Synthesis of indium phthalocyanines for photodynamic antimicrobial chemotherapy and photo-oxidation of pollutants
- Authors: Sindelo, Azole
- Date: 2019
- Subjects: Phthalocyanines , Azo dyes , Indium compounds , Photochemotherapy , Nanoparticles , Photodegradation , Pollutants , Water -- Purification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67581 , vital:29116
- Description: Indium (III) octacarboxyl phthalocyanine (ClInOCPc) alone and when conjugated to magnetic nanoparticles (MNP-ClInOCPc), 2(3),9(10),16(17),23(24)-octapyridylsulfanyl phthalocyaninato chloroindium (III) (ClInOPyPc) and its quaternized derivative 2(3),9(10),16(17),23(24)-octamethylpyridylsulfanyl phthalocyaninato chloroindium (III) (ClInOMePyPc) were synthesized. All Pcs were tested for both photodynamic antimicrobial chemotherapy (PACT) of an unknown water sample and photo-degradation of methyl red (MR). The singlet quantum yield (ΦΔ) for the ClInOCPc and MNP-ClInOCPc in PAN polymer fibers were 0.36 and 0.20 respectively using ADMA as a quencher in water. The photo-inactivation of bacteria in a water sample with unknown microbes was tested, with the MNP-ClInOCPc inactivating 90.6 % of the microbes and the ClInOCPc with 84.8 %. When embedded to the polymer, there was 48% bacterial clearance for ClInOCPc and 64% clearance for the MNP-ClInOCPc. The rate of degradation of MR increased with decrease of the MR concentration, with the MNP-ClInOCPc having the fastest rate. For ClInOPyPc and ClInOMePyPc, the singlet quantum yields were 0.46 and 0.33 in dimethylformamide (DMF), respectively. The PACT activity of ClInOMePyPc (containing 8 positive charges) was compared to those of 9(10),16(17),23(24)-tri-N-methyl-4-pyridylsulfanyl-2(3)-(4-aminophenoxy) phthalocyaninato chloro indium (III) triiodide (1) (containing 3 positive charges) and 2-[4-(N-methylpyridyloxy) phthalocyaninato] chloroindium (III) iodide (2) (containing 4 positive charges). When comparing ClInOMePyPc, 1 and 2, the largest log reduction for E. coli were obtained for complex 2 containing four positive charges hence showing it is not always the charge that determines the PACT activity, but the bridging atom in the phthalocyanine plays a role.
- Full Text:
- Date Issued: 2019
- Authors: Sindelo, Azole
- Date: 2019
- Subjects: Phthalocyanines , Azo dyes , Indium compounds , Photochemotherapy , Nanoparticles , Photodegradation , Pollutants , Water -- Purification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67581 , vital:29116
- Description: Indium (III) octacarboxyl phthalocyanine (ClInOCPc) alone and when conjugated to magnetic nanoparticles (MNP-ClInOCPc), 2(3),9(10),16(17),23(24)-octapyridylsulfanyl phthalocyaninato chloroindium (III) (ClInOPyPc) and its quaternized derivative 2(3),9(10),16(17),23(24)-octamethylpyridylsulfanyl phthalocyaninato chloroindium (III) (ClInOMePyPc) were synthesized. All Pcs were tested for both photodynamic antimicrobial chemotherapy (PACT) of an unknown water sample and photo-degradation of methyl red (MR). The singlet quantum yield (ΦΔ) for the ClInOCPc and MNP-ClInOCPc in PAN polymer fibers were 0.36 and 0.20 respectively using ADMA as a quencher in water. The photo-inactivation of bacteria in a water sample with unknown microbes was tested, with the MNP-ClInOCPc inactivating 90.6 % of the microbes and the ClInOCPc with 84.8 %. When embedded to the polymer, there was 48% bacterial clearance for ClInOCPc and 64% clearance for the MNP-ClInOCPc. The rate of degradation of MR increased with decrease of the MR concentration, with the MNP-ClInOCPc having the fastest rate. For ClInOPyPc and ClInOMePyPc, the singlet quantum yields were 0.46 and 0.33 in dimethylformamide (DMF), respectively. The PACT activity of ClInOMePyPc (containing 8 positive charges) was compared to those of 9(10),16(17),23(24)-tri-N-methyl-4-pyridylsulfanyl-2(3)-(4-aminophenoxy) phthalocyaninato chloro indium (III) triiodide (1) (containing 3 positive charges) and 2-[4-(N-methylpyridyloxy) phthalocyaninato] chloroindium (III) iodide (2) (containing 4 positive charges). When comparing ClInOMePyPc, 1 and 2, the largest log reduction for E. coli were obtained for complex 2 containing four positive charges hence showing it is not always the charge that determines the PACT activity, but the bridging atom in the phthalocyanine plays a role.
- Full Text:
- Date Issued: 2019
The photodecomposition of different polymorphic forms of 1,4-dihydropyridine channel blockers
- Authors: Francis, Farzaana
- Date: 2011
- Subjects: Photodegradation , Nifedipine , Nimodipine , Dihydropyridine
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10378 , http://hdl.handle.net/10948/1496 , Photodegradation , Nifedipine , Nimodipine , Dihydropyridine
- Description: 1,4-Dihydropyridines (DHPs) are a classification of compounds used as calcium channel blockers in the treatment of various conditions. These compounds readily undergo photodegradation. The degradants produced have no pharmaceutical activity and render the drugs ineffective. DHPs also exhibit polymorphism. Nifedipine and Nimodipine are two such drugs. This study aimed to monitor the photodegradation of these two drugs and to establish the effect of particle size, polymorphism and β-Cyclodextrin (β-CD) on the rate of photodegradation. Different polymorphs (namely the amorphous and stable crystalline polymorphs) of the two drugs were prepared for use in the study. Mixtures of each drug with β-CD were also prepared for photostability studies. The mixtures were prepared in a 1:1 molar ratio. The rate of photodegradation was studied with a 500 W metal halide lamp in accordance to ICH guidelines. The study employed samples on a small scale where degradation was analysed with High Performance Liquid Chromatography, and also samples on a larger scale where degradation was monitored with Powder X-ray Diffraction. The two sets of results of observing the degradation process by two analytical techniques where compared in terms of their quantification methods. The extent of photodegradation was suitably modelled and fitted using the Avrami-Erofeyev kinetic equation. Smaller particle size showed increased photodegradation for Nimodipine; the effect was insignificant for Nifedipine however. For both drugs it was found that the amorphous polymorph underwent faster photodegradation. The study showed that β-CD caused an increase in photodegradation for both drugs under these experimental conditions.
- Full Text:
- Date Issued: 2011
- Authors: Francis, Farzaana
- Date: 2011
- Subjects: Photodegradation , Nifedipine , Nimodipine , Dihydropyridine
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10378 , http://hdl.handle.net/10948/1496 , Photodegradation , Nifedipine , Nimodipine , Dihydropyridine
- Description: 1,4-Dihydropyridines (DHPs) are a classification of compounds used as calcium channel blockers in the treatment of various conditions. These compounds readily undergo photodegradation. The degradants produced have no pharmaceutical activity and render the drugs ineffective. DHPs also exhibit polymorphism. Nifedipine and Nimodipine are two such drugs. This study aimed to monitor the photodegradation of these two drugs and to establish the effect of particle size, polymorphism and β-Cyclodextrin (β-CD) on the rate of photodegradation. Different polymorphs (namely the amorphous and stable crystalline polymorphs) of the two drugs were prepared for use in the study. Mixtures of each drug with β-CD were also prepared for photostability studies. The mixtures were prepared in a 1:1 molar ratio. The rate of photodegradation was studied with a 500 W metal halide lamp in accordance to ICH guidelines. The study employed samples on a small scale where degradation was analysed with High Performance Liquid Chromatography, and also samples on a larger scale where degradation was monitored with Powder X-ray Diffraction. The two sets of results of observing the degradation process by two analytical techniques where compared in terms of their quantification methods. The extent of photodegradation was suitably modelled and fitted using the Avrami-Erofeyev kinetic equation. Smaller particle size showed increased photodegradation for Nimodipine; the effect was insignificant for Nifedipine however. For both drugs it was found that the amorphous polymorph underwent faster photodegradation. The study showed that β-CD caused an increase in photodegradation for both drugs under these experimental conditions.
- Full Text:
- Date Issued: 2011
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