INTRODUCTION:

Luliconazole (C₁₄H₉Cl₂N₃S₂), chemically named as 2-[(2E,4R)-4-(2,4-dichlorophenyl)-1,3-dithiolan-2-ylidene]-2-(1H-imidazol-1-yl) acetonitrile),¹ is a broad-spectrum imidazole that is active against various fungi including Tinea, Candida, Aspergillus, Trichophyton andEpidermophyton. It has amolecular weight of 354.28 and melting point in the range 121-125˚C².

Figure 1: Structure of luliconazole

Luliconazole is used for the treatment of interdigital tinea pedis, tinea cruris, and tinea corporis. The mechanism of action for luliconazole's anti-fungal activity is still not known, but luliconazole is thought to prevent the enzyme lanosteroldemethylase³. Lanosterol demethylase is needed for the synthesis of ergosterol, which is a major part of the fungus cell membranes. Luliconazole, an imidazole antifungal activity available as a 1% topical cream, is indicated for the treatment of athlete's foot, jock itch, and ringworm caused by dermatophytes such as Trichophyton rubrum, Microspore gypsum and Epidermophyton floccosum⁴.

MATERIALS AND METHODS⁵:

Materials:

Instrument used:

A double beam UV -visible spectrophotometer (Shimadzu, model 1800) was used for recording of spectra and measuring absorbance. An electronic analytical balance (Shimadzu, AY 220) were used in this study.

Chemical used:

Luliconazole pure drug was a gift sample from IQ-GenX Pvt. Ltd. Mumbai. Methanol and water used as solvent.

Method:

Preparation of standard stock solution:

Accurately weighted 10mg of luliconazole was transferred to 100ml volumetric flask, dissolved in 70ml of methanol and 30ml distilled water by shaking manually. The volume was adjusted with water up to the mark to give the final strength (100g/ml).

Figure 2: UV spectrum of luliconazole at 297 nm.

Selection of wavelength for analysis of luliconazole:

Appropriate volume 5ml of standard stock solution of luliconazole was transferred into a 10ml of volumetric flask, diluted up to the mark with methanol and distilled water to give concentration 50µg/ml. The resulting solution was scanned in the UV range (200-400nm), luliconazole showed absorbance maximum at 297nm (fig. 2).

Validation of the method⁷:

The method was validated as per ICH guidelines in terms of linearity, accuracy, precision, ruggedness and robustness.

Linearity:

Aliquots were prepared from the stock solution 3 to 15µg/ml. The sample was scanned in UV-Visible Spectrophotometer using methanol and water as a blank.

Table No. 1: Linearity of Luliconazole

Sr. No	Concentration (µg/ml)	Absorbance
1	3	0.095
2	6	0.201
3	9	0.294
4	12	0.407
5	15	0.511

Regression equation y=0.0346x - 0.0098

R²=0.9993

Figure 3: Calibration curve of luliconazole in methanol and water.

Range:

The range of an analytical procedure is an interval between upper and lower concentration of an analyte in the sample for which it has been showed that the analytical procedure has a suitable level of linearity, accuracy, precision. The obtained range of an analyte is 3 to 15µg/ml.

Accuracy:

Accuracy was determined by preparing solution of different concentration that is 80%, 100%, 120%. The percentage recovery was calculated. (Table 2)

Table No. 2: Result for accuracy

Name of drug	Level of recovery	Concentration (µg/ml)	Amount recovery	Mean % Recovery
Luliconazole	80%	8	7.9	98.75
	100%	10	9.8	98
	120%	12	11.9	99.16

Precision:

Precision of the method is studied as inter-day precision and inter-day precision. Intra-day precision was determined by analyzing the solution of known concentration i.e. 9µg/ml six times in the day. Inter-day precision was determined by analyzing the same solution for 3d over period of week. The %RSD was found to be 1.051288 and 1.138658 respectively. The %RSD values found to be less than 2.

Table No. 3: precision studies

Sr. No	Concentration (µg/ml)	Intra-day precision	Inter-day precision
1.	9	0.294	0.265
2.	9	0.287	0.295
3.	9	0.295	0.286
4.	9	0.292	0.294
5.	9	0.290	0.291
6.	9	0.289	0.289
	Average Standard deviation %RSD	0.291167 0.003061 1.051288	0.290833 0.003312 1.138658

Sensitivity:

The sensitivity of luliconazole by proposed method was estimated by limit of detection (LOD) and limit of quantification (LOQ). The LOD and LOQ were calculated using following formula

LOD= 3.3σ/ s

LOQ= 10σ /s

Where ‘σ’ is standard deviation of the response and ‘S’ is the slope of the corresponding calibration curve of analyte.

The linearity equation was found to be y= 0.0346x-0.0098. The LOD and LOD of luliconazole was found to be1.1168 and 3.3845 respectively.

Robustness:

Robustness of the proposed method is determined for 6 µg/ml concentration of luliconazole by analysis of aliquots from a homogenous slot for two different wavelengths, at two different temperatures using same environment condition.

Table No. 4: Robustness at wavelength 297 nm and 295 nm (conc.6 µg/ml)

Sr. No	Concentration. µg/ml	Absorbance (297)	Absorbance (295)
1	6	0.201	0.202
2	6	0.198	0.197
3	6	0.202	0.199
4	6	0.195	0.201
5	6	0.198	0.200
6	6	0.200	0.198
	Average SD %RSD	0.199 0.00253 1.271267	0.1995 0.001871 0.937759

Ruggedness

Ruggedness of the proposed method is determined by analysis of aliquots from a homogenous slot by two analysts for 9 µg/ml concentration of luliconazole using same operational and environmental conditions.

Table No. 5: Result of Ruggedness

Sr. No	Concentration (µg/ml)	Absorbance (Analyst 1)	Absorbance (Analyst 2)
1	9	0.294	0.295
2	9	0.292	0.293
3	9	0.289	0.291
4	9	0.291	0.292
5	9	0.295	0.290
6	9	0.290	0.291
	Average Standard deviation %RSD	0.291833 0.002317 0.793812	0.292 0.001789 0.612621

RESULTS AND DISCUSSION:

A validated simple, rapid, sensitive and accurate UV spectrophotometric method was developed for determination of luliconazole in bulk and pharmaceutical formulation. Luliconazole shows maximum absorbance at 297nm in methanol and water. The luliconazole follows Beer’s Lambert’s law in the linearity range of 3 to 15µg/ml. The linear regression coefficient was found to be 0.9993 with equation y= 0.0346x-0. 0098. Accuracy of drug was performed by recovery studies and it is near 100% i.e. 98-99%. The %RSD for intra-day and inter-day precision was found to be 1.051288 and 1.138658 respectively. The LOD and LOQ was found to be 1.1168 and 3.3845µg/ml. Robustness was calculated by two different wavelength 275 and 277 and the %RSD was found to be 1.271267 and 0.937759. ruggedness was calculated by two different analysts and two different laboratories and the %RSD was found to be 0.793812 and 0.612621 respectively.

CONCLUSION:

The developed UV-spectrophotometric technique for quantification of luliconazole in pharmaceutical formulation is quite simple, accurate, precise and sensitive. The developed method was validated for linearity, accuracy, precision (inter-day and intra-day), robustness, ruggedness, LOD and LOQ parameters studies. The result of all these parameters shows that the rapid, accurate, linear and precise. This method can be successfully applied for routine estimation of luliconazole in bulk pharmaceutical dosage form.

ACKNOWLEDGEMENT:

The authors are thankful to the Principal and Management of D.S.T.S. Mandal’s College of Pharmacy, Solapur, Maharashtra for providing the research facility to carry out this work.

REFERENCES:

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2. Manish Kumar. Preparation of luliconazole nanocrystal loaded hydrogel for improvement od dissolution and antifungal activity. Heliyon.2019; 5:1-9.

3. Tomal Majumder. Method development and validation of RP-HPLC method for estimation of luliconazole in marketed formulation (Cream). The Pharma Innovation Journal.2019; 8(5): 103-108.

4. Tambe SR. Estimation of Luliconazole in Formulation and Biofluid. J Anal Pharm Res. 2017; 6(5): 1-7.

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Received on 13.06.2020 Modified on 14.08.2020

Research J. Pharm. and Tech. 2021; 14(7):3826-3828.

DOI: 10.52711/0974-360X.2021.00663