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J Chromatogr Sci. 2016 April; 54(4): 647–652.
Published online 2016 January 12. doi:  10.1093/chromsci/bmv184
PMCID: PMC4885388

HPTLC Method for the Determination of Paracetamol, Pseudoephedrine and Loratidine in Tablets and Human Plasma

Abstract

A sensitive, accurate and selective high performance thin layer chromatography (HPTLC) method was developed and validated for the simultaneous determination of paracetamol (PAR), its toxic impurity 4-aminophenol (4-AP), pseudoephedrine HCl (PSH) and loratidine (LOR). The proposed chromatographic method has been developed using HPTLC aluminum plates precoated with silica gel 60 F254 using acetone–hexane–ammonia (4:5:0.1, by volume) as a developing system followed by densitometric measurement at 254 nm for PAR, 4-AP and LOR, while PSH was scanned at 208 nm. System suitability testing parameters were calculated to ascertain the quality performance of the developed chromatographic method. The method was validated with respect to USP guidelines regarding accuracy, precision and specificity. The method was successfully applied for the determination of PAR, PSH and LOR in ATSHI® tablets. The three drugs were also determined in plasma by applying the proposed method in the ranges of 0.5–6 µg/band, 1.6–12 µg/band and 0.4–2 µg/band for PAR, PSH and LOR, respectively. The results obtained by the proposed method were compared with those obtained by a reported HPLC method, and there was no significance difference between both methods regarding accuracy and precision.

Introduction

Paracetamol (PAR) is acetamide, N-(4-hydroxy phenyl) (1, 2), which is widely used as a minor analgesic, and is used as an alternative to aspirin without the side effects of salicylate on gastric mucosa (3). 4-Aminophenol (4-AP) is considered to be PAR impurity and related substance (1, 2), which has nephrotoxic (4) and teratogenic (5) effects.

Pseudoephedrine HCl (PSH) is (1S,2S)-2-(methylamino)-1-phenylpropan-1-ol hydrochloride (2). It is a stereoisomer of ephedrine and has similar action. PSH and its salts are given by mouth for the symptomatic relief of nasal congestion and are commonly combined with other ingredients in preparations intended for the relief of cough and cold symptoms (6).

Loratadine (LOR) (ethyl-4-(8-chloro-5,6-dihydro-11H-benzo[5,6]cyclohep-ta[1,2-b]pyridin-11-ylidine)-1-piperidine carboxylate) is a second-generation antihistamine. LOR is a selective and moderately strong antagonist of histamine H1 receptors (7). Reviewing the literature in hand, different methods have been reported for determination of PAR, PSH and LOR.

Two reported methods have been published for determination of PAR and LOR in their binary mixtures using the RP-HPLC method. Chromatographic separation was achieved isocratically using methanol–acetonitrile–water–THF (50:40:10:2.5%, by volume) as mobile phase at a flow rate of 0.8 mL/min (8) and the TLC-densitometric method (9).

Different methods have been reported for determination of PSH and LOR using spectrophotometric techniques (1013), HPLC method (1215) and high performance thin layer chromatography (HPTLC). The HPTLC method employs a silica gel 60 F254 on Al foil and a mobile phase comprising n-hexane–dichloromethane–triethylamine in a ratio of (5.5 : 4.0 : 0.5, by volume). Detection was carried out at 235 nm (16). PAR and PSH were determined in the presence of cetirizine using the RP-HPLC method (17).

For the ternary mixture of PAR, PSH and LOR, only two methods have been published. The first method used liquid chromatography-tandem mass spectrometry with a monolithic column. Separation was achieved using a gradient component of methanol–0.1% formic acid at a flow rate of 1.0 mL min−1 (18). The second method employed HPLC for separation of the three drugs using a CN column and mixture of water (0.05% triethylamine, adjusted to pH 3 with phosphoric acid): acetonitrile (45:55) as a mobile phase, and the flow rate was at 1.0 mL min−1 with UV detection at 216 nm (19).

Reviewing the literature up to the present reveals that there were only two HPLC methods for the simultaneous determination of the three studied drugs. The developed HPTLC method is more selective than the reported HPLC method (19) as it can be used for the simultaneous determination of PAR, PSH and LOR together with the nephrotoxic, teratogenic 4-PA and can be considered as time and cost-effective in comparison to the published HPLC method; moreover, our study was also extended to the in vitro determination of the three drugs in spiked human plasma.

No reported method, to the best of our knowledge, was found for the simultaneous determination of PAR, PSH and LOR together with the nephrotoxic, teratogenic 4-PA. This encouraged us to develop a simple, sensitive, selective HPTLC method for their determination.

Experimental

Samples

Pure samples

Pure samples were kindly supplied by Al Rowad Pharmaceutical Industries Co., with certified purities of 99.84, 98.50 and 100.07% for PAR, PSH and LOR, respectively. Pure standard 4-AP was purchased from Sigma-Aldrich Co., Cairo, Egypt, with a certified purity of 99.56%.

Pharmaceutical samples

ATSHI® tablets (batch no. 2234), manufactured by Al Rowad Pharmaceutical Industries Co., 10th of Ramadan City, Egypt, were labeled to contain 500 mg PAR, 120 mg PSH and 5 mg LOR.

Chemicals and reagents

Acetone, hexane, methanol and ammonia 33% were of analytical grade (El Nasr Pharmaceutical Chemicals Co., Abu-Zabaal, Cairo, Egypt).

Solutions

Stock standard solution (1 mg/mL) of PAR, 4-AP,PSH and LOR were prepared in methanol.

Pharmaceutical dosage form solution

Ten tablets were crushed and triturated well in a mortar. The average tablet weight was determined, and a powder sample equivalent to 500 mg of PAR was transferred into a 100-mL volumetric flask. About 75-mL methanol was added, and the flask was sonicated for 15 min. The solution was filtered, and the volume was completed to the mark with methanol.

Apparatus

The used apparatuses are as follows: CAMAG Linomat 5, autosampler (Switzerland); HPTLC aluminum plates, precoated with silica gel 60 F254 (20 × 20 cm), 0.2 mm thickness (Merck, Germany); CAMAG microsyringe, 100 µL (Switzerland); glass chamber (Macherey-Nagel, Germany); UV lamp-short wavelength 254 nm; and CAMAG HPTLC Densitometric Scanner 3S/N 130319 with WINCATS software (CAMAG, Muttenz, Switzerland).

Procedure

Chromatographic conditions

Samples were applied in the form of bands of 6 mm width with a 100-µL sample syringe on aluminum plates precoated with silica gel 60F254 (20 × 10 cm), using an autosampler. A constant application rate of 0.1 µL/s was used, and the space between bands was 8.9 mm. The slit dimension was 6.0 × 0.3 µm, and the scanning speed was 20 mm/s. The mobile phase consisted of acetone–hexane–ammonia (4:5:0.4, by volume). Linear ascending development was carried out in a glass chamber saturated with the mobile phase. Development of the plates was left till the mobile phase migrates 8 cm. Following the development, the plates were air dried, spots were visualized under a UV lamp at 254 nm and densitometric scanning was performed using a CAMAG TLC scanner in the reflectance–absorbance mode at 254 nm for PAR, 4-AP and LOR and at 208 nm for PSH and operated by WINCATS software. The radiation source was a deuterium lamp.

Calibration

Volumes equivalent to 0.1–6 mL for PAR, 0.2–3.5 mL for 4-AP, 1.6–12 mL for PSH and 0.1–2 mL LOR from stock standard solution of each were accurately transferred into four series of 10-mL volumetric flasks, and the volumes were completed to the mark with methanol. Then, 10 µL from each flask was spotted in replicates on HPTLC plates. The procedure under chromatographic conditions was performed. The peak areas were plotted against concentrations to obtain the calibration graphs.

Application to human plasma

Into a series of 10 mL volumetric flasks, 1 mL of drug-free human plasma sample was spiked with different concentrations of PAR, PSH and LOR from their stock solutions (1 mg/mL). The volumes were completed to the mark with methanol to provide final concentrations of 0.5–6, 1.6–12 and 0.4–2 mg/mL for PAR, PSH and LOR, respectively. The flasks were shaken vigorously and then centrifugated at 3,000 rpm for 15 min. Then, 1 mL of the protein-free supernatant was transferred into four series of 10-mL volumetric flasks, and the volume was completed with methanol. Furthermore, 10 µL of each solution was applied to the HPTLC plate and the procedure was followed as described under calibration. The regression equations were calculated.

The freeze–thaw stability

Aliquots equivalent to 2, 4 and 0.8 µg/band for PAR, PSH and LOR, respectively, were prepared. These samples were subjected to three cycles of freeze–thaw operations in three consecutive days (at −25°C).

Application to pharmaceutical dosage form

The procedure under calibration was followed using pharmaceutical dosage form solution.

Results

The HPTLC method offers a simple way to quantify directly on a HPTLC plate by measuring the optical density of the separated bands. The amounts of compounds are determined by comparing to a standard curve from reference materials chromatographed simultaneously under the same condition (20).

The HPTLC densitometric method has advantages of low operating costs and high sample output, and the need for minimal sample preparation and mobile phase having pH 8 or more can be used (21).

Although the proportion of the three studied drugs in their pharmaceutical formulation is complex (500:120:5, for PAR, PSH and LOR, respectively), the proposed method has offered a solution to this problem as HPTLC is a separation method.

The calibration curves were constructed by plotting the peak areas versus the corresponding concentrations, and the regression equations were calculated for the three drugs and 4-AP. The results are summarized in Table TableII.

Table I.
Regression and Analytical Parameters of the Proposed HPTLC-Densitometric Method for the Determination of PAR, 4-Amino Phenol, LOR and Pseudoephedrine

Discussion

Method optimization

Several developing systems were tried to reach the optimum resolution of the four components. Trails were done using chloroform–methanol–acetone (9.5, 0.5, 0.2, by volume), chloroform–methanol–ammonia (9, 1, 0.2, by volume), chloroform–methanol–glacial acetic acid (9.5, 0.5, 0.25, by volume), hexane–ethyl acetate–triethylamine (6, 4, 0.1, by volume) and hexane–ethyl acetate–water (6, 5, 1, by volume); however, all these systems failed to resolve the four components from each other. Finally, a developing system consisting of hexane–acetone–ammonia (4, 5, 0.1, by volume) was used, which resulted in well sharp well-resolved peaks.

Different scanning wavelengths were tried. On using 254 nm for PAR, 4-AP and LOR and 208 nm for PSH, sharper and symmetrical peaks with minimum noise were obtained. The Rf values were 0.18, 0.34, 0.69 and 0.76 for PAR, 4-AP, LOR and PSH, respectively. Typical chromatograms are shown in Figure Figure11.

Figure 1.
HPTLC chromatogram of a mixture of 2 µg/band PAR, 0.5 µg/band 4-AP, 0.5 µg/band LOR and 2 µg/band pseudoephedrine at 208 nm. This figure is available in black and white in print and in color at JCS online.

Method validation

Validation was performed according to USP (1).

Linearity

Under optimum chromatographic conditions, linearity of the method was evaluated by measuring the peak area of different concentrations each of PAR, 4-AP, PSH and LOR and then plotting calibration curves relating the peak area against the corresponding concentrations from which the regression equations were constructed.

The calibration curve showed good relationship over the concentration ranges of 0.1–6 µg/band for PAR, 0.2–3.5 µg/band for 4-AP, 0.1–2 µg/band for LOR and 1.6–12 µg/band for PSH. Regression equation parameters are listed in Table TableII.

Accuracy

Accuracy was checked by determining nine different concentrations of each of PAR, LOR and PSH in the calibration range. It was further assured by performing recovery studies at three levels (80, 100 and 120%), and the average percent recovery was then calculated. Good percentage recoveries were obtained and are given in Table TableII.

Precision

The precision of the method was verified by testing repeatability and intermediate precision. Three concentrations of (1, 2, 4 µg/band for PAR, 0.6, 1, 2 µg/band for 4-AP, 0.4, 0.6, 2 µg/band for LOR and 1.6, 4, 6 µg/band for PSH) were analyzed three times intra-daily by the proposed HPTLC method. The percentage recoveries and the relative standard deviation (RSD) were calculated (see Table TableII).

The intermediate precision of the method was checked by repeating the previous procedure inter-daily seven times on four different days. Good results and acceptable RSD% (Table (TableI)I) were obtained.

Specificity

Specificity of the method was tested by how accurately and specifically the analytes of interest are determined in the presence of other components including impurities, degradates or excipients (22). The selectivity of the method was achieved by the analysis of laboratory prepared mixtures of the three drugs together with 4-AP (Figure (Figure1).1). Furthermore, good results obtained on applying the proposed HPTLC method on ATSHI® tablets (Table (TableII),II), prove that tablet additives do not interfere with any of the three separated components.

Table II.
Determination of PAR, LOR and Pseudoephedrine in ATSHI® Tablets by the Proposed HPTLC-Densitometric Method and Results of the Standard Addition Technique

Robustness

The method was demonstrated to be robust over an acceptable working range of its HPTLC co-operational conditions. Any small deliberate variation in the mobile phase and saturation time showed no dramatic change in Rt value, peak height, area or symmetry of the peaks (see Table TableII).

System suitability

System suitability parameters including resolution (Rs), peak symmetry, selectivity and capacity factor (K) were calculated to prove that the overall system performed well. The obtained values were in the acceptable ranges as shown in Table III.

Table III.
System Suitability Parameters of the Proposed HPTLC-Densitometric Method for PAR, LOR and Pseudoephedrine

Application of the method

The proposed method has been successfully applied for the determination of PAR, PSH and LOR in ATSHI® tablets (Figure (Figure2).2). The accuracy of the method was further assessed by applying the standard addition technique, where good results were obtained and are shown in Table TableIIII.

Figure 2.
HPTLC chromatogram of (A) blank plasma at 254 nm, (B) blank plasma at 208 nm, (C) a mixture of 4 µg/band PAR, 0.8 µg/band LOR and 2 µg/band pseudoephedrine in spiked human plasma at 254 nm and (D) a mixture of 4 µg/band ...

Application to human plasma

No significant interference at the Rf of the three proposed drugs was observed in the plasma blank chromatogram at 254 and 208 nm as shown in Figures Figures2A2A and B.

The proposed HPTLC method was applied for the determination of studied drugs in spiked human plasma in the concentration ranges of 0.5–6, 1.6–12 and 0.4–2 mg/mL for PAR, PSH and LOR with accuracy of the mean percentage recovery of 99.21, 101.02 and 101.20 for PAR, LOR and PSH, respectively (Figure (Figure2C2C and D).

The freeze–thaw stability

The results are shown in Table TableIV.IV. Table TableVV shows statistical comparison of the results obtained by the proposed method and the reported HPLC method (19) by applying on the dosage form (ATSHI® tablets). The calculated t and F values are less than the theoretical ones, indicating that there is no significant difference between the two methods with respect to accuracy and precision.

Table IV.
Results of Freeze–Thaw Stability (Three Freeze–Thaw Cycles) (at −25°C for PAR, LOR and Pseudoephedrine)
Table V.
Statistical Comparison of the Proposed HPTLC Method with the Reported HPLC Method

Conclusion

The HPTLC method was developed for determination of PAR, PSH and LOR in human plasma without interference from biological matrices, which was found to be specific, economical and fast. The proposed method has the advantage over the reported HPLC method in that it offers determination of the three studied drugs in human plasma that can be applied in pharmacokinetic study. On the other hand, the HPTLC method could effectively separate the PAR from its degradation product and it can be employed as a stability indicating method for PAR. Statistical analysis proves that the method is reproducible and selective for the analysis of the studied drugs as bulk drugs and in pharmaceutical formulation

References

1. The United States Pharmacopeia, 32th ed., National Formulary 27, United States Pharmacopeial Convention INC, USA, (2009).
2. The British Pharmacopoeia Her Majesty's, The Stationary Office, London, (2007).
3. Budavari S.; The Merck index, an encyclopedia of chemicals, drugs and biologicals, 14th ed Merck and Co. Inc., Whithouse Station, NJ, (2006).
4. Lock E.A., Cross T.J., Schnellmann P.G.; Studies on the mechanism of 4-aminophenol induced toxicity to renal proximal tubules; Human & Experimental Toxicology, (1993); 12: 383–388. [PubMed]
5. Bloomfield M.S.; A sensitive and rapid assay for 4-aminophenol in paracetamol drug and tablet formulation, by flow injection analysis with spectrophotometric detection; Talanta, (2002); 58: 1301–1310. [PubMed]
6. Martindale-Extra Pharmacopoeia, 34th ed. The complete drug references The pharmaceutical Press, London, UK, (2005).
7. Witiak D.T.; Antiallergenic agents. In Burger A., editor. (ed). Medicinal chemistry, 3rd ed Wiley Interscience, New York, (1970), p. 3.
8. Dubey N., Siddiqui R., Jain D.K.; Simultaneous determination of paracetamol, phenylephrine hydrochloride and loratadine; Asian Journal of Chemistry, (2012); 24(11): 5409.
9. El-Kommos M.E., El-Gizawy S.M., Atia N.N., Hosny N.M.; Thin layer chromatography-densitometric determination of some non-sedating antihistamines in combination with pseudoephedrine or acetaminophen in synthetic mixtures and in pharmaceutical formulations; Biomedical Chromatography, (2014); 28(3): 391–400. [PubMed]
10. Palabiyik I.M., Onur F.; Simultaneous spectrophotometric determination of pseudoephedrine sulphate and loratadine in a pharmaceutical preparation using chemometric techniques; Ankara Universitesi Eczacilik Fakultesi Dergisi, (2007); 36(3): 171–182.
11. Culzoni M.J., Goicoechea H.C.; Determination of loratadine and pseudoephedrine sulfate in pharmaceuticals based on non-linear second-order spectrophotometric data generated by a pH-gradient flow injection technique and artificial neural networks; Analytical and Bioanalytical Chemistry, (2007); 389(7–8): 2217–2225. [PubMed]
12. Singhvi I., Bhatia N.; Spectrophotometric and HPLC methods for simultaneous estimation of pseudoephedrine hydrochloride and loratadine from tablets; Indian Journal of Pharmaceutical Sciences, (2006); 68(1): 72–75.
13. Mabrouk M.M., El-Fatatry H.M., Hammad S., Wahbi A.A.M.; Simultaneous determination of loratadine and pseudoephedrine sulfate in pharmaceutical formulation by RP-LC and derivative spectrophotometry; Journal of Pharmaceutical and Biomedical Analysis, (2003); 33(4): 597–604. [PubMed]
14. Ulavapalli K.R., Sriramulu J., Mallu U.R., Bobbarala V.; Simultaneous determination of pseudoephedrine, fexofenadine and loratadine in pharmaceutical products using high resolution RP-HPLC method; Journal of Pharmacy Research, (2011); 4(4): 1219–1221.
15. Abu-Lathou A., Hamdan I.I., Tahraoui A.; A new HPLC approach for the determination of hydrophilic and hydrophobic components: the case of pseudoephedrine sulfate and loratadine in tablets; Drug Development and Industrial Pharmacy, (2005); 31(6): 577–588. [PubMed]
16. Sane R.T., Francis M., Khedkar S., Pawar S., Moghe A.; Simultaneous HPTLC determination of pseudoephedrine sulfate and loratadine from their combined dosage form; Indian Drugs, (2001); 38(8): 436–438.
17. Sivasubramanian L., Lakshmi K.S.; Reverse phase-high performance liquid chromatographic method for the analysis of paracetamol, cetirizine and pseudoephedrine from tablets; Der Pharma Chemica, (2009); 1(1): 37–46.
18. Abro K., Memon N., Bhanger M.I., Perveen S., Kandhro A.; Multi-component quantitation of loratadine, pseudoephedrine and paracetamol in plasma and pharmaceutical formulations with liquid chromatography-tandem mass spectrometry utilizing a monolithic column; Quimica Nova, (2012); 35(10): 1950–1954.
19. Yang C., Su S.; HPLC simultaneous determination of acetaminophen, pseudoephedrine sulfate and loratadine in compound sustained-release tablets; Yaowu Fenxi Zazhi, (2006); 26(11): 1652–1655.
20. Grinberg N.; Modern Thin-layer Chromatography, Marcel Dekker Inc., New York, (1990), p. 249.
21. Chavhan M.L., Shirkhedkar A.A., Surana S.J.; Development and validation of a stability indicating RP-TLC densitometric method for determination of loratidine in bulk and in tablets; Arabian Journal of Chemistry, (2013), doi:10.1016/j.arabjc.2012.12.014.
22. ICH, Q2 (R1) Validation of analytical procedures. In Proceedings of the International Conference on Harmonization, Geneva, (2005).

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