A quality assurance initiative on improving cefazolin perioperative redose compliance.

OBJECTIVE: Compliance with perioperative antibiotic prophylaxis is crucial for preventing surgical site infection. Anesthesiologists can play a significant role in reducing surgical site infections by following clinical practice guidelines for antibiotic prophylaxis and redosing during surgery. A quality assurance initiative was implemented at a tertiary hospital with the goal of improving cefazolin perioperative antibiotic compliance. DESIGN: This was a retrospective observational study. SETTING: Main operating room of a tertiary care teaching hospital in New York, USA. Our main operating room includes 22 operating rooms that incorporates surgeries from general surgery, vascular surgery, neurology, gynecology, urology, orthopedics, ear, nose and throat (ENT) etc. PARTICIPANTS: All cases in the main operating room from March 1, 2018 to March 31, 2021 that received first dose of Cefazolin and in which the duration of surgery was more than 4 hrs. INTERVENTION: A multifaceted intervention was initiated to address low compliance with cefazolin redosing. Multifaceted interventions included the development of a perioperative antibiotic guide for anesthesia providers, automated reminders in anesthesia electronic medical records, grand rounds education, survey and email communications, and regular feedback reports to the anesthesia department. MAIN OUTCOME MEASURES: Cefazolin perioperative redose compliance rate. RESULTS: Rates of redose compliance were examined in three time periods: preintervention, intervention and postintervention. Cefazolin redosing compliance was 58% in the preintervention period and 90% in the postintervention period. There was a significant positive change in the trend of compliance during the intervention period, indicating that the odds of compliance increased by 13% per month in the intervention period compared to the preintervention period (odds ratio = 1.13, P < 0.001). Redose compliance improvements were sustained a year after the postintervention period (an average of 91%). Surgical site infection rates for colon, coronary artery bypass graft and hip surgeries did not show any significant trend during these time periods. CONCLUSION: Multifaceted interventions led to significant and sustained improvements in cefazolin redosing compliance in the main operating room of a tertiary hospital.

Hydrothermal Synthesis of ß-Nb2ZnO6 Nanoparticles for Photocatalytic Degradation of Methyl Orange and Cytotoxicity Study.

ß-Nb2ZnO6 nanoparticles were synthesized by a hydrothermal process and calcined at two temperatures, 500 °C and 700 °C, and assigned as A and B, respectively. X-ray diffraction, together with transmission electron microscopy, revealed that the ß-Nb2ZnO6 nanoparticles calcined at 700 °C (B) were more crystalline than the ß-Nb2ZnO6 calcined at 500 °C (A) with both types of nanoparticles having an average size of approximately 100 nm. The physiochemical, photocatalytic, and cytotoxic activities of both types of ß-Nb2ZnO6 nanoparticles (A and B) were examined. Interestingly, the photodegradation of methyl orange, used as a standard for environmental pollutants, was faster in the presence of the ß-Nb2ZnO6 nanoparticles calcined at 500 °C (A) than in the presence of those calcined at 700 °C (B). Moreover, the cytotoxicity was evaluated against different types of cancer cells and the results indicated that both types of ß-Nb2ZnO6 nanoparticles (A and B) exhibited high cytotoxicity against MCF-7 and HCT116 cells but low cytotoxicity against HeLa cells after 24 and 48 h of treatment. Overall, both products expressed similar EC50 values on tested cell lines and high cytotoxicity after 72 h of treatment. As a photocatalyst, ß-Nb2ZnO6 nanoparticles (A) could be utilized in different applications including the purification of the environment and water from specific pollutants. Further biological studies are required to determine the other potential impacts of utilizing ß-Nb2ZnO6 nanoparticles in the biomedical application field.

Synthesis of M-Ag3PO4, (M = Se, Ag, Ta) Nanoparticles and Their Antibacterial and Cytotoxicity Study.

Silver Phosphate, Ag3PO4, being a highly capable clinical molecule, an ultrasonic method was employed to synthesize the M-Ag3PO4, (M = Se, Ag, Ta) nanoparticles which were evaluated for antibacterial and cytotoxicity activities post-characterization. Escherichia coli and Staphylococcus aureus were used for antibacterial testing and the effects of sonication on bacterial growth with sub-MIC values of M-Ag3PO4 nanoparticles were examined. The effect of M-Ag3PO4 nanoparticles on human colorectal carcinoma cells (HCT-116) and human cervical carcinoma cells (HeLa cells) was examined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay and DAPI (4',6-diamidino-2-phenylindole) staining. Additionally, we analyzed the effect of nanoparticles on normal and non-cancerous human embryonic kidney cells (HEK-293). Ag-Ag3PO4 exhibited enhanced antibacterial activity followed by Ta-Ag3PO4, Ag3PO4, and Se-Ag3PO4 nanoparticles against E. coli. Whereas the order of antibacterial activity against Staphylococcus aureus was Ag3PO4 > Ag-Ag3PO4 > Ta-Ag3PO4 > Se-Ag3PO4, respectively. Percentage inhibition of E. coli was 98.27, 74.38, 100, and 94.2%, while percentage inhibition of S. aureus was 25.53, 80.28, 99.36, and 20.22% after treatment with Ag3PO4, Se-Ag3PO4, Ag-Ag3PO4, and Ta-Ag3PO4, respectively. The MTT assay shows a significant decline in the cell viability after treating with M-Ag3PO4 nanoparticles. The IC50 values for Ag3PO4, Se-Ag3PO4, Ag-Ag3PO4, and Ta-Ag3PO4 on HCT-116 were 39.44, 28.33, 60.24, 58.34 µg/mL; whereas for HeLa cells, they were 65.25, 61.27, 75.52, 72.82 µg/mL, respectively. M-Ag3PO4 nanoparticles did not inhibit HEK-293 cells. Apoptotic assay revealed that the numbers of DAPI stained cells were significantly lower in the M-Ag3PO4-treated cells versus control.

Synthesis of Bis-indolylmethane sulfonohydrazides derivatives as potent α-Glucosidase inhibitors.

In search of better α-glucosidase inhibitors, a series of bis-indolylmethane sulfonohydrazides derivatives (1-14) were synthesized and evaluated for their α-glucosidase inhibitory potential. All derivatives exhibited outstanding α-glucosidase inhibition with IC50 values ranging between 0.10 ±â€¯0.05 to 5.1 ±â€¯0.05 µM when compared with standard drug acarbose having IC50 value 856.28 ±â€¯3.15 µM. Among the series, analog 7 (0.10 ±â€¯0.05 µM) with tri-chloro substitution on phenyl ring was identified as the most potent inhibitor of α-glucosidase (∼ 8500 times). The structure activity relationship has been also established. Molecular docking studies were also performed to help understand the binding interaction of the most active analogs with receptors. From the docking studies, it was observed that all the active bis-indolylmethane sulfonohydrazides derivatives showed considerable binding interactions within the active site (acarbose inhibition site) of α-glucosidase. We also evaluated toxicity of all derivatives and found none of them are toxic.

Synthesis, α-amylase inhibitory potential and molecular docking study of indole derivatives.

In search of potent α-amylase inhibitor we have synthesized eighteen indole analogs (1-18), characterized by NMR and HR-EIMS and screened for α-amylase inhibitory activity. All analogs exhibited a variable degree of α-amylase inhibition with IC50 values ranging between 2.031 ±â€¯0.11 and 2.633 ±â€¯0.05 µM when compared with standard acarbose having IC50 values 1.927 ±â€¯0.17 µM. All compounds showed good α-amylase inhibition. Compound 14 was found to be the most potent analog among the series. Structure-activity relationship has been established for all compounds mainly based on bringing about the difference of substituents on phenyl ring. To understand the binding interaction of the most active analogs molecular docking study was performed.

Oral Manifestations: A Reliable Indicator for Undiagnosed Diabetes Mellitus Patients.

OBJECTIVES: This article identifies undiagnosed DM (UDM) cases in the Pakistani population by perceiving the signs and symptoms of DM and associating them with oral manifestations. MATERIAL AND METHODS: In this cross-sectional study, patients showing at least three or more classical or warning signs like polydipsia, polyuria, polyphagia, and general weakness were considered UDM cases. Detailed oral examination for gingivitis, periodontitis, halitosis, xerostomia, and tongue manifestations was done followed by the hemoglobin A1c (HbA1c) analysis. RESULTS: Out of 5,878 patients, 214 UDM cases were identified, where 31.8% and 39.7% of the patients were diagnosed as prediabetics and diabetics, respectively, based on HbA1c analysis. Prevalence of gingivitis (97.6%), fissured tongue (91.8%), generalized periodontitis (85.9%), thick saliva (87.1%), xerostomia (84.7%), burning mouth syndrome (63.5%), yellow discoloration of tongue (57.6%), and ecchymosis/ulcers (43.5%) were more in diabetics as compared to prediabetic patients and normal population. CONCLUSION: The oral manifestations can be crucial for identifying UDM cases. Dentists can play a pivotal role by taking detailed history and thorough oral examination. If three or more symptoms as concluded above are present, an HbA1c analysis should be conducted to prevent preop and postop complications associated with DM.

Vitamin D and preeclampsia: A systematic review and meta-analysis.

Objectives: Preeclampsia is one of the most frequent pregnancy disorders, with a global incidence of 2%-8%. Serum 25-hydroxyvitamin D is an essential mineral for human health; some studies suggest link between 25-hydroxyvitamin D deficiency and preeclampsia, while others offer contradictory findings. Thus, the goal of this study is to evaluate the relationships between maternal 25- hydroxyvitamin D concentrations and the risk of preeclampsia. In addition to this, our study also evaluates the effects of 25- hydroxyvitamin D supplementation on the incidence of preeclampsia. Therefore, assessing 25- hydroxyvitamin D's potential as a possible intervention to lower the risk of preeclampsia. Methods: The Medline database was queried from inception until July 2021 for randomized controlled trials and observational studies without any restrictions. The studies assessing the association between 25-hydroxyvitamin D deficiency and preeclampsia and the impact of 25-hydroxyvitamin D supplementation on the incidence of preeclampsia were incorporated. The results were reported using a random-effects meta-analysis and the Mantel-Haenszel odds ratio. A p-value of <0.05 was considered significant for the analysis. Results: This analysis includes 34 papers, including 10 randomized controlled trials and 24 observational studies. According to our pooled analysis, 25-hydroxyvitamin D supplementation was significantly associated with a lower risk of preeclampsia in pregnant women (OR: 0.50; 95% CI: 0.40-0.63; p = 0.00001), while 25-hydroxyvitamin D deficiency was significantly associated with an increased risk of preeclampsia (OR: 4.30; 95 % CI: 2.57-7.18; p < 0.00001, OR: 1.71; 95 % Cl: 1.27-2.32; p = 0.0005, OR 1.61; 95 % Cl: 1.21-2.16; p = 0.001). Conclusion: Results suggest that 25-hydroxyvitamin D has a significant relationship with preeclampsia as confirmed by the findings that low maternal 25-hydroxyvitamin D concentrations cause increased risk of preeclampsia while 25-hydroxyvitamin D supplementation reduces the incidence of preeclampsia. Our findings indicate that 25-hydroxyvitamin D supplementation can be used as a possible intervention strategy in preventing one of the most common causes of maternal mortality around the world, preeclampsia.

Serial transurethral cystometry: A novel method for longitudinal evaluation of reflex lower urinary tract function in adult female rats.

AIMS: The aim of the study is to develop a minimally invasive method for longitudinal evaluation of lower urinary tract function that allows for simultaneous measurements of bladder pressure and external urethral sphincter (EUS) electromyographic (EMG) activity. METHODS: To evaluate the reliability of serial transurethral cystometry (STUC), rats (n = 12) underwent three sessions of STUC, one session a week for 3 weeks. During each session, rats were anesthetized with ketamine-xylazine (90 mg/kg and 10 mg/kg), and micturition reflex data were acquired using transurethral cystometry and percutaneous recording of EUS (EMG) activity during continuous infusion of saline into the bladder. The reliability and consistency of the STUC method were assessed using intra-class correlation (ICC) analysis and repeated measures ANOVA. RESULTS: ICC values calculated from five successive events during the first micturition session indicate good to excellent reliability for measurements of peak bladder pressure, threshold bladder pressure, minimum bladder pressure, volume threshold, duration of EUS bursting, and number of EUS burst events. Across the three recording sessions no significant difference was observed in peak bladder pressure, threshold bladder pressure, minimum bladder pressure, volume threshold, number of EUS burst events, and duration of EUS bursting using repeated measures ANOVA. CONCLUSION: Serial transurethral cystometry under ketamine-xylazine anesthesia with simultaneous percutaneous EUS EMG recording is a novel, reliable, accurate, and minimally invasive method for quantitative assessment of lower urinary tract (LUT) function in adult female rats over extended periods of time.

Estimation of the risk of COVID-19 transmission through aerosol-generating procedures.

BACKGROUND: The outbreak of the coronavirus disease 2019 (COVID-19) pandemic was associated with the provision of multiple guidelines for the dental profession. All elective procedures were restricted, and only emergency procedures were performed. There was fear and anxiety among dentists while performing aerosol-generating procedures (AGPs), as they were considered to pose a high risk of COVID-19 transmission. OBJECTIVES: The aim of this study was to assess the risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during AGPs, and to examine the association between risk severity and the number of AGPs performed per day. The efficacy of personal protective equipment (PPE) was also assessed. MATERIAL AND METHODS: This cross-sectional cohort study was based on an online questionnaire form completed by 629 general and specialized dentists between January 1 and February 28, 2021. The collected data referred to the sources of COVID-19 infection, the type of PPE used and the number of AGPs performed each day by dental healthcare professionals (DHCPs). For each question, the absolute numbers of responses as well as percentages were calculated. RESULTS: Among the 629 DHCPs, 113 (17.97%) contracted COVID-19. The risk of contracting COVID-19 during AGPs was the same as in the case of non-AGPs, and the infection risk was not associated with the number of AGPs performed per day. The efficacy of a surgical mask with a face shield/eye goggles was higher in comparison with all other types of PPE. Differences in the infection risk across the different types of PPE used were statistically significant (p < 0.001). CONCLUSIONS: The risk of COVID-19 transmission during AGPs is the same as in the case of non-AGPs. Thus, restrictions on the performance of elective AGPs should be lifted. On the other hand, the best protection during AGPs is provided by a surgical mask with a face shield/eye goggles.

Synthesis, α-amylase and α-glucosidase inhibition and molecular docking studies of indazole derivatives.

Herein, we report the synthesis and inhibitory potential of indazole (Methyl 1H-indazole-4-carboxylate) derivatives (1-13) against α-amylase and α-glucosidase enzymes. The described derivatives demonstrated good inhibitory potential with IC50 values, ranging between 15.04 ± 0.05 to 76.70 ± 0.06 µM ± SEM for α-amylase and 16.99 ± 0.19 to 77.97 ± 0.19 µM ± SEM for α-glucosidase, respectively. In particular, compounds (8-10 and 12) displayed significant inhibitory activities against both the screened enzymes, with their inhibitory potential comparable to the standard acarbose (12.98 ± 0.03 and 12.79 ± 0.17 µM ± SEM, respectively). Additionally, the influence of different substituents on enzyme inhibition activities was assessed to study the structure activity relationships. Molecular docking simulations were performed to rationalize the binding of derivatives/compounds with enzymes. All the synthesized derivatives (1-13) were characterized with the aid of spectroscopic instruments such as 1H-NMR, 13C-NMR, HR-MS, elemental analysis and FTIR.Communicated by Ramaswamy H. Sarma.

Microwave assisted synthesis of 2-amino-4-chloro-pyrimidine derivatives: Anticancer and computational study on potential inhibitory action against COVID-19.

We report microwave synthesis of seven unique pyrimidine anchored derivatives (1-7) incorporating multifunctional amino derivatives along with their in vitro anticancer activity and their activity against COVID-19 in silico. 1-7 were characterized by different analytical and spectroscopic techniques. Cytotoxic activity of 1-7 was tested against HCT116 and MCF7 cell lines, whereby 6 exhibited highest anticancer activity on HCT116 and MCF7 with EC50 values of 89.24 ± 1.36 µM and 89.37 ± 1.17 µM, respectively. Molecular docking was performed for derivatives (1-7) on main protease for SARS-CoV-2 (PDB ID: 6LU7). Results revealed that most of the derivatives had superior or equivalent affinity for the 3CLpro, as determined by docking and binding energy scores. 6 topped the rest with highest binding energy score of -8.12 kcal/mol with inhibition constant reported as 1.11 µM. ADME, drug-likeness, and pharmacokinetics properties of 1-7 were tested using Swiss ADME tool. Toxicity analysis was done with pkCSM online server. All derivatives showed high GI absorption. Except 1 and 3, all derivatives showed blood brain barrier permeability. Most derivatives showed negative logKp values suggesting derivatives are less skin permeable and bioavailability score of all derivatives was 0.55. The toxicity analysis demonstrated that all derivatives have no skin sensitization properties. 6 and 7 showed maximum tolerated dose (Human) values of -0.03 and -0.018, respectively and absence of AMES toxicity.

Development and validation of stability-indicating HPLC method for the simultaneous determination of paracetamol, tizanidine, and diclofenac in pharmaceuticals and human serum.

A method is described for the simultaneous determination of paracetamol, tizanidine, and diclofenac in mixtures. The method was based on HPLC separation of the three drugs followed by UV detection at 254 nm. The separation was carried out on a Hypersil ODS, C18 (250 x 4.6 mm id, 10 microm particle size) column using the mobile phase aqueous 0.2% ammonium carbonate-methanol (60 + 40, v/v) at a flow rate of 1 mL/min. The linear regression analysis data were used for the regression curve in the range of 170-10 000 ng/mL for paracetamol, 120-10 000 ng/mL for tizanidine, and 20-10 000 ng/mL for diclofenac. No chromatographic interference from tablet excipients was found. In order to check the selectivity of the proposed method, degradation studies were carried out using hydrolysis (acid, basic, and neutral), thermolysis, and oxidation. The developed method, after being validated in terms of precision, robustness, recovery, LOD, and LOQ, was successively applied to the analysis of pharmaceutical formulations and human serum.

Structural elucidation, molecular docking, α-amylase and α-glucosidase inhibition studies of 5-amino-nicotinic acid derivatives.

In this study, 5-amino-nicotinic acid derivatives (1-13) have been designed and synthesized to evaluate their inhibitory potential against α-amylase and α-glucosidase enzymes. The synthesized compounds (1-13) exhibited promising α-amylase and α-glucosidase activities. IC50 values for α-amylase activity ranged between 12.17 ± 0.14 to 37.33 ± 0.02 µg/mL ± SEM while for α-glucosidase activity the IC50 values were ranged between 12.01 ± 0.09 to 38.01 ± 0.12 µg/mL ± SEM. In particular, compounds 2 and 4-8 demonstrated significant inhibitory activities against α-amylase and α-glucosidase and the inhibitory potential of these compounds was comparable to the standard acarbose (10.98 ± 0.03 and 10.79 ± 0.17 µg/mL ± SEM, respectively). In addition, the impact of substituent on the inhibitory potential of these compounds was assessed to establish structure activity relationships. Studies in molecular simulations were conducted to better comprehend the binding properties of the compounds. All the synthesized compounds were extensively characterized with modern spectroscopic methods including 1H-NMR, 13C-NMR, FTIR, HR-MS and elemental analysis.

Synthesis and characterization of cadmium-bismuth microspheres for the catalytic and photocatalytic degradation of organic pollutants, with antibacterial, antioxidant and cytotoxicity assay.

Cadmium-Bismuth microspheres (CdS-Bi2S3) were prepared by facile solvothermal method with polyvinylpyrrolidone (PVP) employed to control the morphology of CdS-Bi2S3. The product was characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), diffuse reflectance UV-vis spectrophotometer and surface area of CdS-Bi2S3 was determined by BET analyzer. It was observed that CdS-Bi2S3 spheres exhibited good catalytic activity for the reduction of 4-nitrophenol. The photocatalytic application of CdS-Bi2S3 was evaluated for the photocatalytic degradation of environmental pollutants such as methyl orange, and methyl green under UV-visible light irradiation and it demonstrated good photocatalytic activity. Furthermore, we studied the antioxidant activity of CdS-Bi2S3 and it was observed that CdS-Bi2S3 showed antioxidant activity at all tested concentrations (5, 3 and 1 mg/mL). Antimicrobial activity of CdS-Bi2S3 microspheres was also studied for microbial control and the tested nanospheres proved to be exceptional antibacterial agent against tested Gram-positive and Gram-negative bacteria. CdS-Bi2S3 microspheres also exhibited significant cytotoxicity activity against HCT 116 (Human colon colorectal tumor) cell line. Our results indicate that CdS-Bi2S3 is good photocatalyst with several biological activities. The effective preparation method of CdS-Bi2S3 could be useful to design and fabricate the novel photocatalyst which may have several applications in the field of catalysis and in the medicine.

Preparation, formation mechanism, photocatalytic, cytotoxicity and antioxidant activity of sodium niobate nanocubes.

A hydrothermal method was employed to prepare the sodium niobate (NaNbO3) nanocubes. We executed time dependent experiments to illustrate the formation mechanism of sodium niobate nanocubes. It was observed that the morphology of NaNbO3 nanocubes was dependent on the reaction time and 12hr reaction time was found to be suitable. Morphology, composition, structure and optical properties of sodium niobate nanocubes were evaluated by scanning electron microscope, X-ray energy-dispersive spectrometer, X-ray diffraction and UV-visible diffuse reflectance spectrometer. The photocatalytic activity of sodium niobate was studied for photocatalytic hydrogen production. It was anticipated that the sodium niobate (NaNbO3) cubes exhibited good photocatalytic activity under UV light irradiation using lactic acid as sacrificial agent. The cytotoxicity activity of sodium niobate nanocubes was studied as well at different concentrations (5 mg/mL, 3 mg/mL, 1 mg/mL, and 0.25 mg/mL) against human colon colorectal carcinoma cell line (HCT116) by MTT assay and EC50 was found to be 1.9 mg/mL. Sodium niobate proved to be a good DPPH free radical scavenging material, tested at different concentrations. It was noticed that peak intensity at 517 nm was decreased after 30 minute incubation, further supporting the antioxidant activity. This study will be useful for design and engineering of materials that can be used in biomedical applications and in photocatalysis.

Review: nanoparticles in delivery of cardiovascular drugs.

Everything in nature is built upward from the atomic level to define limits and structures to everything. Nanomedicines marked the field of medicine from nanobiotechnology, biological micro-electromechanical systems, microfluidics, biosensors, drug delivery, microarrays to tissue microengineering. Since then nanoparticles has overcome many challenges from blood brain barrier to targeting tumors. Where solid biodegradable nanoparticles were a step up liposome, targeting nanoparticles opened a whole new field for drug delivery. In this article, we attempt to discuss how the pioneered technique is serving in the drug delivery to cardiovascular system and how with the manipulation of their properties, nanoparticles can be made to fulfill desired function. Also how nanocarriers are improving molecular imaging to help improve diagnosis and treatment of cardiovascular disease is focused in this article.

In vitro availability of atorvastatin in presence of losartan.

Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) are a group of cholesterol lowering agents that have become the largest selling drugs in the world. They are of proven clinical benefit in coronary heart disease, at least in those patients who do not have overt chronic heart failure (CHF). Co-administration of statins with angiotensin II receptor blockers (ARBs) is most common, since there is strong synergy between hypertension and hypercholesterolemia in terms of risk factors for the development of cardiovascular diseases. In present paper, we describe the in vitro availability of atorvastatin, a potent HMG-CoA reductase inhibitor, in presence of losartan potassium, which is a non-peptide angiotensin II receptor antagonist. These studies were carried out at 37, 48 and 60 degrees C in different pH environments simulating human body compartments. It was observed that in pH 1, 7.4 and 9 the availability of atorvastatin was very high while losartan was not at all available. However in pH 4 these effects were reversed and atorvastatin was not available at all. At 48 degrees C the availability of atorvastatin was high and that of losartan was depressed at pH 9, whereas the later was not available at pH 1, 4 and 7.4 at all. Likewise at 60 degrees C, the availability of atorvastatin at pH 7.4 and 9 was high, whereas the charge-transfer complex formed between the two drugs was broken at pH 1 at this temperature and the entire drug was available. On the other hand the availability of losartan at pH 4 and 9 was high while it was not available at pH 1 and 7.4. The availability of atorvastatin was maximum in simulated gastric juice as compared to buffer of pH 7.4 and 9. This high availability of one drug in presence of other is attributed to the formation of a charge-transfer complex, which was stable at elevated temperatures, except at 60 degrees C in pH 1.

Simultaneous determination of piracetam and its four impurities by RP-HPLC with UV detection.

A simple and rapid high-performance liquid chromatographic method for the separation and determination of piracetam and its four impurities, 2-oxopyrrolidin-1-yl)acetic acid, pyrrolidin-2-one, methyl (2-oxopyrrolidin-1-yl)acetate, and ethyl (2-oxopyrrolidin-1-yl)acetate, was developed. The separation was achieved on a reversed-phase C(18) Nucleosil column (25 cm x 0.46 cm, 10 microm). The mobile phase is composed of an aqueous solution containing 0.2 g/L of triethyl amine-acetonitrile (85:15, v/v). The pH of the mobile phase was adjusted to 6.5 with phosphoric acid at a flow rate of 1 mL/min at ambient temperature and UV detection at 205 nm. The developed method was found to give good separation between the pure drug and its four related substance. The polynomial regression data for the calibration plots showed good linear relationship in the concentration range of 50-10,000 ng/mL, 25-10,000 ng/mL, 45-10,000 ng/mL, 34-10,000 ng/mL, and 55-10,000 ng/mL, respectively, with r(2) = 0.9999. The method was validated for precision, accuracy, ruggedness, and recovery. The minimum quantifiable amounts were found to be 50 ng/mL of piracetam, 25 ng/mL of 2-oxopyrrolidin-1-yl)acetic acid, 45 ng/mL of pyrrolidin-2-one, 34 ng/mL of methyl (2-oxopyrrolidin-1-yl)acetate, and 55 ng/mL of ethyl (2-oxopyrrolidin-1-yl)acetate. Statistical analysis proves that the method is reproducible and selective for the estimation of piracetam as well as its related substance. As the method could effectively separate the drug from the related substances, it can be employed as a stability-indicating one. The proposed method shows high efficiency, allowing the separation of the main component piracetam from other impurities.

Spectrophotometric determination of gabapentin in pharmaceutical formulations using ninhydrin and pi-acceptors.

Simple, rapid and sensitive spectrophotometric procedures are developed for the analysis of gabapentin in pure form as well as in their pharmaceutical formulations. The methods are based on the reaction of gabapentin as n-electron donor with ninhydrin and pi-acceptors namely, 2,3,5,6-tetrachloro-1,4-benzoquinone, chloranilic acid, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, tetracyanoethylene and 7,7,8,8-tetracyanoquinodimethane. The obtained complexes were measured at 568, 230, 314, 304, 335 and 439 nm for ninhydrin, chloranil, Chloranilic acid, DDQ, TCNE and TCNQ respectively. The proposed procedures could be successfully applied to the determination of gabepentin with good recovery; percent ranged from 99.3 to 100.7 The association constants and free energy changes using Benesi-Hildebrand plots are also studied.