Carboxymethyl Tamarind Kernel Research Articles

Synthesis and characterization of novel carboxymethyl tamarind kernel gum - Poly (vinyl alcohol)/guar gum-based hydrogel film loaded with ciprofloxacin for biomedical applications

The current study delineates the synthesis of hydrogel films comprised of carboxymethyl tamarind kernel gum (CMTKG), poly (vinyl alcohol) (PVA), and guar gum (GG) using glutaraldehyde (GL) as cross-linker. The hydrogel films were evaluated in terms of equilibrium swelling ratio (ESR), moisture content, thickness, wetting analysis, thermal, and mechanical analysis. The tensile strength value lies in the range of 95.80 to 149.07 MPa while elongation at break value lies in the range of 1.51 to 5.20 %. The FTIR spectroscopy confirmed the presence of hydrogen bonding between CMTKG, PVA, and GG components of hydrogel film. FE-SEM micrographs indicated the rough surfaces of hydrogel film. TGA-DTA analysis confirmed that the thermal stability of hydrogel film was found to be increased by incorporating the ciprofloxacin (CFX) drug into the hydrogel matrix. CFX was embedded in the best-swelled hydrogel film and in-vitro drug release behavior was studied at alkaline pH 7.4 phosphate buffer solution. It was found that the maximum drug release was to be 73 % after 24 h at pH 7.4. Moreover, the release data was fitted in various kinetic models such as the First-order, Higuchi, and Korsmeyer-Peppas models. The best-fitted Korsmeyer-Peppas model suggested that the release of the drug follows Fickian diffusion and the value of diffusion exponent (n) was determined to be 0.38. The cytocompatibility of the hydrogel film was analyzed by MTT assay while the antibacterial behavior of the hydrogel film against E. coli and S. aureus showed clear zone of inhibition area. Thus, the overall results indicated that CMTKG/PVA/GG hydrogel film have potential to be used in the biomedical applications.

Tailoring pH-sensitive carboxymethyl tamarind kernel gum-based hydrogel for an efficient delivery of hydrophobic drug indomethacin

Polyacrylamide hydrogels have gained attention in the drug delivery field for their pH-dependent nature. Nevertheless, their limited degradability and lower entrapment efficiency for hydrophobic drugs hinder their utility in controlled drug release. This research aims to design a degradable pH-sensitive hydrogel for delivering the hydrophobic drug indomethacin to the colon. This work developed and optimized the hydrogels based on β-cyclodextrin, carboxymethyl tamarind kernel gum, and polyacrylamide with varying amounts of polyethylene glycol diacrylate. The optimized hydrogel exhibits 76.52 % gel fraction, 89.21 % porosity, 1000.27 % swelling, and 90.0 % equilibrium water content. The hydrogel was characterized using Attenuated Total Reflection-Fourier Transform Infrared spectroscopy, confirming the successful crosslinking of the synthesized hydrogel. Powder X-ray Diffraction revealed their amorphous nature while Scanning Electron Microscopy showed a porous surface morphology of the hydrogel. Moreover, rheology confirmed the hydrogel's elastic nature. Notably, the hydrogel demonstrated a drug release of 60.26 % at pH 7.4. Kinetic modelling of indomethacin release data indicated a Fickian diffusion release mechanism. Cytotoxicity tests on HCT-116 cells showed 79 % viability, and the hydrogel fully degraded within 10 days. These results confirmed the potential of synthesized β-CD/PAM/CMTKG hydrogel for controlled indomethacin delivery to the colon.

Fabrication of carboxymethyl tamarind kernel gum-based hydrogel and its applicability in different types of soils for agronomy

An avant-garde agricultural hydrogel - Carboxymethyl tamarind kernel gum-poly sodium acrylate-polyacrylamide hydrogel was designed by free-radical polymerization of biopolymer: carboxy-methyl tamarind kernel gum and monomers: sodium acrylate, acrylamide, using N,N′ methylene bisacrylamide as crosslinker and potassium persulphate as initiator, to explore its application as a soil conditioner. It was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric techniques. Swelling was investigated at different pH and in saline solutions. The fabricated hydrogel absorbed 189 ml/g of distilled water. Minimal 0.1 % hydrogel-amended different soils unveiled an upswing in maximum water holding capacity: Sandy soil (43%), Clay soil (31 %), Silty soil (29 %) & Loamy soil (9 %).; decrease in porosity: Sandy (29 %) > Loamy (15.2 %) > Silty (6 %) > Clay (5.9 %), increase in available water content: Clay soil (17.52 %), Silty (13.45 %), Loamy soil (9.416 %), Sandy soil (10.375 %); increase in bulk density: Clay (1.7 %), Silty (5.3 %), Loamy (10 %) and Sandy (13%) as compared to control sample. These sequels were corroborated by water retention capacity in chickpea plants. The designed hydrogel, as a soil conditioner, was commendable in all types of soils but is worth applying in sandy and loamy soils. This hydrogel richly assists as a soil conditioner and boosts plant performance in a green eco-friendly way.

Synthesis and Assessment of Acacia Gum‐Based Hydrogel as a Promising Novel Biopolymeric Matrix for Delivery of Ciprofloxacin

AbstractIn this current study, hydrogels based on acacia gum (AG), polyacrylamide (PAM), and carboxymethyl tamarind kernel gum (CMTKG) were successfully developed and ciprofloxacin (drug) incorporated into it. To optimize the hydrogel, the concentrations of crosslinker and initiator were varied, and their effects on the swelling were examined. The hydrogel was subjected to characterization techniques such as Powder X‐ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Attenuated Total Reflection‐Fourier Transform Infrared spectroscopy (ATR‐FTIR), and Thermogravimetric analysis (TGA). The hydrogel swelling and in vitro drug release were assessed in pH 1.2 and 7.4 buffer solutions. The findings revealed that an alkaline pH yielded superior results for the swelling and in vitro drug release experiments compared to an acidic pH. The drug release kinetic of the ciprofloxacin‐loaded AG/PAM/CMTKG hydrogel followed the Korsmeyer–Peppas model, demonstrating non‐fickian diffusion at pH 7.4 and fickian mechanism at pH 1.2. The pH‐dependent behavior of ciprofloxacin‐loaded AG/PAM/CMTKG hydrogel displayed its potential implications for site‐specific ciprofloxacin release.

Optimizing antimicrobial efficacy and ammonia sensing in a novel carboxymethyl tamarind kernel gum/Fe nanocomposite

Iron nanoparticles were synthesized utilizing Carboxymethyl tamarind kernel gum (CMTKG), which acted as both a reducing and stabilizing agent. Through an in situ co-precipitation method, CMTKG/FeO nanocomposites were synthesized, employing epichlorohydrin as a cross-linking agent. Characterization of the obtained CMTKG/FeO nanocomposites was conducted through various techniques including Scanning Electron Microscopy (SEM), Dynamic light scattering (DLS), Ultraviolet spectroscopy, Fourier transform infrared (FTIR), Thermal analysis (TGA), and X-ray diffraction analysis (XRD), revealing an average size of 60–90 nm. The application of these nanocomposites was explored in the sensing of ammonia in an aqueous medium at room temperature, demonstrating a noticeable change in the intensity of the surface plasmon resonance peak with increasing ammonia concentration, resulting in a shift from 313 nm to 331 nm. Additionally, the antimicrobial efficacy of the synthesized CMTKG/FeO nanocomposites was evaluated against urinary tract isolates including Pseudomonas aeruginosa, E. coli, and Enterococcus faecalis. Interestingly, the nanocomposites exhibited significant activity specifically against Enterococcus faecalis, manifesting a zone of inhibition measuring 12.4±0.5 mm.

Synthesis and application of zinc-loaded carboxymethyl tamarind kernel gum and xanthan gum-based superabsorbent hydrogels to investigate the effect on sesame plant growth

Synthesis and application of zinc-loaded carboxymethyl tamarind kernel gum and xanthan gum-based superabsorbent hydrogels to investigate the effect on sesame plant growth

Carboxymethyl Tamarind Kernel Gum Nanoparticles; As an Antioxidant Activity

The incorporation of biopolymer nanoparticles with potential antioxidant properties into biomaterials for human health care is significant. The current study focuses on nanoparticles carboxymethyl tamarind kernel gum (CMTKG) composite materials because of their potential applications. The co-precipitation method was used to create carboxymethyl tamarind kernel gum nanoparticles (CMTKG-NPs). This technique was used for the first time to create carboxymethyl tamarind kernel gum nanoparticles. The strength of nanoparticle conformation is reported to be influenced by co-precipitation and stirring time. Nanoparticles were characterised using high-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), fourier transform infrared (FTIR), x-ray diffraction analysis (XRD), and thermo-gravimetric analysis (TGA). Suspense particle sizes have been determined to be in the 40-60 nm range. It was concluded that similar nanoparticles could be used in antioxidant activities.

Removal of Cationic Crystal Violet dye using Zeolite‐ Embedded Carboxymethyl Tamarind Kernel Gum (CMTKG) based Hydrogel Adsorbents

AbstractIn this research paper, various formulations of zeolite‐loaded carboxymethyl tamarind kernel gum (CMTKG) based hydrogels were synthesized and utilized as a potential adsorbent for the removal of crystal violet (CV) dye. The swelling capacity of all the synthesized hydrogels was investigated and the composition of hydrogel which exhibited maximum swelling was used for the characterization and dye removal experiment. The CV dye was chosen as a model dye for the dye removal experiment. The structure of zeolite and zeolite embedded hydrogel was elucidated by XRD, FTIR, FE‐SEM, EDX and elemental papping techniques. The adsorption experiment was investigated by varying the CV concentration, amount of hydrogel adsorbent, temperature, pH of the dye solution, adsorption time, and ionic strength. The Langmuir and Freundlich isotherm models were used to fit the adsorption data and it was observed that the data fitted well with the Langmuir model. Moreover, hydrogel‘s maximum dye adsorption efficiency was found at 123.60 mg g−1. The adsorption kinetic studies were followed by pseudo‐ first‐order and intraparticle diffusion kinetic models. In addition, regeneration studies were performed for the best adsorbent hydrogel using ethanol solvent and the result concluded the desorption efficiency of hydrogel (82 %) over four desorption cycles.

Development and assessment of carboxymethyl tamarind kernel gum-based pH-responsive hydrogel for release of diclofenac sodium

The current research work focuses on the fabrication of carboxymethyl tamarind kernel gum/polyvinylpyrrolidone/polyacrylamide (CMTKG/PVP/PAM) based hydrogel and its loading was done with diclofenac sodium drug (DS) to obtain smart pH-responsive hydrogels. In addition, the effect of concentration of cross-linker- N, N′-methylene bis(acrylamide) (MBA), biopolymer (CMTKG), as well as initiator- potassium persulphate (KPS) on the swelling behavior of smart hydrogel was also analyzed. The synthesized hydrogels were characterized using Scanning Electron Microscopy (SEM), Powder X-ray Diffraction (PXRD), Thermogravimetry Analysis (TGA), and Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR). ATR-FTIR confirms the successful formation of hydrogels, while PXRD and SEM indicate the amorphous and porous nature of the polymeric network. The TGA results indicate higher thermal stability for DS-loaded hydrogel than unloaded hydrogel. However, sol–gel analysis shows a rise in gel fraction, with increased concentrations of CMTKG, MBA, and KPS. The swelling ratio as well as the release of DS were found to be higher under slightly alkaline conditions. The result of drug loading and release indicates that PVP increases drug loading (%) and release (%). The drug release behavior of DS-loaded hydrogel follows the Fickian mechanism of diffusion with the Korsmeyer-Peppas model as the best-fitted one. The synthesized DS-loaded CMTKG/PVP/PAM hydrogels could be a promising substitute for prolonged delivery of sparingly soluble DS in pH 7.4.

Nano ZnO embedded poly (ethylene glycol) diacrylate cross-linked carboxymethyl tamarind kernel gum (CMTKG)/poly (sodium acrylate) composite hydrogels for oral delivery of ciprofloxacin drug and their antibacterial properties

In this research work, a novel hydrogel network based on carboxymethyl tamarind kernel gum/poly (sodium acrylate) was synthesized by using poly (ethylene glycol) diacrylate (PEGDA) as a cross-linker. Zinc Oxide nanoparticles (ZnO NPs) were prepared via the hydrothermal synthetic method and developed ZnO NPs embedded within CMTKG/Poly (sodium acrylate) hydrogel for the controlled release studies of ciprofloxacin drug. Various techniques such as FTIR, XRD, FESEM, and TEM were used to characterize the synthesized ZnO NPs, pure hydrogel, and hydrogel nanocomposites. Various parameters such as drug loading (DL %), drug entrapment (DE %), gel content, and porosity were estimated for all the synthesized hydrogel nanocomposites. The results of swelling and rheological studies of hydrogel nanocomposites concluded that the embedded ZnO NPs increased hydrogel's swelling and thermal stability. The water absorption data were analyzed using the Power and Schott model. The result concluded that the Schott function model fitted the dynamic swelling data. The antibacterial action of CMTKG-based hydrogel nanocomposites was studied using E. coli (gram-negative) bacteria with the help of the disc diffusion method. The result showed that the incorporation of ZnO NPs enhanced the antimicrobial action of ciprofloxacin-loaded CMTKG-based hydrogels. The kinetic modelling of drug release was done using Higuchi and Korsmeyer - Peppas model. The higher value of regression coefficient (R2) close to unity indicated that the mechanistic pathway of drug release from the hydrogels was more fitted in the Korsmeyer-Peppas model followed by Fickian diffusion.

Organic Hybrid Hydrogels: A Sustenance Technique in Waste‐Water Treatment

AbstractWater sustenance is the primary exigency for human survival, besides being significant for food, energy generation, ecology, and socio‐economic modernization. The water crisis headed call for wastewater treatment. Owing to positive aspects of Organic Hybrid Hydrogels (OHH) viz. non‐toxicity, multiple‐functionalities, biodegradability, biocompatibility, and high sorption capacities; researchers are exploring their usage in waste‐water treatment for removal of organic (dyes) and inorganic (heavy metals, radionuclides) contaminants. The boon of OHH application is their ease of separation after the adsorption of pollutants by removing and dewatering them. This review corroborates the complete design of the synthesis of hydrogels, and the adsorption of impurities by them followed by their recovery, required for successful application in the removal of organic and inorganic contaminants from wastewater. It was observed hydrogels employed for the removal of metal ions and dyes follow either Langmuir or Freundlich isotherm or both. The usage of bio‐based hydrogels increased the adsorption of contaminants from wastewater. Due to the scarcer exploration of bio/hybrid hydrogels (especially carboxymethyl tamarind kernel gum), this review is expedient for researchers for developing green hydrogels as a water conservation and sustenance technique.

Carboxy-methyl tamarind kernel gum based bio-hydrogel for sustainable agronomy

The innovative superabsorbent bio-tech hydrogels were concocted by free radical polymerization of sodium-methacrylate & carboxymethyl tamarind kernel gum, for application in agronomical procedures as a soil conditioner & water harvester for sustainable agronomy. The structural morphologies of the hydrogel were characterized by techniques viz. Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The hydrogel was evidenced as a biodegradable hydrogel via the soil burial biodegradability test. The swelling behavior of hydrogel was analyzed as a function of temperature, pH, and salt solutions. The formulated hydrogel engrossed 248 ml/g water and 0.5% CMTKG-PSMA hydrogel amended soil revealed augmentation in the maximum water holding capacity (46.5%), porosity (14%), shoot length (43%), available water content (37%). A decrease in bulk density (8%) was also observed. The water intake was Fickian diffusion following Korsmeyer-Peppas Equation. These upshots were validated upon chickpea plants. These hydrogels proffer a promising substitute as a soil conditioner in agronomy.

Carboxymethyl Tamarind Kernel Gum /ZnO- Biocomposite: As an Antifungal and Hazardous Metal Removal Agent

ZnO nanoparticles (ZnO NPs) were in situ mixed with carboxymethyl tamarind kernel gum to generate the new biocomposite. High-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR), x-ray diffraction analysis (XRD), and dynamic light scattering (DLS)were used to characterize the CMTKG/ZnO nanocomposites. Numerous characterizations were utilized to prove that ZnO NPs had been integrated into the biopolymer matrix. The standard size of the CMTKG/ZnO nanocomposites was developed to be greater than 32–40 nm using high-resolution transmission electron microscopy and x-ray analysis de-Scherer methods. Chromium (VI) was removed from the aqueous solution using the nanocomposite (CMTKG/ZnO) as an adsorbent. The nanocomposite reached its maximum adsorption during 80 minutes of contact time, 30 mg/L chromium (VI) concentration, 2.0 g/L adsorbent part, and 7.0 pH. Further research into the antifungal activity of CMTKG/ZnO nanocomposites against Aspergillus flavus MTCC-2799 was conducted.

Preparation and Characterization of Calcium Cross-linked Carboxymethyl Tamarind Kernel Polysaccharide as Release Retardant Polymer in Matrix

This study aims to improve the efficacy of carboxymethyl tamarind kernel polysaccharide by cross-linking with Ca2+ ion and preparing its diclofenac sodium loaded matrix tablets for sustained drug delivery applications. Ionic gelation technique was used for cross-linking, and calcium chloride was used as a cross-linking agent. The native and cross-linked polysaccharide was characterized to analyze the change. The successful cross-linking of calcium was confirmed by infrared spectra by evaluating change in the functional group, while diffraction patterns revealed the change in crystallinity behavior. The thermal property of modified gum was also improved after Ca2+ cross-linking, whereas microscopical images of both gums revealed the gum's change in shape and surface. Further, calcium cross-linked carboxymethyl tamarind kernel polysaccharide was formulated into a matrix tablet using diclofenac sodium. The weight variation, thickness, hardness, friability, content uniformity, moisture content, swelling index, and in vitro release kinetics were also evaluated. The in vitro release study revealed that modified gum tablets showed a sustained release of diclofenac sodium providing a release of 50.84 % of drug over 24 hours, following first-order kinetics with a super case – II transport mechanism. So, the results indicate that calcium cross-linking of CMTKP modifies its release behavior, making it suitable for preparing sustained release pharmaceutical formulation.

Carboxymethyl Tamarind Kernel Gum based Controlled Drug Delivery Excipients: A Review

The Carboxymethyl Tamarind Kernel Gum (CMTKG) is a natural based polysaccharide which has been derived from the Tamarind kernel gum (TKG) through the carboxymethylation process. The chemical alteration of TKG into CMTKG has resulted in amplifying swelling capacity, in situ gelations, wide pH tolerance, high drug holding efficiency, stability, release kinetics, and hydrophilicity. Out of many application-based areas, it has extensively been used in the field of drug delivery systems via developing various forms like nanoparticles, composites, films, hydrogels, and pellets. This article is planned to fill in as a helpful tool for research scholars, who are engaged in green polymers, and in giving almost every aspect of CMTKG in the sphere of drug delivery.

Correction to: Zinc micronutrient-loaded carboxymethyl tamarind kernel gum-based superabsorbent hydrogels: controlled release and kinetics studies for agricultural applications

Correction to: Zinc micronutrient-loaded carboxymethyl tamarind kernel gum-based superabsorbent hydrogels: controlled release and kinetics studies for agricultural applications

Zinc micronutrient-loaded carboxymethyl tamarind kernel gum-based superabsorbent hydrogels: controlled release and kinetics studies for agricultural applications

The novel zinc-loaded superabsorbent hydrogel (ZSAH) was synthesized through in situ incorporation of zinc micronutrient in carboxymethyl tamarind kernel gum cross-linked network. The synthesized ZSAH was characterized by FTIR, SEM, TGA, swelling studies, etc. and found to have good water absorption capacity (410 g/g in distilled water) and with entanglement of zinc with weak physical forces. The ZSAH thus synthesized was assessed for controlled release application in soil as well as water, to test its application in the field of agriculture. The ZSAH exhibited slow and steady release pattern of zinc with 55% release within 72 h in water, and 83% release within 80 days in soil. Under the release kinetics studies, Korsmeyer-Peppas model was found to be best explaining the zinc release pattern through ZSAH. The ZSAH followed Fickian mechanism for release and it was observed that the diffusion was independent of the structure of the polymeric network. The time for zinc release from ZSAH, predicted as per the Olson’s single exponential model, revealed significantly prolonged T99 (time for release of 99% Zn) in water (12.22 days) as also in soil (625 days). Hence, the novel synthesized ZSAH exhibited great potential as a zinc micronutrient delivery system in agriculture.

Controlled release and release kinetics studies of boron through the functional formulation of carboxymethyl tamarind kernel gum-based superabsorbent hydrogel

The novel Boron micronutrient-loaded superabsorbent hydrogel (BSH) was synthesized via in situ mechanism having carboxymethyl tamarind kernel gum (CMTKG) as its principle component. The synthesis was established by thermal gravimetric analysis examination, scanning electron microscopy micrographs studies, and Fourier transform infrared analysis. The influence of various solvents, such as standard saline solution, different pH solutions (4, 9, 12), and distilled water on the swelling degree of BSH, was examined. Out of all the mentioned solvents, the highest swelling degree was noticed by the distilled water (465 g/g). The BSH was also examined for the agricultural application to assess the release of the boron micronutrient. It was established by studying and calculating the release behavior pattern along with the release kinetics of BSH in water, and as well in soil. It is significant to note that in soil, BSH exhibited 20.07% for the 1st day which notably increased to 76.17% on the 80th day. Release kinetic studies suggested that the Korsmeyer–Peppas model fitted the best out of all the models used, in the case of water, which also revealed that the release of boron from BSH was independent of the polymeric network as it followed Fickian diffusion mechanism. However, in the case of soil, the release was observed to follow the Higuchi model. The half-life and time period for the release of 95% and 99% were calculated as per the Olson’s single exponential model, to predict the pattern of boron release from developed BSH formulation. Release time for 99% boron in the soil, 274 days (with a half-life of 38 days), was found higher than in water, 9.33 days (with a half-life of 1.29 days). Thus, moisture-retaining BSH also successfully revealed slow boron release behavior.

Green fabrication of AuNPs/CMTKP/g-C3N4 nanocomposites with enhanced photocatalytic activity for the removal of nitric oxide under visible-light irradiation

A facile and green method of in-situ photo-reduction was developed to fabrication the AuNPs/CMTKP/g-C3N4 nanocomposites catalyst. Carboxymethyl tamarind kernel polysaccharide (CMTKP) was used to regulate and stabilize the monodispersed AuNPs onto g-C3N4 NSs surface. The morphology, microstructure and composition of the Au-CMTKP-g-C3N4 nanosheets hybrids were systematically characterized. The NO removal experiments showed that AuNPs/CMTKP/g-C3N4 nanocomposites exhibited excellent visible-light response and enhanced photo-oxidization ability to inhibit the generation of NO2. Compared with g-C3N4 NSs, the removal efficiency of 4 wt% Au-CMTKP-g-C3N4 NSs was increased by 27.5%. Reactive radicals during the photocatalysis processes were identified by electron spin resonance (ESR) study. As identified by ESR, ·O2−, ·OH and photogenerated holes could be considered as the main activated species involved in NO removal. The possible mechanism for photocatalytic NO oxidation was also proposed. Meanwhile, this photocatalyst also demonstrates suitable stability, showing good potential in practical applications.

Silica coating of carboxymethyl tamarind kernel polysaccharide beads to modify the release characteristics

In present study, the release characteristics of ibuprofen-loaded carboxymethyl tamarind kernel polysaccharide beads were modified by coating with silica. The influence of concentrations of carboxymethyl tamarind kernel polysaccharide, calcium chloride and tetraethoxysilane on the % entrapment and in vitro release of ibuprofen was optimized using response surface methodology. The coating of beads with silica restricted the drug release from the beads but at the same time the ethanol formed as by-product of the sol gel process leached out the drug. The optimized batch of beads were prepared using carboxymethyl tamarind kernel powder-12.5 (%, w/v), calcium chloride-10.12 (%, w/v) and coated with tetraethoxysilane-0.25 M, entrapped 89.2% and released 92% of drug over 24 h. Energy dispersive X-ray analysis confirmed the coating of silica on the beads. The coating with silica shielded the crevices on the surface of beads but it did not elicit any significant change in thermal stability of beads. Further, in vitro release was found to be in good agreement with the swelling study. Modeling analysis revealed that ibuprofen was released from the beads following zero-order kinetics with erosion of the matrix as the main mechanism of drug release. Thus, silica coating provides a facile strategy to formulate sustained release formulations.