WO2024009240A1

WO2024009240A1 - Electrochemical assembly for degradation of waste pharmaceutical products

Info

Publication number: WO2024009240A1
Application number: PCT/IB2023/056968
Authority: WO
Inventors: Kaushik Palicha; Harinipriya Seshadri
Original assignee: Kaushik Palicha; Harinipriya Seshadri
Priority date: 2022-07-03
Filing date: 2023-07-05
Publication date: 2024-01-11

Abstract

The present disclosure provides an electrochemical assembly for degradation of unused or expired pharmaceutical products, wherein the electrochemical assembly includes a Mg-rich phyllosilicate containing cathode, an Ag/AgCl anode, and MgCl2 as electrolyte. Waste pharmaceutical products are applied onto the phyllosilicate of the cathode, wherein the electrochemical action of the electrochemical assembly breaks the bonds of the drug molecules present in the pharmaceutical product and degrades the drug into a useful product through several degradation mechanisms as outlined in the disclosure.

Description

TITLE

ELECTROCHEMICAL ASSEMBLY FOR DEGRADATION OF WASTE

PHARMACEUTICAL PRODUCTS

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is based upon and claims priority to India complete patent application number 202241038230 filed on April 15, 2023, which claims priority to India provisional patent application number 202241038230 filed on July 03, 2022. The entire contents of all are herein incorporated by reference.

FIELD

The present disclosure relates to an electrochemical assembly for degradation of pharmaceutical products, more particularly relates to an electrochemical assembly through its electrochemical actions breaks the bonds of the drug molecules present in the pharmaceutical product and degrades the drug into a useful product.

DEFINITION

As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicates otherwise.

As used herein, the terms “Waste pharmaceutical products” or “Waste pharmaceuticals”, “waste medicines”, which may have been used interchangeably used in the present disclosure to mean those pharmaceutical products or medicines that are either expired as they were not used during the given period of use, or where a pharmaceutical company decided to stop marketing the product for any reason including availability of alternative or better products in the market, or loss of marketability due to competition. Such pharmaceutical products may be in any form known to a person skilled in the art including but not limited to tablets, capsules, syrups, injections, vaccines, ointments, emulsions, suspensions, creams, and pastes. As used herein, the terms “electrocatalyst” or “phyllosilicates based electrocatalyst” and the like are used interchangeably, wherein “electrocatalyst” means any chemical or compound or substance or mineral that can accelerate the electrode kinetics without altering itself during the electrochemical reaction.

BACKGROUND

Increased population across the globe and health issues associated with stress, natural disasters and contagious disease breakthroughs, increases the pharmaceutical demand continuously. Industrialization and urbanization have been incessantly augmenting the volume of pollutants in the ecosystem especially water bodies thereby making them unsuitable for drinking and other utility purposes. Pharmaceutical compounds may include several regularly used ones including antibiotics, painkillers, blood thinners and hormones among others. Sometimes, unused or expired medications enter waterways as a result of improper disposal, for example, by flushing them down the toilet or drain. Again, due to the increasing demand for pharmaceuticals, accumulation of unused or expired medicinal wastes and micro-plastics from pharmaceutical industries in the water bodies and ecosystem is happening at a disturbing rate. These wastes when enter into the river ecosystem causes chronic risk not only to human beings, but also to animals, and aquatic lives. The major problem in the contamination of water bodies with medicinal wastes include its anthropogenic activities via its ability to change the structure of the microbes and extinct several species of microorganisms. The higher concentration of the medicinal wastes (expired or unused) in water systems leads to myriad infections to animals and human beings.

In order to avoid the adverse effects of these wastes on the human beings, animals, and aquatic creatures, various remediation methods had been investigated such as treating the water streams (including waste water streams) that contains pharmaceuticals and antibiotics wastes.

RO135104A2 discloses a process for preparing an elastomer film to be used in degradation of antitumoral drugs. The process consists in mixing 2 to 6% titanium dioxide related to the elastomer mass, dispersed in a styrene-butadiene star block copolymer (SBS), and 32% polystyrene, by vigorously stirring for 24 h, centrifugal moulding-desolventation at a rotary speed of 2800 to 3000 rpm, while heating from outside without exceeding a working temperature of 60°C, final desolventation in a vacuum oven, at a temperature of 60°C, resulting in a composition as elastomer film with embedded photocatalyst of the SBS/TiCh type-

CN108807853B discloses degradation and recycling methods for theophylline medicines to be used as a lithium-ion battery cathode active material, which is done by mixing ground expired aminophylline medicine with a conductive agent and a binder in an organic solvent to prepare electrode slurry, coating the electrode slurry on a current collector to prepare an electrode.

CN112044915A discloses a method for conversion of waste antibiotic drugs into a carbon material by hydrothermal carbonization treatment.

CN208865501U discloses a treatment container for treating waste pharmaceutical chemicals by a mechanical method including filtration, with the aim to avoid cross reaction between the different chemicals.

SUMMARY

The present disclosure provides an electrochemical assembly for degradation of pharmaceutical products. The electrochemical assembly includes a cathode coated with a Mg-rich phyllosilicate, an Ag/AgCl anode, and MgCh as electrolyte.

Waste pharmaceutical products are applied on the Mg-rich phyllosilicate of the cathode in a suitable form, wherein the electrochemical action of the electrochemical assembly breaks the bonds of the drug molecules present in the pharmaceutical product and degrades the drug into a useful product through several degradation mechanisms as outlined in this disclosure. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Fig. 1A-1F illustrates X-ray Diffraction studies of seven samples of bentonite clay.

Fig. 2A to 2G illustrates the BET analysis of seven samples of bentonite clay.

Fig. 3A to 3E illustrate the High-Resolution Scanning Electron Microscopy (HR- SEM) micrographs of the five bentonite clay samples.

Fig. 4A, 4AA to 4E, 4EE illustrate the ED AX and chemical composition analysis of the bentonite clay samples.

Fig. 5 illustrates the XRD patterns of the pharmaceutical formulations.

Fig. 6A illustrates the FTIR spectra of ECOSPIRIN tablet in the wave number range of 400 to 4000 cm ¹.

Fig. 6B illustrates the FTIR spectra of the SMALL TABLET inside CITIMET capsule with light orange coating in the wave number range of 400 to 4000 cm ¹.

Fig. 6C illustrates the FTIR spectra of the biodegradable encapsulation of CITIMET Capsule (Red-Green) in the wave number range of 400 to 4000 cm ¹.

Fig. 6D illustrates the FTIR spectra of the WHITE POWDER inside CITIMET capsule in the wave number range of 400 to 4000 cm ¹.

Fig. 7 illustrates the UV-Visible spectroscopic analysis of the tested pharmaceutical formulations in the wavelength range of 190 to 790 nm.

Fig. 8 illustrates a three-electrode electrochemical assembly for degradation of ECOSPIRIN tablet.

Fig. 9 illustrates the Cyclic Voltammogram of ECOSPIRIN tablet (pharmaceutical composition) tagged to Bengel-RSI bentonite clay containing working electrode of the three-electrode electrochemical assembly at different scan rates from 1 to 200 mVs ¹ in the potential window of -1.2 to 1.2 V.

Fig. 10 illustrates the Cyclic Voltammogram of CITIMET capsule tagged to Bengel-RSI containing working electrode of the three-electrode electrochemical assembly at different scan rates from 1 to 200 mVs ¹ in the potential window of - 1.2 to 1.2 V.

Fig. 11 illustrates the Proton NMR spectra of the products obtained from the degradation of ECOSPIRIN tablet Fig. 12 illustrates the 1H-NMR spectra of the degradation products of Atorvastatin present in ECOSPIRIN tablet.

Fig. 13 illustrates the 1H-NMR spectra of the degradation products of Clopidogrel present in ECOSPIRIN tablet.

Fig. 14A illustrates the 1H-NMR spectra of cytidine (one of the degradation products of citicholine).

Fig. 14B illustrates the 1H-NMR spectra of choline (one of the degradation products of citicholine).

Fig 15A to Fig. 15D illustrate the degradation mechanism deduced based on the electrochemical studies for the pharmaceutical formulations under consideration.

DETAILED DESCRIPTION

The preferred embodiments of the present disclosure will be described in detail with the following disclosure and examples. The foregoing general description and the following detailed description are provided to illustrate only some embodiments of the present disclosure and not to limit the scope of the present disclosure. The disclosure is capable of other embodiments and can be carried out or practiced in various other ways.

Unless otherwise specified, all the technical and scientific terms used herein have the same meaning as is generally understood by a person skilled in the art pertaining to the present disclosure.

Headings are used solely for organizational purposes, and are not intended to limit the disclosure in any way.

The use of the singular includes the plural unless specifically stated otherwise. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well. The use of “or” means “and/or” unless stated otherwise.

As used herein, the terms “comprises” and/or “comprising” specify the presence of the stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Furthermore, to the extent that the terms “includes,” “having,” “has,” “with,” “composed,” “comprised” or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.”

As used herein, ranges and amounts can be expressed as “about” a particular value or range. “About” is intended to also include the exact amount. Hence “about 5 percent” means “about 5 percent” and also “5 percent.” “About” means within typical experimental error for the application or purpose intended.

It is to be understood that wherein a numerical range is recited, it includes all values within that range, and all narrower ranges within that range, whether specifically recited or not.

Reference throughout this specification to “one embodiment,” “an embodiment,” “one example,” or “an example” means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” “one example,” or “an example” in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combinations and/or sub -combinations in one or more embodiments or examples. In addition, it should be appreciated that if any figures are provided herewith, they are for explanation purposes to persons ordinarily skilled in the art and that the drawings of them are not necessarily drawn to scale.

In this specification, certain aspects of one embodiment include process steps and/or operations and/or instructions described herein for illustrative purposes in a particular order and/or grouping. However, the particular order and/or grouping shown and discussed herein are illustrative only and not limiting. Those of skill in the art will recognise that other orders and/or grouping of the process steps and/or operations and/or instructions are possible and, in some embodiments, one or more of the process steps and/or operations and/or instructions discussed above can be combined and/or deleted. In addition, portions of one or more of the process steps and/or operations and/or instructions can be re-grouped as portions of one or more other of the process steps and/or operations and/or instructions discussed herein. Consequently, the particular order and/or grouping of the process steps and/or operations and/or instructions discussed herein do not limit the scope of the disclosure.

The present disclosure provides an electrochemical assembly for degradation of unused or expired pharmaceutical products. The electrochemical assembly includes a cathode coated with a Mg-rich phyllosilicate, an Ag/AgCl anode, and MgCh as electrolyte.

Cathode preparation:

The cathode of the electrochemical assembly was prepared by the following method.

- Making a slurry of Mg-rich phyllosilicate clay in IM MgCh in deionised water;

- coating the slurry on a stainless-steel (SS) current collector; and

- drying the slurry coated SS current collector at 60°C for 3 hours, wherein, the coating can be done using any suitable coating method known in the art including dip coating.

Waste pharmaceutical products are applied onto the Mg-rich phyllosilicate of the cathode in a suitable form, wherein the electrochemical action of the electrochemical assembly breaks the bonds of the drug molecules present in the pharmaceutical product and degrades the drug into a useful product through several degradation mechanisms as outlined in this disclosure. A person skilled in the art understands that, it is good to use one type of waste pharmaceutical product in one batch, and it is not beneficial to use a mixture of several types of waste pharmaceutical products in a single batch in view of the fact after their degradation, different products will be resulted, which either may not be possible to be segregated, or their segregation is expensive and tedious.

Form of application of waste tablets onto the Mg-rich phyllosilicate of the cathode:

The steps of applying waste tablets onto the Mg-rich phyllosilicate of the cathode include:

- grinding the waste tablets containing a certain drug using a grinder to form a powder;

- making a slurry of the waste tablet powder in acetone or ethanol or isopropanol;

- coating the waste tablet powder slurry onto the Mg-rich phyllosilicate of the cathode; and

- drying the slurry coated cathode at 25°C for 8 hours.

The same method as used for application of waste tablets can be used for waste capsules or similar solid dosage forms.

Form of application of waste syrups onto the Mg-rich phyllosilicate of the cathode:

The steps of applying a waste syrup onto the Mg-rich phyllosilicate of the cathode include:

- mixing the waste syrup containing a certain drug with a binder such as ZnO or TiCh to make a paste;

- coating the waste syrup paste onto the Mg-rich phyllosilicate of the cathode; and

- drying the paste coated cathode at 25°C for 8 hours.

The same method as used for application of waste syrups can be used for waste injections, vaccines, solutions, or similar liquid forms. Form of application of waste semi-solid pharmaceutical products such as ointments, emulsions, suspensions, pastes or creams onto the Mg-rich phyllosilicate of the cathode:

The steps of applying waste semi-solid pharmaceutical products onto the Mg-rich phyllosilicate of the cathode include:

- coating the pharmaceutical semi-solid dosage form onto the Mg-rich phyllosilicate of the cathode;

- drying the pharmaceutical semi-solid dosage form coated cathode at 60°C for 5 hours;

It is to be noted that, it is essential to control the consistency of the slurry to be coated onto the Mg-rich phyllosilicate of the cathode based on the available consistency of the procured waste injections, vaccines, syrups, ointments, emulsions, suspensions, pastes or creams.

In an aspect of the disclosure, the liquid pharmaceutical products such as injections, vaccines, and syrups can be mixed with a binder to form a paste, wherein the paste can be coated onto the Mg-rich phyllosilicate of the cathode.

In an aspect of the disclosure, the semi-solid pharmaceutical products such as can be mixed with a binder to form a paste, wherein the paste can be coated onto the Mg-rich phyllosilicate of the cathode.

Details of Electrochemical Action on the waste pharmaceuticals:

The drug tagged phyllosilicate coated on SS current collector is utilized as the Cathode, Ag/AgCl as anode. The electrolyte employed is IM MgCh. The electrochemical experiments such as Cyclic Voltammetry were carried out using Zahner Zennium E4 electrochemical workstation, in the potential window of -1.5 to 1.5 V at different scan rates from 1 to 200 mV/s. The degradation of the bonds in the waste pharmaceutical products occurs due to the electrochemical action of the present disclosure, wherein the waste pharmaceutical products are converted to useful products.

In an aspect of the disclosure, the scan rate (the rate at which the voltage is applied to the system) of the electrochemical assembly is controlled in order for the degradation of specific bonds of the pharmaceutical products to result in a useful product.

In an aspect of the disclosure, for degradation of specific bonds of the pharmaceutical products, the optimized scan rate is lOOmV/s.

Physiochemical characterization:

In order to estimate the suitability of the phyllosilicates to be used in the electrochemical assembly of the present disclosure, several characterising studies were conducted on the phyllosilicate sample.

It is to be noted that, while in the present disclosure, bentonite clay is considered for carrying out the experimentation, a person skilled in the art may use other Mg- rich phyllosilicates such as smectites, Liquid Crystals of bentonite, the lattice of which are naturally rich in Mg²⁺ ions (generally present in the form of Magnesium oxides) in comparison to the fraction of other metal ions (generally present as metal oxides), or a person skilled in the art can be selective in choosing those phyllosilicates, or other silicates that are known to be Mg rich, or tested and characterised to be found as Mg rich through targeted experimentation, or hit and trial.

Bentonite clay, which is a phyllosilicate was procured from Cutch Oil and Allied Industries Pvt Ltd and used as such without any further purification.

Physiochemical characterization of the natural bentonite clay was carried out via Brunauer-Emmett-Teller (BET) analysis, FTIR, UV-Vis and XRD. The chemical composition of the natural bentonite clay was obtained by Energy dispersive X-ray analysis (ED AX).

X-ray Diffraction studies of phyllosilicates

X-ray Diffraction studies of seven samples of bentonite clay was done using Brucker powder XRD with Koc-Cu source and in the diffraction angle between 0 to 100°. The XRD patterns are provided in Fig. 1A-1F. Out of the seven samples, except for BENGEL-RSI (FIG. 1A) all other bentonite clays transformed into a sticky paste upon addition of aqueous solution of MgCh- The sample BENGEL- RSI (FIG. 1A) is observed to be rich in Ca, Mg Smectite among all the samples tested. This indicated the bentonite clay sample labelled as BENGEL-RSI is a better candidate for electrocatalysis of degradation of waste pharmaceuticals in MgCh electrolyte due to easy Mg²⁺ incorporation and common ion effect between the electrocatalyst and the electrolyte under consideration.

The lettered symbols in Fig. 1A to IF to indicate the XRD peaks has the following meanings. a = Antanase f = Feldspar g = Geothite gy = Gypsum h = Hematite k = Kaolite

1 = Ca-plagioclase m = Mica mag = Meghamite/Magnetite p = Apatite pl = Plagioclase q = Quartz s = Na-smectite (where specifically not mentioned as Na-smectite) The structural composition of the bentonite clays that were tested as procured from Cutch Oil & Allied Industries (P) Ltd. Has been provided in Table 1.

Table 1

Brunauer, Emmett and Teller (BET) analysis for Surface area of the phyllosilicates Fig. 2A to 2G illustrates the BET analysis of the bentonite clays and the parameters extracted therefrom are given in Table 2.

Table 2

From Table 2 and comparison with Fig. 2A to 2G indicates that the order of the surface area in m²/g for the bentonite clay samples are as given below. CAG66-11 > BENGEL-RSI > HYDROPHILIC > SPS-RB > VIVOMIN > V-WE

> OLEOPHILIC.

Although the bentonite clay labelled CAG66-11 possess twice the BET surface area of BENGEL-RSI, like all other bentonite clay samples, this also resulted in a sticky slurry with aqueous solution of MgCL- Thus, BENGEL-RSI labelled bentonite clay with surface area of 89.7152 m²/g, pore volume of 0.421749 cm³/g, with average pore size of 88.268 A is chosen as the electrocatalyst for the electrochemical degradation of the waste pharmaceuticals. High Resolution Scanning Electron Microscopy (HR-SEM) to identify Surface

Morphology of the phyllosilicates: HR-SEM of the bentonite clay samples were carried out at 60x magnification and 500nm. The HYDROPHILIC AND OLEOPHILIC bentonite clays were hygroscopic in nature and hence were resulting in charging in SEM rather than showing any sensible images.

The micrographs of the five bentonite clay samples are provided in Fig. 3A to 3E. As evident from Fig. 3A to 3E, the bentonite clay labelled BENGEL-RSI and CAG 66-11 possess needle like surface morphology with high aspect ratio. This high aspect ratio of the bentonite clay renders high Mg²⁺ ion conductivity and hence act as a better electrocatalyst than other bentonite clays tested. The other samples i.e., SBS-RBW, VIVOMIN and V-WE possess bulk agglomerated surface morphology making them unsuitable for the electrocatalysis purpose.

ED AX analysis of the phyllosilicates:

As observed from the ED AX analysis, the chemical compositions of the bentonite clay samples are as given in the following Tables 3.1 to 3.5.

Table 3.1

Chemical composition of BENGEL-RSI

Table 3.2

Chemical composition of CAG 66-11

Table 3.3

Chemical composition of SPS-RBW

Table 3.4

Chemical composition of VIVOMIN

Table 3.5

Chemical composition of V-WE

The EDAX chemical composition analysis of the bentonite clays indicates that BENGEL-RSI and CAG 66-11 are the ones with appropriate Mg-rich composition to act as electrocatalyst to degrade the used or expired medicines into useful products. These results are in agreement with XRD, BET, HR-SEM inferences. However, owing to the fact that CAG 66-11 results in a sticky slurry with aqueous solution of MgCh, the only Mg-rich bentonite clay bentonite clay bentonite clay bentonite clay bentonite clay identified for the present disclosure is the samples labelled as BENGEL-RSI.

XRD analysis of waste pharmaceuticals:

The pharmaceutical samples that were investigated with XRD analysis are:

1. ECOSPIRIN Tablet is composed of:

- Aspirin 75 mg,

- Atorvastatin lOmg, and

- Clopidogrel,

- TiO2 as pigment, and orange dye.

2. CITIMET capsule is composed of:

- Citicholine as a white crystalline powder inside the capsule,

- a small orange tablet inside the capsule comprising Aspirin and Clopidogrel, and

- the biodegradable encapsulation (Red and green)

The waste pharmaceutical samples were crushed into powder to measure the XRD.

Fig. 5 illustrates the XRD patterns of the pharmaceutical formulations of ECOSPIRIN tablet (represented as ECOSPIRIN), small tablet inside citimet capsule (represented as SMALL TABLET), white crystalline powder contents inside the CITIMET capsule (represented as Citicholine), and the biodegradable encapsulation of the CITIMET capsule (represented as CAP-E).

Tables 4 to 6 elucidate the identification of corresponding 20 peaks for the above- mentioned chemicals in the medicine.

XRD peaks of ECOSPIRIN tablet is provided in Table 4.

Table 4

XRD peaks of white crystalline powder in CITIMET capsule is provided in Table 5.

Table 5

XRD peaks of the small tablet inside CITIMET capsule is provided in Table 6.

Table 6

FTIR analysis of the waste pharmaceuticals

Fig. 6A illustrates the FTIR spectra of ECOSPIRIN tablet in the wave number range of 400 to 4000 cm ¹. Fig. 6B illustrates the FTIR spectra of the SMALL TABLET inside CITIMET capsule with light orange coating in the wave number range of 400 to 4000 cm ¹.

Fig. 6A to 6D confirms the presence of functional groups such as carboxyl, alcohol, ether, esters, aldehydes, ketones, aromatic groups, hetero atomic groups in the pharmaceutical formulation of the tested pharmaceutical formulations of ECOSPIRIN TABLET and the components of the CITIMET capsule as shown in

Table 7.

Table 7

UV- Visible analysis of the waste pharmaceuticals: Fig. 7 illustrates the UV-Visible spectroscopic analysis of the tested pharmaceutical formulations in the wavelength range of 190 to 790 nm.

ECOSPIRIN shows peak at 268 nm, broad peak from 240-300 nm. This is attributed to the presence of (i) Aspirin (peak at 265 nm), (ii) Clopidogrel (peak at 254nm), (iii) Atorvastatin (maxima at 237 nm and minima at 261 nm). All peaks combine and show a broad spectrum around 240 to 300 nm.

As observed from Fig. 7, CITIMET shows peak at 283 nm due to the presence of diphosphocholine of citicoline.

SMALL TABLET - Small tablet inside the CITIMET CAPSULE peaks at 288 nm., and 396 nm. Where, the peak at 288 nm is attributed to citicoline and the peak at 396 nm is the presence of TiCL as pigment.

Examples:

The present disclosure will now be explained in further detail by the following examples. These examples are illustrative of certain embodiments of the disclosure without limiting the scope of the present disclosure.

The waste pharmaceutical products which are either unused or expired were obtained from the pharmacies and used as such. While the waste pharmaceutical products used for the experiments of the present disclosure are tablets of aspirin, atorvastatin, clopidogrel and citicholine (Citimet), other waste pharmaceutical products, and also other forms of pharmaceutical products such as capsules, syrups, injections, vaccines, ointments, emulsions, suspensions, creams can use the teachings of the present disclosure.

Zahner Zennium E4 electrochemical workstation (Germany) is used to perform electrochemical degradation of the waste pharmaceuticals. Electrochemical degradation of waste pharmaceuticals into useful products

Example 1: Three electrode assembly for ECOSPIRIN tablet degradation:

A three-electrode electrochemical assembly for degradation of ECOSPIRIN tablet was prepared as illustrated in Fig. 8 by employing a borosil glass container covered with a three-inlet enabled Teflon cover, wherein,

- In the first inlet: a working electrode (cathode) coated with a Mg-rich BENGEL-RSI labelled bentonite clay, wherein the working electrode was prepared by making a slurry of Mg-rich BENGEL-RSI labelled bentonite clay in IM MgCh in deionised water, the slurry was coated by dip coating on a stainless-steel (SS) current collector having dimension of 5*5 cm², and the slurry coated SS current collector was dried at 60°C for 3 hours. ECOSPIRIN tablet was ground to a fine powder, and a slurry of the ECOSPIRIN powder was made by adding the powder to acetone or ethanol or isopropanol, The slurry of ECOSPIRIN tablet powder was drop casted onto the Mg-rich BENGEL-RSI labelled bentonite clay, and was dried at 25°C for 8 hours.

- In the second inlet: an Ag/AgCl reference electrode (anode),

- In the third inlet: a Pt wire counter electrode, and

- MgCh as electrolyte.

Electrochemical action of three electrode assembly:

Cyclic voltammetry (CV) was conducted at different scan rates from 1 to 200 mVs ¹ in the potential window of -1.2 to 1.2 V to observe the redox behavior of the electrochemical degradation (electro-catalyzation) of the pharmaceutical wastes.

Example 2: Three electrode assembly for CITIMET Capsule degradation:

A three-electrode electrochemical assembly for degradation of CITIMET capsule was prepared, which follows the same method as provided in Example 1 , with the exception of the slurry of CITIMET capsule powder was drop casted onto the Mg- rich BENGEL-RSI labelled phyllosilicate of the working electrode (cathode). The Electrochemical action was conducted with the same method and the same parameters as described under Example 1.

Example 3: Two electrode assembly for ECOSPIRIN tablet degradation:

An electrochemical assembly was prepared in order to degrade ECOSPIRIN tablet into useful products, wherein the electrochemical assembly includes:

- A cathode, which was prepared by making a slurry of Mg-rich BENGEL- RSI labelled bentonite clay in IM MgCE in deionised water, the slurry was coated by dip coating on a stainless-steel (SS) current collector having dimension of 5*5 cm², and the slurry coated SS current collector was dried at 60°C for 3 hours. ECOSPIRIN tablet was ground to a fine powder, and a slurry of the ECOSPIRIN powder was made by adding the powder to acetone or ethanol or isopropanol, The slurry of ECOSPIRIN tablet powder was drop casted onto the Mg-rich BENGEL-RSI labelled bentonite clay, and was dried at 25°C for 8 hours,

- An anode containing Ag/AgCl,

- MgCh as electrolyte,

Electrochemical action of two electrode assembly:

The electrochemical assembly was studied by connecting to an external DC power source and a current density of 10mA/cm² is applied at 1.2 V to allow electrochemical degradation of the pharmaceutical wastes.

Example 4: Two electrode assembly for CITIMET Capsule degradation:

An electrochemical assembly was prepared in order to degrade the CITIMET Capsule into useful products, wherein the electrochemical assembly includes: a cathode as disclosed in Example 3,

An anode containing Ag/AgCl, MgCh as electrolyte.

The Electrochemical action was conducted with the same method and the same parameters as described under Example 3. Evaluation:

Cyclic voltammetry (CV) was conducted for the electrochemical actions of Example 1 and Example 2.

And, Proton-NMR studies were conducted for the degradation products of Example 3 and Example 4.

Evaluation of Example 1:

Fig. 9 illustrates the Cyclic Voltammogram of ECOSPIRIN tablet (pharmaceutical composition) tagged to Bengel-RSI bentonite clay containing working electrode (cathode) of the three-electrode electrochemical assembly having Ag/AgCl as reference electrode (anode) and Pt wire as counter electrode, in IM MgCh electrolyte at different scan rates from 1 to 200 mVs ¹ in the potential window of -1.2 to 1.2 V.

The redox potential and current at 100 mVs ¹ agree satisfactorily with the literature. In the literature, the oxidation potential of aspirin occurs at 0.7 V on edge plane pyrolytic graphite modified with graphene with respect to Ag/AgCl reference electrode (anode). In the present investigation oxidation peak is observed at 0.65 V vs Ag/AgCl for bentonite electrocatalyzed ECOSPIRIN tablet.

Two small humps were noticed at 0.8 and 1.05 V in the forward scan. The peak at 0.8 V could be due to oxidation of atorvastatin. The literature iterates that atorvastatin oxidizes on glassy carbon electrode at 1.004 V (vs Ag/AgCl) at 100 mV/s.

The oxidation peak observed at 1.05V accounts for the clopidogrel base present in the pharmaceutical formulation. The observed oxidation potential of clopidogrel is identical to that of the literature value.

Evaluation of Example 2:

Fig. 10 illustrates the Cyclic Voltammogram of CITIMET capsule tagged to Bengel-RSI containing working electrode (cathode) of the three-electrode electrochemical assembly, having Ag/AgCl reference electrode (anode) and Pt wire counter electrode, in IM MgCh electrolyte at different scan rates from 1 to 200 mVs ¹ in the potential window of -1.2 to 1.2 V.

The redox potential and current at 100 mVs ¹ agree satisfactorily with the literature. In the literature, the oxidation potential of citicholine occurs at 0.62 V on Ni-Al LDHs/CD modified Glassy Carbon Electrode (GCE) with respect to Ag/AgCl reference electrode (anode) in IM KOH electrolyte. In the present disclosure, oxidation peak is observed at 0.43 V vs Ag/AgCl on BENGEL RSI coated SS working electrode (cathode) with Citimet drop casted on the same.

Evaluation of Example 3

Nuclear magnetic resonance (NMR) of the products obtained from the degradation of waste ECOSPIRIN

Proton NMR spectra of the products obtained from the degradation of ECOSPIRIN tablet is provided in Fig. 11. The multiplet peak in the chemical shift from 6.5 to 8 ppm accounts for the aromatic hydrogen (Ar-H) in the salicylic acid. The peak at the chemical shift of 10.39 ppm represents the hydroxyl group of the salicylic acid.

Proton NMR spectra of the atorvastatin present in ECOSPIRIN tablet is provided in Fig. 12 and Table 8.

Table 8

Proton NMR spectra of Clopidogrel component in ECOSPIRIN tablet is provided in Fig. 13 as (400 MHz, DMSO-d6) 5 ppm 1.39 (s, 1 H, 5) 2.15-2.35 (m, 2 H, 3) 2.7-2.85 (m, 2 H, 4) 3.4 - 3.6 (m, 2 H, 6) 6.35 (d, J=5.10 Hz, 1 H, 7) 6.89 (d, J=5.10 Hz, 1 H, 8) indicating that the product formed is Methyl (+)-(S)-a-(o- chlorophenyl)-6,7-dihydrothieno (3,2-c) pyridine (5-4-H)-o substituted compound.

Evaluation of Example 4

Nuclear magnetic resonance (NMR) of the products obtained from the degradation of waste CITIMET

Proton NMR spectra of the products obtained from the degradation of CITIMET is provided in Fig. 14A and Fig. 14B, and Table 9 for the product cytidine.

Table 9

The degradation mechanism of the bonds in the pharmaceutical products deduced based on the electrochemical studies for the pharmaceutical formulations under consideration are given in Fig 15A to Fig. 15D.

Advantages:

The phyllosilicate based electro-catalyzed pharmaceutical drug degradation of the present disclosure has the following non-limiting advantages.

- Degradation of otherwise waste pharmaceuticals into useful products.

- Low carbon footprint of the device and the cathode is completely degradable into value added product upon recycling.

- Environmentally benign and safe electrolyte:

Applications:

The phyllosilicate based electro-catalyzed pharmaceutical drug degradation of the present disclosure has the following non-limiting industrial applications.

- The value-added products are raw materials for the chemical and pharma industry upon proper separation and purification

- Zero waste, Reduce, Reuse, Renew, Recycle, Repurpose (5R) compliance, circular economy and supply chain sustenance

Although the present disclosure is described in terms of certain preferred embodiments, it is to be understood that they have been presented by way of example, and not limitation. Thus, the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. An electrochemical assembly for degradation of a pharmaceutical product into a useful product, wherein the electrochemical assembly includes:

- a Mg-rich phyllosilicate containing cathode;

- an Ag/AgCl anode; and

- MgCh as electrolyte, wherein, the pharmaceutical product is applied onto the phyllosilicate of the cathode, wherein electrochemical action of the electrochemical assembly breaks the bonds of the drug molecules present in the pharmaceutical product and degrades the drug molecules into a useful product.

2. The electrochemical assembly for degradation of a pharmaceutical product into a useful product as claimed in claim 1 , wherein the Mg-rich phyllosilicate has a BET surface area of 89.7152 m²/g.

3. The electrochemical assembly for degradation of a pharmaceutical product into a useful product as claimed in claim 1 , wherein the Mg-rich phyllosilicate has a pore volume of 0.421749 cm³/g.

4. The electrochemical assembly for degradation of a pharmaceutical product into a useful product as claimed in claim 1 , wherein the Mg-rich phyllosilicate has an average pore size of 88.268 A.

5. A method of degradation of a pharmaceutical product into a useful product through electrochemical action comprising the steps of:

- preparing an electrochemical assembly containing a Mg-rich phyllosilicate containing cathode; an Ag/AgCl anode; and MgCh as electrolyte, wherein the Mg-rich phyllosilicate containing cathode is prepared by making a slurry of Mg-rich phyllosilicate in IM MgCh in deionised water; coating the phyllosilicate slurry on a current collector; and drying the slurry coated SS current collector at 60°C for 3 hours; - making the pharmaceutical product into a suitable consistency to be coated onto the Mg-rich phyllosilicate of the cathode;

- coating the pharmaceutical product in suitable consistency onto the Mg- rich phyllosilicate of the cathode; and

- initiating electrochemical action for the degradation of the drug molecules.

6. The method of degradation of a pharmaceutical product into a useful product through electrochemical action as claimed in claim 5, wherein when the pharmaceutical product is available in a solid dosage form, the solid dosage form is powdered; and a slurry of the powder is made in acetone, ethanol or isopropanol, wherein the slurry is coated onto the Mg-rich phyllosilicate of the cathode.

7. The method of degradation of a pharmaceutical product into a useful product through electrochemical action as claimed in claim 5, wherein when the pharmaceutical product is available in a semi-solid dosage form, the semisolid dosage form is directly coated onto the Mg-rich phyllosilicate of the cathode.

8. The method of degradation of a pharmaceutical product into a useful product through electrochemical action as claimed in claim 5, wherein the semi solid dosage forms include ointments, emulsions, suspensions, creams, and pastes.

9. The method of degradation of a pharmaceutical product into a useful product through electrochemical action as claimed in claim 5, wherein when the pharmaceutical product is available in a liquid dosage form, the liquid dosage form is mixed with a binder as ZnO and TiCT to form a paste, wherein the paste is coated onto the Mg-rich phyllosilicate of the cathode.

10. The method of degradation of a pharmaceutical product into a useful product through electrochemical action as claimed in claim 5, wherein the liquid dosage forms include vaccines, injections and syrups.

11. The method of degradation of the pharmaceutical product into a useful product through electrochemical action as claimed in claims 5 to 10, wherein the scan rate of voltage per second is controlled to break specific bonds of the drug molecules in order to obtain a desired useful product.