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Search Results: 1 - 10 of 468063 matches for " Mansoor A. Khan "
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Stability Characterization, Kinetics and Mechanism of Degradation of Dantrolene in Aqueous Solution: Effect of pH and Temperature  [PDF]
Saeed R. Khan, Mobin Tawakkul, Vilayat A. Sayeed, Patrick Faustino, Mansoor A. Khan
Pharmacology & Pharmacy (PP) , 2012, DOI: 10.4236/pp.2012.33037
Abstract: The mechanism of degradation of dantrolene in aqueous buffer solutions was studied at various pH values in the range of pH 1.2-9.5 and at temperatures ranging from 25℃ to 75℃ to determine the optimum pH and temperature requirements for its stability and eventual product performance over the human gastrointestinal pH range. Dantrolene was analyzed by reversed phase ultra-performance liquid chromatographic (UPLC). Chromatographic separation was achieved on a Waters Acquity UPLC system using a Waters BEH C18 analytical column and Waters BEH C18 guard column. The compounds were eluted with a linear acetonitrile gradient (25%-75%) over three minutes with a buffer composition of 2.0 mM of sodium acetate at pH 4.5 for degradation studies. The flow rate was maintained at 0.5 mL/min. Column temperature was maintained at 35℃. Injection volume was 4 μL and the degradation products were detected by a photodiode array (PDA) detector at 375 nm. Degradation products, including compound B and C were analyzed by mass spectroscopy (MS) and nuclear magnetic resonance spectroscopy (NMR) and the degradation pathways were proposed. Degradation of dantrolene followed pseudo first–order kinetics and a V-shaped pH-rate profile over the pH range 1.2-9.5. The maximum stability was observed at pH 7.4 and 37℃. Although the focus of this paper was on the mechanism of hydrolysis of dantrolene, the poor aqueous solubility of dantrolene, the developed understanding can be utilized to improve the quality of the formulation and the risk associated with the extravasation of dantrolene sodium solution in its current form.
A Comparative Evaluation of Polystyrene Divinylbenzene Copolymer HPLC Columns on the Chromatographic Performance of the Compendial Method for Doxycycline Hyclate Capsules: Implications for Method Implementation of a Medical Countermeasure Medication  [PDF]
Firat Yerlikaya, Adil Mohammad, Patrick J. Faustino, Mansoor A. Khan, Saeed R. Khan
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2015, DOI: 10.4236/jasmi.2015.53003
Abstract: The purpose of this study was to evaluate the impact of polystyrene divinylbenzene copolymer HPLC columns on the chromatographic performance of the USP compendial method for doxycycline hyclate. The compendial method was implemented based on the assessment of the chromatographic performance of six USP defined L21 polystyrene divinylbenzene HPLC columns. Modifications to the method were based on USP <621> for chromatography. The method was validated for the determination of doxycycline hyclate and its impurities in commercially available drug products. A number of different polystyrene-divinylbenzene columns were tested and failed to provide selectivity for the resolution of doxycycline and its impurities. Separation was optimally achieved on an Agilent PLPR-S column (250 × 4.6 mm, 8 μm) by using an Agilent 1260 series HPLC system. Doxycycline hyclate and its impurities were eluted isocratically at a flow rate of 1 mL/min with mobile phase and detected at 270 nm. The column temperature was maintained at 60oC. The method was validated according to USP category I requirements for Assay. Validation acceptance criteria were met in all cases. The analytical range for doxycycline hyclate was 50 - 250 μg/mL and the linearity was r2 > 0.999 over three days. The method was determined to be specific. Both accuracy (95.1% - 102.4%) and precision (0.50% - 4.8%) were established across the analytical range for low, intermediate and high QC concentrations. Method applicability was demonstrated by analyzing marketed products of doxycycline hyclate, in which results showed potency meeting USP acceptance criteria. In conclusion, this study described the remarkable differences in selectivity that were encountered during the implementation phase for the compendial methods for doxycycline and its impurities in marketed products and it could be used in the future to assss the product quality of doxycycline hyclate capsules stored in the National stockpiles.
Development and Application of a Validated HPLC Method for the Determination of Clindamycin Palmitate Hydrochloride in Marketed Drug Products: An Optimization of the Current USP Methodology for Assay  [PDF]
Geoffrey K. Wu, Abhay Gupta, Mansoor A. Khan, Patrick J. Faustino
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2013, DOI: 10.4236/jasmi.2013.34026

A simple efficient isocratic reversed-phase HPLC method was developed and validated for the determination of clindamycin palmitate hydrochloride (CPH) and its commercially available oral solution products. Separation was achieved on a Phenomenex Zorbax (Luna) cyano column (150 × 4.6 mm, 5 μm) with a Phenomenex cyano guard cartridge (4 × 3.0 mm) on Agilent 1050 series HPLC system. CPH and its resolution standard lincomycin were eluted isocratically at a flow rate of 1 mL/min with a simplified mobile phase (potassium phosphate buffer (5 mM, pH 3.0)—acetonitrile—tetrahydrofuran (20:75:5, v/v/v)) and detected at 210 nm. The column was maintained at 25?C. The method was validated according to USP category I requirements. Robustness and forced degradation studies were also conducted. CPH marketed drug products were obtained from a drug distributor and assayed for potency using the validated method. Validation acceptance criteria were met in all cases. The analytical range for CPH was 15 - 500 μg/mL and the linearity was r2 > 0.999 over three days. The method was determined to be specific and robust. Both accuracy (92.0% - 103.8%) and precision (0.67% - 1.52%) were established across the analytical range for low, intermediate and high QC concentrations. Method applicability was demonstrated by analyzing two marketed products of CPH, in which results showed potency >98%. The method was determined to be an enhancement over the current USP methodology for assay as a result of increased efficiency, reduced organic solvents and the elimination of matrix modifiers. This method was successfully applied for the quality assessment of: 1) currently marketed drug products and 2) will in future assess the product quality of novel dosage forms of CPH for pediatric use.

Polymerase Chain Reaction-based Detection of Cotton Leaf Curl and Other Whitefly-transmitted Geminiviruses from Sindh
S. Mansoor,M. Hussain,S. H. Khan,A. Bashir
Pakistan Journal of Biological Sciences , 1998,
Abstract: Samples of cotton plants showing symptoms of cotton leaf curl disease were collected from cotton fields in Sindh. Samples of some other plants including tomato, chillies, okra and Hibiscus suspected for whitefly-transmitted geminiviruses were also collected from these areas and total DNA was extracted. Degenerate primers designed to amplify DNA-A of whitefly-transmitted geminiviruses were used in PCR for the amplification of viral DNA. A product of expected (1.4 kb) was obtained from all these samples which confirmed the infection of whitefly-transmitted geminiviruses. PCR primers specific for the two whitefly-transmitted geminiviruses species namely CLCuV-Pk1 and CLCuV-Pk2 found associated with cotton leaf curl disease in Punjab were also used to confirm the identity of cotton leaf curl virus in Sindh. A product specific for CLCuV-Pk1 was obtained from all four symptomatic cotton samples. The results showed that cotton samples were infected with CLCuV-Pk1 while CLCuV-Pk2 was not detected in these samples. This is the first report of detection of whitefly-transmitted geminiviruses on these crops from Sindh. Our data not only confirm the presence of a whitefly-transmitted geminivirus on cotton but also showed that the disease is caused by one of the virus species found in Punjab.
Mansoor Ali Khan
The Professional Medical Journal , 1998,
Abstract: It is well known that the outcome of pregnancy is related to the weight of the fetus because abnormalitiesof labor and neonatal complications may be associated with extremes of birth weight. We selected fourdifferent formulas (one volume model, others exponential models) to estimate birth-weight. To the best ofmy knowledge no such study has been conducted to evaluate the accuracy and usefulness of these formulasin estimation of fetal weight in Pakistan. One hundred and seven pregnant women were selected withsingleton term pregnancy, normal fetal anatomy, and delivery within three days of sonography. We testedthe fitness of the four different formulas by calculating various errors and applying Kuraskal Wallis H andMann-Whitney U Tests. This study suggests that all the four formulas investigated, over estimated the birthweight.Though the Formula-4 Combs et al, Volume Model 1993, over estimated the birth weight but tomuch lesser extent. More data is required to further establish these facts.
Mansoor Ali Khan
The Professional Medical Journal , 1999,
Abstract: There is now growing body of evidence which linksthe abdominal obesity to the increased risk ofdevelopment cardiovascular disease, respiratoryproblems, infertility. Insulin resistance, Obesity ison an increase with improved socio-economicconditions in Pakistan and other developingcountries. The anthropometry of the body for fatprevious useful information. Ultrasonography isnow importance as a method for assessment of bodycomposition i.e. fat and fat free mass, the purposeof this study was to determine, the influence of ageand obesity on male human anterior abdominalsubcutaneous fat. In this study 260 healthy men (20-50 years) were studied by ultrasonographicanthropometric method at even different sites ofabdomen. Pearson’s correlation coefficient wascomputed and the result were analyzed statisticallyby regression analysis and were found to be highlysignificant (p<0.01-0.001). Both age and obesityinfluenced the abdominal subcutaneous fatthickness. The influence of age and obesity onabdominal wall resulted in an increased depositionof subcutaneous fat whereas, interestingly the effectof age was found more marked in normal weightindividuals than in overweight or obese.
Video Shot Boundary Detection Using Normalized Periodogram Distance Metric  [PDF]
A. Sasithradevi, S. Mohamed Mansoor Roomi
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.710246
Abstract: Video shot boundary detection is the primary task for content based video management and retrieval system. This paper proposes a shot boundary detection strategy by exploiting the pros of Normalized Periodogram for efficiently representing the content of the video. A Normalized Periodogram based distance metric to detect the key frames using shot boundary, namely Distance- Left-Right (DLR), is addressed, which is computed on a sliding sub-window basis. The DLR sequence is used to detect the suspected shot boundary frames and a transition type detection procedure is adapted to these suspected frames for discriminating the abrupt and gradual transitions. The proposed shot boundary detection methodology yields Precision—95.02%, Recall—93.15% and F1 score—94.07% for cut, Precision—86.57%, Recall—86.67% and F1 score—86.61% for gradual, Precision—90.6%, Recall—90.02% and F1 score—90.3% for overall transitions. Experimental results show that the proposed approach is superior to the recently available shot boundary detection techniques because of its robustness and simplicity, and presents an effective distance metric to detect the shot boundary.
PrimavistTM in the Diagnosis of Oxaliplatin Induced Sinusoidal Obstruction: a Case Report  [PDF]
Mansoor Ali Khan, Tony Blakeborough, Nick Tiffin, Ahmed Al-Mukhtar
Journal of Cancer Therapy (JCT) , 2011, DOI: 10.4236/jct.2011.23052
Abstract: This is a case report of a patient who underwent Oxaliplatin based neo-adjuvant chemotherapy for colorectal liver metastases, and subsequently developed sinusoidal obstruction, which was detected by Primavist enhanced MRI scan.
A rare cause of right iliac fossa pain
Khizer Mansoor,Samujh Ram,Khan Abdul
Journal of Indian Association of Pediatric Surgeons , 2009,
Abstract: A child with torsion of appendix epiploicae presenting as acute right iliac fossa pain in abdomen is reported.
Symmetric Algorithm Survey: A Comparative Analysis
Mansoor Ebrahim,Shujaat Khan,Umer Bin Khalid
Computer Science , 2014,
Abstract: Information Security has become an important issue in modern world as the popularity and infiltration of internet commerce and communication technologies has emerged, making them a prospective medium to the security threats. To surmount these security threats modern data communications uses cryptography an effective, efficient and essential component for secure transmission of information by implementing security parameter counting Confidentiality, Authentication, accountability, and accuracy. To achieve data security different cryptographic algorithms (Symmetric & Asymmetric) are used that jumbles data in to scribbled format that can only be reversed by the user that have to desire key. This paper presents a comprehensive comparative analysis of different existing cryptographic algorithms (symmetric) based on their Architecture, Scalability, Flexibility, Reliability, Security and Limitation that are essential for secure communication (Wired or Wireless).
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