A novel green spectrofluorimetric method for simultaneous determination of antazoline and tetryzoline in their ophthalmic formulation.

A novel spectrofluorimetric method has been developed for determination of antazoline (ANT) and tetryzoline (TET) in their pharmaceutical formulation. A combined application of synchronous spectrofluorimetry and second derivative mathematical treatment was developed. The proposed method depends on reacting the cited drugs with dansyl chloride (DNS-Cl) being a suitable derivatizing agent generating highly fluorescent derivatives measured at emission wavelengths of 703.0 and 642.0 nm after excitation wavelengths of 350.0 and 320.0 nm for ANT and TET, respectively. The joint use of synchronous spectrofluorimetry with second derivative mathematical treatment is for the first time to be developed and optimized in aid of using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for ANT and 516.7 nm for TET. Linear responses have been represented over a wide range of concentration (0.5-12.0 µg/mL for ANT and 0.5-10.0 µg/mL for TET). Additionally, statistical comparison of the developed method with the official ones has been carried out where no significant difference was found. Additionally, greenness profile assessment was accomplished by means of four metric tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.

Exquisite integration of quality-by-design and green analytical approaches for simultaneous determination of xylometazoline and antazoline in eye drops and rabbit aqueous humor, application to stability study.

This work implements a stability indicating HPLC method developed to simultaneously determine xylometazoline (XYLO) and antazoline (ANT) in their binary mixture, rabbit aqueous humor and cited drug's degradates by applying analytical quality-by-design (AQbD) combined with green analytical chemistry (GAC) experiment for the first time. This integration was designed to maximize efficiency and minimize environmental impacts, as well as energy and solvent consumption. Analytical quality-by-design was applied to achieve our aim starting with evaluation of quality risk and scouting analysis, tracked via five parameters chromatographic screening using Placket-Burman design namely: pH, temperature, organic solvent percentage, flow rate, and wavelength detection. Recognizing the critical method parameters was done followed by optimization employing central composite design and Derringer's desirability toward assess optimum conditions that attained best resolution with satisfactory peak symmetry with short run time. Optimal chromatographic separation was attained by means of an XBridge® C18 (4.6 × 250 mm, 5 µm) column through isocratic elution using a mobile phase consists of phosphate buffer (pH 3.0): ethanol (60:40, by volume) at a 1.6 mL/min flow rate and 230.0 nm UV detection. Linearity acquired over a concentration range of 1.0-100.0 µg/mL and 0.5-100.0 µg/mL for XYLO and ANT, respectively. Furthermore, imperiling cited drugs' stock solutions to stress various conditions and satisfactory peaks of degradation products were obtained indicating that cited drugs are vulnerable to oxidative degradation and basic hydrolysis. Degradates' structures were elucidated using mass spectrometry. Applying various assessment tools; namely: analytical greenness (AGREE), green analytical procedure index (GAPI), analytical eco-scale, and national environmental method index (NEMI), Greenness method's evaluation was applied and proved to be green. In fact, the developed method is established to be perceptive, accurate, and selective to assess cited drugs for routine analysis.

Characterization of In Vitro and In Vivo Metabolism of Antazoline Using Liquid Chromatography-Tandem Mass Spectrometry.

Antazoline (ANT) was recently shown to be an effective and safe antiarrhythmic drug in the termination of atrial fibrillation. However, the drug is still not listed in clinical guidelines. No data on ANT metabolism in humans is available. We used liquid chromatography coupled with tandem mass spectrometry to identify and characterize metabolites of ANT. We analyzed plasma of volunteers following a single intravenous administration of 100 mg of ANT mesylate and in in vitro cultures of human hepatocytes. We revealed that ANT was transformed into at least 15 metabolites and we investigated the role of cytochrome P450 isoforms. CYP2D6 was the main one involved in the fast metabolism of ANT. The biotransformation of ANT by CYP2C19 was much slower. The main Phase I metabolite was M1 formed by the removal of phenyl and metabolite M2 with hydroxyl in the para position of phenyl. Glucuronidation was the leading Phase II metabolism. Further study on pharmacokinetics of the metabolites would allow us to better understand the activity profile of ANT and to predict its potential clinical applications. Ultimately, further investigation of the activity profile of the new hydroxylated M2 metabolite of ANT might result in an active substance with a different pharmacological profile than the parent molecule, and potentially a new drug candidate.

The Development of Spectrophotometric and Validated Stability- Indicating RP-HPLC Methods for Simultaneous Determination of Ephedrine HCL, Naphazoline HCL, Antazoline HCL, and Chlorobutanol in Pharmaceutical Pomade Form.

BACKGROUND: Allergic rhinitis, acute nasal congestion and sinusitis are one of the most common health problems and have a major effect on the quality of life. Several medications are used to improve the symptoms of such diseases in humans. Pharmaceutical pomade form containing Ephedrine (EPD) HCl, Naphazoline (NPZ) HCl, Antazoline (ANT) HCl, and Chlorobutanol (CLO) is one of them. OBJECTIVE: For these reasons, this study includes the development of spectrophotometric and chromatographic methods for the determination of EPD HCl, NPZ HCl, ANT HCl, and CLO active agents in the pharmaceutical pomade. METHOD: In the spectrophotometric method, third-order derivative of the amplitudes at 218 nm n=5 and the first-order derivative of the amplitudes 254 nm n=13 was selected for the determination of EPD, ANT, respectively while NPZ was determined by the second derivative at 234 nm and n=21. Colorimetric detection was applied for assay analysis of CLO at 540 nm. Furthermore, a reverse phase high performance liquid chromatographic (RP- HPLC) method has been developed and optimized by using Agilent Zorbax Eclipse XDB C18 (75 mm x 3.0 mm, 3.5µm) column. The column temperature was 40°C, binary gradient elution was used and the mobile phase consisted of 15 mM phosphate buffer in distilled water (pH 3.0) and methanol, and the flow rate was 0.6 mL min-1 and the UV detector was detected at 210 nm. The linear operating range was obtained as 11.97-70, 0.59-3, 2.79-30, and 2.92-200 µg mL-1 for EPD HCl, NPZ HCl, ANT HCl, and CLO respectively. RESULTS: The LOD values were found to be 3.95, 0.19, 0.92 and 0.96 µg mL-1 for EPD HCl, NPZ HCl, ANT HCl, and CLO in the spectrophotometric method, respectively. The linear ranges in the RP-HPLC method were 8.2-24.36 µg mL-1, 0.083 - 0.75 µg/mL, 2.01-7.5 µg mL-1 and 2.89-24.4 µg mL-1 for EPD HCl, NPZ HCl, ANT HCl, and CLO, respectively. The LOD values in the validation studies were 2.7, 0.025, 0.66 and 0.86 µg mL-1 for EPD HCl, NPZ HCl, ANT HCl, and CLO in RP-HPLC method respectively. CONCLUSION: The results of the spectrophotometric and chromatographic methods were compared and no differences were found between the two methods.

Determination of antazoline and tetrahydrozoline in ophthalmic solutions by capillary electrophoresis and stability-indicating HPLC methods.

Capillary electrophoretic (CE) and high performance liquid chromatographic (HPLC) methods were developed and optimized for the determination of antazoline (ANT) and tetrahydrozoline (TET) in ophthalmic formulations. Optimum electrophoretic conditions were achieved using a background electrolyte of 20mM phosphate buffer at pH 7.0, a capillary temperature of 25°C, a separation voltage of 22 kV and a pressure injection of the sample at 50 mbar for 17s. HPLC analysis was performed with Kinetex (150 × 4.6mm ID × 5 µm) (Phenomenex, USA) analytical column with 1 mL min(-1) flow rate of mobile phase which consisted of 0.05% TFA in bidistilled water (pH adjusted to 3.0 with 5M NaOH) and acetonitrile/buffer in the ratio of 63:37 (v/v) at room temperature. Injection volume of the samples was 10 µL and the wavelength of the detector was set at 215 nm for monitoring both analytes. Calibration graphs showed a good linearity with a coefficient of determination (R(2)) of at least 0.998 for both methods. Intraday and interday precision (expressed as RSD%) were lower than 2.8% for CE and 0.92% for HPLC. The developed methods were demonstrated to be simple and rapid for the determination of ANT and TET in ophthalmic solutions providing recoveries in the range between 97.9 and 102.70% for CE and HPLC.

Comparative study between recent methods manipulating ratio spectra and classical methods based on two-wavelength selection for the determination of binary mixture of antazoline hydrochloride and tetryzoline hydrochloride.

A comparative study was developed between two classical spectrophotometric methods (dual wavelength method and Vierordt's method) and two recent methods manipulating ratio spectra (ratio difference method and first derivative of ratio spectra method) for simultaneous determination of Antazoline hydrochloride (AN) and Tetryzoline hydrochloride (TZ) in their combined pharmaceutical formulation and in the presence of benzalkonium chloride as a preservative without preliminary separation. The dual wavelength method depends on choosing two wavelengths for each drug in a way so that the difference in absorbance at those two wavelengths is zero for the other drug. While Vierordt's method, is based upon measuring the absorbance and the absorptivity values of the two drugs at their λ(max) (248.0 and 219.0 nm for AN and TZ, respectively), followed by substitution in the corresponding Vierordt's equation. Recent methods manipulating ratio spectra depend on either measuring the difference in amplitudes of ratio spectra between 255.5 and 269.5 nm for AN and 220.0 and 273.0 nm for TZ in case of ratio difference method or computing first derivative of the ratio spectra for each drug then measuring the peak amplitude at 250.0 nm for AN and at 224.0 nm for TZ in case of first derivative of ratio spectrophotometry. The specificity of the developed methods was investigated by analyzing different laboratory prepared mixtures of the two drugs. All methods were applied successfully for the determination of the selected drugs in their combined dosage form proving that the classical spectrophotometric methods can still be used successfully in analysis of binary mixture using minimal data manipulation rather than recent methods which require relatively more steps. Furthermore, validation of the proposed methods was performed according to ICH guidelines; accuracy, precision and repeatability are found to be within the acceptable limits. Statistical studies showed that the methods can be competitively applied in quality control laboratories.

Determination of antazoline hydrochloride in rat plasma and excreta by reversed-phase ion-pair chromatography and its application to pharmacokinetics.

A reversed-phase ion pair chromatography method with liquid-liquid extraction analytical method was developed and validated for the determination of antazoline hydrochloride in plasma and excreta of rat. The aim of our study was to characterize the preclinical pharmacokinetics and excretion profiles of antazoline hydrochloride in rats after intravenous injection at the dose of 10 mg/kg. Plasma and excreta samples were extracted with ethyl acetate, and phenacetin was used as the internal standard. The result showed that the method is suitable for the quantification of antazoline hydrochloride in plasma and excreta samples. Analysis of accuracy (90.89-112.33%), imprecision (<7.1%) and recovery (>82.5%) showed adequate values. After a single intravenous administration at 10 mg/kg to rats, plasma concentration profile showed a relative fast elimination proceeding with a terminal elimination half-life of 3.53 h. Approximately 61.8 and 14.2% of the administered dose were recovered in urine and bile after 72 and 24 h post-dosing respectively; 5.9% of the administered dose was recovered in feces after 72 h post-dosing. The above results show that the major elimination route is urinary excretion.

Simultaneous determination of antazoline and naphazoline by the net analyte signal standard addition method and spectrophotometric technique.

A novel net analyte signal standard addition method (NASSAM) was used for simultaneous determination of the drugs anthazoline and naphazoline. The NASSAM can be applied for determination of analytes in the presence of known interferents. The proposed method is used to eliminate the calibration and prediction steps of multivariate calibration methods; the determination is carried out in a single step for each analyte. The accuracy of the predictions against the H-point standard addition method is independent of the shape of the analyte and interferent spectra. The net analyte signal concept was also used to calculate multivariate analytical figures of merit, such as LOD, selectivity, and sensitivity. The method was successfully applied to the simultaneous determination of anthazoline and naphazoline in a commercial eye drop sample.

A rapid derivative spectrophotometric method for simultaneous determination of naphazoline and antazoline in eye drops.

A zero-crossing first-derivative spectrophotometric method is applied for the simultaneous determination of naphazoline hydrochloride and antazoline phosphate in eye drops. The measurements were carried out at wavelengths of 225 and 252 nm for naphazoline hydrochloride and antazoline phosphate, respectively. The method was found to be linear (r2>0.999) in the range of 0.2-1 microg/ml for naphazoline hydrochloride in the presence of 5 microg/ml antazoline phosphate at 225 nm. The same linear correlation (r2>0.999) was obtained in the range of 1-10 microg/ml of antazoline phosphate in the presence of 0.5 microg/ml of naphazoline hydrochloride at 252 nm. The limit of determination was 0.2 microg/ml and 1 microg/ml for naphazoline hydrochloride and antazoline phosphate, respectively. The method was successfully used for simultaneous analysis of naphazoline hydrochloride and antazoline phosphate in eye drops without any interference from excipients and prior separation before analysis.

Simple HPLC determination of benzalkonium chloride in ophthalmic formulations containing antazoline and tetrahydrozoline.

A simple and rapid analytical procedure for routine quantification of n-C12H25 and n-C14H29 benzalkonium chloride (C-12 and C-14 BKC) homologs in ophthalmic formulations containing antazoline HCl and tetrahydrozoline HCl by high-performance liquid chromatography was developed and validated. The ophthalmic solution samples can be directly analyzed by reversed-phase on HiQ-Sil C18 column (4.6 mm x 150 mm, i.d., 5-microm particle size) with acetonitrile-sodium acetate buffer (pH 5.0; 0.2 M) (70:30, v/v) as mobile phase. UV Detection was carried out at 262 nm. The method was linear over the selected concentration and ranged from 0.03 to 0.10 mg/ml (r2 = 0.9999) and from 0.01 to 0.05 mg/ml (r2 = 0.9979) for C-12 and C-14 BKC homologs, respectively. The mean percent recoveries were 100.2 and 102.6 and the percent CV values were 1.3 and 3.5 for C-12 and C-14 BKC homologs, respectively. The results demonstrated the good linearity, accuracy, and precision. The method was applied to determine two commercial ophthalmic formulations, and the percent label amounts of total BKC contents were found to be 99.7 and 103.2.

Determination of antihistamines based on the formation of mixed aggregates with surfactants.

The determination of antihistamines based on the measurement of the critical micelle concentration (c.m.c.) of mixed sodium dodecyl sulfate (SDS)-antihistamine aggregates is proposed. The dye Coomassie Brilliant Blue G (CBBG) was used as a photometric probe for the rapid determination of c.m.c.s. The micellar properties of these drugs permitted the determination of diphenhydramine, antazoline, tripelennamine, diphenylpyraline and clemizole at the micron level with detection limits ranging between 0.1 and 0.7 microns. Hence the proposed method surpassed existing alternative photometric methods used routinely in the quality control of these drugs in sensitivity and featured similar detection limits to fluorimetric methods. The relative standard deviation for 6 micron diphenhydramine was 3.7%. The method was applied to the determination of these drugs in pharmaceutical preparations (solutions, capsules, creams and pills). which were analyzed directly after dissolution of the samples in distilled water.

Synthesis and identification of the primary degradation product in a commercial ophthalmic formulation using NMR, MS, and a stability-indicating HPLC method for antazoline and naphazoline.

HPLC analysis of an anti-infective ophthalmic solution (Albalon-A), containing the active drugs naphazoline and antazoline, revealed a degradation peak of unknown identity. To elucidate the identity of the degradant, the active drugs were each hydrolyzed by refluxing at high pH, and their respective hydrolysis products were isolated and spectrally characterized by NMR, FT-IR, and MS for conclusive structure elucidation. The degradant's identity was confirmed by HPLC-MS analysis of Albalon-A ophthalmic solution to be the antazoline hydrolysis product N-[(N-benzylanilino)acetyl]ethylenediamine (IV). A stability-indicating HPLC method was then developed which was able to resolve IV from the active drugs. This HPLC method was then validated for quantitating the active drugs and IV. Validation studies demonstrated linear UV response at 280 nm, recovery > 98%, good reproducibility, and a detection limit of 2 micrograms/mL IV. Overall, the data demonstrated that the HPLC method was quantitative and specific for antazoline, naphazoline, and IV. Analysis of an expired stabilitry lot of the ophthalmic solution indicated the concentration of IV was 0.002% (w/v).

Diode array detection of low level co-eluting species in high-performance liquid chromatography.

A simple and sensitive method for detecting low levels (0.5 and 1.0%, w/w) of co-eluting species in HPLC has been developed. This method is based on the subtraction of normalized peak up-slope and down-slope spectra from that of the apex. Visual inspection of the resultant "difference spectra" allows for a qualitative judgement regarding the integrity of the peak under consideration.

Simultaneous high-performance liquid chromatographic determination of antazoline phosphate and tetrahydrozoline hydrochloride in ophthalmic solution.

A method for the determination of 2-[(N-phenyl)benzylaminomethyl]-2-imidazoline X H3PO4 (antazoline phosphate) and 2-(1,2,3,4-tetrahydro-1-naphthyl)-2-imidazoline X HCl (tetrahydrozoline hydrochloride) in ophthalmic solution is described. The pharmaceutical preparation is analysed directly by reversed-phase ion-pair high-performance liquid chromatography and the method is very rapid, selective and simple.

Improved spectrophotometric determination of antazoline.

A simple, precise, and accurate spectrophotometric determination of antazoline salts was developed by improving the ceric sulfate procedure. Replacement of water with acetic acid for the preparation of all assay solutions permitted reproducible measurements of the chromogen that absorbed at 505 nm. An appreciable increase in color stability was attained by the controlled addition of perchloric acid to the ceric reagent prior to interaction with antazoline at room temperature. Evidence is provided to account for the oxidation of antazoline at the expense of a complex ceric species. Other 2-imidazolines or phenylephrine did not interfere with the investigated color reaction. In addition to the high value of the chromogen molar absorptivity, ideal adherence of color absorption to Beer's law permitted accurate and reproducible estimation of antazoline over the 1--10-microgram range. The procedure was applied to the analysis of different antazoline dosage forms.

Polarographic estimation of antazoline hydrochloride.

The dc-polarographic investigation of antazoline hydrochloride in aqueous acidic media is described. Using potassium chloride-hydrochloric acid mixture as the supporting electrolyte (pH = 3.25), antazoline hydrochloride was electrochemically reduced at the dropping mercury electrode, with the production of two waves with E1/2 values of --1.35 and --1.65 V respectively. As revealed from the study of the effect of mercury column height, pH of the medium and concentration of the depolarizer, the polarographic reduction of the antazolinium cation is preceded by a catalytic H-wave. The diffusion-controlled nature of the electrode process permitted the quantitative determination of antazoline hydrochloride in concentrations down to 1.0 . 10(-4)M. Application of the presented procedure to the analysis of different dosage forms of the compound studied proved successful and compared favourably with official estimations of anatazoline salts. In view of its simplicity, accuracy and sensitivity, the presented polarographic method can be recommended for routine analysis of antazoline formulations.