International Journal of PharmTech Research CODEN (USA): IJPRIF ISSN : 0974-4304 Vol. 3, No.2, pp1169-1173, April-June 2011 Development and Validation of Densitometric Method for Metronidazole and Tetracycline hydrochloride in capsule Dosage form S. Sharma1, M. C. Sharma* 1Department of Chemistry Chodhary Dilip Singh Kanya Mahavidyalya, Bhind (M.P) India *School of Pharmacy, Devi Ahilya Vishwavidyalaya, Indore (M.P) 452001, India *Corres.author: [email protected] Abstract: A new, simple, precise, and accurate HPTLC method for simultaneous quantitation of Metronidazole (MET) and and Tetracycline hydrochloride (TET) as the bulk drug and in capsule dosage forms have been developed. Chromatographic separation of the drugs was performed on aluminium plates precoated with silica gel 60 F254 as the stationary phase and the solvent system consisted of benzene: ethyl acetate: toluene: methanol: glacial acetic acid (9.5:2.0:5.0:1.5:0.5 v/v/v/v/v),Densitometric evaluation of the separated zones was performed at 254 nm. The two drugs were satisfactorily resolved with Rf values of 0.43 ± 0.02 and 0.74± 0.02 for MET and TET, and 0.29 Ofloxacin (OF)
respectively. The accuracy and reliability of the method was assessed by evaluation of linearity (600-2400ng spot-1 for MET and 600-1800ng spot-1 for TET).Ofloxacin (OF) was used as an internal standard. Linearity was observed over the concentration range of 600-2400 ng.band-1. The linearity of the calibration plots was confirmed by the high value of the correlation coefficients (r2 = 0.9998 for MET and 0.9991 for TET). Hence it can be applied for routine quality control analysis of Metronidazole and Tetracycline hydrochloride in capsule Dosage form. Keywords: Metronidazole, Tetracycline hydrochloride, Ofloxacin, Densitometric. Introduction
dosage form5-9. The proposed method overcomes manydifficulties of tracing out lowest determination and
Chemically Metronidazole (MET) is 2-(2-methyl-5-
quantification of related substances the products. Also
nitro-1H-imidazole-1y1) ethanol, acts by causing loss
the affirmative points are; less instrument set up time
of helical structure of DNA, strand breakage and
by mean of simple isocratic elution which results into a
accompanying the impairment of DNA’s function and
negligible noise as compare to gradient methods.
used in the trichomoniasis, amoebiasis, girardiasis1,2while Tetracycline hydrochloride (TET) is (4s, 4as,
Materials and methods
5as, 6s, 12as)-dimethylamino-1,4, 4as, 5a, 6, 11, 12a-octa hydro-10, 12, 12a-pentahydroxy-6-methyl-1,11-
Toluene, acetonitrile, methanol and formic acid used
dioxo naphthacene-2-carboxamide hydrochloride
were of analytical grade. All dilutions were performed
which acts by inhibiting subsequent binding of amino
in standard volumetric flasks. The commercially
acyl transfer RNA to ribosomes resulting in
available capsules; Meklin (Label claim: MET
termination of peptide chain growth and used to
400mg, TET 333mg) manufactured by Bennett
S.T.D., U.T.I. infection, traveller’s diarrhea3,4. Author
Pharmaceuticals, Baroda, Gujarat, India was procured
of the article and his research team has developed a
from local market. Acetonitrile and Phosphate buffer
HPTLC Method development different pharmaceutical
AR grade was obtained from Merck Limited, India. M. C. Sharma et al /Int.J. PharmTech Res.2011,3(2) Instrument
1.0 mL of Ofloxacin (OF), internal standard stock
Chromatographic separation of drug was performed on
solution in 50.0 mL volumetric flask.
Merck TLC plate pre-coated with silica gel 60 F254 (10
cm ×10 cm with 250 mm layer thickness) from E. Preparation of sample solution
Merck, Germany. The samples were applied onto the
Twenty tablets were Meklin (Label claim: MET
plates as a band with 6 mm width using Camag 100 μl
400mg, TET 333mg) weighed and average weight was
sample syringe with a Linomat 5 applicator. Linear
calculated. These tablets were crushed, powdered and
ascending development was carried out in a twin
taken in a 10 mL volumetric flask weight equivalent to
trough glass chamber (for 10 x 10 cm). Densitometric
one tablet and dissolved in minimum amount
scanning was performed using Camag TLC scanner 3
acetonitrile. To this flask 1.0 mL of stock\ solution of
in the range of 600-3000 ng/spot and operated by win
internal standard was added and diluted up to the mark
CATS software (V 1.4.2, Camag). The plates were
with methanol and sonicated for 30min. This solution
developed in a twin through chamber previously
was then filter through Whatman no. 41.The filtrate
saturated for 30 min with mobile phase, benzene: ethyl
was collected in the flask and used as sample solution.
acetate: toluene: methanol: glacial acetic acid(9.5:2.0:5.0:1.5:0.5 v/v/v/v/v), for a distance of 8 cm. Selection of Detection Wavelength
The spots on the air dried plate were scanned with a
After chromatographic development bands were
scanner III at 283 nm using the deuterium source. The
scanned over the range of 200-400 nm. It was
plates were prewashed by methanol and activated at
observed that the drug showed considerable
120oC for 5 min prior to chromatography. A constant
application rate of 0.1 was employed and spacebetween two bands was 5 mm. The slit dimension was
Method Validation10-12
kept at 5mm, 0.45mm and 10 mm/s scanning speed
Linearity
was employed. The monochromatic bandwidth was set
Seven different concentrations of mixture of MET and
at 20 nm, each track was scanned thrice and baseline
TET were prepared from stock solution of MET and
correction was used. The optimized chamber
TET in the range of 600 to 2400.50 μg/mL and 600to
saturation time for mobile phase was 20 min at
1800 μg/mL respectively, in methanol to obtain desire
room temperature (35 oC) at relative humidity of 60%
linearity range. 10 μL of each solution was applied to a
. The length of chromatogram run was 8 cm.
plate (i.e. 0.5-2.5 μg/spot for MET and 0.75-3.75
Subsequent to the development; TLC plates were dried
μg/spot for TET) by sample applicator and the plate
in current of air with the help of air dryer in wooden
was developed. The detector response to the different
chamber with adequate ventilation. The flow rate in
laboratory was maintained unidirectional (laminarflow, towards exhaust). The solution was sonicated
Limit of detection (LOD) and Limit of
for 15min. the extracts were filled through Whatmann
quantification (LOQ):
filter paper No. 41 and residue washed thoroughly with
The LOD and LOQ were calculated using following
methanol. The extracts and washings were transferred
equations as per International conference on
to 25ml volumetric flask and volume was made up to
25ml with methanol. Required dilutions were made to
Where σ = standard deviation of the response and S =the standard deviation of y intercept of regression
Preparation of Standard Stock Solutions
50 mg of each drug MET and TET were weighedseparately and dissolved in 20 ml of methanol and then
Precision
volume was made up to 50 ml so as to get the
Precision of the method was verified by repeatability
concentration 1 mg mL-1. From each of these solutions
and intermediate precision studies. Repeatability
1ml of solution was pipette out and transferred to 10
studies were performed by analysis of three different
ml volumetric flasks and volume was made up to the
concentrations (600- 2400 ng.band-1) of the drug, each
mark using methanol so as to get the concentration 100
concentration injected six times on the same day.
μg mL-1. The stock solution was stored at 2–8 0C
Intermediate precision of the method was checked by
repeating studies on three different days. Preparation of working solution Robustness of the method
Further, the mixture of working solution was prepared
Small changes in the mobile phase composition (± 0.1
by diluting 50 mL of MET and 12 mL of TET with
mL for each component) were made and the effects on
M. C. Sharma et al /Int.J. PharmTech Res.2011,3(2)
the results were examined. Time from spotting to
Recovery experiments were carried out to check for
chromatography and from chromatography to scanning
the presence of positive or negative interferences from
excipients present in the formulation, and to study theaccuracy and precision of the method. Recovery
Accuracy
experiment was performed by the standard addition
Accuracy was determined by recovery studies. It was
method. The recovery of the added standard was
studied at three different levels viz 110%, 120% and
120% of the standard drugs to the pre-analysed
130% of the estimated amount of the drug.
marketed sample of MET and TET. Threedeterminations were performed at each level. Method precision (repeatability) – The precision of the instrument was checked by Tablet formulation Assay
repeatedly injecting (n= 6) mixed standard solution of
50 μL of sample solution was spotted along with same
concentration of working solution (.5-2.5 μg/spot forMET and 0.75-3.75 μg/spot for TET) on to the plate
Intermediate precision (reproducibility) –
under the optimized chromatographic conditions. The
The intraday and interday precision of the proposed
procedure was repeated seven times. The peak area
method was determined by analyzing mixed standard
ratio values of MET and TET to the internal standard
solution of MET and TET at concentration 600, 1800,
were calculated. The densitometric responses from the
2400 ng/spot; 700, 1400, 1800 ng/spot three times on
standard and sample were used to calculate the
the same day and on three different days. The results
are reported in terms of relative standard deviation. Recovery studies Table 1 Regression Analysis of Calibration Graph for MET and TET Parameter Table 2 -Recovery Study %recovery %recovery in(μg/ml) in(μg/ml) M. C. Sharma et al /Int.J. PharmTech Res.2011,3(2) Table 3 Result of Assay of Tablet Formulation Amount claimed Amount found Amount claimed Amount found (mg/tablet) (mg/tablet) (mg/tablet) (mg/tablet) Results and Discussion
precoated on aluminium sheet. The mobile phasecomprises benzene: ethyl acetate: toluene: methanol:
To optimize the HPTLC parameters, several mobile
glacial acetic acid (9.5:2.0:5.0:1.5:0.5 v/v/v/v/v),
phase compositions were tried. Satisfactory
which gives good separation between Ofloxacin (R
separations for AT, RA and AS were obtained with
mobile phase consisting of benzene: ethyl acetate:
was observed over the concentration range of 600-
2400 ng.band-1. The linearity of the calibration plots
(9.5:2.0:5.0:1.5:0.5 v/v/v/v/v), Quantification was
was confirmed by the high value of the correlation
achieved with UV detection at 283 nm based on peak
coefficients (r2 = 0.9998 for MET and 0.9991 for
area. Better resolution of the peaks with clear baseline
TET). The LOD and LOQ for a signal to noise ratio of
separation was found. Small changes in the mobile
8:1 and 12:1 was found to be 81 and 97 ng.band-1 for
phase composition, the effects on the results were
MET and TET which indicates the method has
examined. Mobile phases having different composition
sufficient sensitivity. There was no indication of
like Chloroform: Methanol: Toluene: Acetic acid (8.1:
degradation in solutions of MET and TET as revealed
1:1:0.1 v/v/v/v), were tried and chromatograms were
by peak purity data and from the value of RSD (< 2%)
run. The plates were prewashed by methanol and
for peak areas of bands of solution stored at different
activated at 110oC for 5, 10, 15 min respectively prior
times. In Conclusion proposed HPTLC method was
validated as per ICH guidelines. The standard
chromatography and from chromatography to scanning
deviation, %RSD and standard error calculated for the
was varied from 0, 20, 40 and 60 minutes. Robustness
method are low, indicating high degree of precision of
of the method was done at three different
the methods. The results of the recovery studies
concentration levels 600, 1200, 2400ng spot-1and 600,
performed show the high degree of accuracy of the
1400, 1800ng spot-1 for MET and TET, respectively.
proposed methods. The proposed method is highly
The method was a normal phase HPTLC method. It
accurate, selective and precise hence can be used for a
makes use of a silica gel 60F254 stationary phase
routine quality-control analysis and quantitative
M. C. Sharma et al /Int.J. PharmTech Res.2011,3(2)
simultaneous determination of MET and TET in
Acknowledgement We are grateful to referee for given valuable suggestions. References
6. Sharma, M. C.; Sharma, S.; Kohli, D. V.Annals of
1. Nagulwar, V.; Upadhye, P.A.; Mehta, N.K.;
7. Sharma, M. C.; Sharma, S.; Kohli, D. V.; Sharma,
Upadhye, K.;Bakhe, S.;Deshpandey, S.;Dixit, G.
A. D. Der Pharma Chemica. 2010, 2(1), 121-126
Indian J. Pharma . Sci. 2005, 67(2), 258-260.
8. Sharma, M. C.; Sharma, S.; Kohli, D. V.; Sharma,
2. Patel, P.U.; Suhajia, B.N.; Patel, M.M. Indian
A. D. Der Pharmacia Lettre. 2010, 2 (1) 489-494.
9. Sharma,S.;Sharma,M.C. Indian Drugs .47(11),68-
3. Indian Pharmacopoeia, Vol. 2, Ministry of Health
and Family Welfare, Government of India, New
10. ICH, Q2A Validation of Analytical Procedure:
4. Mitscher, L.A. Antibiotics and antimicrobial
Harmonization, Geneva, October 1994.
agents, In; Foye’s Principle of Medicinal
11. ICH, Q2B Validation of Analytical Procedure:
Chemistry, 5th Edn., Lippincott Williams and
Wilkins, Philadelphia P.A., 2003, p.p.857.
5. Sharma, M. C.; Sharma, S.; Kohli, D. V.; Sharma,
12. ICH Guidance on Analytical Method Validation,
A. D. Archives of Applied Science Research.
in: Proceedings of the International Convention on
Quality for the Pharmaceutical Industry, Toronto,Canada, September 2002.
NOUVEAUTÉS 2e semestre 2008 FRANCAIS JEUNESSE Mikaël Ollivier : Frères de sang, Thierry Magnier, 2008, ISBN 978-2-84420-434-9 Rick Riordan : Le sort des titans, Albin Michel, 2008, ISBN : 978-2226183316 Rick Riordan : La mer des monstres. Percy Jackson T. 2, Albin Michel, 2008, ISBN : 978-2226186089 Anne Robillard : Les chevaliers d'Emeraude (7 tomes) Michel Lafon, 2007 -