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Home > Study of Hydrogel Based Controlled Release Drug Delivery System for Captopril and its In-Vitro, In-Vivo Evaluation

Study of Hydrogel Based Controlled Release Drug Delivery System for Captopril and its In-Vitro, In-Vivo Evaluation

Thesis Info

Access Option

External Link

Author

Muhammad Iqbal, Furqan

Program

PhD

Institute

The Islamia University of Bahawalpur

City

Bahawalpur

Province

Punjab

Country

Pakistan

Thesis Completing Year

2015

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/8848/1/Furqan%20Muhammad%20Final%20Ful%20thesis.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727375711

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A foremost step towards controlled and targeted administration of therapeutic agents is development of new drug delivery systems. Oral administration is mostly preferred and desired as a non-invasive mean of providing drug at controlled rate. In present research work, hydrogels were prepared for controlled release of captopril, an angiotensin converting enzyme (ACE) inhibitor, used for the treatment of hypertension. Three types of hydrogel formulations were prepared by different proportions of polymers and monomers. A chemical crosslinking method, free radical polymerization was selected for synthesis of polymeric networks, involving use of thermostatic water bath as well as induction by microwave radiations. A microwave assisted hydrogel synthesis, was used for preparation of hydroxypropyl methylcellulose-graft-poly(vinyl alcohol)-co-poly(acrylic acid) copolymeric network. N,N-methylenebisacrylamide and potassium persulfate (KPS) were used as crosslinking agent and initiator, respectively. Formulations with same combinations of polymers and monomers were also prepared by utilizing conventional thermostatic water bath. The hydrogels obtained by these techniques were compared with each other in terms of morphological properties, swelling ratios, drug loading and drug release behavior. The hydrogel formulations were also prepared by crosslinking of 2-acrylamido-2-methyl-1- propanesulfonic acid (AMPS) and acrylic acid with hydroxypropyl methylcellulose (HPMC). These hydrogels had shown higher ability to absorb and retain aqueous solutions and solute particles. Another type of polymeric network was synthesized under influence of microwaves radiations, with lower initiator concentration, by crosslinking of poly(vinyl alcohol) (PVA) with 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). They have ability to exhibit relatively higher swelling behavior at pH 2 in comparison to pH 7.4 and have gastro retentive characteristics. Due to their massive swelling tendencies, these could be retained in stomach and unable to pass through next segment of gastrointestinal tract. Thus, after oral administration of captopril loaded hydrogels, they could have ability to release drug continuously at acidic pH of stomach, in a control manner for longer time periods. The results of drug release are according to swelling powers of formed copolymeric hydrogels. 6 All types of hydrogel formulations prepared were evaluated by in-vitro and in-vivo analytical procedures. The in-vitro characterization was done by Fourier Transform Infrared Spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), swelling properties, drug loading and release. The drug release was evaluated by the application of zero order kinetics, first order kinetics, Higuchi model, Korsmayer-Peppas model and Weibull model. The hydrogels selected on the basis of their in-vitro evaluation were subjected to in-vivo characterization. High performance liquid chromatography (HPLC) method, with UV detector was utilized for in-vivo characterization. The study was performed on twenty four rabbits and liquid-liquid extraction procedure was used for separation of captopril from plasma samples. The bioavailability and pharmacokinetic parameters were determined by kinetica (version 5.0). The maximum concentration (Cmax) of captopril was reduced while time to reach maximum concentration (Tmax) was increased by hydrogels in comparison to control (free drug enclosed in hard gelatin capsules). The values of area under curve AUC (calculated by trapezoidal rule) and elimination half-life were higher for controlled release hydrogel formulations than control. The drug could be available for longer periods of time after administration of captopril loaded hydrogels, maintaining optimum concentration in blood, exerting its efficacious effects as an antihypertensive therapeutic agent.
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حوالہ جات کا طریق کار

موضوع6:حوالہ جات کا طریق کار
حوالوں کی ضرورت و اہمیت:
تحقیقی کتابوں اور مقالات میں حوالے بڑی اہمیت کے حامل ہوتے ہیں۔حوالوں کے بغیر تحقیقی کام کی تصدیق کرنا مشکل ہو جاتا ہے۔ جس طرح ایک وکیل اپنے دلائل کو تقویت دینے کے لیے قانون کی کتابوں سے حوالے دیتا ہے بالکل اسی طرح ایک محقق اپنے خیالات کو تقویت دینے کے لیے دوسرے ماہرین کی تحریروں کے حوالے دیتا ہے اور ان کا اندراج باقاعدہ طے شدہ اصولوں کے مطابق کرتا ہے۔ حوالوں کی اہمیت کا اندازہ درج ذیل باتوں سے لگایا جا سکتا ہے :
• قارئین کو مقالے کی بہتر تفہیم میں مدد دیتے ہیں۔
• محقق کے مطالعے کی وسعت کا پتہ چلتا ہے۔
• قارئین کوتحقیق میں استعمال کیے گئے ماخذ سے آگاہی ہوتی ہے۔
• ماخذات کے ذرائع اور اقتباسات کے مصنفین کی کاوشوں کو خراج تحسین پیش کرنے میں مدد دیتے ہیں۔
حوالے دینے کے مختلف طریقے:
حوالہ بالحاظ صفحہ:
ہر صفحہ کے متن کے نیچے آخری سطور پر حوالے درج کیے جاتے ہیں۔ایسی صورت میں ہر صفحہ کا حوالہ نمبر 1،2،3سے شروع ہوگا
حوالہ بالحاظ باب:
باب کے آخر میں حوالہ دینا:ایسی صورت میں حوالہ نمبر مسلسل دینے ہوں گے ،گویاجہاں باب ختم ہوگا وہاں حوالے درج کیے جائیں گے۔
حوالہ بالحاظ مقالہ/کتاب:
پورے مقالے یا کتاب کے آخرمیں ابواب کی ترتیب باب نمبر 1،2،3وغیرہ سے حوالے درج کیے جاتے ہیں۔
نوٹ: مشقی کام یا اسائنمنٹ کے لیے حوالہ بالحاظ صفحہ اور مقالہ کیلیے حوالہ بالحاظ باب نمبر کو زیادہ موزوں خیال کیا جاتا ہے۔
حوالے کے اندراج کے اصول:
• حوالہ میں صرف طے شدہ ،مختصر تفاصیل درج ہونی چاہییں۔
• پہلی بار حوالہ مکمل صورت میں درج کرنا ہوگا۔
• دوسری بار صرف مصنف،تحریر کا عنوان اور ص نمبر کا اندراج ہوگا۔
• اگر حوالہ مسلسل ہے...

An Investigation of English as Foreign Language Students' Attitudes Toward Improving Their Speaking Abilities at KRI Universities

The study examines English as Foreign Language (EFL) students’ attitude towards developing their speaking abilities at KRI University in order to better understand the disparities in speaking competency among undergraduates. The study utilized a quantitative approach and employed a 4-item interview survey to gather data for the study. The survey interview questionnaire was adopted from Wang, Kim, Bong, and Ahan (2013) and administered to 100 students in the departments of English of six universities in Iraq's Kurdistan Region. A semi-structured interview was developed for EFL students. The questionnaire was online and an open-ended one. The data from the participants was analyzed using thematic analysis with (SPSS) software. The finding revealed a perceived failure in EFL students' English-speaking skills and this was reported along with causes of the perceived difficulty. The finding also revealed a poor level of speaking ability among EFL undergraduates as well as little education in the skill at the university level. Apart from these, the study discovered some major challenges for EFL students such as lack of confidence, lack of planning, a demotivating atmosphere, incorrect word choice, poor gestures, and incorrect style which made the students not to be successful in their speaking abilities. The study suggested that EFL learners' competency should be securitized to strengthen their speaking abilities in the light of the results of the study. Speaking is a crucial ability in language acquisition and EFL teachers should help their students acquire it. As a means of improving students' communicative ability, task-based instruction should be utilized in educational institutions and universities. The implication of this paper is that speaking difficulties among EFL students in the Iraqi Kurdistan Region institution can be solved by putting greater focus on this ability. There are several issues to consider, including teachers, instructional methodologies, the curriculum, extracurricular activities, and assessment rules.

Prevalence, Etiology and Management of Blackleg and Soft Rot of Potato

Potato (Solanum tuberosum L.) is the most important vegetable crop of the world, including Pakistan, ranking number one among all vegetables both in production and consumption. Although bacterial diseases (such as blackleg and soft rot) cause substantial damage to potato crop in Khyber Pukhtunkhwa, yet no significant research has been done so far on any aspect of these diseases. We conducted extensive surveys (2007-2009) to document the status of these diseases in our province and found that disease severity and incidence, at different locations, ranged from 2-40 % and 5-75 %, respectively. The frequency of the three causal organisms was found to be 47.61% for Erwinia carotovora subsp. atroseptica (Eca), 45.23% for E. carotovora subsp. carotovora (Ecc), and 7.14% for E. chrysanthemi (Ech). As there is some debate about the role of tuber-borne, soil-borne, and diseased plant-debris-borne primary inoculum of Eca in causing primary infections, we studied these sources of inocula. The results indicated that the pathogen population in inoculated tubers kept increasing during the entire duration (80 days) of the study whereas that in diseased plant debris declined very slowly. No bacteria could be detected in artificially inoculated soil after two months. Therefore, it was concluded that the infected tubers are the best source of inoculum followed by diseased plant debris. Because studying pathogen population helps in the control of the disease it causes, therefore, we were interested in finding diversity among the isolates of the pathogens causing potato blackleg and soft rot. The intra-specific diversity among the isolates of Ecc, and Ech is well known but that among the isolates of Eca is debatable. For this reason, we used randomnly amplified polymorphic DNA (RAPD) to amplify DNA from 20 Eca isolates using 2 selected random primers. The data (bands) generated were used to perform cluster analysis using the un-weighted pair-group method with arithmetical average (UPGMA) of Genetyx software, version 7.0 and the viiresulting 4 main clusters were presented as dendrogram. We were also interested in knowing if the genotypic differences among the Eca isolates would be correlated to some phenotypic character; so, we used potato stem rot assay to divide the 20 Eca isolates among 4 aggressiveness groups. Our data suggested that although the isolates genetically differed from each other by as much as 40%, these differences were not tightly correlated to the pathogenic differences found among them. Because blackleg and soft rot of potato is a hard-to-control disease, we were interested in an integrated management of the disease. The components of the integrated management that we studied included: (i) use of different plant extracts as seed tuber treatment to kill the contaminating blackleg and soft rot bacteria, (ii) use of balanced nutrition to enhance the competitiveness of the plant host against the pathogen, and (iii) finding resistance, if any, against blackleg and soft rot of potatoes among the popular commercial potato cultivars available to local farmers. Among the different aqueous extracts used, neem extract was found to be the best which decreased the disease incidence and disease severity by 71.18% and 56.86%, respectively as compared to the control. Neem extract also increased yield per plant by 344.44% as compared to that of control. The results of the host fertilization studies concluded that the fertilizer combination of N 3 P 1 K 3 (262/252/262 kg.ha -1 ) which is slightly higher than the normally practiced dose (247/247/247 kg.ha -1 ) was the best in bringing the disease to a minimum and subsequently increasing the yield. In case of varietal screening, based upon our overall results, no variety was found to be resistant against blackleg and soft rot of potatoes. However, field performance of variety Kuroda was comparatively better than other varieties whereas variety Desiree seemed to be the most susceptible.