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Home > Photostabilization of Some Drugs by Liposomal Drug Delivery Systems

Photostabilization of Some Drugs by Liposomal Drug Delivery Systems

Thesis Info

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Author

Adeel Arsalan

Program

PhD

Institute

Baqai Medical University

City

Karachi

Province

Sindh

Country

Pakistan

Thesis Completing Year

2016

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/8015/1/Adeel_Arsalan_Pharmaceutics_HSR_2017_BMU%2c%20Karachi_7.12.2017.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726891301

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The present work involves a study of the photolysis of riboflavin (vitamin B2) (RF), norfloxacin (antibiotic) (NF) and cyanocobalamin (vitamin B12) (B12) in various liposomal preparations having a composition of cholesterol (CH) and phosphatidylcholine (PC) with a ratio of CH:PC (13.50: 10.80–16.20 mM) and the evaluation of the effect of compositional variations on the kinetics of degradation and photostabilization of these drugs. UV and visible spectroscopy, fluorimetry, dynamic light scattering (DLS), atomic force microscopy (AFM) and high performance liquid chromatography (HPLC) have been employed to investigate various aspects of this work. The literature on the analytical methods used in the study of liposomes, formulation of liposomes and stabilization of liposomal drugs has extensively been reviewed. The observations on the study of the individual drugs used are as follows. Riboflavin (RF) The apparent first–order rate constants (kobs) for the photolysis of RF in liposomal preparations lie in the range of 1.73–2.29×10–3 min–1 compared with a value of 8.08 × 10–3 min–1 for the photolysis of RF in aqueous solution (pH 7.4). The values of kobs decrease linearly with an increase in PC concentration in the range of 12.12–14.85 mM, indicating the stabilization effect of PC on RF with a stabilization ratio of around 4. This is confirmed by a loss of fluorescence intensity of RF with an increase in PC content as a result of the quenching of excited singlet state and the formation of a charge–transfer complex between PC and RF. The values of kobs decrease with an increase in PC concentration indicating the effect of PC on RF stabilization. The entrapment efficiency of RF in liposomes has been determined as 25.9–42.3%. The assay of RF and its photoproduct, lumichrome (LC), in liposomal preparations has been carried out by a two– ii component spectrometric assay at 445 and 356 nm with a correction for linear irrelevant absorption to eliminate interference from liposomal components. The study indicates that RF can be stabilized against light by a modification of the liposomal formulation with an increase in PC concentration. The mechanism of RF and PC interaction has been discussed. Norfloxacin (NF) The values of kobs for the photolysis of NF in liposomal preparations are in the range of 1.05–2.40×10–3 min–1 and depend on the concentration of PC in liposomes. The value of kobs for the photolysis of NF in aqueous solution (pH 7.4) is 8.13×10–3 min–1 indicating a stabilization ratio of 3–7 in various liposomal preparations. A linear relation between kobs and PC concentration with a negative slope has been observed to show that PC exerts a stabilizing effect on NF in liposomes. DLS has indicated an increase in the size of NF encapsulated liposomes with an increase in PC concentration. Similar to RF the quenching of excited singlet state of NF by PC indicated by a loss of fluorescence suggests an interaction between NF and PC to form a charge–transfer complex. It results in the reduction of NF to form [NF–] species which cause stabilization of NF in liposomal preparations. The entrapment efficiency of NF in liposomal preparations amounts to 41–56%. The mode of interaction of NF and PC is similar to that of RF and PC to cause stabilization of NF in liposomal preparations. Cyanocobalamin (B12) B12 is a relatively large molecule compared to RF and NF and its photochemical behavior in liposomes has also been studied. The values of kobs for the photolysis of B12 in liposomes have been found to be in the range 0.52–2.24 ×10–3 min–1, compared to that of 3.21×10–3 min–1 for B12 in aqueous solution (pH 5.0) and an entrapment efficiency in the range of 26.4–38.8%. In this case also a linear relation has been observed between the values of kobs and PC concentration with iii a negative slope indicating the influence of PC in inhibiting the rate of photolysis of B12. This also appears to be due to the involvement of a charge–transfer complex between B12 and PC that results in the stabilization of vitamin B12. The stabilization ratio of B12 in liposomal preparations has been determined as 1–6. The present study on the photolysis of RF, NF and B12 suggests that these drugs may be stabilized in liposomal preparations. The mode of stabilization involves the participation of a charge–transfer complex to cause the reduction of the drug to the species that have low susceptibility to photolysis. The values of the second–order rate constants for the photochemical interaction of RF, B12 and NF with PC are 1.48, 0.32 and 8.92×10–2 M–1 min–1, respectively, suggesting that PC exerts the greatest effect on the stabilization of RF, followed by those of B12 and NF. This could be due to the relative ease of electron donation from PC to the drug and charge–transfer complex formation between them. This would probably depend on the redox potentials of these drugs under the reaction conditions involved. On the basis of the results obtained in this study it may be suggested that such an approach could be useful in the stabilization of photoliable drugs in liposomal preparations.
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باب اول: قدرتی وسائل کا مطالعہ

قدرتی وسائل کا تعارف

فیروز اللغات میں قدرتی کے لغوی معنی " طبعی، فطری، اصلی، حقیقی، پیدائشی" [1] بیان کئے گئےہیں۔ جبکہ وسائل کا لفظ وسیلہ کی جمع ہے اس لئے فروز اللغات میں وسیلے کے لغوی معنی "وسیلے، واسطے"[2] کے بیان کئے گئے ہیں۔ علمی اردو لغت کے قدرتی کےلغوی معنی "قدرت سے منسوب، فطری، خلقی، پیدائشی، اصلی، ذاتی۔ "[3] بیان کئے گئے ہیں۔ جبکہ اردو لغت میں وسیلہ کے معنی "ذریعہ، واسطہ، سبب"[4] بیان کئے گئے ہیں۔

"البحث اللغوی عند العرب "میں قدرتی وسائل کو بیان کیا گیا ہے:

"المعجم مبوب بحسب ما في الكون كله من آثار في الأرض، وآيات في السماء وبكل ما تحمل الدنيا ويدب فيها من إنسان أو حيوان أو طير أو نبات، وما تحفل به بطنها من معدن، أو ينتأ فوقها من صخر"[5]

 کائنات میں زمین اہم قدرتی وسیلہ ہے جس پر انسان، جانور، پرندے، حیوانات اور دوسری اشیاء پائی جاتی ہیں۔ زمین کا پیٹمعدنیات سے بھرا ہوا ہے جبکہ دوسرے قدرتی وسائل زمین کی سطح پر پھیلی ہوئے ہیں۔ پانی، ہوا، خوراک اور روشنی و حرارت جیسےقدرتی وسائل کرہ ارض پر جانداروں کی حیات و بقا کے لئے بنیادی ضروریاتِ زندگی ہیں۔

 معروف مسلم فلاسفر امام غزالیؒ لکھتے ہیں:

" الأموال إنما تحصل من المعادن والنبات والحيوان"[6]

امام غزالی ؒ کے مطابق انسان کی معاشی ضروریات کرہ ارض پر پائی جانے والے قدرتی وسائل معدنیات، نباتات اور حیوانات سے پوری ہوتی ہیں۔ پس ثابت ہوا کہ دنیا کا پورا معاشی نظام تین بنیادی اور بڑے قدرتی وسائل معدنیات، نباتات اور حیوانات پر انحصار رکھتا ہے۔

بھارت کا ماہر ماحولیات A R Agwᾱn لکھتا ہے:

اسلام کا قانون سدذرائع اور اصلاح معاشرہ

Forming Islamic Society, a dutiful, lawful and culturly civilized society; religion of Islam presents many rules and laws. One those beautiful laws are Saddu Zara’i (prevention law from means, leading to prevented things in Islam). It helps stop unlawful activities by using legal means. If a cultural change drives Muslim away from the objectives of Islam, it will alter that person to Islamic law. In betterment of society andmorality and ethics of people, Saddu Zara’i has great influence. If this law of Sharia leads to something good without damaging the objectives of Sharia, it will be accepted. This article discusses concept, meaning and the study of Saddu Zara’i and its importance and influence in reforming social and ethical values of society. It is illustrated by example of various scholars of Islam. It also discusses the different opinions of Islamic Jurisprudential scholars on Saddu Zara’i. The authors of this paper, then, deliberate its use for its applications to solve the new problems being faced by the Muslims across the world related to ethics and reformation of society.

Suppression of Isoproterenol Induced Mi Through Combination Plant Therapy

Myocardial infarction (MI) was induced in rabbits by isoproterenol (85 mg/Kg body wt.). Five indigenous plants Allium sativum, Allium cepa, Zingiber officinale, Terminalia arjuna and Moringa oleifera were selected to prepare 64 possible combinations. Native as well as gemmomodified plant extracts of selected parts of Allium sativum, Allium cepa, Zingiber officinale, Terminalia arjuna and Moringa oleifera were prepared and combined to make treatment combinations against isoproterenol induced MI. Both the preventive & curative ways of treatment were employed on different treatment groups prepared by placing 140 healthy rabbits in specific groups. The effects of different plant combinations were assessed through the serum level of biochemical markers at calculated time intervals. Plant combinations decreased the isoproterenol induced rise in biomarkers as CK-MB, LDH, ALT, AST, ALP, total cholesterol, triglycerides, glucose, urea and uric acid to the level of these parameters in C1 and C2 control groups as compared to C3 (isoproterenol group). Sharp decrease in the level of enzymes/parameters was observed in class III (GP: combination of gemmo extracts used in preventive way) followed by class I (GC: combination of gemmomodified extracts used in curative way). Out of 64 combinations of five plants, 16GP (gemmomodified combination of Allium sativum, Allium cepa, Zingiber officinale, Terminalia arjuna and Moringa oleifera used in preventive mode) gave the excellent cardioprotective potential followed by 16GC (gemmomodified combination of Allium sativum, Allium cepa, Zingiber officinale, Terminalia arjuna and Moringa oleifera used in curative mode) throughout the study. Findings were further strengthened by gross and histopathological studies. Isoproterenol also affected the organs other than heart as liver, kidney and lungs. There was no genotoxicity imposed by any of the combinations as biomonitored by Comet Assay. GC-MS analysis revealed the presence of 4-(4-hydroxy-3methoxyphenyl)-2-butanone, n- Hexadecanoic acid and oleic acid as actively curing constituents with antioxidant and cardioprotective potential in 16G. The 16G (gemmomodified combination of Allium sativum, Allium cepa, Zingiber officinale, Terminalia arjuna and Moringa oleifera) was further applied on human volunteers suffering from chronic tachycardia and hypertension. There was a significant decrease in pulse rate and blood pressure in the patients who were treated with 16G in combination with inderal (inderal+16G) as compared to patients who were treated with inderal and 16G separately.