G. Kaur, R. Kaur, Jasmeet Kaur, Harleen Singh, H. Kumar, Pooja Sharma
Abstract The study aims to scrutinize the mixed micellization and interfacial behavior of two 1-alkyl-3-butylimidazolium based surface-active ionic liquids (SAILs) i.e., 1-decyl-3-butylimidazolium bromide [C10bim][Br] and 1-tetradecyl-3-butylimidazolium bromide [C14bim][Br] under the influence of streptomycin sulphate (SS) drug in 5 mM concentration in aqueous media. Imidazolium-based SAILs have unique physicochemical properties and greater surface activity than conventional surfactants, which allows them to increase drug permeability, making them better drug carriers than currently available formulations. To fully utilize [C14bim][Br] and [C10bim][Br] in drug delivery applications, deep insight into the interactions occurring in the mixed micellar [C10bim][Br]/[C14bim][Br] systems in the drug’s presence are necessary to be examined. Thus, the study is conducted using conductivity and surface tension measurement techniques to fully exploit the self-assembly, micellization behavior and interactions occurring in the pure and mixed micellar system of [C10bim][Br]/[C14bim][Br] in water and 5 mM of SS solution in aqueous media. For this, various thermodynamic, surface-active and mixed micellar parameters of micellization have been calculated and analyzed with respect to change in mole fraction, temperature and addition of SS in solution.
{"title":"Analyzing the modulations induced in the mixed micellar behavior of 1-alkyl-3-butylimidazolium based surface-active ionic liquids with an antibiotic drug in aqueous media","authors":"G. Kaur, R. Kaur, Jasmeet Kaur, Harleen Singh, H. Kumar, Pooja Sharma","doi":"10.1515/tsd-2023-2512","DOIUrl":"https://doi.org/10.1515/tsd-2023-2512","url":null,"abstract":"Abstract The study aims to scrutinize the mixed micellization and interfacial behavior of two 1-alkyl-3-butylimidazolium based surface-active ionic liquids (SAILs) i.e., 1-decyl-3-butylimidazolium bromide [C10bim][Br] and 1-tetradecyl-3-butylimidazolium bromide [C14bim][Br] under the influence of streptomycin sulphate (SS) drug in 5 mM concentration in aqueous media. Imidazolium-based SAILs have unique physicochemical properties and greater surface activity than conventional surfactants, which allows them to increase drug permeability, making them better drug carriers than currently available formulations. To fully utilize [C14bim][Br] and [C10bim][Br] in drug delivery applications, deep insight into the interactions occurring in the mixed micellar [C10bim][Br]/[C14bim][Br] systems in the drug’s presence are necessary to be examined. Thus, the study is conducted using conductivity and surface tension measurement techniques to fully exploit the self-assembly, micellization behavior and interactions occurring in the pure and mixed micellar system of [C10bim][Br]/[C14bim][Br] in water and 5 mM of SS solution in aqueous media. For this, various thermodynamic, surface-active and mixed micellar parameters of micellization have been calculated and analyzed with respect to change in mole fraction, temperature and addition of SS in solution.","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"60 1","pages":"338 - 355"},"PeriodicalIF":1.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46956571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The impact of different concentrations of sodium carboxymethyl cellulose (NaCMC) on the micellization process in cationic, ester-functionalized, ethyl-substituted imidazolium-based surface-active ionic liquids (SAILs) ([C n Eeim]Br where, n = 12, 14, 16) were investigated using specific conductivity and surface tension measurements at 298 K. The study focused on determining the critical micelle concentration (CMC) of the three pure SAILs and their mixtures with NaCMC to evaluate various thermodynamic and interfacial parameters. The results showed that the CMC values decreased significantly with increasing hydrophobicity of the SAILs, while the CMC increased with a gradual increase in the NaCMC mole fraction in the SAIL–NaCMC mixed systems. It was observed that the excess free energy of micellization ( ∆ G e x m ${{increment}G}_{ex}^{m}$ ) and the minimum free energy of surface at equilibrium ( ∆ G min s ${{increment}G}_{mathrm{min}}^{s}$ ) exhibited an opposite behaviour, indicating that the formed mixed micelles were stable while the formed surface was unstable. The results of this study are useful for evaluating the properties of SAIL–NaCMC mixed systems to improve and better understand their applications in the food, medical and cosmetic industries.
摘要使用298℃下的比电导率和表面张力测量，研究了不同浓度的羧甲基纤维素钠（NaCMC）对阳离子、酯官能化、乙基取代咪唑基表面活性离子液体（SAILs）（[Cn-Eeim]Br，其中n=12，14，16）中胶束化过程的影响 K.本研究的重点是确定三种纯SAIL及其与NaCMC的混合物的临界胶束浓度（CMC），以评估各种热力学和界面参数。结果表明，在SAIL–NaCMC混合体系中，CMC值随着SAIL疏水性的增加而显著降低，而CMC值随着NaCMC摩尔分数的逐渐增加而增加。观察到胶束化的过量自由能（∆G e x m$｛｛increment｝G｝_｛ex｝^｛m｝$）和平衡时表面的最小自由能（⏴G min s$｛增量｝G}_｛mathrm｛min｝｝^｝s｝美元）表现出相反的行为，表明形成的混合胶束是稳定的，而形成的表面是不稳定的。本研究的结果有助于评估SAIL–NaCMC混合体系的性能，以改进和更好地了解其在食品、医疗和化妆品行业的应用。
{"title":"Investigation of aggregation behavior and surface properties of cationic surface-active ionic liquids and sodium carboxymethylcellulose mixed systems","authors":"Safiya Ahsan, Arun Dhanagar, A. Shaheen","doi":"10.1515/tsd-2022-2487","DOIUrl":"https://doi.org/10.1515/tsd-2022-2487","url":null,"abstract":"Abstract The impact of different concentrations of sodium carboxymethyl cellulose (NaCMC) on the micellization process in cationic, ester-functionalized, ethyl-substituted imidazolium-based surface-active ionic liquids (SAILs) ([C n Eeim]Br where, n = 12, 14, 16) were investigated using specific conductivity and surface tension measurements at 298 K. The study focused on determining the critical micelle concentration (CMC) of the three pure SAILs and their mixtures with NaCMC to evaluate various thermodynamic and interfacial parameters. The results showed that the CMC values decreased significantly with increasing hydrophobicity of the SAILs, while the CMC increased with a gradual increase in the NaCMC mole fraction in the SAIL–NaCMC mixed systems. It was observed that the excess free energy of micellization ( ∆ G e x m ${{increment}G}_{ex}^{m}$ ) and the minimum free energy of surface at equilibrium ( ∆ G min s ${{increment}G}_{mathrm{min}}^{s}$ ) exhibited an opposite behaviour, indicating that the formed mixed micelles were stable while the formed surface was unstable. The results of this study are useful for evaluating the properties of SAIL–NaCMC mixed systems to improve and better understand their applications in the food, medical and cosmetic industries.","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"60 1","pages":"356 - 367"},"PeriodicalIF":1.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45825325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. A. Aziz, R. Yusoff, N. G. Cheng, Z. Idris, Nur Aainaa Syahirah Ramli
Abstract A heterogeneous transesterification over a Zn-doped CaO catalyst was developed as a new alternative route to conventional homogeneous catalysis for the production of N-methyldiethanolamine-based esterquats. In this study, the optimum heterogeneous transesterification conditions for the production of N-methyldiethanolamine di-ester, a precursor of esterquats, in high yield were determined. At a temperature of 143 °C, a vacuum of 288 mbar, a molar ratio of 2:1 (methyl ester:N-methyldiethanolamine) and a catalyst dosage of 6 %, a maximum N-methyldiethanolamine di-ester yield of 83 % was obtained. The reused catalyst showed consistent activity in three consecutive runs, demonstrating the robustness of the Zn-doped CaO catalyst in the transesterification process. This route can reduce production costs due to the reusability of the catalyst and the elimination of water consumption in the neutralisation process for catalyst removal.
{"title":"Production of high content of N-methyldiethanolamine di-ester via heterogeneous transesterification","authors":"H. A. Aziz, R. Yusoff, N. G. Cheng, Z. Idris, Nur Aainaa Syahirah Ramli","doi":"10.1515/tsd-2022-2494","DOIUrl":"https://doi.org/10.1515/tsd-2022-2494","url":null,"abstract":"Abstract A heterogeneous transesterification over a Zn-doped CaO catalyst was developed as a new alternative route to conventional homogeneous catalysis for the production of N-methyldiethanolamine-based esterquats. In this study, the optimum heterogeneous transesterification conditions for the production of N-methyldiethanolamine di-ester, a precursor of esterquats, in high yield were determined. At a temperature of 143 °C, a vacuum of 288 mbar, a molar ratio of 2:1 (methyl ester:N-methyldiethanolamine) and a catalyst dosage of 6 %, a maximum N-methyldiethanolamine di-ester yield of 83 % was obtained. The reused catalyst showed consistent activity in three consecutive runs, demonstrating the robustness of the Zn-doped CaO catalyst in the transesterification process. This route can reduce production costs due to the reusability of the catalyst and the elimination of water consumption in the neutralisation process for catalyst removal.","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"60 1","pages":"394 - 408"},"PeriodicalIF":1.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45759070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-20eCollection Date: 2023-07-01DOI: 10.1093/haschl/qxad011
Qiwei Wilton Sun, Joseph J Cavallo, Howard P Forman
Following the recent expansion of the Open Payments program to include advanced-practice clinicians (APCs) as covered recipients, we characterized the geographical distribution of general industry payments to nurse practitioners and physician assistants using the Open Payments database. The number and dollar value of payments, as well as the average and median payment amount earned per provider, varied by state. However, a significantly higher proportion of APCs received payments in states with more restrictive scope-of-practice laws. Understanding how and why payments to APCs vary by state can elucidate how industry-APC relationships are related to changing scope-of-practice and state-specific transparency/disclosure laws, informing future legislation.
{"title":"Geographic distribution of general industry payments to advanced-practice clinicians.","authors":"Qiwei Wilton Sun, Joseph J Cavallo, Howard P Forman","doi":"10.1093/haschl/qxad011","DOIUrl":"10.1093/haschl/qxad011","url":null,"abstract":"<p><p>Following the recent expansion of the Open Payments program to include advanced-practice clinicians (APCs) as covered recipients, we characterized the geographical distribution of general industry payments to nurse practitioners and physician assistants using the Open Payments database. The number and dollar value of payments, as well as the average and median payment amount earned per provider, varied by state. However, a significantly higher proportion of APCs received payments in states with more restrictive scope-of-practice laws. Understanding how and why payments to APCs vary by state can elucidate how industry-APC relationships are related to changing scope-of-practice and state-specific transparency/disclosure laws, informing future legislation.</p>","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"33 1","pages":"qxad011"},"PeriodicalIF":0.0,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10986193/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89594382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Ionic liquids (IL) have attained immense interest as substitutes for conventionally available surfactants because of their exceptionally favorable physicochemical properties. Most synthesized IL surfactants are not environmentally benign, and even utilizing high concentration, they form unstable micelles. In this regard, we have synthesized biocompatible and halogen free choline based ionic liquids by varying anions (choline oleate and cholinium bis(2-ethylhexyl) sulfosuccinate) and further investigated their micellization behavior in presence of the drug Cetrizine dihydrochloride. Characterizations of these synthesized ionic liquids were performed utilizing 1HNMR spectroscopy. The thermodynamic investigation and determination of various surface-active parameters were based on tensiometry and conductometric titrations. The CMC value of choline oleate ([CHO][Ole]) was found to be lower than that of [Cho][AOT] and thus it has a better surface activity. The thermodynamic parameters (ΔGm0${{Delta}G}_{m}^{0}$, ΔHm0${{Delta}H}_{m}^{0}$, and ΔSm0${{Delta}S}_{m}^{0}$) signifies spontaneous, stable, exothermic and entropy driven nature of micellization process. The various interfacial and surface parameters have been evaluated employing tensiometry. These environmentally friendly ionic liquids have been utilized as substitute for conventional surfactants including their applications in biology and pharmaceutical industries.
{"title":"Thermodynamics and micellization behavior of choline based ionic liquids in presence of drug Cetrizine dihydrochloride","authors":"Pooja Sharma, J. Kaur, R. Kaur, H. Kumar, G. Kaur","doi":"10.1515/tsd-2023-2506","DOIUrl":"https://doi.org/10.1515/tsd-2023-2506","url":null,"abstract":"Abstract Ionic liquids (IL) have attained immense interest as substitutes for conventionally available surfactants because of their exceptionally favorable physicochemical properties. Most synthesized IL surfactants are not environmentally benign, and even utilizing high concentration, they form unstable micelles. In this regard, we have synthesized biocompatible and halogen free choline based ionic liquids by varying anions (choline oleate and cholinium bis(2-ethylhexyl) sulfosuccinate) and further investigated their micellization behavior in presence of the drug Cetrizine dihydrochloride. Characterizations of these synthesized ionic liquids were performed utilizing 1HNMR spectroscopy. The thermodynamic investigation and determination of various surface-active parameters were based on tensiometry and conductometric titrations. The CMC value of choline oleate ([CHO][Ole]) was found to be lower than that of [Cho][AOT] and thus it has a better surface activity. The thermodynamic parameters (ΔGm0${{Delta}G}_{m}^{0}$, ΔHm0${{Delta}H}_{m}^{0}$, and ΔSm0${{Delta}S}_{m}^{0}$) signifies spontaneous, stable, exothermic and entropy driven nature of micellization process. The various interfacial and surface parameters have been evaluated employing tensiometry. These environmentally friendly ionic liquids have been utilized as substitute for conventional surfactants including their applications in biology and pharmaceutical industries.","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"60 1","pages":"312 - 327"},"PeriodicalIF":1.0,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44400236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Methyl ester sulfonate (MES) is considered as an efficient and novel surfactant used as main active ingredient in cleansing products. MES is often produced via sulfonation of methyl ester (ME) with sulfonating agent. In this study, ME was synthesized from used cooking oil (UCO) via transesterification and then sulfonated to produce MES using two different sulfonating agents (chlorosulfonic acid (CSA) and sodium bisulfite (NaHSO3)). The influence of various factors (temperature, sulfonating agent/ME molar ratio and time) on MES yield was investigated. Analysis of optimal MES samples was carried out using different techniques (GC-FID, FTIR and 1H NMR). The maximum MES yield of 88.2 % was achieved with CSA/ME molar ratio of 1.2:1 at 70 °C for 3 h while the highest MES yield of 79.4 % was obtained with NaHSO3/ME molar ratio of 1.2:1 at 90 °C for 3 h. FTIR and 1H NMR analyses revealed the presence of methyl (CH2− asymmetric and CH2− symmetric stretching vibrations), esters (C=O, C–O, and O–CH3), and sulfonate (S=O) groups in MESCSA and MESNaHSO3 samples, thereby affirming the desired product. Surface tension analysis showed that the MESCSA and MESNaHSO3 have low critical micelle concentrations of 0.079 g/L and 0.14 g/L, respectively while the corresponding surface tensions were 51.9 mN/m and 30.94 mN/m for MESCSA and MESNaHSO3 respectively.
{"title":"Comparing the performances of different sulfonating agents in sulfonation of methyl esters synthesized from used cooking oil","authors":"A. Yusuff, Favour B. Bode‐Olajide","doi":"10.1515/tsd-2023-2513","DOIUrl":"https://doi.org/10.1515/tsd-2023-2513","url":null,"abstract":"Abstract Methyl ester sulfonate (MES) is considered as an efficient and novel surfactant used as main active ingredient in cleansing products. MES is often produced via sulfonation of methyl ester (ME) with sulfonating agent. In this study, ME was synthesized from used cooking oil (UCO) via transesterification and then sulfonated to produce MES using two different sulfonating agents (chlorosulfonic acid (CSA) and sodium bisulfite (NaHSO3)). The influence of various factors (temperature, sulfonating agent/ME molar ratio and time) on MES yield was investigated. Analysis of optimal MES samples was carried out using different techniques (GC-FID, FTIR and 1H NMR). The maximum MES yield of 88.2 % was achieved with CSA/ME molar ratio of 1.2:1 at 70 °C for 3 h while the highest MES yield of 79.4 % was obtained with NaHSO3/ME molar ratio of 1.2:1 at 90 °C for 3 h. FTIR and 1H NMR analyses revealed the presence of methyl (CH2− asymmetric and CH2− symmetric stretching vibrations), esters (C=O, C–O, and O–CH3), and sulfonate (S=O) groups in MESCSA and MESNaHSO3 samples, thereby affirming the desired product. Surface tension analysis showed that the MESCSA and MESNaHSO3 have low critical micelle concentrations of 0.079 g/L and 0.14 g/L, respectively while the corresponding surface tensions were 51.9 mN/m and 30.94 mN/m for MESCSA and MESNaHSO3 respectively.","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"60 1","pages":"277 - 285"},"PeriodicalIF":1.0,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41905109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Ali, Sarzamin Khan, Samrein Ahmed, Serab Khan, H. Ali, Raiz Ullah Shafiullah, M. Shah, Z. A. Shah
Abstract In order to improve the solubility and bioavailability of poorly water-soluble drugs, the synthesis of cost-effective nonionic surfactants has been the subject of greater scientific interest. The present study focuses on the synthesis of sulfonyl chloride derivatives as nonionic surfactants (surfactant 1 and surfactant 2) and their evaluation for the preparation of a clarithromycin-loaded niosomal drug delivery system. Surfactants 1 and 2 were characterised by EI-MS and 1H NMR spectroscopy. The shape and size of the drug-loaded niosomal vesicles from the synthesised surfactants were examined by atomic force microscopy (AFM) and revealed a round morphology with an average size of (230.8 ± 2.35) nm and (248.1 ± 2.54) nm for the vesicles of surfactant 1 and surfactant 2, respectively. The zeta potential of surfactant 1-based niosomal vesicles was (– 7.70 ± 1.00) mV and that of surfactant 2 was (−14.6 ± 1.08) mV. The lower zeta potential values for surfactant 1 and surfactant 2-based niosomal vesicles showed that these vesicles were neutral and relatively stable. The vesicles of surfactant 1 and 2 have a capacity to entrap the drug of about (62 ± 2.26) % and (69.67 ± 3.23) %, respectively. The vesicles of surfactant 1 released the largest amount of drug, i.e. (70.00 ± 2.45) % at pH 1.2. Biocompatibility in human blood and toxic effects on various cell lines were also studied for surfactants 1 and 2, and they were found to be biocompatible and non-cytotoxic.
{"title":"Synthesis of non-ionic surfactants nano-vesicles for clarithromycin oral delivery","authors":"I. Ali, Sarzamin Khan, Samrein Ahmed, Serab Khan, H. Ali, Raiz Ullah Shafiullah, M. Shah, Z. A. Shah","doi":"10.1515/tsd-2022-2476","DOIUrl":"https://doi.org/10.1515/tsd-2022-2476","url":null,"abstract":"Abstract In order to improve the solubility and bioavailability of poorly water-soluble drugs, the synthesis of cost-effective nonionic surfactants has been the subject of greater scientific interest. The present study focuses on the synthesis of sulfonyl chloride derivatives as nonionic surfactants (surfactant 1 and surfactant 2) and their evaluation for the preparation of a clarithromycin-loaded niosomal drug delivery system. Surfactants 1 and 2 were characterised by EI-MS and 1H NMR spectroscopy. The shape and size of the drug-loaded niosomal vesicles from the synthesised surfactants were examined by atomic force microscopy (AFM) and revealed a round morphology with an average size of (230.8 ± 2.35) nm and (248.1 ± 2.54) nm for the vesicles of surfactant 1 and surfactant 2, respectively. The zeta potential of surfactant 1-based niosomal vesicles was (– 7.70 ± 1.00) mV and that of surfactant 2 was (−14.6 ± 1.08) mV. The lower zeta potential values for surfactant 1 and surfactant 2-based niosomal vesicles showed that these vesicles were neutral and relatively stable. The vesicles of surfactant 1 and 2 have a capacity to entrap the drug of about (62 ± 2.26) % and (69.67 ± 3.23) %, respectively. The vesicles of surfactant 1 released the largest amount of drug, i.e. (70.00 ± 2.45) % at pH 1.2. Biocompatibility in human blood and toxic effects on various cell lines were also studied for surfactants 1 and 2, and they were found to be biocompatible and non-cytotoxic.","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"60 1","pages":"328 - 337"},"PeriodicalIF":1.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42584624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Srivastava, Ruchi Singh, N. Srivastava, R. Naik
Abstract The kinetic investigation of Ru(III) promoted oxidation of L-phenylalanine (L-PheAla) by [Fe(CN)6]3− has been performed in anionic sodium dodecyl sulfate (SDS) micellar medium by recording the decrease in absorbance at 420 nm corresponding to [Fe(CN)6]3− using an UV–visible spectrophotometer. Using the pseudo-first-order condition, the course of the reaction was studied as a function of [Fe(CN)63−], ionic strength, [OH−], [SDS], [Ru3+], [L-PheAla] and temperature by changing one variable at a time. The results exhibit that [OH−], [SDS], and [L-PheAla] are the crucial parameters that have an appreciable influence on the reaction rate. The reaction exhibits first-order kinetics in concentration ranges of Ru(III), [Fe(CN)6]3− and at low [L-PheAla] and [OH−] concentrations. The incremental trend observed in the reaction rate with electrolyte concentration shows a positive salt effect. The reaction rate is almost 10 times faster in SDS micellar medium than in aqueous medium. [Fe(CN)6]3− has no appreciable effect on the CMC of SDS, since the polar head of SDS and [Fe(CN)6]3− are both negatively charged. The K+ obtained from K3[Fe(CN)6] and KNO3 decreases the repulsion between the negatively charged heads of the surfactant molecules, which decreases the CMC of SDS. The activation parameters also support the outer-sphere electron transfer mechanism.
{"title":"Kinetic study of Ru(III) – catalyzed oxidation of L-phenylalanine by hexacyanoferrate(III) in an anionic surfactant medium","authors":"A. Srivastava, Ruchi Singh, N. Srivastava, R. Naik","doi":"10.1515/tsd-2022-2477","DOIUrl":"https://doi.org/10.1515/tsd-2022-2477","url":null,"abstract":"Abstract The kinetic investigation of Ru(III) promoted oxidation of L-phenylalanine (L-PheAla) by [Fe(CN)6]3− has been performed in anionic sodium dodecyl sulfate (SDS) micellar medium by recording the decrease in absorbance at 420 nm corresponding to [Fe(CN)6]3− using an UV–visible spectrophotometer. Using the pseudo-first-order condition, the course of the reaction was studied as a function of [Fe(CN)63−], ionic strength, [OH−], [SDS], [Ru3+], [L-PheAla] and temperature by changing one variable at a time. The results exhibit that [OH−], [SDS], and [L-PheAla] are the crucial parameters that have an appreciable influence on the reaction rate. The reaction exhibits first-order kinetics in concentration ranges of Ru(III), [Fe(CN)6]3− and at low [L-PheAla] and [OH−] concentrations. The incremental trend observed in the reaction rate with electrolyte concentration shows a positive salt effect. The reaction rate is almost 10 times faster in SDS micellar medium than in aqueous medium. [Fe(CN)6]3− has no appreciable effect on the CMC of SDS, since the polar head of SDS and [Fe(CN)6]3− are both negatively charged. The K+ obtained from K3[Fe(CN)6] and KNO3 decreases the repulsion between the negatively charged heads of the surfactant molecules, which decreases the CMC of SDS. The activation parameters also support the outer-sphere electron transfer mechanism.","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"60 1","pages":"376 - 386"},"PeriodicalIF":1.0,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43820630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Richa Mahesh Natekar, C. E. M. DCruz, L R Amruth Kumar, P. Bhide, R. Shirodkar
Abstract Felodipine is a dihydropyridine calcium channel blocker commonly used for the treatment of mild to moderate hypertension and angina pectoris. Felodipine undergoes extensive hepatic first pass metabolism resulting in low oral bioavailability of 15 %. The aim of this study is to develop a formulation of nanovesicular Spanlastics to improve the transdermal delivery of felodipine and solve the problem of low bioavailability. The felodipine-loaded Spanlastics were prepared using the ethanol injection method with Span 60 as surfactant and Tween 80, which provides elasticity to the vesicles, according to the 23 factorial design using Design Expert® Software version 13. The solution that had the highest desirability was optimized. The final five runs were incorporated into a gel base and evaluated for in vitro drug release, spreadability and viscosity. Stability studies were conducted over a period of 3 months. The formulated Spanlastics had a particle size in the range of (132–155) nm and an entrapment efficiency in the range of (80–94) %. The final five runs were found to have optimum characteristics. Differential scanning calorimetry, X-ray diffraction studies and Fourier transform infrared studies were performed to ensure the encapsulation of the drug in the nanovesicles. The developed hydrogel showed in vitro drug release in the range of (80–94) % and the formulation was found to be stable after a period of 3 months. The optimized formula comprised of Span 60 and Tween 80 in ratio of 8:2. Overall, the results confirmed that Spanlastics loaded with felodipine proved to be superior nanocarriers for transdermal delivery of felodipine.
{"title":"Felodipine-loaded Spanlastics: superior nanocarriers for transdermal delivery","authors":"Richa Mahesh Natekar, C. E. M. DCruz, L R Amruth Kumar, P. Bhide, R. Shirodkar","doi":"10.1515/tsd-2022-2483","DOIUrl":"https://doi.org/10.1515/tsd-2022-2483","url":null,"abstract":"Abstract Felodipine is a dihydropyridine calcium channel blocker commonly used for the treatment of mild to moderate hypertension and angina pectoris. Felodipine undergoes extensive hepatic first pass metabolism resulting in low oral bioavailability of 15 %. The aim of this study is to develop a formulation of nanovesicular Spanlastics to improve the transdermal delivery of felodipine and solve the problem of low bioavailability. The felodipine-loaded Spanlastics were prepared using the ethanol injection method with Span 60 as surfactant and Tween 80, which provides elasticity to the vesicles, according to the 23 factorial design using Design Expert® Software version 13. The solution that had the highest desirability was optimized. The final five runs were incorporated into a gel base and evaluated for in vitro drug release, spreadability and viscosity. Stability studies were conducted over a period of 3 months. The formulated Spanlastics had a particle size in the range of (132–155) nm and an entrapment efficiency in the range of (80–94) %. The final five runs were found to have optimum characteristics. Differential scanning calorimetry, X-ray diffraction studies and Fourier transform infrared studies were performed to ensure the encapsulation of the drug in the nanovesicles. The developed hydrogel showed in vitro drug release in the range of (80–94) % and the formulation was found to be stable after a period of 3 months. The optimized formula comprised of Span 60 and Tween 80 in ratio of 8:2. Overall, the results confirmed that Spanlastics loaded with felodipine proved to be superior nanocarriers for transdermal delivery of felodipine.","PeriodicalId":22258,"journal":{"name":"Tenside Surfactants Detergents","volume":"60 1","pages":"296 - 311"},"PeriodicalIF":1.0,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43470034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：