Modified Potato Starch as a Potential Retardant for Prolonged Release of Lidocaine Hydrochloride from Methylcellulose Hydrophilic Gel

Exploring starch-based excipients in pharmaceutical formulations: Versatile applications and future perspectives

Starch, a naturally abundant and biocompatible polysaccharide, serves as a key excipient in pharmaceutical formulations, enhancing drug stability, efficacy, and manufacturability. This review explores the properties, modifications, and diverse applications of starch-based excipients. Native starches from corn, potato, rice, and wheat are commonly used as disintegrants, binders, and fillers. Physical (e.g., pre-gelatinization), chemical (e.g., cross-linking, acetylation), and enzymatic modifications improve their functionality, such as enhanced stability and colon-specific drug delivery. Starch excels as a binder, improving tablet cohesion and strength, and as a disintegrant, promoting rapid drug release. It also supports controlled and sustained-release systems and advanced drug delivery methods, like nanoparticles and microparticles. Compared to other natural and synthetic excipients, starch offers advantages in biodegradability, non-toxicity, and cost-effectiveness, despite challenges like stability and batch variability. Innovations such as starch nanocrystals show promise in boosting drug solubility and bioavailability. Looking ahead, starch-based excipients hold potential for sustainable pharmaceutical development, personalized medicine, and 3D printing.

Effect of Co-Solvents, Modified Starch and Physical Parameters on the Solubility and Release Rate of Cryptotanshinone from Alcohologels

(1) Background: The aim of the work was to investigate the influence of selected physico-chemical factors on the solubility and release rate of CT (cryptotanshinone) in alcohologels. (2) Methods: The alcohologels of methylcellulose (MC), hydroksyethylcellulose (HEC), polyacrylic acid (PA) and polyacrylic acid crosspolymer (PACP) with CT were prepared and/or doped with native potato starch (SN) and modified citrate starches (SM2.5 and SM10). The analytical methods included evaluation of CT release profiles, Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and electrospray ionization mass spectrometry (ESI-MS), and scanning electron microscope (SEM) images were performed. (3) Results: The release and decomposition kinetics of CT in relation to the phosphate buffer solution (PBS) and methanol were observed. The amount of cryptotanshinone (CT) released into PBS was significantly lower (2.5%) compared to its release into methanol, where 22.5% of the CT was released into the model medium. The addition of SM2.5 to the alcohologel significantly increased the CT content to 70% in the alcohologel preparation containing NaOH (40%), and this enhanced stability was maintained for up to two months. The ATR-FTIR exhibited interactions between PA and 2-amino-2-methyl-1,3-propanediol (AMPD) as well as between PA and NaOH in case of the alcohologels. Moreover, it indicated the interaction between CT and NaOH. PXRD diffractograms confirmed the FTIR study. (4) Conclusions: The study observed the influence of a number of factors on the solubility and release rate of CT, as: alkalizers and their concentration, SM2.5 addition. The transition of CT in the presence of NaOH to the tanshinone V sodium (T-V sodium) form was suspected.

Self-healing hyaluronic acid/polylysine hydrogel prepared by dual-click chemistry from polyrotaxane slidable crosslinkers

A new type of pH-sensitive hydrogel containing supramolecular structures was fabricated from maleimide-functionalized polyrotaxane, ɛ-polylysine and furan-functionalized hyaluronic acid by Diels-Alder reaction and amino-maleimide reaction. Firstly, pseudo polyrotaxane was obtained through self-assembly of polyethylene glycol and α-cyclodextrin, and then capped with 1-adamantanecarboxylic acid to convert it into polyrotaxane. Secondly, a maleimide-functionalized slidable crosslinker was obtained by modifying the polyrotaxane with 3-maleimide propionic acid, and furan-functionalized hyaluronic acid was prepared by modifying it with 2-furanmethylamine. Thirdly, the hydrogel cotaining supramolecular structures was fabricated from the prepared slidable crosslinker, ɛ-polylysine, and furan-functionalized hyaluronic acid in mixed solvent of water and N,N-dimethylformamide. Taking gel mass fraction and swelling ratio as two indicators, the formation parameters of hydrogel were optimized through single- factor experiments. The pH-sensitivity, rheological properties, self-healing performance, and degradation behavior of the hydrogel were investigated. Cytotoxicity assay, live/dead stains, and hemolysis assay were done to verify the biocompatibility of the hydrogel. Finally, the slow-release behavior of the hydrogel containing lidocaine hydrochloride was studied. The hydrogel possesses good biocompatibility, pH-sensitivity, self-healing behavior, degradation, and drug-controlled release, and can find broad application in biomaterials.

Optimization and comparison of unidirectional lidocaine-loaded buccal patch with the articaine-loaded buccal patch to reduce injection pain and increment of patients' compliance in dental procedures: A double-blind randomized controlled trial

Introduction

Nervous patients often postpone dental visits until they are in severe pain, exacerbating anxiety. Buccal patches provide a noninvasive method of delivering drugs between the upper gum and cheek, offering local and systemic effects. Prior research has demonstrated the effectiveness, safety, and reliability of topical lidocaine or articaine patches for oral anesthesia. Consequently, this study aimed to develop a three-layered buccal drug delivery system for topical anesthetics.

Methods

The first step was preparing and optimizing lidocaine-loaded three-layer patches using Design-expert software. The effects of ethylcellulose, Eudragit, and carbopol concentrations were investigated on patch characteristics, including mucoadhesion, Young's modulus, and Elongation-at-break. Subsequently, patches were fabricated according to the optimized formulation determined by the software, and their efficacy was studied in a randomized, double-blind clinical trial. Participants received either lidocaine or articaine-loaded compared with placebo in a split-mouth study. They evaluated their pain levels using the Visual Analogue Scale (VAS), and the onset and duration of action were recorded for each treatment.

Results

According to the results, increasing ethyl cellulose and Eudragit concentrations improved mucoadhesion force (p < 0.05) while increasing ethyl cellulose and reducing Eudragit concentrations increased Young's modulus (p < 0.05). Increasing Carbopol and decreasing Eudragit concentrations also raised elongation at break significantly in the patch (p < 0.05). Treatment with lidocaine-loaded patches resulted in lower VAS scores and faster onset of action in patients than articaine-loaded patches. However, the duration of the effect was longer in the former(p < 0.001).

Conclusion

Based on the responses' analysis, the formulation of the 3-layered buccal patch was optimized. This formulation comprised 4.72 % ethyl cellulose, 2 % Carbopol, and 5 % eudragit. Clinical evaluation results showed that loading the optimized formulation with lidocaine was more efficient in controlling the injection pain than articaine.

Trial registration

This trial was prospectively registered with irct.behdasht.gov.ir (registration number: IRCT20210118050067N2) on Aug 19, 2022.

Recent Advances in Micro- and Nano-Drug Delivery Systems Based on Natural and Synthetic Biomaterials

Polymeric drug delivery technology, which allows for medicinal ingredients to enter a cell more easily, has advanced considerably in recent decades. Innovative medication delivery strategies use biodegradable and bio-reducible polymers, and progress in the field has been accelerated by future possible research applications. Natural polymers utilized in polymeric drug delivery systems include arginine, chitosan, dextrin, polysaccharides, poly(glycolic acid), poly(lactic acid), and hyaluronic acid. Additionally, poly(2-hydroxyethyl methacrylate), poly(N-isopropyl acrylamide), poly(ethylenimine), dendritic polymers, biodegradable polymers, and bioabsorbable polymers as well as biomimetic and bio-related polymeric systems and drug-free macromolecular therapies have been employed in polymeric drug delivery. Different synthetic and natural biomaterials are in the clinical phase to mitigate different diseases. Drug delivery methods using natural and synthetic polymers are becoming increasingly common in the pharmaceutical industry, with biocompatible and bio-related copolymers and dendrimers having helped cure cancer as drug delivery systems. This review discusses all the above components and how, by combining synthetic and biological approaches, micro- and nano-drug delivery systems can result in revolutionary polymeric drug and gene delivery devices.

The interactions of model cationic drug with newly synthesized starch derivatives

Background and purpose

The aim of the work was to compare the interactions of three newly synthesized non-toxic starch derivatives, with varied anionic and non-ionic functional groups with methylene blue (MB) as a model cationic drug, and selection of starch derivative with highest affinity to the MB.

Experimental approach

The native potato starch (SN), modified via acetylation (SM1), esterification and crosslinking (SM2) and crosslinking (SM3), was evaluated in MB adsorption studies and assessed by FTIR, PXRD, and DSC.

Key results

The adsorption of MB on SM2 and SM3 matched the BET isotherm model, which confirmed physisorption on the low-porous surface. In the case of SM1, adsorption took place via electrostatic attraction between the heterogeneous adsorbent surface and the adsorbate, as demonstrated by the Freundlich plot. The FTIR confirmed vibrations assigned to N=C stretching bonds at 1600 cm-1 in the case of MB adsorbed on the SN and SM2. The most intense PXRD peaks belonged to SN and the least to SM2. In the DSC study, the thermal stability via ΔT was assessed, with SM2 of lowest ΔT value (179.8 °C).

Conclusion

SM2 presented the best adsorption capacity, followed by SM3 and the weakest SM1. The interactions were confirmed in the adsorption studies and may reflect applications of the modified starches as drug carriers. In the FTIR study, a probable interaction between the OH- groups of SM2 and N+ of MB was revealed. The most amorphous structure was shown for SM2, which was correlated with the lowest thermal stability provided by the DSC study.