Tetrahydrozoline Research Articles

Novel Deliberately Sensitive and Selective Tetrahydrozoline Voltammetric Sensors Integrated with a Copper Oxide Nanoparticle/Zeolite Platform.

The present study introduced a novel disposable screen-printed carbon electrodes (SPCEs) modified with copper oxide/zeolite nanostructures for eco-friendly selective differential pulse voltammetric quantification of tetrahydrozoline (THZ) in eyedrop samples and biological fluids. Modification of the electrode matrix with copper oxide nanoparticles/zeolite nanostructures (CuONPs/ZY) with their effective and synergistic electrocatalytic activity enhanced the electrode performance against electrooxidation of THZ at 0.960 V in BR at pH 9.0 with a diffusion-controlled reaction mechanism. The tentative oxidation mechanism based on molecular orbital calculations postulates the oxidation of THZ molecules through oxidation of a nitrogen atom five-membered ring and the participation of two electrons/protons in the electrode reaction. Linear calibration curves were illustrated within a wide THZ concentration range from 0.24 to 57.2 μg mL-1 recording a limit of detection (LOD) value of 0.0799 μg mL-1. The CuONPs/ZY/SPEs exhibited improved performance compared with the sole reported THZ sensor-based gold film-plated carbon paste electrodes, in addition to their high reproducibility of fabrication and measurement and prolonged shelf lifetime. Tetrahydrozoline was successfully assayed in the presence of excipients, degradation products, and chloramphenicol. The presented voltammetric sensor can be considered as an eco-friendly and reliable analytical approach for monitoring THZ residues in eye drop samples and biological fluids with high recovery compared with the official pharmacopeial analytical protocol. The presented sensors were assessed according to an EcoScale tool and also compared with the reported THZ sensor.

Novel Carbon Nanotubes/Gold Nanoparticles Modified Carbon Paste Electrochemical Sensor for Antazoline Determination in Aqueous Humor

Antazoline (ANT) is a H1 histamine receptor antagonist having anticholinergic properties used to decrease nasal congestion. It is found in eye drops usually in combination with either tetryzoline (TET) or xylometazoline (XLO). In this work, a novel electrochemical sensor based on carbon paste electrode (CPE) is developed for simple, rapid, sensitive, and selective determination of antazoline in pure form, different pharmaceutical formulations and in presence of aqueous humor. CPE is modified with nanoparticles multiwalled carbon nanotube (MWCNT) composite and further decorated with gold nanoparticles using amperometric electrodeposition technique to attain Au-NP@MWCNT/CPE for enhancing sensor sensitivity. Linearity is divided into two linear segments and found to be 2 × 10–7 − 2 × 10−6 (1st Linear segment) and 2 × 10–6 − 2 × 10−5 (2nd Linear segment) with limit of detection and quantification of 1.77 × 10−7 and 5.37 × 10−7, respectively. High sensitivity, selectivity, and reproducibility of the modified electrode towards determination of antazoline have promoted its applicability in different dosage forms and in rabbit aqueous humor. This method has noticeable potential applications in quality control, pharmacokinetic studies, and routine determination of antazoline drug in binary pharmaceutical formulations.

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 642.0nm after excitation wavelengths of 350.0 and 320.0nm 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 556.5nm for ANT and 516.7nm for TET. Linear responses have been represented over a wide range of concentration (0.5-12.0μg/mL for ANT and 0.5-10.0μg/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.

Green TLC-Densitometric Method for Simultaneous Determination of Antazoline and Tetryzoline: Application to Pharmaceutical Formulation and Rabbit Aqueous Humor.

Abstract Ophthalmic pharmaceutical preparation containing antazoline (ANT) and tetryzoline (TET) is prescribed widely as an over the counter medication for allergic conjunctivitis treatment. Development of a selective, simple and environmentally friendly thin-layer chromatographic method established to determine both ANT and TET in their pure forms, pharmaceutical formulation and spiked aqueous humor samples. By using silica gel plates and means of a developing system consists of ethyl acetate:ethanol (5:5, by volume), the studied drugs separation was achieved, and scanning was carried out at 220.0 nm for the separated bands with a 0.2–18.0 μg/band concentration range for each of ANT and TET. Standard addition technique application was carried out to determine the proposed method validity. Statistical comparison was made between the proposed method and the official methods ANT and TET showing no significant difference concerning accuracy and precision. Furthermore, greenness profile assessment was accomplished by means of four metric tools, namely, analytical greenness, green analytical procedure index, analytical eco-scale and national environmental method index. Highlights

Managing allergic conjunctivitis via ophthalmic microemulsions: Formulation, characterization, in vitro irritation studies based on EpiOcular™ eye irritation assay and in vivo studies in rabbit eye

AbstractThe purpose of this work was the development of an alternative ocular tetrahydrozoline hydrochloride (THZ) microemulsion for the management of allergic conjunctivitis. Pseudo‐ternary phase diagrams were used to produce the microemulsions. For the formulation of the microemulsions, isopropyl myristate was selected as oil. Furthermore, various surfactants were applied for the determination of their suitability; ME‐1 and ME‐4 were developed using Sorbitan monolaurate 80 and Polysorbate 80, for ME‐2 and ME‐5 Sorbitan monolaurate 80 and macrogolglycerol ricinoleate while for ME‐3 and ME‐6 Sorbitan monolaurate 80 and Polysorbate 20. For ME‐1, ME‐2, and ME‐3 propylene glycol and ethanol, for ME‐4, ME‐5, and ME‐6 ethanol and polyethylene glycol were used as co‐surfactants. Various characterization parameters of microemulsions were evaluated such as droplet size, conductivity, zeta potential, viscosity, and pH. In addition, the drug release, stability, sterility, safety, ex vivo, and in vivo experiments were studied. The characterization showed that the formulations can act as suitable carriers for eye application. In addition, it was revealed that microemulsions were found stable and sterile. The formulations released the drug in a sustained manner. Ex vivo diffusion studies exhibited that the microemulsions can be used for topical delivery to the eye. Assessment of in vitro ocular irritation was conducted by an in vivo prediction model, EpiOcular™ eye irritation test. Based on the in vivo studies, the chosen ideal microemulsion showed longer contact time to the cornea than the commercial product. Moreover, the developed ocular carrier was found to be safe from the viewpoint of in vitro ocular irritancy and mutagenicity. In conclusion, according to characterization results, the THZ microemulsions can act as a hopeful approach for topical eye application.

Tetrahydrozoline: Death by Eyedrops

Tetrahydrozoline (THZ) is an alpha-adrenergic receptor agonist most commonly used in eyedrops to reduce redness. Reported plasma concentrations are less than 1 ng/mL after normal use. Adverse effects following oral ingestion include drowsiness, tremors, irregular heartbeat and respiratory depression. Several cases of individuals surviving accidental THZ exposure and drug facilitated crimes victims rendered unconscious by the drug have been reported. The purpose of this study is to summarize THZ concentrations from cases submitted to a reference laboratory and examine its role in death cases. Data were extracted from NMS Labs’ (Horsham, PA, USA) Laboratory Information Management System for all cases received from December 2010 to December 2021. Cases with a reported blood THZ concentration were classified as postmortem (PM), driving under the influence of drugs (DUID), drug facilitated crime (DFC) or unknown. The mean, median and concentration ranges for each group were determined. The number and types of other drugs reported were also examined in cases which underwent comprehensive testing. 129 cases were positive for THZ. The reported concentrations are summarized below: – Case Type N Mean (ng/mL) Median (ng/mL) Range (ng/mL) – PM 112 20 1.7 0.19–290, – DUID 1 0.64 0.64 -, – DFC 3 0.35 0.35 <0.10–0.52, – UNKNOWN 13 18 1.2 0.27–130. Comprehensive testing was performed on approximately 100 cases. The most commonly detected other drugs were ethanol, Delta-9 THC), diphenhydramine, fentanyl, amphetamine, and morphine. THZ concentrations ≥100 ng/mL were reported in 10 cases. One case (THZ = 100 ng/mL) was from a living individual and the status of the patient could not be determined in another case (THZ = 130 ng/mL). The remaining cases included a dual suicide, one sudden death, one “suspected poisoning”, one homicide and one case still under active investigation. A woman admitted to lacing her boyfriend's water with tetrahydrozoline on multiple occasions from 2009–2012 to get him to pay more attention to her. The man, who survived, sought medical attention for trouble breathing, irregular blood pressure and nausea and had a blood THZ concentration of 49 ng/mL. The THZ concentration in cardiac blood from a decedent whose death was originally believed to be due to natural causes was 68 ng/mL. THZ, an uncommon finding in toxicology testing, has been reported in multiple homicide, suicide and drug facilitated crimes highlighting the importance of its inclusion in comprehensive post-mortem toxicology testing.

Optimization and validation of Eco-friendly RP-HPLC and univariate spectrophotometric methods for the simultaneous determination of Fluorometholone and Tetrahydrozoline hydrochloride

AbstractA sensitive RP-HPLC method is presented for the simultaneous quantification of Fluorometholone (FLM) and Tetrahydrozoline hydrochloride (THZ). The method has the advantages of being rapid, accurate, reproducible, ecologically acceptable and sensitive. The separation utilized C8 Xbridge® column and mobile phase mixture of Acetonitrile/phosphate buffer pH 3 ± 0.1 (70:30, v/v) with UV detection at 230 nm. Stepwise optimization and factors affecting separation are properly discussed. Different factors were optimized such as stationary phase, selection of organic solvent and its content, buffer pH and concentration, flow rate, elution type and detection wavelength. The studied drugs were efficiently separated in 3.4 min with high resolution. Also, two univariate spectrophotometric methods have been optimized for the quantification of the studied drugs. Method 1: dual wavelength for THZ and iso-absorptive point for FLM, Method 2: ratio difference (RD) for THZ and first derivative FLM utilizing methanol as a solvent. These methods are accurate, precise with minimal data manipulation. Greenness of the methods was estimated using eco-scale tool where the presented methods were found to be excellent green with eco-score of 83 for HPLC and 80 for spectrophotometry. The methods are validated in conformance with ICH guidelines, with acceptable accuracy, precision, and selectivity. The suggested methods can be employed for the economic analysis of THZ and FLM in their pure form and binary ophthalmic formulation, that can be employed by quality control laboratories.

Separation of tetrahydrozoline enantiomers in capillary electrophoresis with cyclodextrin-type chiral selectors and investigation of chiral recognition mechanisms

The recognition power and affinity pattern of various cyclodextrins (CD) towards the enantiomers of tetrahydrozoline (THZ) were studied using capillary electrophoresis (CE). As expected, affinity of THZ enantiomers and selectivity of recognition towards CD derivatives was strongly dependent on the cavity size and substituent type and pattern on the CD rims. Not only were the affinity strength and selectivity of recognition affected by the size of the cavity and chemistry of the CDs but also the affinity pattern. Another interesting example of opposite affinity pattern of enantiomers towards α- and β-CD was observed here. In addition, opposite affinity pattern of THZ enantiomers was seen towards β-CD and its acetylated derivatives, while methylation of β-CD did not affect the affinity pattern of THZ enantiomers. In order to get more information about structural mechanisms of the multivariate dependences mentioned above, rotating frame Overhauser enhancement spectroscopy (ROESY) and computation techniques were used. Significant differences between the structure of THZ complexes with different CDs with both methods were encountered. Good correlations between experimentally determined and computed structure of complexes, as well as between computed complex stabilities and enantiomer migration order (EMO) in CE were observed.

COMMERCIAL EYE DROPS TRIGGERS NECROTIC EFFECT IN Acanthamoeba sp.

Eye infection due to microbial infection is hard to treat and painful. Two types of eye drops that are commonly used to relieve eye pain offered by pharmacists have been tested in this study namely solution A (containing tetrahydrozoline hydrochloride) and solution B (containing gentamicin and dexamethasone). The efficacy and the activities of these eye drops were tested on Acanthamoeba sp. (a clinical isolate from an Acanthamoeba keratitis patient) to study the cytotoxicity effects of the solutions on the Acanthamoeba. The Acanthamoeba were exposed to solution A and B for 24 hr and cell viability was assessed using MTT assays, morphological changes using the light microscope and through acridine orange and propidium iodide (AO/PI) staining for cytoplasmic biochemical activities. The IC50 value for Acanthamoeba cell viability was 45.1% and 20.3% for solutions A and B respectively. Morphological observation shows the inhibition of acanthapodia formation on the surface of the cells. Solution A and B-treated Acanthamoeba appeared in the red color of the cytoplasm upon staining with AO/PI indicating a necrotic mode of cell death. This is due to loss of membrane integrity of Acanthamoeba cell membrane after exposed to solution A and B at their IC50 value. It is shown that solutions A and B can cause cell death in trophozoite of Acanthamoeba cells at moderate IC50 value. Unfortunately, the necrosis mode of cell death is not a preferable type of cell death for treating Acanthamoeba infection. Therefore, it can be concluded that solutions A and B are not suitable to treat eye infected with Acanthamoeba sp. as it does not promise absolute healing as the solution concentration needed is quite high and the cell death mechanism is necrosis.

High performance liquid chromatography analysis of tetrahydrozoline hydrochloride in ophthalmic solution by silica column eluted with aqueous solvent mixtures

A HPLC method using bared silica column eluted with aqueous solvent mobile phase was developed for determination of tetrahydrozoline hydrochloride in ophthalmic preparations. A mixture of methanol and water (70:30, v/v) containing 0.03% triethylamine and 0.02% acetic acid was used as mobile phase, and chlorpheniramine maleate as an internal standard. The flow rate was 1 mL/min and the detection was at 254 nm. The quantitation limit was 1.0, μg/mL. Average recoveries range from 98.9 to 99.9%. The linearity of the calibration curve of tetrahydrozoline hydrochloride was well correlated (r 2 = 0.9996) within the range from 12.5 to 500 μg/mL as well as from 1.0 to 20 μg/mL (r 2 = 0.9997). This study further reports a simple and quick method for routine quantitative analysis of tetrahydrozoline hydrochloride in an ophthalmic solution that contains a relatively high concentration of sulfamethoxazole sodium and methyl paraben.

ВИБІР СКЛАДУ БУФЕРНОЇ СИСТЕМИ ДЛЯ ОЧНИХ КРАПЕЛЬ З ТЕТРАГІДРОЗОЛІНУ ГІДРОХЛОРИДОМ

The purpose of this article is developing the optimal formulation of excipients for eye drops with tetrahydrosoline hydrochloride and researching of the locally irritating effect of the selected formulation of eye drops. The objects of the research are experimental solutions of eye drops with tetrahydrosoline hydrochloride using different combinations of excipients. Evaluation of test results in the selection of the formulation was performed according to the physico-chemical parameters of the prepared eye drops solution along with researching of stability. Assessment of the local irritation was performed on Chinchilla rabbits, particularly on the mucous membrane of the rabbit’s eye. The optimal formulation of the eye drops with tetrahydrozoline hydrochloride of a medicinal product using citrate buffer solution was developed. The result solution represents a clear homogeneous aqueous solution to physical and chemical properties. The developed formulation contains (in grams): tetrahydrozoline hydrochloride - 0.05; benzalkonium chloride - 0.01; disodium edetate - 0.01; sodium chloride - 0.84; citrate buffer - to a pH of 6.2 to 6.5; injection water - up to 100 ml. Samples of the experimental series of eye drops meet the requirements of HFC on ophthalmic drugs in terms of physico-chemical quality indicators as description, transparency, osmolality, pH of the solution, quantitative content of tetrahydrazoline hydrochloride. The results obtained in the research of stability of the eye drops experimental series throughout a long-term and accelerated storage during 6-months observation indicate the invariance of critical quality indicators, such as description, transparency, pH of the solution and the quantitative content of tetrahydrazoline hydrochloride. The results of determining the locally irritant effect on the mucous membrane of the rabbit’s eye showed that developed formulation of the eye drops does not cause any local irritation, neither visual reaction from the mucous membrane of the eye. The damaging effect level was 0 points in comparison with the other drugs. It is proved that the proposed formulation of eye drops meets the requirements of SPhU, stable and comfortable to use. The results of this experiment have a practical importance for development of new generic drugs.

Simultaneous determination of fluorometholone and tetrahydrozoline hydrochloride in ophthalmic suspension by HPLC

Simultaneous determination of fluorometholone and tetrahydrozoline hydrochloride in ophthalmic suspension by HPLC

Stability-Indicating HPLC Method for Simultaneous Determination of Chloramphenicol, Dexamethasone Sodium Phosphate and Tetrahydrozoline Hydrochloride in Ophthalmic Solution.

A simple stability-indicating RP-HPLC assay method was developed and validated for quantitative determination of Chloramphenicol, Dexamethasone Sodium Phosphate and Tetrahydrozoline Hydrochloride in ophthalmic solution in the presence of 2-amino-1-(4-nitrophenyl)propane-1,3-diol, a degradation product of Chloramphenicol, and Dexamethasone, a degradation product of Dexamethasone Sodium Phosphate. Effective chromatographic separation was achieved using C18 column (250 mm, 4.6 mm i.d., 5 μm) with isocratic mobile phase consisting of acetonitrile - phosphate buffer (pH 4.0; 0.05 M) (30:70, v/v) at a flow rate of 1 mL/minute. The column temperature was maintained at 40°C and the detection wavelength was 230 nm. The proposed HPLC procedure was statistically validated according to the ICH guideline, and was proved to be stability-indicating by resolution of the APIs from their forced degradation products. The developed method is suitable for the routine analysis as well as stability studies.

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 22kV and a pressure injection of the sample at 50mbar for 17s. HPLC analysis was performed with Kinetex (150×4.6mm ID×5μm) (Phenomenex, USA) analytical column with 1mLmin−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 10μL and the wavelength of the detector was set at 215nm for monitoring both analytes.Calibration graphs showed a good linearity with a coefficient of determination (R2) 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.

Stability-Indicating RP-HPLC Methods for the Determination of Fluorometholone in Its Mixtures with Sodium Cromoglycate and Tetrahydrozoline Hydrochloride.

Two stability-indicating reversed-phase liquid chromatographic methods were developed and validated for the determination of fluorometholone (FLU) in its mixtures with sodium cromoglycate (SCG) and tetrahydrozoline hydrochloride (THZ). The first HPLC method (Method 1) was based on isocratic elution of FLU and SCG along with their alkaline degradation products on a reversed phase C18 column (250 × 4.6 mm id)-ACE Generix 5, using a mobile phase consisting of methanol-water (70 : 30, v/v), pH adjusted to 2.5 using orthophosphoric acid at a flow rate of 1.2 mL min(-1) Quantitation was achieved with UV detection at 240 nm. The second HPLC method (Method 2) was based on isocratic elution of FLU, its alkaline degradation product and THZ on a reversed phase C8 column (250 × 4.6 mm)-ACE Generix 5, using a mobile phase consisting of acetonitrile-50 mM potassium dihydrogen orthophosphate (40 : 60, v/v) at a flow rate of 2 mL min(-1) Quantitation was achieved by applying dual-wavelength detection, where FLU and its alkaline degradation product were detected at 240 nm and THZ was detected at 215 nm at ambient temperatures. Linearity, accuracy and precision were found to be acceptable over the concentration range of 5-50 and 10-500 μg mL(-1) for FLU and SCG (Method 1) and over the concentration range of 5-80 and 5-60 μg mL(-1) for FLU and THZ (Method 2), respectively. Besides, the FLU alkaline degradation product was verified using IR, NMR and LC-MS spectroscopy. The two proposed methods could be successfully applied for the routine analysis of the studied drugs either in their pure bulk powders or in their pharmaceutical preparations without any preliminary separation step.

Application of α-adrenomimetic decongestants as chemical agents for gingival retraction

PURPOSE : The purpose of this study is to observe, compare and evaluate the effect of two α-adrenomimetic decongestants which are clinically approved nasal and eye drops - 0,05% xylometazoline hydrochloride and 0,05% tetrahydrozoline hydrochloride, when applied as chemical agents for chemo-mechanical retraction of free gingiva prior to impression making in fixed prosthodontics. MATERIALS AND METHODS : The study includes 90 prepared abutment teeth indicated for fixed prosthodontic treatment. α-adrenomimetic decongestants in the composition of 2 approved for clinical usage nasal and eye drops commercial products were applied as chemical agents for gingival retraction - Xylometazoline ( 0,05% xylometazoline hydrochloride) and Visine ( 0,05% tetrahydrozoline hydrochloride). Ultrapak retraction cord of four different sizes impregnated with the investigated chemical agents was used. Two steps two-layered impressions with polyvinyl and polydimethylsiloxane were taken from the prosthetic fields. Impression sections were fabricated and studied under microscope. RESULTS : The low viscosity polyvinyl and polydimethyl siloxane layers tend to penetrate deeper in the gingival groove after chemo-mechanical retraction with Xylometazoline compared to the second group impressions fabricated after Visine retraction. CONCLUSION : The conducted testing demonstrated that effective retraction of the free marginal gingiva is possible to obtain with α-adernomimetic decongestants. 0,05% xylometazoline hydrochloride (Xylometazoline) provides better results in comparison to the eye decongestant drops 0,05% tеtrahydrozoline hydrochloride (Visine).

Spectrophotometric Determination of Distigmine Bromide, Cyclopentolate HCl, Diaveridine HCl and Tetrahydrozoline HCl via Charge Transfer Complex Formation with TCNQ and TCNE Reagents.

The purpose of this investigation was directed to propose sensitive, accurate and reproducible methods of analysis that can be applied to determine distigmine bromide (DTB), cyclopentolate hydrochloride (CPHC), diaveridine hydrochloride (DVHC) and tetrahydrozoline hydrochloride (THHC) drugs in pure form and pharmaceutical preparations via charge-transfer complex formation with 7,7,8,8-tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) reagents. Spectrophotometric method involve the addition a known excess of TCNQ or TCNE reagents to DTB, CPHC, DVHC and THHC drugs in acetonitrile, followed by the measurement of the absorbance of the CT complexes at the selected wavelength. The reaction stoichiometry is found to be 1:1 [drug]: [TCNQ or TCNE]. The absorbance is found to increase linearly with concentration of the drugs under investigation which is corroborated by the correlation coefficients of 0.9954-0.9981. The system obeys Beer's law for 6-400, 20-500, 1-180 and 60-560 µg mL(-1) and 80-600, 10-300, 1-60 and 80-640 µg mL(-1) for DTB, CPHC, DVHC and THHC drugs using TCNQ and TCNE reagents, respectively. The apparent molar absorptivity, sandell sensitivity, the limits of detection and quantification are also reported for the spectrophotometric method. Intra- and inter-day precision and accuracy of the method were evaluated as per ICH guidelines. The method was successfully applied to the assay of DTB, CPHC, DVHC and THHC drugs in formulations and the results were compared with those of a reference method by applying Student's t and F-tests. No interference was observed from common pharmaceutical excipients.

The rabbit gingival tissue response to retraction liquids and tetrahydrozoline

BACKROUND/AIM: Retraction agents for temporary vertical and lateral suppression of gingival tissue as well as bleeding control and fluid flow in the gingival sulcus are expected to have maximal efficiency without irreversible damage of local tissue and adverse systemic effects. The research started from the assumption that tetrahydrozoline is a biologically more acceptable means of gingival retraction than commercially available preparations. The aim of the study was to comparatively analyse the inflammatory effects of different retraction materials and tetrahydrozoline. The effect of retraction liquid on the basis of aluminum chloride and epinephrine and tetrahydrozoline hydrochloride on gingival tissue of rabbits was investigated. The application time in the rabbit's gingival sulcus was 7 minutes. Tissue biopsy was performed after an hour, a day, and 7 and 30 days. Tissue preparations were analyzed under a microscope. The obtained results indicate a reversible damage of gingival tissues as a result of local application of aluminum chloride- and epinephrine-based retraction agents. Their use led to acute inflammatory response after an observation period of 1 and 7 days. After 30 days reparation of damaged tissue was observed. The use of tetrahydrozoline resulted in a visibly weaker inflammatory response. Retraction liquids insertion led to an acute inflammatory response of gingival tissue which in time assumed a chronic character. The inflammatory response to the administered tetrahydrozoline was significantly lower with complete reparation of gingival tissue. Taking this fact into account it is recommended as a potential retraction agent.

Use of tetrahydrozoline for chemical submission

We report two cases of drug-facilitated sexual assault which presented with CNS depression rendering the victims vulnerable to sexual assault and unable to recall the events surrounding the crimes. In each tetrahydrozoline (THZ) was quantified. Case #1 ingested an unknown amount of eye drops containing THZ mixed with alcoholic beverages. Case #1 presented to the emergency department (ED) approximately 7h after reportedly being sexually assaulted and was without symptoms in the ED. Earlier reports from individuals who saw her indicated the victim to be "heavily intoxicated". Case #2 also ingested an unknown amount of eye drops containing THZ mixed with alcoholic beverages. Case #2 presented to an ED without symptoms approximately 23h after reportedly being sexually assaulted. Urine obtained from both cases was assessed for THZ concentrations using gas-chromatography-mass spectrometry. Case #1 had a 0.15g% (by weight by volume) urine ethanol concentration and a urinary THZ concentration of 1.481ng/ml, approximately 7h after ingestion. Case #2 was negative for ethanol but had a urine THZ concentration of 108ng/ml at 23h post-ingestion. Few case reports have been published documenting the use of THZ to facilitate sexual assault. We report two cases of drug-facilitated sexual assault involving the use of THZ where alcoholic beverages were concomitantly consumed. This is the first paper to our knowledge which discusses pharmacology of THZ ingestion and the significance of alcohol being present.

Development and validation of a reversed-phase HPLC method for analysis of tetrahydrozoline hydrochloride in eye drop formulations

A simple, precise, accurate, and stability-indicating method is developed and validated for analysis of tetrahydrozoline hydrochloride in eye drop formulations. Separation was achieved on a reversed-phase C8 column (125mm×4.6mm i.d., 5μm) using a mobile phase consisting of acetonitrile/phosphate buffer of pH 3.0 (20:80, v/v) at a flow rate of 1.0mL/min and UV detection at 240nm. This method is validated according to United States Pharmacopeia requirements for new methods, which include accuracy, precision, selectivity, robustness, and linearity and range. This method shows enough selectivity, accuracy, precision, and linearity and range to satisfy Federal Drug Administration/International Conference on Harmonization regulatory requirements. The current method demonstrates good linearity over the range of 0.025–0.075mg/mL of tetrahydrozoline with r2 0.999. The average recovery of the method is 100.8% with a relative standard deviation of 0.47%. The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing analytical operators has proven that the method is robust and rugged.