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Home > Synthesis and Characterization of Some Novel N-Vinyl Pyrrolidone Based Copolymers for Controlled Drug Delivery

Synthesis and Characterization of Some Novel N-Vinyl Pyrrolidone Based Copolymers for Controlled Drug Delivery

Thesis Info

Access Option

External Link

Author

Huma, Farhat

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2013

Thesis Completion Status

Completed

Subject

Chemistry

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2555/1/2595S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727465950

Similar


Six series of N-vinyl pyrrolidone based copolymers were synthesized by free radical solution polymerization of N-vinyl pyrrolidone and n-alkyl methacrylate monomers. The n-butyl methacrylate and n-hexyl methacrylate were selected as the hydrophobic counterpart. In the first part of the study properties of uncrosslinked poly(N-vinyl pyrrolidone-co-n-alkyl methacrylate) copolymers were modified by varying the weight % ratio of the two monomers. Elemental analyses, FTIR, 1H and 13C NMR spectroscopic analyses techniques were used for structure elucidation of the copolymers. Thermal stabilities and glass transition temperatures of the copolymers were directly related to the amount of n-alkyl methacrylate as well as the alkyl chain length of methacrylate comonomer. The water uptake characteristics of the copolymers were related to the amount of hydrophilic NVP incorporated into these copolymers. The hydrophobic drug dexamethasone was loaded into the copolymers with optimum water uptake and prolonged aqueous stability. The drug release studies were carried out at physiological temperature 37 °C and pH 7.4 for 35 days. Controlled drug release was observed from the selected copolymer films during the study time period. The cumulative drug release was found to be mainly controlled by the amount of hydrophilic monomer and molecular weight of the copolymers. In the second part of present study crosslinked poly(N-vinyl pyrrolidone-co-n-alkyl methacrylate) copolymers were synthesized at fixed weight % ratio of N-vinyl pyrrolidone and n-alkyl methacrylate monomers (i.e NVP : nAMA = 90:10) using various concentrations of polyfunctional monomers employed as crosslinking agents. The effect of crosslinker concentration and functionality on gel content, thermal stability, water uptake, internal morphology and drug release was investigated. Gel contents and thermal stability of the crosslinked copolymers increased with increasing crosslinker concentration as well as its functionality. The water uptake at 37 °C decreased with increasing crosslinker concentration and functionality however the increase in alkyl chain length of alkyl methacrylate resulted in increased water uptake. The crosslinked copolymers with optimized crosslinker concentrations exhibited controlled drug release patterns at 37 °C and pH 7.4. Higher amounts of cumulative drug release were observed for copolymers crosslinked with trifunctional crosslinkers leading to complete drug release in 20-22 days while the copolymers crosslinked with difunctional crosslinker exhibited controlled drug release upto 35 days. The kinetics and mechanism of the drug release was also analyzed.
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الفصل الأول: أشعار نازك الملائكة وبروين شاکر(المتشابهة)

الفصل الأول: أشعار نازك الملائكة وبروين شاکر(المتشابهة)

 سأتناول في ھذا الفصل بعض أشعار نازك الملائکۃ وبروین شاکر ثم سأتحدث عن المتشابھات في بعض أبیاتھما بشکل أجمالي، واتضح لي من خلال عملي ھذا أن ھناک متشابھات فیما بینھما (نازك الملائکۃ وبروین شاکر) مع أن واحدۃ منهما عربیۃ والثانیۃ غیر عربیۃ، فمن خلال بحثي استنتجت بأنھما من الشاعرات الجدیدات لذلك ھُناک تشابہ في عصرھما وأحوالھما السیاسیۃ والدینیۃ والعلمیۃ والإجتماعیۃ وجمیع ھذہ المؤثرات لھا الدور الکبیر في تکوین الأفکار والأسالیب المتشابھة مع بعضھما البعض وأنھما من مشجعي الشعر الحر وصدق التعبیر لہ الید الأکبر في إیضاح أفکارھما وإیصال المعنیٰ الصحیح إلی القاريء أو السامع۔

 وقد أخذت قصیدۃ من نازک الملائکۃ وقصیدۃ من بروین شاکر وقمت بمقارنتھما، ووضعت أسماء من خیالي لکل قصیدتین (قصیدۃ لنازك الملائکۃ وقصیدۃ لبروین شاکر) وھکذا۔

جدول القصائد المتشابهة

اسم قصیدۃ بروین شاکر أو بیت من غزلھا

اسم قصیدۃ نازك الملائکۃ

الإسم الخیالي

المبحث

کیسی بے چہرہ رُتیں آئیں وطن میں اب کے

موجودہ وبائی ماحول میں عسل کی طبی افادیت جدیدسائنس اور اسلامی تعلیمات کی روشنی میں

 Honey is an unparalleled treasure of medicinal properties. Honey has the ability to strengthen the human body's immune system. Therefore, the use of honey and other natural foods is extremely beneficial and effective in current epidemic environment. Honey is one of the most appreciated and valued natural blessing of Allah for human being. Medicinal importance of honey hase been described in Holy Quran. Holy prophet (SAW) has advised to use honey because honey provides body instant energy. There are several varieties of honey are found in different areas of the world. Honey has been taken for research because of its nutritional popularity and medicinal quality. Honey is high in important nutrients of benefits and uses. Honey contains carbohydrates, vitamins, minerals and a significant amount of fiber. Nutrients of honey can improve digestive system by preventing constipation. Immunity system can be improved by using honey in epidemic environment. Honey is a source of fructose, which does not harm patients of diabetes. The fructose makes a better substitute for sugar because of the fiber, nutrients and antioxidants. Honey is comprised of several minerals including phosphorus, iron, potassium, calcium and magnesium. Honey has very small amount of protein and fats. This research paper analyzes ingredients and minerals of honey in Islamic perspective. The research work highlights medical benefits of honey in the light of modern science and Islamic teachings in the current epidemic environment.

Heavy Metal Accumulation in Dietary Vegetables and its Toxicological Impact on Human Health

Municipal wastewater contaminated with heavy metals is used in for growing crops in the sub urban metropolitan localities. The use of highly polluted wastewater for irrigation purpose by local farmers has been in practice since long which has contaminated and drastically polluted the irrigation soil. Those pollutants are believed to have been transferred to our food chains leading to serious heath related issues. Prolong utilization of unhygienic wastewater for vegetable cultivation has contaminated the soil and accumulate heavy metals in dietary vegetables. Health risk assessment of this unhygienic practice is important to understand because it can provide valuable source of information about any serious health threat to the local population. Untreated effluents from Hayatabad Industrial Estate of Peshawar city and Gadoon Amazai Industrial Estate of Swabi are regularly released into local irrigation channels (streams and canals). Blood analysis of industrial workers was important to know about the heavy metal effect on human health. The aim of the present study is to investigate whether exposure to Pb induces lipid peroxidation and biochemical abnormalities in spent lead acid battery (LAB) workers. An investigation has been conducted to ascertain metal concentrations in the wastewater, soil, vegetables and in the blood of spent battery workers. The concentration of heavy metals (Pb, Cd, Cr, Ni, Zn, Cu, Fe and Mn) was determined by using Atomic Absorption Spectrophotometer. Pb level in blood was determined by graphite furnace Atomic Absorption Spectrophotometer. Oxidative stress parameters were examined by Spectrophotometer. Liver function tests were conducted with Abbott architect Ci8200 and hematological parameters were measured with automated hematology analyzer sysmex. The present study was conducted in five districts (Peshawar, Mardan, Nowshera, Charsadda and Swabi) of Khyber Pakhtunkhwa (KPK), Pakistan. Fresh vegetables were collected from fields of Peshawar and Swabi, while bucket survey method was used for random sampling of vegetables from markets of three districts (Mardan, Nowshera and Charsadda). Blood samples were collected from various spent lead acid battery workers from Peshawar. Heavy metals found higher in wastewater irrigated sectors as compared to fresh water sectors. pH and total suspended solids (TSS) in wastewater were found to be higher than permissible limit set by World Health Organization (WHO, 2007). These results revealed that Cr concentration in the wastewater was well above the permissible limits of United State Environmental Protection Agency (USEPA) which may lead to a detrimental effect on soil quality deterioration, ultimately leading to food contamination. The source identification analysis carried out by Principal component analysis (PCA) and Cluster analysis (CA) showed that ground water and soil were being polluted by the trace metals coming out from industries and domestic wastes. Moreover, PCA extracted two factors for wastewater, each contributing 61.086 % and 16.229 % of the total 77.315 % variance. PCA extracted two factors, for soil samples, having total variance of 79.912 % factor I and II contributed 63.889 % and 16.023 % of the total variance. Anova analysis showed significant difference in soil samples for Pb, Cr, Cd, Ni, Zn and Cu at P ≤ 0.001, for Mn at P ≤ 0.05 while no significant difference was observed for Fe respectively. Anova analysis also exhibited highest mean value for Pb in cabbage, Cr in cauliflower, Cd and Ni in lettuce, Zn in green pepper, Cu in red pepper, Fe and Mn in green pepper respectively. In bucket survey method analysis, concentration of Pb was found to be higher in cabbage, Cr in cauliflower, Cd in cabbage, Ni in garlic, Zn, Fe and Mn in green pepper respectively. Substantial positive correlation was found among the soil and vegetable contamination. Transfer factor for some metals including Cr, Pb, Zn, Mn, Ni, Cd and Cu was greater than 0.5 which showed enhance accumulation of these metals due to contamination caused by domestic discharges and industrial effluents. Linear regression analysis indicated significant correlation of heavy metals viz Pb, Cr, Cd, Ni, Zn, Cu, Fe and Mn in vegetables with concentration in soil of 0.964 at P ≤ 0.001. Health assessment via consumption of dietary vegetables revealed higher than permissible limit (HRI > 1) for Pb and Cd in children and adults. Health risk of Pb and Cd due to consumption of wastewater irrigated vegetables in the study areas is of much concern. Enrichment factor (EF) due to consumption of vegetables was found to be higher for Pb and Cr respectively. The blood samples result showed that blood lead level, superoxide dismutase (SOD) and malondialdehyde (MDA) levels were found to be significantly higher (p < 0.001) while the level of glutathione (GSH) was significantly lower (p < 0.001) in exposed groups compared to control group. Pb showed positive significant correlation with SOD (smoker, exposed group II) and MDA (non smoker, unexposed group II). The values of liver function tests of lead acid battery workers were found to be within the normal range in all age groups except for the albumin content and alkaline phosphatase (AP) activity. Pb showed negatively significant correlation with total bilirubin of unexposed group II. AP activity was significantly higher in both the exposed groups I and II, while Albumin level was found to be lower both in the exposed groups I and II. Pb showed positively significant correlation with WBC and platelet of unexposed group II. The present study revealed that prolonged exposure to Pb is likely to induce lipid peroxidation and biochemical abnormalities in battery workers. Moreover, the likelihood of higher pollution load index for vegetables in the study area due to metal polluted soil has opened a new study area for proper legislation to protect local population from further contamination of vegetables. It is envisaged that the current research work may reveal further serious health risks to human population of the study area.