
6	10	0.3229

Table no. 3: Intermediate Precision.

Concentration taken

[ug/ml]

Intraday precision

Interday precision

Absorbance

% RSD

Absorbance

Mean

% RSD

0.3238

0.3231

0.3234

0.0139

0.1396

0.3238

0.3231

0.3234

0.0139

0.1396

0.4501

0.4481

0.4485

0.0488

0.3258

0.4504

0.4481

0.4485

0.0488

0.3258

0.5689

0.5698

0.5711

0.0439

0.2220

0.5684

0.5698

0.5711

0.0439

0.2220

Table no.4: Determination of accuracy results of Lornoxicam solid SMEDDS.

Spiked level

[%]

Formulation concentration [ug/ml]

Absorbance

Amount recovery

% Amount recovery

RSD

0.5233

0.5229

0.5227

17.9167

17.7900

17.8929

98.95

98.75

98.66

0.0121

0.0677

100

0.5233

0.5229

0.5227

19.8452

19.8571

19.8730

98.45

98.57

98.73

0.0139

0.0702

120

0.6208

0.6211

0.6216

21.797

21.809

21.829

98.31

98.41

98.43

0.0160

0.0735

Table no.5: Ruggedness of Lornoxicam solid SMEDDS for different analyst.

Concentration [ug/ml]	Analyst 1	% mean recovery± S.D.	% R.S.D.	Analyst 2	% Mean recovery± S.D.	% R.S.D.
Concentration [ug/ml]	Absorbance	% mean recovery± S.D.	% R.S.D.	Absorbance	% Mean recovery± S.D.	% R.S.D.
10	0.3211	99.11±0.34	0.34	0.3201	98.96±0.34	0.35
10	0.3219			0.3215
10	0.3208			0.3208
10	0.3206			0.3227
10	0.3222			0.3209
10	0.3228			0.3211

Table no.6: Assay studies of Lornoxicam solid SMEDDS.

Formulation	% purity	Mean ± SD	% RSD
Solid SMEDDS	98.7037	98.70± 0.21	0.2168

Conclusion:

Regression equation like slope [b], intercept [a] and correlation coefficient [R²] using the method of least squares were calculated and are presented in table. 8. The results show that the methods are reasonably precise. The developed UV Spectrophotometric method was found to be simple, economic, easy, accurate, precise, reproducible and highly sensitive and can be used for routine estimation of Lornoxicam in bulk and formulations.

Table no.7: Summary of UV Spectrophotometric method for estimation of Lornoxicam Solid SMEDDS.

Parameters	Bulk formulation	Solid SMEDDS formulation
λmax [nm]	375	375
Correlation coefficient	0.9978	0.9966
Regression equation	0.0251x+0.0718	0.0249x+0.0775
Slope	0.0251	0.0249
Intercept	0.0718	0.0775

ACKNOWLEDGEMENTS:

The authors are grateful to R. G. Sapkal College of Pharmacy for providing necessary research facilities to carry out the research work and to Glenmark Pharmaceuticals, India for providing the gift sample of the drug.

REFERENCES :

1. John H. Block, John M. Beale, Wison and Gisvolds textbook of organic medicinal and pharmaceutical chemistry, 11^th edition, Lippincott Williams and Wilkins, page no. 812 -813.

2. Clarks analysis of drugs and poisons, 3^rd edited by Anthony Moffat, volume 2. Page no. 1057.

3. Remington the science and practice of pharmacy, 21^st edition volume 1. Lippincott Williams and Wilkins. Page no. 643.

4. US 797262626, July 5, 2011. Inventor- Imtiaz Chaudry, having patent on Fluticasone propionate pharmaceutical nasal formulation.

Received on 10.08.2016 Modified on 27.08.2016

Res. J. Pharm. Dosage Form. & Tech. 2016; 8(4): 269-272

DOI: 10.5958/0975-4377.2016.00037.9