Eco-Friendly Pharmaceutical Analysis of Multicomponent Drugs Coformulated in Different Dosage Forms Using Multivariate Curve Resolution and Partial Least Squares: A Comparative Study

Background: Considering the environmental impact of analytical procedures necessitates replacing the polluting analytical methods with green alternatives. Objective: This study aims to develop and validate a multivariate curve resolution-alternating least-squares (MCR-ALS) method with correlation constraint for the simultaneous determination of theophylline, ambroxol, and guaifenesin as target analytes in the presence of methylparaben and propylparaben as interfering components. In addition, a partial least-squares regression (PLSR) method was also developed and optimized. Method: The developed methods were validated according to International Conference on Harmonization guidelines and successfully applied for the quantification of the target analytes in different pharmaceutical dosage forms. Results: Figures of merit such as root mean square error of prediction, bias, standard error of prediction, and relative error of prediction for both models were calculated, and they showed similar and satisfactory results. Correlation coefficients ranged between 0.9988 and 0.9992, reflecting high predictive ability. The optimized methods were compared with a reported HPLC method using one-way analysis of variance and showed no significant difference regarding accuracy and precision. Conclusions: The proposed chemometrics methods can be used as an eco-friendly alternative for chromatographic techniques for the quality control analysis of the studied mixture in different pharmaceutical dosage forms. Highlights: An MCR-ALS model was developed. The developed model was compared with a PLSR model. Both models were validated and successfully used for the determination of a multicomponent pharmaceutical mixture. The developed method is eco-friendly, fast, reliable, and cost-effective.

Validated derivative and ratio derivative spectrophotometric methods for the simultaneous determination of levocetirizine dihydrochloride and ambroxol hydrochloride in pharmaceutical dosage form

Three simple, precise, accurate and validated derivative spectrophotometric methods have been developed for the simultaneous determination of levocetirizine dihydrochloride (LCD) and ambroxol hydrochloride (ABH) in bulk powder and in pharmaceutical formulations. The first method is a first derivative spectrophotometric method ((1)D) using a zero-crossing technique of measurement at 210.4 nm for LCD and at 220.0 nm for ABH. The second method employs a second derivative spectrophotometry ((2)D) where the measurements were carried out at 242.0 and 224.4 nm for LCD and ABH, respectively. In the third method, the first derivative of the ratio spectra was calculated and the first derivative of the ratio amplitudes at 222.8 and 247.2 nm was selected for the determination of LCD and ABH, respectively. Calibration graphs were established in the ranges of 1.0-20.0 μg mL(-1) for LCD and 4.0-20.0 μg mL(-1) for ABH using derivative and ratio first derivative spectrophotometric methods with good correlation coefficients. The developed methods have been successfully applied to the simultaneous determination of both drugs in commercial tablet dosage form.

HPLC and chemometrics-assisted UV-spectroscopy methods for the simultaneous determination of ambroxol and doxycycline in capsule

High-performance liquid chromatography (HPLC) and multivariate spectrophotometric methods are described for the simultaneous determination of ambroxol hydrochloride (AM) and doxycycline (DX) in combined pharmaceutical capsules. The chromatographic separation was achieved on reversed-phase C(18) analytical column with a mobile phase consisting of a mixture of 20mM potassium dihydrogen phosphate, pH 6-acetonitrile in ratio of (1:1, v/v) and UV detection at 245 nm. Also, the resolution has been accomplished by using numerical spectrophotometric methods as classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS-1) applied to the UV spectra of the mixture and graphical spectrophotometric method as first derivative of the ratio spectra ((1)DD) method. Analytical figures of merit (FOM), such as sensitivity, selectivity, analytical sensitivity, limit of quantitation and limit of detection were determined for CLS, PLS-1 and PCR methods. The proposed methods were validated and successfully applied for the analysis of pharmaceutical formulation and laboratory-prepared mixtures containing the two component combination.

Direct, non-destructive quantitative measurement of an active pharmaceutical ingredient in an intact capsule formulation using Raman spectroscopy

The active pharmaceutical ingredient (ambroxol) in an intact capsule formulation has been non-destructively quantified using Raman spectroscopy. To improve the problem of insufficient representative sampling inherent in Raman measurements, we have employed a wide area illumination (WAI) scheme that enables much improved sample coverage through a circular excitation laser spot with a 6 mm diameter. One of the anticipated sources of variation for this measurement was variation in the capsule shells. However, the WAI scheme significantly decreased the spectral variation among empty capsules compared to a measurement with a traditional small-spot excitation. Therefore, measurement variations emanating from the capsule shell did not significantly influence the accuracy of the determination of ambroxol concentrations. The resulting standard error of prediction (SEP) using the WAI scheme was comparable to that from previous Raman measurements which used a conventional small-spot excitation and employed a sampling scheme that involved rotation of an ambroxol pellet. It is further noteworthy that the SEP was also similar to that obtained from the use of transmission NIR spectroscopy, which was achieved by collection of spectra of the powdered capsule contents removed from the shell. The proposed Raman measurement using the WAI scheme in this case was sufficient to achieve the quantitative measurement of the active pharmaceutical ingredient (API) content of capsules non-destructively.

Spectrophotometric estimation of ambroxol and cetirizine hydrochloride from tablet dosage form

Fixed dose combination tablets containing ambroxol HCl and cetirizine HCl are clinically used as mucolytic and antiallergic. Several spectrophotometric and HPLC methods have been reported for simultaneous estimation of these drugs with other drugs. The drugs individually and in mixture obeys Beer's law over conc. range 1.2-4.4 microg/mL for cetirizine HCL and for ambroxol HCL 15-52 microg/mL at all five sampling wavelengths (correlation coeff. well above 0.995). The mean recoveries from tablet by standard addition method were 100.18% (+/-2.4) and 100.66 % (+/-2.31). The present work reports simple, accurate and precise spectrophotometric methods for their simultaneous estimation from tablet dosage form.

Determination of ambroxol hydrochloride, methylparaben and benzoic acid in pharmaceutical preparations based on sequential injection technique coupled with monolithic column

The porous monolithic columns show high performance at relatively low pressure. The coupling of short monoliths with sequential injection technique (SIA) results in a new approach to implementation of separation step to non-separation low-pressure method. In this contribution, a new separation method for simultaneous determination of ambroxol, methylparaben and benzoic acid was developed based on a novel reversed-phase sequential injection chromatography (SIC) technique with UV detection. A Chromolith SpeedROD RP-18e, 50-4.6 mm column with 10 mm precolumn and a FIAlab 3000 system with a six-port selection valve and 5 ml syringe were used for sequential injection chromatographic separations in our study. The mobile phase used was acetonitrile-tetrahydrofuran-0.05M acetic acid (10:10:90, v/v/v), pH 3.75 adjusted with triethylamine, flow rate 0.48 mlmin(-1), UV-detection was at 245 nm. The analysis time was <11 min. A new SIC method was validated and compared with HPLC. The method was found to be useful for the routine analysis of the active compounds ambroxol and preservatives (methylparaben or benzoic acid) in various pharmaceutical syrups and drops.

Determination of roxithromycin in rat lung tissue by liquid chromatography-mass spectrometry

A liquid chromatography-mass spectrometry (LC-MS) method for the determination of roxithromycin in rat lung tissue is described. Liquid-liquid extraction was adopted for sample preparation with recoveries from 72.5 to 76.9% at levels of 0.1, 5.0 and 20.0 microg/ml. Chromatographic separation was performed on a C18 column using a mixture of methanol, water and formic acid (80:20:1, v/v/v) as mobile phase delivered at a flow rate of 0.5 ml/min. Positive selected ion monitoring (SIM) mode was used for the quantification of roxithromycin at m/z 837.7 and clarithromycin (internal standard) at m/z 748.7. The linearity was obtained over the concentration range of 0.05-20.0 microg/ml and the lower limit of quantification was 0.05 microg/ml. For each QC level of roxithromycin, the intra- and inter-day precisions relative standard deviation (R.S.D.) were less than 4.1 and 7.5%, respectively, and accuracy (RE) was +/-10.0%. The proposed LC-MS method has been successfully used for the determination of roxithromycin in rat lung tissue after oral administration of roxithromycin formulations to 44 SD rats. The present study demonstrates that the concentration of roxithromycin in rat lung tissues can be significantly increased by ambroxol when they are formulated in combination.

Nondestructive determination of the ambroxol content in tablets by Raman spectroscopy

We describe a method for determining the ambroxol content in tablets nondestructively. To obtain a reliable quantitative calibration, we prepared 20 pellet samples (ambroxol content: 8.30-16.25 wt.%) and acquired their Raman spectra while rotating the pellets. The spectra of the rotated samples reflected the compositional variations better than those that were recorded without rotation. To reduce both the baseline variations and the spectral noise simultaneously, the spectra were pre-processed using wavelet transformation (WT). Then, we used the normalization method before partial least-squares (PLS) regression to correct Raman intensity variation from laser power fluctuation. The achieved standard error of cross validation (SECV) was 0.30%. Two different datasets where Raman intensity was artificially changed were prepared and the corresponding spectra were quantitatively analyzed. The result was reproducible even if laser intensity was fairly changed. Additionally, two different commercial tablets were analyzed and the accuracy of measurement was better for a tablet that had the similar spectral features of the standard pellet samples. The proposed method can be utilized for the analysis of commercial tablets if standard tablets of various ambroxol concentrations that have the same chemical components including additives and the same physical shape of tablets are available.

Adsorptive stripping voltammetric determination of ambroxol

An electrochemical procedure for the determination of ambroxol in mucolytics was described. The method was based on adsorptive accumulation of the species at the hanging mercury drop electrode (HMDE), followed by one of different modes of stripping sweep, viz. direct current tast (DCT), differential pulse (DP), square wave (SW) and first harmonic alternating current (AC1). The behaviour of adsorptive stripping response was studied under various experimental conditions, e.g. type of supporting electrolyte, pH, accumulation time, pulse amplitude, scan rate and mode of sweep. In Britton-Robinson buffer solution, an irreversible reduction process involving transfer of one electron and one proton was took place. The response was linear over the 0.2-6 microg/ml concentration range. Determination of the compound in oral dosage forms was achieved using the standard addition method. The average of determinations obtained by the squarewave adsorptive voltammetric method with its relative standard deviation was 99.8 +/- 2.40%.

Determination of Ambroxol in an Automated Multi-Pumping Pulsed Flow System

A new flow methodology exploiting the multi-pumping approach was developed for the spectrophotometric determination of ambroxol hydrochloride in pharmaceutical preparations. The flow manifold was implemented by using, exclusively, multiple solenoid-actuated micro-pumps, which acted simultaneously as sample insertion, solutions propelling and reagents commutation units. Linear calibration plots were obtained over an ambroxol concentration ranging from 10 to 200 mg l(-1) (r.s.d. < 0.5%, n = 15) and a sampling rate of about 60 samples per hour (flow rate = 1.92 ml min(-1), sample volume = 80 microl).

Simultaneous determination of roxithromycin and ambroxol hydrochloride in a new tablet formulation by liquid chromatography

A rapid and accurate liquid chromatographic method is described for the simultaneous determination of roxithromycin and ambroxol hydrochloride in a new tablet formulation. Chromatographic separation of the two drugs was achieved on a Diamonsil C(18) column (200 mm x 4.6 mm, 5 microm). The mobile phase consisting of a mixture of acetonitrile, methanol and 0.5% ammonium acetate (39:11:50 (v/v), pH 5.5) was delivered at a flow rate of 1.0 ml/min. Detection was performed at 220 nm. Linearity, accuracy and precision were found to be acceptable over the concentration range of 201.2-2012.0 microg/ml for roxithromycin and 42.7-427.0 microg/ml for ambroxol hydrochloride, respectively. Separation was complete in less than 10 min. The proposed method can be used for the quality control of formulation products.

[A near-infrared diffuse reflectance analysis method for the noninvasive quantitative analysis of ambroxol hydrochloride tablets]

AIM

To develop a near-infrared diffuse reflectance analysis (NIRDRA) method for rapid noninvasive quantitative determination of ambroxol hydrochloride in half-finished product particles and non-blister-packed, blistered tablets.

METHODS

All spectra were measured with a Fourier transform spectrometer equipped with a PbS and a InGaAs detector, an external integrating sphere, a rotating sample cup, and a fibre-optic probe for reflectance measurements. All samples were scanned from 12,000 cm-1 to 4,000 cm-1, and each sample spectrum was obtained as an automatic mean of 64 scans. No spectrum pre-processing method was used, and spectral regions, 4,602-4,247, 12,000-7,498 and 6,102-5,446, 12,000-5,446 cm-1 were selected to develope mathematical models by partial least square method for half-finished product particles and non-blister-packed, blistered tablets samples, respectively.

RESULTS

The optimal rank and mean square error determined for half-finished product particles and non-blister-packed, blistered tablets samples by cross validation method all was 6 and 0.306, 0.972 and 1.492, respectively, the average recovery was 100%, 100% and 102% respectively; and the RSD was 1.17%, 1.70% and 1.78% respectively.

CONCLUSION

Results showed that the NIRDRA method was rapid, simple, noninvasive and sensitive, and it can be applied to assay the content of ambroxol hydrochloride in half-finished product particles non-blister-packed and blistered tablets.

Simultaneous high-throughput determination of clenbuterol, ambroxol and bromhexine in pharmaceutical formulations by HPLC with potentiometric detection

Potentiometric detection of clenbuterol, ambroxol and bromhexine in marketed pharmaceuticals was described in six isocratic HPLC systems. The podant- and macrocyclic-type neutral ionophores, N,N,N',N'-tetracyclohexyl-oxybis(o-phenyleneoxy)diacetamide (TOPA) and hexakis(2,3,6-tri-O-octyl)-alpha-cyclodextrin (OCD), were applied in poly(vinyl)chloride (PVC)-based liquid membrane electrodes. Both types of neutral ionophores improve the sensitivity for all mentioned drugs when compared with a tetrakis(p-chlorophenyl)borate (BOR)-based electrode as well as with single wavelength UV detection. Detection limits (S/N=3) of 2.6 x 10(-10) mol l(-1) (injected concentration) for the highly hydrophobic bromhexine were achieved with the TOPA-based electrode and a cyano reversed-phase (RP)-HPLC with Uptisphere UP5CN-25QS silica column (250 x 4.6 mm i.d.) eluted with acetonitrile (AcN)-ethanol-perchloric acid (1.66 mM) (60:2:38, v/v/v) (pH* 2.45). Comparable result was obtained with OCD-based electrodes and an XTerra RP18 hybrid silica-polymer column eluted with AcN-phosphoric acid (20 mM) (25:75, v/v) (pH* 2.60). In the mobile phases containing 60-75% v/v AcN or methanol, stable and reproducible response of both types of neutral ionophore-based electrodes was observed for at least 3 days. The results of the validated procedure for reliable simultaneous determination of the drugs in fortified representative samples of pharmaceuticals were also presented.

Determination of ambroxol hydrochloride in pure solutions and some of its pharmaceutical preparations under batch and FIA conditions

New ambroxol (Amb) ion selective plastic membrane electrodes of both conventional and coated graphite types based on the ion-pair of ambroxolium tetraphenylborate (Amb-TPB) ion-pair are prepared. The conventional type electrode was fully characterized in terms of membrane composition, life span, pH, ionic strength and temperature. It was applied to potentiometric determination of ambroxol in pure solutions and pharmaceutical preparations under batch and flow injection conditions. The potentiometric determination was used in the determination of ambroxol in muco syrup in four batches of different expiry dates, also the amounts of ambroxol released after 1, 8 and 16 h from the muco sustained release type (S.R.) capsules were also assayed. The selectivity of the electrode toward a large number of excipient like inorganic cations, sugars and amino acids was tested. The solubility product of the ion-pair and the formation constant of the precipitation reaction leading to the ion-pair formation were determined conductimetrically.

Quantitative determination of ambroxol in tablets by derivative UV spectrophotometric method and HPLC

A derivative UV spectrophotometric method for the determination of ambroxol in tablets was developed. Determination of ambroxol in tablets was conducted by using first-order derivative UV spectrophotometric method at 255 nm (n = 5). Standards for the calibration graph ranging from 5.0 to 35.0 microg/ml were prepared from stock solution. The proposed method was accurate with 98.6+/-0.4% recovery value and precise with coefficient of variation (CV) of 1.22. These results were compared with those obtained by reference methods, zero-order UV spectrophotometric method and reversed-phase high-performance liquid chromatography (HPLC) method. A reversed-phase C(18) column with aqueous phosphate (0.01 M)-acetonitrile-glacial acetic acid (59:40:1, v/v/v) (pH 3.12) mobile phase was used and UV detector was set to 252 nm. Calibration solutions used in HPLC were ranging from 5.0 to 20.0 microg/ml. Results obtained by derivative UV spectrophotometric method was comparable to those obtained by reference methods, zero-order UV spectrophotometric method and HPLC, as far as ANOVA test, F(calculated) = 0.762 and F(theoretical) = 3.89, was concerned.

Validation of an HPLC method for the quantification of ambroxol hydrochloride and benzoic acid in a syrup as pharmaceutical form stress test for stability evaluation

A method is described for ambroxol, trans-4-(2-amino-3,5-dibromobenzylamino) cyclohexanol hydrochloride, and benzoic acid separation by HPLC with UV detection at 247 nm in a syrup as pharmaceutical presentation. Optimal conditions were: Column Symmetry Shield RPC8, 5 microm 250 x 4.6 mm, and methanol/(H(3)PO(4) 8.5 mM/triethylamine pH=2.8) 40:60 v/v. Validation was performed using standards and the pharmaceutical preparation which contains the compounds described above. Results from both standards and samples show suitable validation parameters. The pharmaceutical grade substances were tested by factors that could influence the chemical stability. These reaction mixtures were analysed to evaluate the capability of the method to separate degradation products. Degradation products did not interfere with the determination of the substances tested by the assay.

Determination of ambroxol or bromhexine in pharmaceuticals by capillary isotachophoresis

Expectorant drugs ambroxol (AX) and bromhexine (BX) were determined by capillary isotachophoresis (ITP) with conductimetric detection. The leading electrolyte (LE) was a buffer solution that contained 5 mM picolinic acid and 5 mM potassium picolinate (pH 5.2). The terminating electrolyte (TE) was 10 mM formic acid. The driving current was 80 microA (for approximately 200 s) or 50 microA (for approximately 350 s) and the detection current was 20 microA (a single analysis took about 8 min). The effective mobilities of AX and BX (evaluated with tetraethylammonium as the mobility standard) were 18.8 x 10(-9) m2 V(-1) s(-1) and 14.3 x 10(-9) m2 V(-1) s(-1) respectively. The calibration graphs relating the ITP zone length to the concentration of the analytes were rectilinear (r = 0.9993-0.9999) in the range 10 mg L(-1) (20 mg L(-1) for BX) to 200 mg l(-1) of the drug standard. The relative standard deviations (RSD) were 1.2 1.6% (n = 6) when determining 100 mg l(-1) of the analytes in pure test solutions. The method has been applied to the assay of AX or BX in seven commercial mass-produced pharmaceutical preparations. According to the validation procedure based on the standard addition technique the recoveries were 97.5-102.7% of the drug and the RSD values were 0.11-2.20% (n = 6).

High performance liquid chromatographic determination of ambroxol in the presence of different preservatives in pharmaceutical formulations

A high-performance chromatographic method is described for simultaneous determination of ambroxol in the presence of different preservatives in syrups. The method separates ambroxol from methyl- ethyl-, propyl- and butyl paraben and from other multi-component mixtures. The retention behaviour of ambroxol and parabens as a function of both pH and mobile phase composition was investigated. The eluents were monitored with a UV detector at 247 nm. Linear relationships between the amount of pharmaceutical compounds and peak heights were confirmed at the concentrations of 0.74-14.08 microg ml(-1). The high recovery (no extraction of the samples is required) and the low %RSD confirm the suitability of the proposed method for the determination of ambroxol in different pharmaceutical preparations.

Determination of bromhexine and ambroxol in pharmaceutical dosage forms, urine and blood serum

Data presented in this paper show that bromhexine and its pharmacologically active metabolite can easily be determined by capillary zone electrophoresis. The composition of the running buffer had a significant effect on the reproducibility of the migration time for which a carrier solution containing 30 mM phosphate buffer (pH 3.0), 5 M urea and 10% (v/v) acetonitrile was used. The method was validated with respect to its response linearity and reproducibility. The method is suitable for the determination of bromhexine and ambroxol in several samples such as pharmaceuticals, urine and serum. Photodiode-array detection permitted the rapid identification of both drugs in the sample analyzed.

Assay of ambroxol in biological fluids by capillary gas-liquid chromatography

A sensitive and rapid method for the determination of ambroxol in biological fluids is described. It comprises a single extraction step, derivatization and selective determination with capillary gas-liquid chromatography (in split-mode) and electron-capture detection. The limit of quantification in plasma is ca. 3 ng/ml. The method is applied to the pharmacokinetics of ambroxol in humans.

[Prevention and therapy of respiratory distress syndrome in premature infants by means of bromhexine metabolite VIII. Animal experimental studies on the therapeutic efficacy of bromhexine metabolite VIII in premature respiratory distress syndrome]

In preparing a clinical study 14C-labelled bromhexine metabolite VIII was applied intraamnially in animal experiments. The distribution was measured in different maternal and fetal organs by thinlayer chromatography and autoradiography. A complete placental passage was found in both directions. An organspecific accumulation in the fetal lungs could not be demonstrated.