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

Thesis Info

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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

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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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’’خدائے سخن‘‘ کی نظمیں

خدائے سخن‘‘ کی نظمیں

نظم کے معنی ’’موتیوں کی لڑی‘‘ کے ہیں۔موتیوں کو لڑی میں پرونا ہے۔لیکن ادبی اصلاح میں نظم سے مراد اشعار کا وہ مجموعہ ہے جس میں کوئی ایک مرکزی خیال ہوتا ہے۔بہت زیادہ اشعار ہونے کی صورت میں خیال کی درجہ بدرجہ بڑھوتری کو ظاہر کرنے کے لیے اشعار کو مختلف حصوں میں تقسیم کر لیا جاتا ہے تاکہ نظم کے معنی اور مفہوم کو اجاگر کیا جا سکے۔نظم میں ایک خیال یا تصور کو موضوع بنایا جاتا ہے۔نظم میں اشعار کی تعداد مقرر نہیں ہوتی صرف خیال کے تسلسل کو سامنے رکھا جاتا ہے۔

نظم میں موضوع کی کوئی پابندی نہیں ہوتی۔اس میں کسی بھی موضوع پر اظہار خیال کیا جا سکتا ہے موضوع چاہے تاریخی ہویا جغرافیائی دینی ہویا دنیاوی،تہذیبی ہویا ثقافتی،معاشی ہو یا معاشرتی،سیاسی ہو یا مذہبی،قومی ہو یا انقلابی،قدیم ہو یا جدیدعلمی ہو یا ادبی غرض ہر موضوع اور دنیا کے ہر معاملے،زندگی کے ہر مسئلے اور کائنات کے ہر پہلو پر نظم لکھی جا سکتی ہے۔

موضوع کی طرح نظم کے لیے خاص ہیئت کی پابندی ضروری نہیں جس طرح نظم کا کوئی بھی موضوع منتخب کیا جا سکتا ہے اسی طرح نظم لکھنے کے لیے کوئی بھی ہیئت اختیار کی جا سکتی ہے۔اگرچہ روائیتی طور پر نظم کی کچھ خاص اصناف کے لیے خاص ہیئت مخصوص ہیں۔مگر عام طور پر نظم کے لیے کوئی خاص ہیئت مقرر نہیں کی گئی،یہ بات ہمیں عطا محمد عنبر کی نظموں کی کتاب ’’خدائے سخن‘‘ میں دیکھنے کو ملتی ہے۔انہوں نیاپنے اس شعری مجموعہ میں جو نظمیں شامل کی ہیں۔ان کو مختلف ہیئتوں میں لکھا ہے کہیں کہیں نظم کا تاثر پھیکا پڑتا دکھائی دیتا ہیاور غزلیہ رنگ نمایا ں نظر آتا ہے۔کیونکہ آپ کی بہت ساری نظموں میں سے ایک سے...

Ijaz Hussain, Political and Legal Dimensions of Indus Water Treaty (Book Reviews)

Of the many issues that the partition of India in 1947 did not address in time, and were left to worsen the relations between India and Pakistan, the issue of riparian rights was only next in importance to the issue of Kashmir. In many respects the two issues have direct bearing on each other as well, as some important rivers emanate from Indian-held Kashmir. As the time passes more and more historians are coming to the conclusion that the massacre at the time of partition, the uprooting of more than 12 million people from their native homes, horrendous violence against women, burning and looting, etc, all owe mainly to the colonial administration that failed to ensure peaceful transition to two independent countries. No less than a person than a former Prime Minister of Great Britain, Winston Churchill, described the attitude of the then British government as the ‘biggest escape of human history’. In its urge to get rid of Indian responsibility, the government of Prime Minister Clement Atlee, showed extraordinary haste in relinquishing its responsibilities without ascertaining that the partition of a country of a subcontinental size would involve a huge amount of work. It required taking into consideration all administrative and security aspects so that the two countries could move along their independent journey as good neighbours. Unfortunately, the failure of the British government, both in London and, through its viceroy, in Delhi, left a number of issues unsettled, which the two independent countries have been trying to resolve for the last seven decades. Moreover, with the passage of time, new factors emerged which further complicated the original issues.

پاکستانی اردوغزل کی تنقید کا ارتقاء

“Ghazal”is evergreen genere of Urdu literature. With the passage of time, it has gone through changes in its subjects, and structure. Because of these changes, not only variety of Urdu Ghazal was amplified, but also there was an addition in the critical treasure of Ghazal. After the Partition, Urdu Ghazal in Pakistan has also got gradually distinctiveness in its thematic approach, topical variation and artistic characteristics. Today where “Pakistani Ghazal” has got a solitary identity, the critics on it has become most comprehensive, accurate, modern and most helpful in its consideration and explanation. The criticism of Urdu Ghazal not only focused the changes coming in the language and expression, methods and rhythm of Urdu Ghazal but also harmonized itself with the changes. This research is an effort to know and evaluate the trends in critiquing “Urdu Ghazal of Pakistan” and the nature and quality of its development. This study will be helpful not only in knowing the characteristics, trends and inclination of Urdu Ghazal of Pakistan but also will support in consideration of periodical changes in trends and views of critical analysis of Pakistani Urdu Ghazal and identifying the nature, pace and direction of its future journey. The following kinds of materials have been considered fundamental, to cover up the authentic sources and materials: 1. The critical books containing discussions, as a whole, on Pakistani Urdu Ghazal. 2. Constant Critical Books on Urdu Ghazal/Ghazal poets. 3. General reviews which contain references of Pakistani Urdu Ghazal. 4. Articles containing analytical discussions of Pakistani Urdu Ghazal. 5. Articles consisting of comprehensive evaluation on Pakistani Urdu Ghazal. 6. Critical Books containing any article written on Pakistani Ghazal or any Pakistani Ghazal poet. 7. Compiled Books, Prefaces and Flaps on the collection of Ghazal of renowned poets. 8. Important analytical articles on Pakistani Ghazal or Ghazal poet. 9. The special volumes of journals and magazines on Ghazal poet or Ghazal. 10. Published or unpublished degree thesis. In making a comprehensive study, chapters have been presented as under: Chapter one is consisted of the discussion on the critical culture of Urdu Ghazal and basic points in which the initial stages of critic on Ghazal and prominent features are included. The second chapter presents an analysis of the different trends of critics on Pakistani Urdu Ghazal from 1947 to 1960. The third chapter presents a review of the trends of critic on Ghazal in the critical books and famous journals and publications which are written in respect of movements of lingual development in 1960’sand 1970’s. The fourth chapter is consisted on the analysis of critics on Ghazal and different trends in 1980’s and 1990’s. The fifth chapter presents an analysis of the critics of Ghazal from 2000 till now in respect of an established Pakistani consciousness. The sixth chapter presents a collective analysis of critics of Ghazal in the light of the initial and evolutionary trends and modern critical views and discussions of Pakistani Urdu Ghazal, and there are some recommendations and suggestions as well.