Charge variants of proposed biosimilar to Omalizumab: Isolation, purification and analysis by HPLC methods.

Omalizumab (Xolair) is a humanized monoclonal antibody derived by recombinant DNA technology. It binds specifically to immunoglobulin E (IgE) which plays a major role in allergic reaction by releasing histamine and other inflammatory factors from mast cells. Omalizumab binds circulatory IgE with high affinity and prevents from its binding to mast cell receptor. Charge variants are one of the critical quality attributes (CQAs) in biological drug development and sources of heterogeneity which needs to be considered in biosimilarity assessment. In this study, biosimilar product of Xolair was expressed in mammalian cell culture process in laboratory to isolate charge variants (acidic, main peak and basic). Different charge variants were isolated from intermediate purified biosimilar product of Xolair. Isolated charge variants were purified with preparative cation exchange chromatography technique and characterized with different analytical tools includes size exclusion chromatography (SEC-HPLC) and cation exchange chromatography (CEX-HPLC). Purity of acidic, main peak and basic variants was 99.58%, 99.98% and 98.64% respectively as per SEC-HPLC and according to CEX-HPLC purity was 94.25%, 95.58% and 91.33% respectively. The study data indicates that isolated charge variants were purified with desired purity and can be further used for process characterization, in vitro potency and in vivo kinetics studies.

A UPLC method development and validation study of Upadacitinib and its impurities in extended - release oral tablet dosage forms.

OBJECTIVE: The primary objective was to develop a concomitant isocratic ultra-performance liquid chromatographic photo-diode array detection method to estimate Upadacitinib and its process-related impurities: impurity-1 and impurity-2. Further validation was conducted and studied for possible degradants under stress environments. MATERIALS AND METHODS: All the chemicals and reagents used were of HPLC (acetonitrile, methanol) and analytical grade (trifluoro acetic acid). The ultra-performance liquid chromatography (Agilent 1290 Infinity II LC system) consists of a quaternary pump, a BEH C18 (50×2.1mm, 1.7µ) column, and photo-diode array detector. The method was developed with acetonitrile: methanol: 0.1% v/v trifluoro acetic acid (50:20:30 v/v/v) mobile phase at 0.2mL/min flow rate within a run time of 5.5min The detection was carried at 231.2nm. RESULTS: The respective retention times achieved were 2.289min (Upadacitinib), 0.972min (Upadacitinib impurity-1), and 3.508min (Upadacitinib impurity-2). The optimized method was validated further, and the linearity range was best fit at 15.0-180.0µg/mL for Upadacitinib and 1.0-12.0µg/mL for both Upadacitinib impurity-1 and 2 respectively. The detection and quantification limits were 4.50µg/mL, 15.00µg/mL (Upadacitinib) and 0.30µg/mL, 1.0µg/mL (Upadacitinib impurity-1 and 2). CONCLUSION: A fast, isocratic, specific, and reproducible ultra-performance liquid chromatographic method was developed and validated for various parameters according to the ICH Q2 (R1) guidelines studies. Stress studies were conducted exposing the sample dilution to various treatments (acid, alkali, peroxide, HPLC water, heat, and UV light). The degradants were well-separated apart from the peaks of the active substance. The stability indicating nature was observed during the degradation. The optimized method can be applied for the separation and estimation of Upadacitinib and its process-related impurities in pharma sector in tablet dosage forms.

Assessment of gas chromatography methodology approach for the trace evaluation of carcinogenic impurity, methyl chloride, in trimetazidine dihydrochloride.

OBJECTIVE: A simple and robust head space/gas chromatography with flame ionisation sensor (HS/GC/FIS) approach for the trace evaluation of carcinogenic impurity, methyl chloride, in trimetazidine dihydrochloride (TRD) drug ingredient and its formulation is described. METHOD: This HS/GC/FIS approach was based on separation and analysis of CH3Cl content on DB-624 [75.0m - length, 0.53mm - internal diameter, 3.0µm - film thickness] column using nitrogen as carrier gas flowing through the column at 3mL/min stream rate. Detection of eluted CH3Cl was accomplished with flame ionization sensor at a set temperature of 260̊C. RESULTS: The optimised HS/GC/FIS methodological approach was thoroughly validated, demonstrating that it was linear with range of 5.0ppm to 1508.4ppm, sensitive with detection limit of 1.65ppm and quantification limit of 5.01ppm, reproducible with RSD values of 2.10-2.35%, accurate with recoveries of 81.9-99.0%, robust with percent variation of 7.5-12.22% with respect to changes in oven temperature, injector temperature, detector temperature and practical for regular TRD quality control. CONCLUSION: The findings revealed that with this optimised HS/GC/FIS methodological approach, the trace amounts of carcinogenic impurity (methyl chloride) in TRD drug ingredient and formulation could be successfully measured.

A simultaneous liquid chromatographic analysis of niclosamide and bicalutamide in rat plasma by protein precipitation extraction.

OBJECTIVE: The aim of the study was to develop a simple, sensitive and cost-efficient bioanalytical method for the simultaneous determination of niclosamide and bicalutamide in rat plasma with appropriate validation. MATERIAL AND METHODS: Real-time estimation was carried out using Ultra Flow Liquid Chromatography. The solvent system consisting of 20mM sodium acetate buffer at pH 4.0 and acetonitrile (65: 35% v/v) is used as the mobile phase. The analytes were extracted by protein precipitation with acetonitrile and separated on an Eclipse plus C18 Column (25cm×5cm×4.6µm) with L1 packing in isocratic mode with a flow rate of 1ml/min at 254nm. The developed method was validated on the basis of the bioanalytical guidelines of the US American FDA. RESULT: The retention times of niclosamide and bicalutamide were 4.19min and 8.61min, respectively, with a running time of 15minutes. The calibration ranges are 50-600ng/ml for niclosamide and 100-1200ng/ml for bicalutamide. Regression equations for niclosamide and bicalutamide were y=55746x - 1E+06 and y=22051x-576888 with regression coefficient (R2) 0.9952 & 0.9982 using the unweighted and weighted linear regression with a weighting factor of 1/xo, 1/x, 1/√x, and 1/x2. The accuracy of niclosamide and bicalutamide were 46.01ng/ml to 584.10ng/ml and 82.30ng/ml to 1149.13ng/ml, respectively. The percentage recoveries for niclosamide and bicalutamide were 86.51-90.29% & 88.64-93.99%, respectively. CONCLUSIONS: The result of the present study show that the method developed is a simple, fast and precise method and is used in bioavailability and bioequivalence studies as well as during routine therapeutic drug monitoring of niclosamide and bicalutamide.

Phytotoxin of rice aggregate sheath spot pathogen Rhizoctonia oryzae-sativae and its biological activities.

Rice aggregate sheath spot disease occurs in many countries and causes serious yield losses. In China, the disease-causing fungus Rhizoctonia oryzae-sativae was reported in 1985, and since then, it has rarely been reported in major rice-growing areas after almost 30 years. Compared with Rhizoctonia solani, R. oryzae-sativae has a significantly different physiological morphology and growth status, although both fungi affect rice leaves in very similar ways. The optimum temperature for the suitable growth of R. oryzae-sativae is 31 °C, which is consistent with previous reports. We extracted phytotoxins from R. oryzae-sativae and analyzed its biological activity via the detached leaf and radicle inhibition methods. Rhizoctonia solani and R. oryzae-sativae exhibit differences in terms of pathogenicity and toxin activity, which indicates that these fungi may produce different toxin components. Based on gas chromatography-mass spectrometry data, esters, phenols, and other components were present in the crude toxin extract of R. oryzae-sativae. Our research provides a new method for studying the phytotoxins of R. oryzae-sativae. However, further studies are needed to elucidate the pathogenic mechanisms responsible for aggregate sheath spot disease in rice.

[Detection and functions of viral RNA modifications: perspectives in biology and medicine]. / Détection et fonctions des modifications de l'ARN viral : perspectives en biologie et en médecine.

Viral RNAs (either derived from DNA viruses and genomic/mRNAs of RNA viruses) produced and replicated in eukaryotic cells are exposed to the activity of host cell RNA modification machinery. Moreover, some complex viruses encode their own RNA modification enzymes, generally cap-related m7G-and 2'-O-methyltransferases whose expression allows specific modification of viral transcripts and modulation of viral RNA recognition by host restriction systems. Here we review current achievements in the detection of viral RNA modifications by liquid chromatography coupled to mass spectrometry (LC-MS) and deep sequencing-based approaches. The presence, origin and characterized functions of RNA modifications in viral RNAs are discussed.

Pharmacokinetic profile of the selective 5-HT3 receptor antagonist ondansetron in the rat: an original study and a minireview of the behavioural pharmacological literature in the rat.

The availability of agonists and antagonists to modulate the activity of the 5-hydroxytryptamine (5-HT) type 3 (5-HT3) receptor has renewed interest in its role as a therapeutic target. Ondansetron is a highly selective 5-HT3 receptor antagonist that is well tolerated as an anti-emetic for patients undergoing chemotherapy. Preclinical studies in rat have shown the effects of small doses of ondansetron on cognition, behavioural sensitisation, and epilepsy. However, the pharmacokinetic (PK) profile of ondansetron in rat has not been described, which limits the translational relevance of these findings. Here, we aim to determine, in the rat, the PK profile of ondansetron in the plasma and to determine associated brain levels. The plasma PK profile was determined following acute subcutaneous administration of ondansetron (0.1, 1, and 10 µg/kg). Brain levels were measured following subcutaneous administration of ondansetron at 1 µg/kg. Plasma and brain levels of ondansetron were determined using high-performance liquid chromatography - tandem mass spectrometry. Following administration of all three doses, measured ondansetron plasma levels (≈30-3000 pg/mL) were below levels achieved with doses usually administered in the clinic, with a rapid absorption phase and a short half-life (≈30-40 min). We also found that brain levels of ondansetron at 1 µg/kg were significantly lower than plasma levels, with brain to plasma ratios of 0.45 and 0.46 in the motor and pre-frontal cortices. We discuss our findings in the context of a minireview of the literature. We hope that our study will be helpful to the design of preclinical studies with therapeutic end-points.

Pharmacokinetics and tissue distribution study of herpetotriol in rats by ultrahigh-performance liquid chromatography with tandem mass spectrometry.

Herpetotriol, a typical lignan in Herpetospermum pedunculosum Wall's seeds that has long been used to treat icterhepatitis and indigestion and other related diseases in Tibet, is of potential hepatoprotection. This study aims to study the pharmacokinetics features of herpetotriol, including the blood drug concentration - time curve and tissue distribution. The ultrahigh-performance liquid chromatography with tandem mass spectrometry method was established to detect herpetotriol concentration in plasma and tissues, and the method showed good linearity from 10 to 2000 ng/mL (r ≥ 0.9972) and sensitivity (≥10 ng/mL). Our blood drug concentration - time curve indicated that herpetotriol was distributed quickly in rats with a Tmax value at about 0.083 h and eliminated rapidly with a clearance rate at 98.13 ± 8.05 and 137.04 ± 9.48 L·h-1·kg-1 with doses of 5 and 2.5 mg/kg, respectively. Although herpetotriol was detectable in all tested tissues, it has a higher concentration in liver than in heart, lung, spleen, and kidney, which is in line with its hepatoprotection. The pharmacokinetics features uncovered by the present study could provide more information for future pharmacological and toxicological study of herpetotriol.

Biological activity of Echinops spinosus on inhibition of paracetamol-induced renal inflammation.

This study was designed to evaluate the possible mechanisms through which Echinops spinosus (ES) extract demonstrates nephroprotective effect on the paracetamol acetominophen (N-acetyl-p-aminophenol (APAP)) induced nephrotoxicity in rats. Twenty-four Swiss albino rats were divided into four groups (six rats each). The placebo group was orally administered sterile saline, the APAP group received APAP (200 mg·kg-1·day-1 i.p.) daily, the ES group was given ES extract orally (250 mg/kg), and the APAP + ES group received APAP as for the APAP group and administrated the ES extract as for the ES group. Pretreatment of methyl alcohol extract of ES reduced the protein expression of inflammatory parameters including cyclooxygenase-2 and nuclear factor κB in the kidney. It also reduced the mRNA gene expression of tumor necrosis factor-α and interleukin-1ß. The ES extract compensated for deficits in the total antioxidant activity, suppressed lipid peroxidation, and amended the APAP-induced histopathological kidney alterations. Moreover, ES treatment restored the elevated levels of urea nitrogen in the blood and creatinine in the serum by APAP. The ES extract attenuated the APAP-induced elevations in renal nitric oxide levels. We clarified that the ES extract has the potential to defend the kidney from APAP-induced inflammation, and the protection mechanism might be through decreasing oxidative stress and regulating the inflammatory signaling pathway through modulating key signaling inflammatory biomarkers.

Investigation of intestinal elimination and biliary excretion of ibuprofen in hyperglycemic rats.

An in vivo intestinal perfusion model was used to investigate how experimental hyperglycemia affects intestinal elimination and biliary excretion in the rat. Experimental diabetes was induced by administration of streptozotocin (65 mg/kg, i.v.). The intestinal perfusion medium contained 250 µM (±)-ibuprofen. An isocratic high-performance liquid chromatography method with UV-visible detection was developed to quantitate ibuprofen in the intestinal perfusate, while a gradient method was applied to quantitate ibuprofen and ibuprofen-ß-d-glucuronide in the bile. The limit of quantitation of ibuprofen was found to be 0.51 µM in the perfusate of the small intestine. In the bile, the limit of quantitation of ibuprofen and ibuprofen-ß-d-glucuronide was 4.42 and 10.3 µM, respectively. Unconjugated ibuprofen and ibuprofen-ß-d-glucuronide were detected in the bile; however, no ß-d-glucuronide of ibuprofen could be detected in the intestinal perfusate. The results indicate that experimental diabetes can cause a decrease in the disappearance of ibuprofen from the small intestine. Excretion of both ibuprofen and ibuprofen-ß-d-glucuronide decreased to the bile in experimental diabetes. The results can be explained by the results of molecular biological studies indicating streptozotocin-initiated alterations in the intestinal and hepatic transport processes.

Optimization of morphine extraction method for the assay of its urinary 3-glucuronideconjuguate by gas chromatography-mass spectrometry.

In the field of doping, a great interest is carried for the analysis of morphine, a powerful narcotic analgesic opiate which use is prohibited during competitions. In order to confirm the abnormal analytical result in our anti-doping laboratory, a sensitive and selective gas chromatography-mass spectrometry (GC-MS) method was performed for the quantification of urinary morphine. As sample preparation is a key step for the determination of drugs in biological samples, the aim of this work consists of the optimization of the urinary human sample pretreatment conditions before quantification by GC/MS. Enzymatic hydrolysis associated with liquid-liquid extraction constitute the major pre-treatment steps. Our study has first focused on the optimization of the extraction solvents then to enzymatic hydrolysis which morphine is released from its glucuronide conjugated form. Onboard premiums, a study involving the effect of "amount of enzyme", "incubation temperature" and "duration of hydrolysis" was conducted. This univariate study has enabled us to evaluate the influence of each of these operating variables on the area ratio of morphine to the internal standard (Amorphine/AIS) response and to set the experimental fields for each one of them. Based on these results, an experimental design was established using the Box-Behnken model to determine, by multivariate analysis, the optimal operating conditions maximizing the "Amophine/AIS" response. After validation, the analysis of response surface makes it possible to set the optimum operating conditions, which the ratio "Amorphine/AIS" is maximized. The retained conditions for enzymatic hydrolysis are 160µl of Escherichia coli glucuronidase enzyme during 6hours of incubation at a temperature of 36°C. The solvent mixture Methyl-t-Butyl Ether/isopropanol (4:1, v/v) was selected since it has improved morphine extraction from the urinary matrix allowing a gain of 50% when compared to that used in our routine laboratory. Our developed extraction method can be successfully applied for our forensic anti-doping analysis of morphin in human sample urine.

Development of a new stability indicating method for the simultaneous separation of voriconazole from its impurities along with sodium benzoate used as a preservative in a powder for oral suspension.

Voriconazole is a second-generation triazole derived from fluconazole, having an enhanced antifungal spectrum, compared with older triazoles. It is the drug of choice for treatment of invasive aspergillosis and many Scedosporium/Pseudallescheria Fusarium infections. Voriconazole is available in both intravenous and oral formulations. Since there is much interest in pharmaceutical quality control, separation of impurities from the main drug substances and accurate assay quantification, and since there is no reference or monograph until nowadays reported for the simultaneous separation of voriconazole from its specified and unspecified impurities along with sodium benzoate used as an antimicrobial preservative, our aim of this work is to develop a new simple, sensitive and stability indicating assay method allowing thus separation by high-performance liquid chromatography. The development of our method consisted in optimizing the following analytical parameters: nature and composition of the mobile phase, its pH, buffer concentration, nature of the stationary phase, column temperature and detection wavelength. After optimisation, separation was achieved on a stainless steel column NOVAPACK C18 (3.9mm×150mm; 4µm particle size) using a gradient mode with methanol, acetonitrile R and an aqueous solution acidified by acetic acid at 1% and adjusted to pH 2.77. The eluted compounds were monitored at 254nm. The flow rate was set at 1.0mL/min, the injection volume at 10µL, and the column oven temperature was maintained at 35°C. Under these conditions, separation was achieved with good resolution and symmetrical peaks' shape. The developed method was validated according to the International Conference on Harmonization (ICH) guidelines, and then it was successfully applied to establish inherent stability of the pharmaceutical formulation subjected to different ICH prescribed stress conditions. The developed method was proved to be simple, specific and precise. Hence, it can be considered as a method for stability study and for routine quality control analysis of voriconazole and sodium benzoate in a powder for oral suspension.

Micellar HPLC method for the simultaneous determination of three anticonvulsant drugs in dosage forms and biological fluids. Application to dissolution-rate testing.

This work describes a micellar liquid chromatographic method which was developed and validated to determine simultaneously three structurally-related antiepileptic drugs; namely carbamazepine (CMZ), oxcarbazepine (OCZ) and eslicarbazepine acetate (ECZ). The analysis was achieved using a phenyl column (250mm×4.6mm i.d., 5µm particle size), a mobile phase consisting of a mixture of 0.3% triethylamine and 10% n-butanol in a solution of 0.05M sodium dodecyl sulphate adjusted to pH 7.0 using 0.02M orthophosphoric acid. The mobile phase was pumped at a flow rate of 1.5mLmin-1 and detection was adjusted at 215nm. The method showed good linearity (r2>0.998) over the concentration ranges of 0.1-10 for CMZ and OCZ and 0.2-20µgmL-1 for ECZ. The suggested method was successfully applied for the analysis of the studied drugs in their dosage forms and for the determination of CMZ and OCZ in spiked human urine and plasma without prior extraction. The proposed method was further extended to the analysis of real samples of plasma and urine of volunteers receiving therapy of CMZ and OCZ. Furthermore, the method was successfully applied to tablets dissolution-rate testing, and the results were satisfactory.

Human papillomavirus (HPV) awareness and vaccine receptivity among Senegalese adolescents.

OBJECTIVE: To examine HPV vaccine awareness and receptivity among adolescents and young adults in Senegal. METHODS: Participants from six high schools and five community centres across five regions of Senegal (n = 2286) completed a self-administered questionnaire in October and November 2014. The study assessed HPV awareness and receptivity towards receiving the HPV vaccine. Multivariable logistic regression explored statistically significant relationships between the predictor variables and both outcomes. RESULTS: Twenty-seven percent had heard of HPV. Among those who had heard of HPV (n = 616), only 28% indicated willingness to vaccinate. Multivariable analysis showed that respondents from rural areas had 63% higher odds (95% CI: 1.24, 2.12) of having heard of HPV than those in urban areas. Respondents with fathers who had completed higher education had 41% higher odds (95% CI: 1.04, 1.92) of being aware of HPV (P < 0.05); however, every level of father's education (as compared to no education at all) was negatively associated with willingness to vaccinate. Respondents who had previously spoken to a healthcare professional about the HPV vaccine had 80% higher odds (95% CI: 1.16, 2.81) of willingness to vaccinate than those who did not speak to a provider about the vaccine. CONCLUSIONS: Healthcare providers and parents are important stakeholders in disseminating HPV vaccine information. Given the overall low levels of awareness, there is a great opportunity for public health communication efforts to craft health messaging and information in a way to maximise receptivity, outlining benefits and providing information on the minimal risks associated with the vaccine.

Assessment of analytical methods to determine pyrethroids content of bednets.

OBJECTIVE: To present and evaluate simple, cost-effective tests to determine the amount of insecticide on treated materials. METHODS: We developed and evaluated a competitive immunoassay on two different platforms: a label-free impedimetric biosensor (EIS biosensor) and a lateral flow. Both approaches were validated by gas chromatography (GC) and ELISA, gold standards for analytical methods and immunoassays, respectively. Finally, commercially available pyrethroid-treated ITN samples were analysed. Different extraction methods were evaluated. RESULTS: Insecticide extraction by direct infusion of the ITN samples with dichloromethane and dioxane showed recovery efficiencies around 100% for insecticide-coated bednets, and >70% for insecticide-incorporated bednets. These results were comparable to those obtained with standard sonication methods. The competitive immunoassay characterisation with ELISA presented a dynamic range between 12 nm and 1.5 µm (coefficient of variation (CV) below 5%), with an IC50 at 138 nm, and a limit of detection (LOD) of 3.2 nm. EIS biosensor had a linear range between 1.7 nm and 61 nm (CV around 14%), with an IC50 at 10.4 nm, and a LOD of 0.6 nm. Finally, the lateral flow approach showed a dynamic range between 150 nm and 1.5 µm, an IC50 at 505 nm and a LOD of 67 nm. CONCLUSIONS: ELISA can replace chromatography as an accurate laboratory technique to determine insecticide concentration in bednets. The lateral flow approach developed can be used to estimate ITN insecticide concentration in the field. This new technology, coupled to the new extraction methods, should provide reliable guidelines for ITN use and replacement in the field.

[The origins of analysis and of drugs control]. / Les origines de l'analyse et du contrôle des médicaments.

Analytical concerns were quite ancient. As soon as the 12th century, Al-Chayzari searched drugs falsifications. During the 17th century, retort analysis was much practiced. Selective extraction constituted a great progress. During the 18th century, gas volumetric analysis appeared. Descroizilles created volumetric analysis in liquid phase, and that gave him the opportunity for creating acidi-alcalimetry methods. Following the works of Gay-Lussac and Thénard, Liebig invented an apparatus for performing elemental analysis of organic compounds. Michael Tswett created chromatography. Polarimetry was used for dosing glucose in human urines. Kirchhoff and Bunsen created spectroscopic analysis. All these methods allowed the great development of analysis during the 20th century.

Regulation of expression of the p21CIP1 gene by the transcription factor ZNF217 and MDM2.

Using mouse double minute 2 (MDM2) protein-specific affinity chromatography and mass spectrometry, we have isolated the protein product of the oncogene znf217, which is a transcription factor and a component of a Hela-S-derived HDAC1 complex, as a novel MDM2-interacting protein. When co-expressed in cultured cancer cells, ZNF217 forms a complex with MDM2 and its ectopic over-expression reduces the steady-state levels of acetylated p53 in cell lines, suppressing its ability to activate the expression of a p21 promoter construct. In-silico analysis of the p21 promoter revealed the presence of several ZNF217-binding sites. These findings suggest that MDM2 controls p21 expression by at least 2 mechanisms: through ZNF217-mediated recruitment of HDAC1/MDM2 activity, which inhibits p53 acetylation; and through direct interaction with its binding site(s) on the p21 promoter.

Implementation of 350-2500 nm diffuse reflectance spectroscopy and High-Performance Thin-Layer Chromatography to rapidly assess manufacturing consistency and quality of cotrimoxazole tablets in Tanzania.

OBJECTIVE: To assess the quality of cotrimoxazole tablets produced by a Tanzanian manufacturer by a newly instituted quality assurance programme. METHODS: Tablets underwent a diffuse reflectance spectroscopy procedure with periodic quality assessment confirmation by assay and dissolution testing using validated HPTLC techniques (including weight variation and disintegration evaluations). RESULTS: Based on results from the primary test methods, the first group of product was <80% compliant, whereas subsequent groups reached >99% compliance. CONCLUSIONS: This approach provides a model for rapidly assuring product quality of future procurements of other products that is more cost-effective than traditional pharmaceutical testing techniques.

Long-term stability of ketamine hydrochloride 50mg/ml injection in 3ml syringes.

INTRODUCTION: Ketamine hydrochloride (Ketalar(®)) injection is often used as a general anesthetic agent. It is particularly suited to short-term interventions. It can also be used as an inducer of anesthesia before the administration of other anesthetic agents. The aim of this study was to evaluate the stability of ketamine hydrochloride in 3ml polypropylene syringes after storage for up to 180days at room temperature. METHOD: Syringes containing ketamine hydrochloride (50mg/ml) were prepared and stored at room temperature (25°C) for 180days. The concentrations were measured by validated ultra-performance liquid chromatography-diode array detection at 0, 7, 14, 28, 60, 84, 112, 140 and 180days. A degradation test was performed to evaluate the specificity of the analysis. At each time point, the pH, color and visible particles of each solution were also assessed. RESULTS: Degradation tests proved no interfering peaks with ketamine. All solutions were physically stable during the storage. The lower confidence limit of the concentration for these solutions remains superior to 90% of the initial concentration at this date as recommended by the Food and Drug Administration (FDA) until 180days (100%±2%). CONCLUSION: Solutions of ketamine (50mg/ml) were chemically stable for 180days in polypropylene syringes with storage at room temperature and could be prepared in advance by a centralized intravenous admixture service.

Stability indicating RP-HPLC method development and validation for the simultaneous determination of aminexil and minoxidil in pharmaceutical dosage form.

The objective of the present work is to develop stability indicating high-performance liquid chromatographic method for the simultaneous determination of aminexil and minoxidil in pharmaceutical dosage form. The chromatographic separation was achieved with BDS Hypersil C18 column (250 mm×4.6 mm×5 µ) as stationary phase and phosphate buffer and acetonitrile (78:22) as mobile phase. The method was employed by using a flow rate of 1.1 mL/min kept at 30°C. The detection wavelength was kept at 238 nm by using photo-diode array detector. The retention times of the aminexil and minoxidil were found to be 2.3 min and 3.9 min, respectively. The method developed was validated in accordance with ICH guidelines with respect to the stability indicating capacity of the method including system suitability, accuracy, precision, linearity, range, limit of detection, limit of quantification and robustness. The linearity responses of aminexil and minoxidil were found to be in the concentration ranges of 18.75-112.5 µg/mL and 25-150 µg/mL, respectively. The LOD and LOQ values for aminexil were found to be 0.31 and 0.92 µg/mL and minoxidil were found to be 0.03 and 0.10 µg/mL respectively. The percentage recoveries for both the drugs were found in the range of 98-101%. This method is accurate, precise and sensitive; hence, it can be employed for routine quality control of aminexil and minoxidil in pharmaceutical industries and drug testing laboratories.