ALOE VERA EXTRACT STABILISED NANO SILVER- REDUCED GRAPHENE OXIDE NANO COMPOSITES AS VISIBLE LIGHT PHOTOCATALYST FOR OXIDATIVE DEGRADATIONS OF RANITIDINE HYDROCHLORIDE AND SODIUM DICLOFENAC IN AQUEOUS MEDIUM: A KINETIC STUDY

ALOE VERA EXTRACT STABILISED NANO SILVER- REDUCED GRAPHENE OXIDE NANO COMPOSITES AS VISIBLE LIGHT PHOTOCATALYST FOR OXIDATIVE DEGRADATIONS OF RANITIDINE HYDROCHLORIDE AND SODIUM DICLOFENAC IN AQUEOUS MEDIUM: A KINETIC STUDY

R. Vijayalakshmi *, J. Santhanalakshmi and J. Sangeetha

Department of Chemistry, Quaid E Millath Government College for Women, Annasalai, Chennai, Tamil Nadu, India.

ABSTRACT: Nano composites of reduced graphene oxide (rGO) and silver nanoparticles (AgNps) were prepared in this work, adopting green reaction conditions. Aloe vera plant extract was used as the stabilizing agent in the AgNps system and graphite precursor has been chosen for rGO preparation adopting mild hydrothermal and sonication methods. AgNps and AgNp–rGO Nano composites are characterized using UV-VIS SPR; powder XRD, HR-TEM and FE-SEM measurements. The catalytic ability of AgNp–rGO nano composites in the as-synthesized form has been confirmed by following the oxidative degradation of the two therapeutically potential drugs such as sodium diclofenac (NaDF) and ranitidine hydrochloride (RHCl) under visible light irradiation in aqueous medium at 25°C. Reaction kinetic parameters and the oxidant peroxo monosulfate (Na₂S₂O₅) effect in presence of AgNp–rGO nano-composites as the catalyst under visible light irradiation exhibited remarkable catalytic behavior in presence of visible light for the degradation of the two drug both in presence and absence of oxidant. However presence of oxidant enhanced the speed of drug degradations with AgNp–rGO nano composites and visible light. Among the two studied drugs, RHCl degraded quickly and also, efficiently mineralized compared to NaDF. Degradation or carcinogen NDMA was not observed and the two drugs are mineralized to near completion. The results are favourable towards the use of AgNp–rGO nano composite as a potential catalyst in AgNPs employed in the treatment of drug polluted waste waters.

Keywords: Aloe vera stabilized silver nano particles, Reduced graphene oxide nanocomposites, Visible light drug degradations, Oxidative mineralization, Ranitidine hydrochloride, Sodium diclofenac

INTRODUCTION: Immobilisation of transition metal nanoparticles into synergetic and extensively conjugated carboneous supports like graphene are exploited widely in reaction catalysis, photoactivity and electronic sensing cum conduction applications in current science ^1-6.

Recently research reports exists on graphene and its functionalized forms like graphene oxide (GO) and reduced graphene oxide(rGO) as suitable and strong supports for deposition of metal nano particles, resulting in multi-functional nano composites ^7-10.

Among many metal nano particles, sliver nano particles (AgNps) exhibit potential photo catalytic activity with photo sensing applications in and UV-visible radiations ranges ^11-15. In this work, AgNps are prepared in a green pathway ^16-17 using Aloe vera plant as the stabilising agent instead of synthetic polymeric substrates. Numerous biomolecules present in plant extract function as both reducing and stabilising agent during the synthesis of AgNps ^18-21. The as synthesised AgNps are characterized by UV-VIS SPR, and powder XRD measurement, using graphite powder, GO was synthesized adopting mild, and eco-friendlier hydro thermal process conditions followed by step wise GO formations and AgNps deposition. By doing so, literature reported procedures with minor modifications are adopted ^{22, 23}. The designed AgNps-rGO nano composites are subjected to HR-TEM and FE-SEM analysis. The applicability of AgNps-rGO nano composites as efficient photo sensing and photo catalytic agent in industrial waste waters treatment has been attempted on medicinal drug polluted waters. Environmental aquatic sources suffer severe damages such as reduced light penetration, lesser solubility of oxygen and other gases, and threatening of life systems etc, mainly due to pharmaceutical waste water effluents ^24-26. Pharmaceutical drugs possess synthetic complex organic structures that are difficult to self-degrade. In this work two potential therapeutically used drugs such as Ranitidine hydrochloride (RHCl) and Sodiumdiclofenac (NaDF) are chosen among the many existing drugs that cause severe water pollutions. RHCl is a histamine H₂- antagonist widely applied in the treatment of peptic ulcers and gastro oesophageal reflux diseases ^{27, 28}. RHCl prolonged leakage into environmental water bodies cause  eco – toxicity to aqua life systems and another dangerous risk of RHCl polluted waters, may be the formation of N-nitrosodimethylamine (NDMA)which is a potential carcinogen and its removal from waste waters is mostly weak and poor  ^{29, 30}. NaDF, belongs to a non-steroidal anti-inflammatory drug (NSAID) which is widely used as analgesic, antiarthritic and antirhenmatic ^{31, 32}. NaDF polluted water treatment needs efficient AOPs, due to its stability and slow removal of organic matter.

In Fig. 1 molecular structures of RHCl and NaDF are given. Photo catalytic oxidative degradation processes under UV or visible light irradiations involving designed nano composites materials may be used in the treatment of drugs polluted waters.

FIG. 1: MOLECULAR STRUCTURES OF RHCL AND NADF

In this work, AgNps-rGO nano composites are used as the photo catalyst to degrade the two chosen drugs RHCl and NaDF in presence of an oxidant sodium peroxo mono sulphate (Na₂S₂O₅) under visible light irradiation at 25°C. AgNps, due to the narrow band gap, in the presence of visible light and aerobic conditions, produce reactive oxygen species (ROS) such as OH and O₂ which are released in aqueous medium. These ROS, tend to react non selectively with drug molecules and mineralize completely in rapid pathways. Presence of rGO with AgNps, suppresses the photo electron and whole recombination and deactivation of OH radicals via forming H₂O₂ steps. Henceforth, adopting pseudo first order reaction conditions, the photo oxidative degradations are followed by recording the UV-spectra absorbance decrease with the time of progress of the reactions. The wave length maxima for RHCl is 313 nm and for NaDF is 280 nm respectively, are fixed for absorbance- time data of small aliquots drawn out at intervals of time. Also, the overall pseudo first order rate co-efficient (k) values and % mineralisation of the two drugs are found out. The results indicate that AgNps-rGO nano composite serves as an efficient photo catalyst in AOP for facile and complete mineralization of RHCl and NaDF in visible light.

EXPERIMENTAL: Sodium hydroxide pellets, silver nitrate (AgNO₃), sodium peroxo-monosuphate, graphite powder with particle size < 50 µm, 98% sulphuric acid, potassium permanganate and potassium nitrate were procured from Merck India. Ranitidine hydrochloride and Sodium diclofenac with 99% purity were purchased from Sigma-Aldrich. Fresh triply distilled water was used in all solution preparations.

Synthesis of Ag Nano particles (AgNps): Fresh and sliced Aloe Vera pieces (40gms ) were ground to a fine paste adding 50 ml of NaOH solution at pH = 6.0. The slimy solution was filtered and the clear filtrate was used 20 ml of 1 mM Ag NO₃ solution prepared in 0.1M KNO₃ solution was taken and 50 ml of Aloe vera extract solution was added drop wise  maintaining 40°C as the solution temperature with constant stirring for 90 minutes period of time. Formation of a lemon yellow coloured solution indicated the formation of AgNp.

Repeated ultra-centrifugations and washings of residue resulted in AgNp in wet condition. This procedure was repeated several times and the AgNp suspension in dilute (0.01M) KNO₃ solution was stored for size characterizations as reported earlier ^{33, 34, 35}. UV-Visible, SPR recorded showed a prominent peak at 405 nm confirming the presence of AgNp. Solid AgNp were collected after vacuum drying and stored in N₂ purged dark container.

Graphene oxide was synthesized from Graphite powder through improved Hummer’s method. The procedure followed being 30 ml of 9:1 (V/V) mixture of concentrated H₂SO₄ and H₃PO₄ was added to 1.5g of graphite powder and 9.0g of KMnO₄ with constant stirring for 12 hrs at 45°C. The reaction mixture was cooled to 25°C and added 5ml of 30% H₂O₂ to convert MnO₂ residue to soluble sulphate form. Excess (250ml) triple distilled water was added and stirred for1hr at 70°C. After cooling, the mixture was ultra-centrifuged several times with    repeated washings. The final solid was coagulated with ether solvent and dark brown crystalline GO was vacuum dried and stored in dark and N₂ purged container.

AgNp-rGO nano composites are prepared by carrying out a procedure with minor modification to the reported one 33. 50 mg powder of GO was dispersed into 100 ml of triple distilled water and ultrasonicated for 1 hr to form yellowish brown exfoliated GO sheets. To this slurry, 30 mg of AgNps mixed in 50ml of 0.01 M KNO₃ was added slowly under constant stirring at 60°C as the medium temperature of 1hr time period. The black precipitate (AgNp-rGO) obtained was washed several times to remove any unbound AgNps and other impurities. Vacuum dried AgNp-rGO nano composites are stored for further use.

Spectra Measurements and Size Characterization: All UV-visible spectra were recorded on a Schimadzu (UV-1650 Pc) spectrometer fitted with thermostat for temperature control. Powder XRD patterns were obtained using Bruker diffractometer D8 Advance with CuKα radiation. HR-TEM measurements were carried out using TEM Hitachi Technai G20 and for FE-SEM, Hitachi FESEM S4800 microscopes respectively.

Reaction Photo Catalysis: 50 ml of 1 mm drug solution was left in dark for 3hrs to reach equilibrium and loaded into glass Pyrex cylindrical photo reactor equipped with continuous N2 or air purging, magnetic stirrer and a temperature controller. The photo reactor was irradiated by 20 series white light LEDs (nominal power 6W) with wave length emission in the visible range 400-800 mm. 50ml of 0.1M Na₂S₂O₅ cool solution was added and N2 purged after each addition of any component into the reaction vessel.

After the addition of AgNp-rGO nano composite catalyst, small aliquots of the drug solution was drawn out at regular intervals of time and subjected to UV spectra measurements. The completion of the reaction was known from the decrease in the absorbance of peak maximum to zero value. Pseudo first order conditions on the compositions of the drug, catalyst and oxidant are maintained, and the pseudo first order rate coefficient values are determined from the absorbance time variance data.

RESULTS AND DISCUSSION: The UV visible spectrum and Powder XRD of Aloe Vera stabilized AgNp and AgNp-rGO is given Fig. 2 and Fig. 3 respectively.

The powder PXRD patterns of AgNp confirm with the JCPDS file no 04-0783. Using Scherrer equation, the size range of the AgNp has been found within 12+ 2.0 nm. FE – SEM and HR –TEM micro images of AgNp– rGO nano composites are shown in Fig. 4 and Fig. 5 respectively. In the SEM nano image, layers of rGO and AgNp depositions on the surface are observed.

Similar AgNps decoration on rGO surface are detected in HR – TEM images and the average size value of AgNps are found to be 16+1.0 nm indicating a marginal increase in the average size of AgNp due to surface interactions with rGO nano composites ³³.

FIG. 2: UV-VISIBLE SPR SPECTRA OF AgNp WITH INSET FIGURE OF AgNp-rGO                                            

FIG. 3: POWDER XRD OF ALOE VERA AgNp-rGO

FIG. 4: FE-SEM IMAGES OF AgNp-Rgo NANO COMPOSITES

FIG. 5: HR-TEM MICRO PHOTO OF AgNp-rGO NANO COMPOSITES

In order to ascertain the photo catalytic behaviour of the fabricated AgNp–rGO nano composites prepared in green pathways, degradations of RHCl and NaDF dyes are studied separately and the followings alient observations are found.

The degradation of the drug started up only upon the start of visible light irradiation in the presence of nano composites and drug degradation oxidant. Also, the drug degradation was extremely slow in the absence of light but even in the presence of Ag NPs – rGO nano composite and the oxidant. In the absence of the oxidant but in the presence of nano composites and visible light, the dye decolouration was again found slow and took more than 8 hrs for complete degradation. Thus to sum up the degradation was faster only in the presence of light, oxidant and catalyst. The absorbance of the wave length maximum peak in the UV spectra for each of the drug was found to decrease with increase in the time of progress of the oxidation. In Fig. 6 and Fig. 7, such time variances in the spectra are shown for RHCl and NaDF drugs respectively. The corresponding absorbance versus time plots for the two drugs are shown in Fig. 8(A) and 8(B). The extent of absorbance decrease with time has been found to be more for RHCl than NaDF dye degradations.

These data are used for the kinetic plots from which the overall pseudo first order rate coefficient values are determined. These are shown in Fig. 8(A) and 8(B), Fig 9(A) and 9(B) respectively. The completion of the reaction was indicated from the absorbance values reaching zero value. The nanocomposite catalysts were recovered by filtration and washed repeatedly followed by ultra-centrifugation. The catalyst residue is vacuum dried and as well as stored in dark for 24 hrs to attain equilibrium. The catalyst activity of AgNp-rGO nano composite was tested by repeating, the dye degradation procedures.

FIG. 6: VISIBLE SPECTRA WITH TIME VARIANCE OF NADF IN AQUEOUS MEDIUM IN HE PRESENCE OF AGNP-RGO NANO COMPOSITES AND PEROXO MONOSULFATE UNDER VISIBLE LIGHT IRRADIATION AT 25°C

FIG. 7: VISIBLE SPECTRA WITH THE TIME VARIANCE OF RHCL IN AQUEOUS MEDIUM IN PRESENCE OF AGNP-RGO NANO COMPOSITES AND S₂O₅ UNDER VISIBLE LIGHT IRRADIATION AT 25°C

FIG. 8: ABSORBANCE VARIATION WITH TIME PLOTS FOR (A) RHCL AND (B) NADF PHOTO DEGRADATION UNDER VISIBLE LIGHT IRRADIATIONS AND AGNP-RGO NANOCOMPOSITE CATALYS WITH S₂O₅^2- OXIDANT AT 25°C

FIG. 9: PSEUDO FIRST ORDER KINETIC PLOTS FOR RATE COEFFICIENT DETERMINATION OF (A) RHCL AND (B) NADF PHOTO DEGRADATIONS UNDER VISIBLE LIGHT AND AGNP-RGO NANO COMPOSITE CATALYST AND S₂O₅^2- OXIDANT AT 25°C

However, the drug degradation took hours, indicating that the recycled nano composites have lost the catalytic activity significantly. This may be attributed to the tarnishing of Ag metal surfaces by air oxygen. The reaction filtrate was analysed for the drug mineralization. In Table 1 the kinetic parameters including the overall rate co efficient values for the pseudo first order reaction conditions and % mineralization of the drugs are put forth. The data indicate that RHCl degraded faster than NaDF in the visible irradiation and AgNp–rGO nano composite surface catalyses RHCl molecules more rapidly than NaDF molecules in the presence of S₂O^2-₅ oxidant. The plausible photo oxidation pathways of the two drugs are given in Fig. 10. Presence of Ag nanoparticles on the rGO matrix enhances the absorption of visible light, due to the strong SPR and facilitates the electron transfers as well as the H atoms transfers from the drug and the oxidant molecules. The rGO being a good electron acceptor and excellent charge transporter with excess π electrons facilitates the anchoring of the drug molecules suitable for e¯ and H transfers. This contributes to the rate determining step .In consequence, cascadic mineralization of the organic drug molecules with CO₂ evolution wherever occured was detected. Also, no trace of NDMA was detected in RHCl degradations. These steps are essential in the water treatment by AOP during drug leakages into aquatic sources.

TABLE 1: THE OVERALL PSEUDO FIRST ORDER RATE COEFFICIENT (KX10^-2 SEC^-1) VALUES FOR THE OXIDATION REACTIONS OF RHCL AND NADF USING PEROXOMONOSULFATE AND AGNP-RGO AS PHOTO CATALYST AT 25°C

FIG. 10: PLAUSIBLE PHOTO MECHANISM OF OXIDATION OF DRUGS WITH S2O5^2- OXIDANT UNDER VISIBLE LIGHT IRRADIATION

CONCLUSION: AgNps synthesized by a green pathway using Aloe vera plant extract resulted in stable nano particles which are conveniently deposited on to rGO surface resulting in AgNps-rGO nano composites. The fabricated nano composite material is used as the photo catalyst for the oxidative degradation of the two popular drugs RHCl and NaDF under visible light in the presence of peroxomonosulfate oxidant. Remarkable drug degradations took place and RHCl degraded more rapidly than NaDF along with near complete drug mineralisations. Also, no trace of NDMA was found in RHCl degradation products. These results indicate the potential utility of the designed nano composites as drug nano sensors and initiators for destruction of the aqueous drug molecules leading to near complete mineralisations.

ACKNOWLEDGEMENTS: All the authors, thank the National Center for Nano science and Nanotechnology, University of Madras, for the electron microscopic measurements.

CONFLICT OF INTEREST: None declared

REFERENCES:

1. Ahare SS and Pandit SV: Anticancer potential of nanogold conjugated toxin GNP-NN-32 from naja naja venom. J Venom Anim Toxins Incl Trop Dis 2020; 26: 1-13.
2. Banerjee R: Nanotechnology in drug development presents status and a glimpse into the future. Their Delivery 2018; 9: 231-232.
3. Arenas – vivo A, Amaici G, Ayvado, Rosal R and Horcajada P: An Ag-loaded photoactive nanometal organic frame work as a promising bioflim treatment. Acta Biomaterials 2019; 97: 490–500.
4. Asim Ali Yaqooh, hilal Ahmad Tabasasum Parveen and Akil Ahamd: Recent Advances in metal decorated nanomaterials and their various biological applications. A Review Frontierschem – sec.  Nanoscience 2020; 19: 8.
5. Aishwary AS and Sanjay KR: E. coil based Synthesis of Cadmium Sulfide nanoparticles characterization, antimicrobial and cytotoxicty studies. Braz J Microbiology 2020; 17: 1 -10.
6. Arakawa FS, Shimabuku – Biadola QL, Fernandes Silva M and Bergamasco: Development of new Vacuum impregnation method at room atmosphere to produce silver – copper oxide nano particles on activated carbon for antibacterial applications Environ Technology 2019; 1: 1–12.
7. Durna K Boruah, Darabdhara G and Das MR: Polydopamine functionalized graphene sheets decorated with magnetic metal oxide nano particles as efficient nonozyme for the detection and degradation of harmful triazine pesticides. Chemosphere 2021; 268: 129389.
8. Boruah PK and Harzrad J: mater: Dual responsive magnetic Fe₃o₄ – T1-O₂/ graphene nanocomposite as an artificial nanozyme for the colorimetric delection and photo degradation of pesticide in an aqueous medium. J Hrazrd Materials 2020; 385: 121516.
9. Lu L, Xu O, Tang S and Yu Y: Using post – graphene 2D materials to detect and remove pesticides: Recent advances and future recommendations. Bull Environ contain Toxicology 2021; 107(2): 185–193.
10. Lan Zhu, Chen L, Gi J, Ma H and Wu H: Carbon based nanomaterials for sustainable Agriculture: Their application as light converters nanosensors and delivery tools. Basel 2022; 11(4): 511.
11. Amalan Das, Ramkumar Chandran and Archana Mallik: Decoration of graphene sheets with silver nanoparticles and their characterization. Materials Today Proceedings 2022; 62: 6265–6271.
12. Dhung Nhat Minh, Van Tuan Haong, Ngo XuanDinh, ong Van Hoang, Nguyen Van Cuong, Dang Thi Bich Hop, Tran Quoc Tuan, Nguyen Tien Khi, Tran Quang Huy and Anh – Tuan Le: Reduced graphene oxide – wrapped sliver nanoparticles for applications in ultra sensitive colorimetric delection of Cr (VI) ions and the carbaryl pesticide. New Journal of Chemistry 2020; 18.
13. Krishnaja C, Kalianngounder VK, Rajan R, Ramesh T, Kim CS, Park Ch, Liu B and Yun SI: Silver nanoparticles decorated reduced graphene oxide: Ecofriendly synthesis characterization, biological activities and embryo toxicity studies. Environ Res 2022; 210: 1122864.
14. Rachel Fanelwa Ajay, Siphokazi Tshoko, Yonela Mgwilli, Siphamandla Nqunqa, Takalani Mulandzi, Noluthando Mayedwa and Emmanuel Iwuoha: Green method synthesized Graphene Sliver electrochemical Nanobiosensors for Ethambutol and pyrazinamide. MDPI – Processes 2020; 8-878.
15. Nidhi Pal, Somesh Banerjee, Partha Proteem Roy and Kaushik Pal: Cellulose nanocrystals – Sliver nanoparticles – reduced graphene oxide based hybrid PVA nanocomposites and its antimicrobial properties. International J of Biological Macromolecules 2021; 191.
16. Supriya G and Chaitanya Kumari S: Green synthesis of silver nano particles from Aloe vera extract and assessing their anti microbial activity against skin infections. International Journal of Scientific research in Biological Sciences 2019; 6(1): 60-65.
17. Anju TR, Parvathy S, Mohanan Valiye Veettil, Rosemary J, Ansatra TH, Shahzabanu MM and Devkika S: Green synthesis of silver nano particles from Aloe vera leaf extract and its antimicrobial activity: Materials Today Proceedings 2021; 43: 63956-3960.
18. Md. Rashid Anjum and Rakibul Islam: Effect of neem extract with Zinc oxide nanoparticles for burn wound treatment. Journal of Applied Life Science International 2023; 26–1: 17-23.
19. Gandhimathi Chinnasamy, Smitha Chandrasekharan, Tong Wey Koh and Somika Bhatnagar: Synthesis, Characterization, Antibacterial and Wound Healing Efficacy of Sliver Nanoparticles from Azadirachta indicia. Frontiers in Microbiology 2021; 12: 611560.
20. Shubhrat Maheshwari, Ritesh Kumar Tiwari, Lalit Singh and Green Expertise: Synthesis of Sliver Nanoparticles for wound healing application an overview. Research J Pharm and Tech 2021; 14(2): 1149-1154.
21. Tamara Bruna” Francisa Maldonado – Bravo, Paul Jara and Nelson Caro: Silver Nanoparticles and their Antibacterial applications. International Journal of Molecular Sciences 2021; 22: 7202.
22. Kotsyubyusky VO: Structural properties of graphene oxide materials synthesized according to hummers, tour and modified methods: XRD and Raman study: Phy Chem Solid Stud 2021; 22: 31–38.
23. Yoxkin Estenez – Martinez, Rubi Vazquz, Yesica Itzel Meudez Ramiez and Elizabeth Chavira: Antibacterical nanocomposite of chitosan/ silver nanocrystals graphene oxide: (chAgG) development for its potential use in bioactive wound dressing. Scientific Reports 2023; 13: 10234.
24. Nadeem Ahamad, Sirajuddin Ahamed and Viola Vambol; Treatment of drug residues (emerging contaminants) in hospital effluent by the combination of biological and physiological treatment process: a review. Fin Engi & B Environ 2021; 1: 1-13.
25. Kundan Samal, Saswat Mahapatra and Md Hibzur Ali: Pharmaceutical waste water as Emerging Contaminants (EC): Treatment technologies, impact on environment and human health. Energy Nexus 2022; 6: 100076.
26. Abdelfattah I, Abuarab ME and El-Shamy AM: Integrated system for pharmaceutical wastewater. Int J Environ Sci & Technol 2022.
27. Swati S, Rawat:  Spectrophotometric method development and validation for estimation of Ranitidine hydrochloride in bulk and pharmaceutical World. J of Pharma Res 2022; 11: 698-707.
28. Subrata Paul, Labani Barai, Faruk Husen MD, Sabarani Sarker, Tarun Kumar Pal, Puja Bal, Abdul Matin Sarker, MD, Syed Saima Alam and Sheta Biswas: Analytical method development and validation for estimation of Ranitidine in solid Dosage form by UV- spectrophotometric method. OJC 2020; 6: 1161-1167.
29. Baria Tahir, Maryam un Nissa, Muhammad Tahir, Asma, Gul Zaman, Farrah Batool, Somayeh Azadi, Muhammad Ishaq and Faheem Abbas: UV Spectrophotometric HPLC method development, validation and f2 factor for quantitative estimation of Diclofenac Sodium with market product. Int J Sci & Res 2021; 11: 647-657.
30. Benjamin O, Orimolade and Omotayo A, Arotiba: Enhanced photoelectrocatalytic degradation of diclofenac sodium using a system of Ag- BiVO₄ /BiOl Anode and Ag-BiOl cathode. Rep 2022; 12: 4214.
31. Muhammad Shahzad Chohan, Rafea Elamin Elgack Elgorashe, Abdulmalek Ahamed Balgoname, Mahesh Attimarad, Nagaraja SreeHarsha, Katharigatta Narayanaswamy Venugopala, Anroop Balachandran Nair, and Shinu Pottahil: Eco- friendly derivation UV Spectrophotometric methods for simultaneous determination of Diclofenac sodium and Moxifloxacin in laboratory mixed ophthalmic preparation. Indian J of Pharma Edu & Res 2022; 53: 166-174.
32. Paul Harmon, Ranitidine: A Proposed Mechanistic Rationale for NDMA formation and a potential control strategy.  J of Pharma Sci 2022; 1-5.
33. Wijetunga S, Li X F and Jian C and Hazard J: Effect of Organic load on decolourization of textile wastewater containing acid dyes in upflow anaerobic sludge blanket reac: Mater. Today Proceedings 2021; 43; 3956–60.
34. Vijayalakshmi R, Ramapriya L and Santhanalakshmi J: Aloe vera Stabilized  Nano Sliver – Reduced Graphene Oxide Nano composites for Facile Catalytic Degradation of Ponceau 4R and Eosin – Y Dyes in Visible Light. J Adv Sci Res 2021; 110-117.
35. Mona S Alwhib, Dina A Soliman, Manal A, Awad, Asma B, Alangery Horiah Al Dehaush, and Yasmeen A Alwasel.  Green synthesis of silver nano particles: characterization and its potential bio medical applications. Green Processing and Synthesis 2021; 10: 412-420.
36. Anandalakshmi K, Venugobal J and Ramasamy V: Characterisation of silver nanoparticles by green synthesis methods using Pedalium murex leaf extract and their antibacterial activity. Applied Nanoscience 2016; 6: 399-408.
    

    ---

    How to cite this article:

    Vijayalakshmi R, Santhanalakshmi J and Sangeetha J: Aloe vera extract stabilised nano silver- reduced graphene oxide nano composites as visible light photocatalyst for oxidative degradations of ranitidine hydrochloride and sodium diclofenac in aqueous medium: a kinetic study. Int J Pharm Sci & Res 2024; 15(6): 1711-18. doi: 10.13040/IJPSR.0975-8232.15(6).1711-18.

    ---

    All © 2024 are reserved by International Journal of Pharmaceutical Sciences and Research. This Journal licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.