Synthesis and evaluation of the structural and physicochemical properties of carboxymethyl pregelatinized starch as a pharmaceutical excipient

Citric acid cross-linked pomegranate peel extract-loaded pH-responsive β-cyclodextrin/carboxymethyl tapioca starch hydrogel film for diabetic wound healing

Pomegranate peel extract (PPE) hydrogel films filled with citric acid (CA) and β-cyclodextrin-carboxymethyl tapioca starch (CMS) were designed mainly to prevent wound infections and speed up the healing process. FTIR and NMR studies corroborated the carboxymethylation of neat tapioca starch (NS). CMS exhibited superior swelling behavior than NS. The amount of CA and β-CD controlled the physicochemical parameters of developed PPE/CA/β-CD/CMS films. Optimized film (OF) exhibited acceptable swellability, wound fluid absorptivity, water vapor transmission rate, water contact angle, and mechanical properties. Biodegradable, biocompatible, and antibacterial films exhibited pH dependence in the release of ellagic acid for up to 24 h. In mice model, PPE/CA/β-CD/CMS hydrogel film treatment showed promising wound healing effects, including increased collagen deposition, reduced inflammation, activation of the Wingless-related integration site (wnt) pathway leading to cell division, proliferation, and migration to the wound site. The expression of the WNT3A gene did not show any significant differences among all the studied groups. Developed PPE-loaded CA/β-CD/CMS film promoted wound healing by epithelialization, granulation tissue thickness, collagen deposition, and angiogenesis, hence could be recommended as a biodegradable and antibacterial hydrogel platform to improve the cell proliferation during the healing of diabetic wounds.

Chemical and Physical Architecture of Macromolecular Gels for Fracturing Fluid Applications in the Oil and Gas Industry; Current Status, Challenges, and Prospects

Hydraulic fracturing is vital in recovering hydrocarbons from oil and gas reservoirs. It involves injecting a fluid under high pressure into reservoir rock. A significant part of fracturing fluids is the addition of polymers that become gels or gel-like under reservoir conditions. Polymers are employed as viscosifiers and friction reducers to provide proppants in fracturing fluids as a transport medium. There are numerous systems for fracturing fluids based on macromolecules. The employment of natural and man-made linear polymers, and also, to a lesser extent, synthetic hyperbranched polymers, as additives in fracturing fluids in the past one to two decades has shown great promise in enhancing the stability of fracturing fluids under various challenging reservoir conditions. Modern innovations demonstrate the importance of developing chemical structures and properties to improve performance. Key challenges include maintaining viscosity under reservoir conditions and achieving suitable shear-thinning behavior. The physical architecture of macromolecules and novel crosslinking processes are essential in addressing these issues. The effect of macromolecule interactions on reservoir conditions is very critical in regard to efficient fluid qualities and successful fracturing operations. In future, there is the potential for ongoing studies to produce specialized macromolecular solutions for increased efficiency and sustainability in oil and gas applications.

Process and isothermal storage stabilities of a live veterinary vaccine formulated with Plectranthus esculentus tuber starch derivatives as stabilizers

Comparability stability studies of a live Newcastle Disease LaSota vaccine were conducted post freeze-drying and during storage at 5±2, 25±2 and 37±1 °C to demonstrate the equivalence/inequivalence of stability profiles of vaccines stabilized with peptone (reference), trehalose and starch derivatives (acetylated xerogel and carboxymethylated) from Plectranthus esculentus tubers. Variations in moisture content during storage at 5±2 °C; physical collapse/shrinkage, partial microcollapse, and hydrophilicity of lyophilisates were prominent in starch stabilized vaccines without additives. Using the mean embryo infective dose (EID50) test, the derivatives and peptone stabilized vaccines had < 0.5 logEID50 loss in titre during freeze-drying. At the storage temperatures of 5±2, 25±2 and 37±1 °C, using peptone, acetylated xerogel starch, carboxymethylated starch, and trehalose, the average shelf lives of the vaccines were 23-55, 21-26, and 2.6-4.9 months respectively. Acetylated xerogel and carboxymethylated derivatives of Plectranthus esculentus tuber starch with/without additives were able to keep the live ND LaSota vaccine stable during freeze-drying at 1-3 % w/v. The stability of all the vaccines declined as storage temperatures increased. The acetylated xerogel stabilized vaccines were more stable than all of the others at 25±2 and 37±1 °C temperatures.

Preparation of Neohesperidin-Taro Starch Complex as a Novel Approach to Modulate the Physicochemical Properties, Structure and In Vitro Digestibility

Neohesperidin (NH), a natural flavonoid, exerts multiple actions, such as antioxidant, antiviral, antiallergic, vasoprotective, anticarcinogenic and anti-inflammatory effects, as well as inhibition of tumor progression. In this study, the NH-taro starch complex is prepared, and the effects of NH complexation on the physicochemical properties, structure and in vitro digestibility of taro starch (TS) are investigated. Results showed that NH complexation significantly affected starch gelatinization temperatures and reduced its enthalpy value (ΔH). The addition of NH increased the viscosity and thickening of taro starch, facilitating shearing and thinning. NH binds to TS via hydrogen bonds and promotes the formation of certain crystalline regions in taro starch. SEM images revealed that the surface of NH-TS complexes became looser with the increasing addition of NH. The digestibility results demonstrated that the increase in NH (from 0.1% to 1.1%, weight based on starch) could raise RS (resistant starch) from 21.66% to 27.75% and reduce RDS (rapidly digestible starch) from 33.51% to 26.76% in taro starch. Our work provided a theoretical reference for the NH-taro starch complex's modification of physicochemical properties and in vitro digestibility with potential in food and non-food applications.

An investigation on the adsorption and removal performance of a carboxymethylcellulose-based 4-aminophenazone@MWCNT nanocomposite against crystal violet and brilliant green dyes

The multistep chemical modification of carboxymethylcellulose (CMC) in the presence of 4-aminophenazone (A-PH) and multiwall carbon nanotubes (MWCNTs) has been successfully conducted. The environmental performance of this material has been thoroughly investigated. Crystal violet (CV) and brilliant green (BG) were eliminated by utilising a new hybrid nanocomposite material (A-PH-CMC/MWCNTs) from a simulated textile wastewater solution. Using SEM, EDX, XRD and FTIR spectroscopy methods, the detailed characterisation of A-PH-CMC/MWCNT nanocomposites was investigated. The results indicated that the adsorption capacity was dependent on six factors (e.g., contact duration, starting concentration, adsorbent mass, the effect of the solution pH, temperature and the effect of KNO3). In addition, thermodynamic and regeneration studies have been reported. According to the theories of pseudo-second-order kinetics, the removal process involves chemical adsorption. The experimental results were best suited by the Langmuir model, in which maximum adsorption capacities of 20.83 and 22.42 mg g-1 were predicted for the BG and CV dyes, respectively. The research is a preliminary case study demonstrating the excellent potential of A-PH-CMC/MWCNT nanocomposites as a material for CV and BG dye removal.

Effects of Autoclaving and Freeze-Drying on Physicochemical Properties of Plectranthus esculentus Starch Derivatives

The goal of this research was to assess the effects of autoclaving followed by freeze-drying on acetylated xerogel (AXS) and carboxymethylated (CMS) derivatives of Plectranthus esculentus starch as potential vaccine stabilizers. Starch extracted from tubers of P. esculentus were modified by single (carboxymethylation) and dual (acetylation followed by xerogel formation) methods. The derivatives were formulated into vaccine stabilizer suspensions, autoclaved, and freeze-dried without additives or antigen. The derivatives and freeze-dried products were assessed by physical appearance, titration, moisture content (MC), TGA, DSC, XRD, SEM, and FTIR analyses. The degrees of substitution (DS) of the CMS and AXS derivatives were 0.345 and 0.033, respectively. Modification significantly reduced the MC of the derivatives. Freeze-dried AXS (FAXS) had lower MC than freeze-dried CMS (FCMS). The lower degree of hydrophilicity/MC of AXS and FAXS was confirmed by TGA and FTIR band intensities and shifts. Reduction in DSC water desorption/evaporation enthalpies (ΔH) from - 1168.8 mJ (NaS) to - 407.48 mJ (AXS) confirmed the influence of modification on moisture. FTIR confirmed acetylation and carboxymethylation of the derivatives by the presence of 1702.9 cm^-1 and 1593 cm^-1 bands, respectively (FTIR). Increasing concentrations of the derivatives yielded uncollapsed/unshrunken lyophilisates. SEM and XRD showed that modification, autoclaving, and freeze-drying yielded beehive-like microstructures of FCMS and FAXS that were completely amorphous. Processing (autoclaving and freeze-drying), therefore, enhanced the amorphousness of the starch derivatives which is required in vaccine stability during processing and storage. These findings indicate that these starch derivatives have potential as novel vaccine stabilizers.

Physicochemical and Functional Properties of Modified KJ CMU-107 Rice Starches as Pharmaceutical Excipients

Starch extracted from KJ CMU-107 rice, with amylose content of 13.4%, was modified to yield pre-gelatinized starch (PGS), carboxymethyl starch (CMS), crosslinked carboxymethyl starch (CLCMS), crosslinked starch (CLS), and hydroxypropyl starch (HPS). Their physicochemical properties were assessed in comparison with the native starch (NS), and their functional properties were then evaluated for potential use as pharmaceutical excipients. Scanning electron microscopic (SEM) images and X-ray diffraction (XRD) patterns showed that granules of all but one of the modified starches retained the native character and crystalline arrangement. The exception, PGS, exhibited extensive granular rupture, which correlated with the loss of crystallinity suggested by the amorphous halo in XRD. Energy-dispersive X-ray (EDX) data confirmed the modification by the presence of related elements. Carboxymethylation increased solubility in unheated water, while crosslinking improved swelling. All modified starches displayed improved oil absorption capacity by 17–64%, while CMS and CLCMS also exhibited significant moisture sorption at above 75% RH PGS and HPS exhibited lower gelatinization temperature (Tg) and enthalpic change (ΔH), while CLS showed higher Tg and ΔH. CMS, CLCMS, and CLS showed adequate powder flow and compactibility, qualifying as potential tablet excipients. The 5% w/v solutions of CMS, CLMS, and HPS also formed intact films with suitable tensile strength. Overall, modified starches derived from KJ CMU-107 could potentially be developed into new pharmaceutical excipients.

Starch chemical modifications applied to drug delivery systems: From fundamentals to FDA-approved raw materials

Starch derivatives are versatile compounds that are widely used in the pharmaceutical industry. This article reviews the advances in the research on hydrophilic and hydrophobic starch derivatives used to develop drug delivery systems over the last ten years, specifically microparticles, nanoparticles, nanocrystals, hydrogels, and scaffolds using these materials. The fundamentals of drug delivery systems, regulatory aspects, and chemical modifications are also discussed, along with the synthesis of starch derivatives via oxidation, etherification, acid hydrolysis, esterification, and cross-linking. The chemical modification of starch as a means to overcome the challenges in obtaining solid dosage forms is also reviewed. In particular, dialdehyde starches are potential derivatives for direct drug attachment; carboxymethyl starches are used for drug encapsulation and release, giving rise to pH-sensitive devices through electrostatic interactions; and starch nanocrystals have high potential as hydrogel fillers to improve mechanical properties and control drug release through hydrophilic interactions. Starch esterification with alginate and acidic drugs could be very useful for site-specific, controlled release. Starch cross-linking with other biopolymers such as xanthan gum is promising for obtaining novel polyelectrolyte hydrogels with improved functional properties. Surface modification of starch nanoparticles by cross-linking and esterification reactions is a potential approach to obtain novel, smart solid dosages.

Foldable/Expandable Gastro-retentive Films Based on Starch and Chitosan as a Carrier For Prolonged Release of Resveratrol

BACKGROUND

Resveratrol exerts a number of therapeutic effects, notably anti-inflammatory, antioxidant and anti-cancer activities which are beneficial for the treatment of gastric diseases. However, the efficacy of resveratrol is severely limited due to the poor aqueous solubility and rapid metabolism following oral administration. As a result, foldable/expandable devices based on natural polymers merging with solid dispersion technology have been developed to increase the solubility, prolong the gastric residence time, and provide a controlled release therapy of resveratrol.

OBJECTIVES

This research aimed to invent foldable/expandable films based on natural polymers, including starch and chitosan, for stomach-specific delivery and prolonged release of resveratrol.

METHODS

The films were prepared by solvent casting using either rice, tapioca, corn starch or pre-gelatinized corn starch combined with chitosan in different weight to weight ratios. Glycerol was included as a plasticizer. Resveratrol solid dispersions (Res-SD) prepared by solvent evaporation and employing PVP-K30 as a hydrophilic polymer were loaded into the polymeric film, which was subsequently folded prior to insertion in a hard gelatin capsule.

RESULTS

The solid dispersions improved the solubility of resveratrol by a factor of 500. All Res-SD loaded film formulations completely unfolded in simulated gastric fluid at 37oC within 10 min. Fluid absorption by the films was influenced by the ratio of amylose and amylopectin in the starch granules, with tapioca starch formulations displaying the highest fluid uptake. Films prepared from pre-gelatinized corn starch and chitosan resulted in highly efficient delivery of resveratrol, with more than 80%of the content released over a period of 12 hrs. Furthermore, the released polyphenol exhibited cytotoxic activity against human gastric adenocarcinoma cells and anti-inflammatory effects against lipopolysaccharide-stimulated murine, macrophage-like cells.

CONCLUSIONS

These findings demonstrate the potential of foldable/expandable films based on natural polymers as a promising stomach-specific carrier for improving the treatment of gastric disorders.

The Use of Natural Materials in Film Coating for Controlled Oral Drug Release

BACKGROUND

Although synthetic materials have been used in film coating processes for drug delivery for many years, substantial studies on natural materials have also been conducted because of their biodegradable and unique properties.

METHODS

Because of the ability to form and modify films for controlled oral drug delivery, increasing attention has been shown to these materials in the design of film coating systems in recent research.

RESULTS

This review aims to provide an overview of natural materials focusing on film coating for oral delivery, specifically in terms of their classification and their combinations in film coating formulations for adjusting the desired properties for controlled drug delivery.

CONCLUSIONS

Discussing natural materials and their potential applications in film coating would benefit the optimization of processes and strategies for future utilization.

Carboxymethyl Cellulose and Carboxymethyl Starch as Surface Modifiers and Greying Inhibitors in Washing of Cotton Fabrics

This research is focused on cellulose and starch derivatives, carboxymethyl cellulose (CMC) and carboxymethyl starch (CMS), added to the detergent in washing reference cotton fabric in soft and hard water at 40, 60 and 90 °C. The applied polymers were analyzed through the potential of surface cellulose modification and inhibition of stain transfer from standard stain donors to modified and initial cotton fabrics. The surface modification of the cotton fabrics, characterized by the zeta potential and amounts of deposits, was coupled with the cluster analysis as well as a whiteness assessment. The obtained results of the zeta potential and degree of whiteness of the reference cotton fabrics before and after washing showed differences between CMC and CMS. The appropriateness of the cluster analysis was confirmed in assessing the potential of applied polymers for surface modification of cotton fabrics and greying inhibition.

Effect of thermal modification on the release characteristics of pink potato starch of Jharkhand, India

Excipient plays an essential role in drug delivery system, which promotes the drug to reach a particular site of action. Excipients directly or indirectly affect the duration and rate of drug release and absorption. In the current study, physicochemical properties, flow properties and release characteristics of native and modified pink potato starches were investigated to determine their excipient characteristics. Amylose content, water holding capacity, swelling and solubility properties were found to increase after pregelatinization and retrogradation. The SEM micrographs reveals the loss of granular structure of native after thermal modification. The FT-IR study confirms the gelatinization characteristics of the pregelatinized starch. X-ray diffraction pattern confirms the reduction of crystallinity after thermal modification. Tablets containing Paracetamol as a model drug showed that native, pregelatinized and modified pink potato starch could be useful for the manufacturing of immediate release formulation.

Insight on the changes of cassava and potato starch granules during gelatinization

Gelatinization is an important property of starch for biomedical applications. However, studies on the changes in starch granules in terms of morphology, swelling, amylose leaching and so on during gelatinization, which are key to uncovering the starch gelatinization process, have rarely been reported. Herein, changes of cassava and potato starch granules during gelatinization were investigated. It was found that there is a substantial difference in the granule changes during gelatinization between cassava and potato starch. Cassava starch granules remain intact with slight swelling, with approximately 8.5% amylose leaching in water for 30 min at 60 °C. In sharp contrast, potato starch granules swell very well and rapidly, losing much integrity with 51.05% amylose leaching. The gelatinization time and temperature have much greater effects on the changes of potato starch granules than cassava starch granules.

Factorial analysis of the binding properties of acetylated ginger starch in metronidazole tablet formulations

INTRODUCTION

The delivery of drug is often affected by formulation processes and the excipients used in the formulation.

MATERIALS AND METHODS

A 2³ factorial analysis was used in this study to evaluate the effect of acetylated ginger starch (AGS) (Zingiber officinale) as a binder in metronidazole tablets, in comparison to corn starch (CS) BP. The individual and interacting effects of variables (binder type X₁, binder concentration X₂, and compression pressure X₃) used on tablet properties such as friability, crushing strength, crushing strength friability ratio (CSFR), disintegration and crushing strength friability/disintegration time ratio (CSFR/DT) were determined. The effect of these binders on the granule properties using Hausner's ratio, Carr's index (CI), angle of repose, and densities as response parameters was also determined.

RESULTS

Granules prepared with AGS had high densities and small granule sizes when compared with those containing CS. Granules containing CS have better flow properties. X₁ (binder type) has a significant effect on the crushing strength of the tablet. It also had the highest effects on CSFR and CSFR/DT. The combination of X_IX₃ had the highest effect on crushing strength and DT.

CONCLUSION

This study shows that, in formulations, care must be taken in choosing the excipients and the process parameters required for the formulation since these can affect the delivery of the drug individually or in combination. AGS could be useful as a binder when a tablet with low crushing strength and fast disintegration is desired.