Simultaneous Estimation of Chlorpheniramine Maleate and Glyceryl Guaiacolate in Pure and Capsule Dosage form by using different Spectrophotometric Methods

Chlorpheniramine Maleate (CPM) and Glyceryl Guaiacolate (GUA) are the β‐lactum antibiotic drug. Sensitive, precise, accurate and simple, UV spectrophotometric methods have been developed for the simultaneous estimation of Chlorpheniramine Maleate (CPM) and Glyceryl Guaiacolate (GUA) in dosage form. Two spectrophotometric methods (simultaneoue equations and Q‐Absorbance ratio) were applied for the determination of the drugs as mixture. The maximum absorbance of drug in solvent mixture composed of water – acetontrile – methanol in a ratio of (80% H2O – 10% ACN – 10% MOH) was found to be at (261.4 nm and 273 nm) for CPM, GUA respectively, and the Q – isosbestic point was found at 270.4 nm. These wavelengths were selected for the analysis of drugs as mixtures standard and in the manufactured samples using the two developed methods. The methods were linear in the range of (1- 100) μg/mL for (CPM, GUA), with an R2 of (0.9996) for CPM and GUA respectively in the mixture. Recovery means were found to be (99.79 % - 100.30 %) for the standard drugs CPM and GUA respectively and in formulating drugs was found to be (99.71 – 100.41 %). LOD and LOQ were established and found to be (0.1 and 0.33) for CPM and GUA respectively. The method was applied for the estimation of the active gradient of the drugs in different samples of manufactured dosage. The accuracy of method was validated by mean percentage recovery, which was found to be in the acceptable range.

Evaluation of Different Brands of Cefixime Available in Pakistan by Newly Developed Spectrophotometric Method

A fast, simple and valued method is developed to observe the quality and quantity of different pharmaceutical brands of cefixime. A spectrophotometric method has been developed for analysis of cefixime (CFX) by reacting with 4-dimethylamino benzaldehyde (DAB) as derivatizing agent. The molar absorptivity of CFX-DAB, newly synthesized derivative was calculated as 3.2 x 105 L.mole-1cm-1 and λ maximum was 393 nm. The calibration curve was developed in range of 5-25 µg.mL-1as this concentration followed beers law. The derivatization reaction is stable and didn’t show any difference in absorbance with radiation interaction for up to one day. The percentage recovery of CFX was checked and calculated in different pharmaceuticals was within 95 to 99.5% with RSD value calculated in between RSD 0.69-0.96% (n=3), respectively. This newly developed and validated procedure was proved to be accurate and precise for the analysis of CFX. This method was successfully applied to check amount of CFX from 7 different brands of pharmaceutical preparations commercially available in Pakistan.

Development of a Solid - Phase System for the Extraction of Diazinon from Water

A selected sorbent granulated activated charcoal solid - phase extraction was developed and used to extract diazinon from distilled water (TDW), distilled deionized water (DDW) and stream water (DW) was studied in the laboratory. Prior to the extraction, the half-live of the diazinon was determined in buffer solutions of pH 6, 7 and 8. The study showed that the half-lives were found to be 0.074, 0.022 and 0.077 hours respectively. Aqueous solution of diazinon was extracted in triplicate from distilled water, deionized distilled water and stream water using SPE systems. The extracted analyte was analysed by uv-visible spectrophotometer. The mean percentage recovery from distilled water, deionized distilled water and stream water using SPE 88.58%, 78.74% ad was 67.85% respectively while diazinon recovery using Liquid-liquid Extraction techniques gave a mean percent recovery of 96.60%, 93.80% and 75.54% for DW, DDW ad SW respectively. The mean percent analyte loss for SPE systems was 32.79%. The value was approximately twice higher than those obtained from LLE techniques with a value of 14.16%. The mean percentage recovery and analyte loss for SPE and LLE were compared. Similarly, the second order rate constant of diazinon of pH6, 7 and 8 were 2.6 x 10-3, 8.8 x10-3 ad 2.5 x 10-3 M-1S-1respectively. The study suggests that granulated activated charcoal can be used as an sorbent to extract diazinon from water.

The Effects of Homogenizing and Quenching and Tempering Treatments on Crack Healing

After thermal deformation and heat treatment, it can be observed that there are small, newly formed grains in the crack healing zone, which indicates that the internal crack is fully healed. However, in our previous study, the impact properties of the internal healing zone could only be partially healed. In this study, the process of homogenizing treatment was adopted to achieve grain size homogeneity. The effects of homogenizing treatment and quenching and tempering treatment on crack healing were also systematically analyzed. With the same heat treatment method, SA508-3 samples, which were subjected to multi-pass deformation, had a higher percentage recovery than those that underwent uniaxial compression. The percentage recovery of the crack healing zone was significantly improved after the process of homogenizing treatment. The impact property of the crack healing zone could be fully restored after homogenizing treatment followed by quenching and tempering treatment. However, after several episodes of heating, the grain-boundary strength decreased, and the impact value was relatively low.

EXTRACTION AND DETERMINATION OF TEBUCONAZOLE IN ENVIRONMENTAL SAMPLES FROM THE CITY OF KERBALA, IRAQ AND IN ITS FORMULATION USING HIGH- PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC)

The triazole, tebuconazole pesticide, was determined in its formulation and also in the river water samples collected from different agriculture areas in the Iraqui city of Kerbala using developed high-performance liquid chromatography method(HPLC) with UV-visible detection, The mobile composition phase was a mixture of acetonitrile:methanol (50:50 v/v) and the column was C18 (250 cm x 4.6 mm,5μm). Also modified dispersive liquidliquid microextraction (DLLME), which is regarded as an ecological -friendly method, was used for the extraction of tebuconazole from water samples using acetonitrile and chloroform as solvents extraction and dispersive agent, respectively. Linearity to maintain the calibration curve was achieved from (0.1-70) μg.mL-1 with a limit of detection(0.053) μg.mL-1 and limit of quantification (0.174) μg.mL-1. Three spiked levels of concentration (1.0, 5.0, and 10) μg.mL-1 were used for the validation of the method. The relative standard deviation (RSD%) was (0.294- 0.813)%, and the percentage recovery was (100.001-100.005). The formulation studies for two different concentrations (10 and 40) μg.mL-1, which prepared from tebuconazole formulation (Raxil ODS2 2%), gave acceptable percentage recovery between (98.956-99.833). The developed method can be used accurately for the determination of tebuconazole in water samples and in the formulation of tebuconazole effectively.

Evaluation of percentage recovery together with modified reference range in hyperprolactinemia

Objective Macroprolactinemia is an important cause of hyperprolactinemia. The aim of this study was to examine the added value of the consideration of modified reference range in determination of macroprolactinemia and true hyperprolactinemia. Materials and methods Three hundred and ninety patients with high and 131 with normal prolactin (PRL) levels were included in this study. PRL had been analyzed before and after polyethylene glycol precipitation (post-PEG PRL). Recovery percentage (R%) <40% and >60% had been reported as macroprolactinemia and true hyperprolactinemia, respectively. Post-PEG PRL levels were evaluated according to the modified reference range obtained from those of the normoprolactinemic subjects. Results According to the R% criterion; macroprolactinemia had been detected in 24.9% and true hyperprolactinemia in 67.4% of hyperprolactinemic patients. When the data were evaluated considering the post-PEG PRL levels according to the modified reference range; 13 (13.4%) of the 97 macroprolactinemia reports would be considered as true hyperprolactinemia and 6 (2.3%) of the 263 true hyperprolactinemia reports would be changed as macroprolactinemia. Conclusion Discrimination capacity of R% criterion for true hyperprolactinemia and macroprolactinemia is limited, and we suggest that, in accordance with R% criterion, laboratory reports should include the post-PEG PRL levels along with the modified reference range.

Laboratory Comparison of Permanent Deformation and Fatigue Behavior of Neat, Polymer, and Rubber-Asphalt Binders

Fatigue cracking and rutting are among the major types of distresses to be considered in flexible pavement design. In this context, the choice of the asphalt binder plays a major role in both the fatigue behavior and permanent deformation resistance of the asphalt mixture. This study was conducted to assess the permanent deformation and fatigue behavior of a field-blended rubber-asphalt (CRMA) and compare the results with typical binders used in Brazil. The neat binder used for modification was also employed as a control and as a base for polymer modification (SBSA). The binders were evaluated using the multiple stress creep and recovery (MSCR) for permanent deformation behavior, and the time sweep (TST) and linear amplitude sweep (LAS) tests for fatigue behavior. Modification of the neat binder resulted in an increase in percentage recovery in the MSCR, whereas the percentage recovery for CRMA was the highest among the three binders at any given temperature. The non-recoverable creep compliance for the CRMA was lower than that exhibited by the neat and SBSA binders for both stress levels for the range of temperatures tested. Binder modification resulted in an improved fatigue behavior compared with the neat binder according to the TST and LAS, whereas rubber modification resulted in the best fatigue behavior. Fatigue life prediction by TST was consistently higher than fatigue life prediction in the LAS test, probably because different criteria were used for determining failure in each test (ranking of the binders remained constant regardless of the criteria used).

Prevalence and fate of antibiotics and its derivatives in sewage treatment in Durban and the receiving environment

Antibiotics are released to the environment either directly in an unchanged form or partially metabolized. The discharge is usually through untreated waste or through wastewater treatment effluents. The stable antibiotics in reduced amounts persist through the wastewater treatment processes and end up in receiving waters, where they may impact crops through irrigation or affect drinking water intakes. Antibiotics in the waste and sludge fractions may similarly impact crops and arable land through their use as fertilizers. Conventional wastewater treatment plants are not designed for the removal of antibiotics but may to a varying extent reduce their concentrations. Their quantitative occurrence within the water matrices depends on the frequency and quantities of use for therapeutic purposes or as growth promoters in animal production. Additional inputs may emanate from individual waste discharges. Antibiotics present in sub-inhibitory concentrations may predicate for resistance among the resident bacteria in the water matrix, biofilms or in humans and animals. In South Africa antibiotics are extensively used both in human therapy and in animal husbandry without clearly followed regulations and are sometimes readily available. The available studies have focused on the presence of antibiotic resistant bacteria in wastewater influent and effluent but there is a paucity of information relating to these antibiotics as emerging contaminants in South Africa wastewater. In this thesis a rapid and sensitive analytical methodology was initially assessed and applied, based on the use of HPLC/diode array UV detector for six antibiotics (ethionamide (ETI), metronidazole (MET), trimethoprim (TRI), ciprofloxacin (CIP), sulfisoxazole (SUF) and albendazole (ALB). Validation of the method was performed by screening assessment in selected wastewater treatment plants (WWTPs) with the aim of determining the sensitivity of the equipment (Shimadzu 2020), assess the limit of detection, optimize the extraction procedure (solid phase extraction) and screen for the most prevalent antibiotics. The percentage recovery for the optimized method using wastewater sample was above 65 % for all antibiotics of interest. The limit of detection, which ranges from 0.03 to 0.48 mg L-1, enables the determination of a range of concentration of antibiotics in polluted sample such as the wastewater influent sample. Furthermore in this thesis, a more advanced, online solid phase extraction – high performance liquid chromatography mass spectrometry (SPE-HPLC-MS) method, was applied to measure the concentration of these and an additional seven antibiotics, norfloxacin (NOR), ofloxacin (OFL), clindamycin (CLI), sulfamethoxazole (SUL), erythromycin (ERY), clarithromycin (CLA), azithromycin (AZI) and roxithromycin (ROX) in ng L-1 concentrations. The quantity and occurrence of the selected antibiotics was assessed in untreated wastewater in four wastewater treatment plants in Durban, KwaZulu-Natal (KZN), at different treatment stages and in the effluent and recipient surface water environment. In the influent the additive concentration of the antibiotics associated to the separated sediment fraction through centrifugation and in the supernatant of samples collected were accounted for and analyzed. The limit of detection (LOD) and the limit of quantification (LOQ), ranged from 0.07 – 0.33 ng L-1 and 0.23 – 1.09 ng L-1, respectively for the 13 assessed antibiotics and the percentage recovery were in the range of 51 to 111 %. The percentage of antibiotics recovered from the sediment (centrifuged) samples, which would have been lost to filtration if not analyzed in parallel, were in the range of 2.6% – 97% (n = 32), while the frequency of detection in the influent samples for the sampling period ranges from 62.5 – 100 % (n = 32). All the studied antibiotics were detected in the influent of each WWTP and the concentration was in the rage of 1.3 ng L-1 (AZI) – 81748 ng L-1 (CIP). The antibiotics with the highest concentrations (median) detected in the receiving water (downstream) for each of the four WWTPs in KZN, were TRI (217 ng L-1), SUL (239 ng L-1), CIP (708 ng L-1) and ALB (325 ng L-1) respectively. The overall percentage removal efficiency for the four WWTPs ranged from 21 % - 100 %. The most effective treatment steps were assessed with the focus on activated sludge filter and trickling filter. Within these, it was actually the sedimentation treatment stages (secondary clarifier), after these steps that played the most vital role in the reduction of antibiotics where > 70 % of the antibiotics was removed. Finally, the impact of post chlorination was analyzed for the effluent of the WWTPs. The presence of transformation product as a result of post chlorination was examined in a parallel study using a controlled experiment and full scale analysis. The efficiency of chlorine in the reduction of antibiotics was more of transformation of antibiotics than degradation. The oxidative ability of chlorine enhances its reaction with antibiotics thereby transforming the antibiotics. The percentage reduction of antibiotics in relation to chlorination was >85 % (pilot experiment) and ranged between 14 % - 97 % in the field experiments. Likewise, UV was effective in the degradation of antibiotics, with longer exposure time producing higher degradation. Future research should focus on determining the toxicological impact of these transformation products. The concentration of the antibiotics in the downstream samples were generally low when compared to their influent concentrations.

Enhancing production of pharmaceutically valuable alkaloids in plant cells, tissues and extracts of Catharanthus roseus

The important pharmaceutically valuable anticancer alkaloids, Vinblastine and Vincristine, are produced by Madagascar periwinkle plant called Catharanthus roseus (C. roseus). Given their cytotoxicity, these vinca alkaloids are produced in very minuscule quantities and are abundant in the aerial parts of the plant. For example, Vincristine has suffered from the disadvantage of very low yieldsin industrial production; one-tonne leavesfrom traditionally cultivated plants could produce 0.5 - 50g crude extract of Vincristine and yet its current world demand lies between 3 – 10kg per annum (Koul et al., 2013). The high cost of isolating pharmaceutical drugs has led to research efforts to increase the content of alkaloids in C. roseus seedlings, cell and tissue cultures. In the present study, enhancing production levels of the four pharmaceutically valuable alkaloids of C.roseus, namely: Vincristine, Vinblastine, Ajmalicine and Vindoline was investigated in vitro, in callus differentiation through somatic embryogenesis, cell suspension cultures through elicitation, as well as ex-vitro in highly differentiated hairy roots derived from seedlings inoculated with Agrobacterium rhizogenes. There was a significant eight-fold percentage recovery of Vinblastine in the second stage of somatic embryogenesis when compared to percentage recovery in the wild type plants. The other stage 3 of somatic embryogenesis which was the unsuccessful plant conversion stage of development exhibited a significant four-fold low level of Vinblastine relative to that in the maturation stage but two-fold higher with that of wild type plant. The ex vitro generated hairy roots exhibited a 6.5-fold percentage recovery of Ajmalicine levels when compared to the wild type plant, while the other compounds could not be detected in the roots. This exhibited the importance of light or sunlight in order for plants to synthesize Vindoline, and consequently, the absence of Vindoline would mean that the plant hairy roots could not synthesize Vinblastine and Vincristine

Stress degradation studies of hydrochlorothiazide and development of validated method by UV spectroscopy

To develop a simple, precise, accurate, and stability indicating a UV-method for estimation of Hydrochlorothiazide(HCT)in bulk and formulated dosage form.The drug was alsosubjected to stress degradation at different conditions recommended by the International Conference on Harmonization (ICH). The samples are generated and used for the degradation studies.The λmax of the HCTwas found to be 273nm.The linearity of calibration curve (Absorbance Vs Concentration) in pure solution was checked over the concentration ranges of about 5-30μg/mLwith the correlation coefficient higher than 0.99. The regression equation of the curve was Y = 0.598x + 0.0042.% RSD was found to be within the limit as per ICH guidelines. The obtained percentage recovery of HCTwas found to be within the limit100% ± SD. Stress degradation studies revealed thatitwas within the limit(5-20%).