Semi-synthetic Polymers Research Articles

Recent advance in renewable materials and green processes for optoelectronic applications

With the growing global environmental awareness, the development of renewable and green materials has gained increased worldwide interest. Being at the heart of current scientific research studies, renewable polymers, include natural, semisynthetic, and microbial polymers, have a scope in vast diverse applications in packaging, agriculture, medicine, and optoelectronic technological fields. In recent years, research interest has been increasingly focused on integrating biodegradable polymers into optoelectronic devices for the sake of reducing non-degradable waste and conserving our environment. Numerous biobased materials have been successfully incorporated in organic field-effect transistor memory, resistor memory, and organic photovoltaic (OPV) devices. Besides natural biomaterials, there are also various biobased synthetic polymers used in electronic devices; for example, sugar-based block copolymers have been synthesized to fabricate stretchable memory devices. Several recent studies have also been devoted to integrating green materials into OPV devices in hope of fulfilling sustainable development. In this mini-review, science development of exploiting renewable materials, introducing environmentally friendly processing solvents, and their corresponding applications toward an environmental sustainable life will be briefly narrated.

Promising Polymeric Drug Carriers for Local Delivery: The Case of in situ Gels.

At present, the controlled local drug delivery is a very promising approach compared to systemic administration, since it mostly targets the affected tissue. In fact, various drug carriers for local delivery have been prepared with improved therapeutic efficacy. in situ polymer gels are drug delivery systems that not only present liquid characteristics before their administration in body, but once they are administered, form gels due to gelation. Their gelation mechanism is due to factors such as pH alteration, temperature change, ion activation or ultraviolet irradiation. in situ gels offer various advantages compared to conventional formulations due to their ability to release drugs in a sustainable and controllable manner. Most importantly, in situ gels can be used in local drug delivery applications for various diseases. This review includes the basic knowledge and theory of in situ gels as well as their various applications according to their administration route. Various natural, semisynthetic, and synthetic polymers can produce in situ polymeric gels. For example, natural polysaccharides such as alginic acid, chitosan, gellan gum, carrageenan etc. have been utilized as in situ gels for topical delivery. Besides the polysaccharides, poloxamers, poly(Nisopropylacrylamide), poly(ethyleneoxide)/ (lactic-co-glycolic acid), and thermosensitive liposome systems can be applied as in situ gels. In most cases, in situ polymeric gels could be applied via various administration routes such as oral, vaginal, ocular, intranasal and injectable. To conclude, it can be revealed that in situ gels could be a promising alternative carrier for both chronic and immediate diseases.

Applications of Natural, Semi-Synthetic, and Synthetic Polymers in Cosmetic Formulations

Cosmetics composed of synthetic and/or semi-synthetic polymers, associated or not with natural polymers, exhibit a dashing design, with thermal and chemo-sensitive properties. Cosmetic polymers are also used for the preparation of nanoparticles for the delivery of, e.g., fragrances, with the purpose to modify their release profile and also reducing the risk of evaporation. Besides, other cosmetically active nutrients, dermal permeation enhancers, have also been loaded into nanoparticles to improve their bioactivities on the skin. The use of natural polymers in cosmetic formulations is of particular relevance because of their biocompatible, safe, and eco-friendly character. These formulations are highly attractive and marketable to consumers, and are suitable for a plethora of applications, including make-up, skin, and hair care, and as modifiers and stabilizers. In this review, natural synthetic, semi-synthetic, and synthetic polymers are discussed considering their properties for cosmetic applications. Their uses in conventional and novel formulations are also presented.

Recent Advances in the Development of In Situ Gelling Drug Delivery Systems for Non-Parenteral Administration Routes

In situ gelling drug delivery systems have gained enormous attention over the last decade. They are in a sol-state before administration, and they are capable of forming gels in response to different endogenous stimuli, such as temperature increase, pH change and the presence of ions. Such systems can be administered through different routes, to achieve local or systemic drug delivery and can also be successfully used as vehicles for drug-loaded nano- and microparticles. Natural, synthetic and/or semi-synthetic polymers with in situ gelling behavior can be used alone, or in combination, for the preparation of such systems; the association with mucoadhesive polymers is highly desirable in order to further prolong the residence time at the site of action/absorption. In situ gelling systems include also solid polymeric formulations, generally obtained by freeze-drying, which, after contact with biological fluids, undergo a fast hydration with the formation of a gel able to release the drug loaded in a controlled manner. This review provides an overview of the in situ gelling drug delivery systems developed in the last 10 years for non-parenteral administration routes, such as ocular, nasal, buccal, gastrointestinal, vaginal and intravesical ones, with a special focus on formulation composition, polymer gelation mechanism and in vitro release studies.

An Innovative Approach for Development and Evaluation of Nanosized Lamotrigine Loaded Bionanoparticles Using Biopolymer from Fragaria × ananassa Fruit

The purpose of this research was to isolate the smart biopolymer from the fruit pulp of Fragaria × ananassa (garden strawberry). We isolated natural fruit pulp to evaluate the potentiality of biopolymer in delivery of nanosized lamotrigine as an antiepileptic drug. Lamotrigine was nanosized by screening its nano-size particle by UV method. The nanosized lamotrigine was used for preparation of bionanoparticles (LF1-LF8) by sonication method. The isolated biopolymer was characterized for DSC, FTIR, NMR, Mass and Zeta particle size analysis. The obtained results confirm its polymeric nature in different analysis. The prepared bionanoparticles showed the release of lamotrigine in sustained manner over 36 hours. The release kinetic study was done by using the BIT-SOFT 1.12 software and T50% and T80%, r2 were calculated. All the formulation showed more than 99.78% drug release. The In-vitro release study of different formulations showed the % drug release from 90.92% to 99.78%. The different formulations were evaluated for the In-vitro release study and release kinetic was studied. The formulation LF5 was found to be the best formulation having T50% of 17 hours and T80% of 29 hours with r2 value of 0.9925. The best formulation LF5 showed up to 90.925% drug release over 36 hours. According to the release kinetic study, the best-fit model was found to be Koresmayer-Peppas and the mechanism of drug release was found to be anomalous transport. The results obtained from different evaluations like percentage entrapment efficiency, particle size, release study, kinetic studies and stability study revealed that isolated biopolymer has good potentiality to form bionanoparticles and it can be safely used as an alternative to synthetic and semisynthetic polymers for the preparation of lamotrigine loaded stable bionanoparticles

Evaluating Natural Alternatives to Synthetic Acrylic Polymers: Rheological and Texture Analyses of Polymeric Water Dispersions.

The natural cosmetics market is growing, in line with the interest of public opinion on environmental safety. The availability of polysaccharides for cosmetic use is very wide; each raw material has its own sensorial specificities and hardly matches the performance of synthetic polymers. We developed an instrumental protocol based on rheology and texture analysis to evaluate alternatives to acrylic polymers. The study has been carried out on a set of water dispersions prepared with different synthetic, semisynthetic, and natural polymers at different concentrations. Using statistical principal component analysis, three different clusters have been identified: group A includes polymers with a stringy viscoelastic behavior, group B includes polymers with low firmness and a weak-gel rheological pattern, and group C includes polymers which formed soft and elastic gels. This work showed that this instrumental approach is a powerful tool to comprehensively characterize new rheological modifiers and to forecast their contribution to the formulation based on their applicative features. Moreover, rheology and texture analysis turned out to be complementary tools useful to compare polymeric raw materials and to identify appropriate alternatives to synthetic ones in order to formulate green cosmetic products.

Evaluation of diclofenac niosomal gel formulated with <i>Grewia</i> gum for topical delivery

The purpose of this study was to formulate niosomal gel for topical delivery of diclofenac using Grewia gum as gelling agent. Niosomes containing 1g of diclofenac were formed using the thin film hydration (TFH) method. Niosomal gels were then formulated using a semi-synthetic polymer, hydroxypropylmethylcellulose (HPMC) and a natural polymer, Grewia gum as gelling agents. The formulated gels were evaluated for spreadability, viscosity, extrudability, homogeneity, clarity and pH. Results show that gels having pH and viscosity ranges of 6.8-7.3 and 265-490 Poise respectively were formed. The gels were homogenous, clear and showed good spreadability and extrudability except for batches F7 and F8. The gels formulated using the test gum, Grewia gum compared favourably with those of the standard polymer, HPMC as well as with the marketed gel. Formulation F5 containing 2% w/w Grewia gum, the optimized batch, showed viscosity of 265 poise, pH of 6.9, spreadability and extrudability values of 5.55 cm and 5.00 g/s respectively. In conclusion, Grewia gum at a concentration of 2% w/w could be used in the formulation niosomal gel for the delivery of diclofenac, which would help to circumvent the potential gastric irritation of diclofenac when used orally.
 Keywords: Niosomes; Grewia gum; Diclofenac; Lipid hydration; Topical delivery

Electrospun Orodispersible Films of Isoniazid for Pediatric Tuberculosis Treatment.

Child-appropriate dosage forms are critical in promoting adherence and effective pharmacotherapy in pediatric patients, especially those undergoing long-term treatment in low-resource settings. The present study aimed to develop orodispersible films (ODFs) for isoniazid administration to children exposed to tuberculosis. The ODFs were produced from the aqueous solutions of natural and semi-synthetic polymer blends using electrospinning. The spinning solutions and the resulting fibers were physicochemically characterized, and the disintegration time and isoniazid release from the ODFs were assessed in simulated salivary fluid. The ODFs comprised of nanofibers with adequate thermal stability and possible drug amorphization. Film disintegration occurred instantly upon contact with simulated salivary fluid within less than 15 s, and isoniazid release from the ODFs in the same medium followed after the disintegration profiles, achieving rapid and total drug release within less than 60 s. The ease of administration and favorable drug loading and release properties of the ODFs may provide a dosage form able to facilitate proper adherence to treatment within the pediatric patient population.

Formulation and comparative characterization of nanoparticles of curcumin using natural, synthetic and semi-synthetic polymers for wound healing

AimThe present research work aimed to prepare and characterize nanoparticles of curcumin using polymers from different sources like natural, synthetic and semi-synthetic, and compare their activity for wound healing. Curcumin, BCS class II drug, is a polyphenol with proven wound healing activity. Material and methodsThe curcumin-loaded chitosan and carboxymethylcellulose (CMC) nanoparticles were prepared by ionotropic gelation method. In contrast, poly-lactic co-glycolic acid (PLGA) nanoparticles were prepared by a double emulsion solvent evapouration method. The different sources of polymers include natural (chitosan), synthetic (PLGA) and semi-synthetic CMC were used for the preparation of nanoparticles. Key findingsThe percentage entrapment efficiency of curcumin-loaded nanoparticles was found to be in the order of polymers PLGA>chitosan>CMC. The in-vitro release study of carboxymethyl cellulose -curcumin nanoparticles was found to be 74.96% for 24 h. The presence of a specific peak of curcumin in all the polymeric nanoparticles specifies drug incorporation in the polymeric matrix. The in-vivo study revealed that curcumin-loaded chitosan nanoparticles fasten the healing process of the wound due to the synergistic effect produced by using a combination of curcumin and chitosan. SignificanceCurcumin-loaded nanoparticles showed significant enhancement in wound healing action by lowering the dose of curcumin and effecting synergistically due to the use of chitosan.

Effect of various anti-washout admixtures on the properties of non-dispersible underwater concrete

The present study investigates the effectiveness of using various viscosity modifiers admixtures (VMAs) as anti-washout admixtures (AWAs) to fabricate non-dispersible underwater concrete (UWC). Three types of AWAs categorized as natural, semi-synthetic, and synthetic polymers were used on this study; which include gum Arabic (GA), Xanthan gum (XG), super absorbent polymer (SAP), modified starch (MS), and Veegum (VG). The performance of UWC mixes was assessed in terms of rheological behaviour, mechanical performance, anti washout resistance, and physical phenomena such as bleeding and drying shrinkage The results indicate that among all AWAs, the GA, SAP, and XG are most suitable AWAs for fabricating UWC. Besides, improved compressive strength, higher anti washout resistance and lower shrinkage, these AWAs also increased plastic viscosity and thixotropic properties of UWC. The XRD, SEM, EDX, and FTIR analyses confirmed the greater formation of hydration products in UWC mixes fabricated using GA, SAP, and XG.

Hydrogels for Skeletal Muscle Regeneration

Skeletal muscle is made up of hundreds of multinucleated, aligned fibers that work together during contraction. While smaller injuries are typically able to be repaired by the body, large volumetric muscle loss (VML) typically results in loss of function. Tissue engineering (TE) applications that use cells seeded onto hydrogels are one potential option for regenerating the lost tissue. Hydrogels are described as soft crosslinked polymeric networks with high water content that simulates the body’s natural aqueous environment. They can be formulated from many different starting materials into biocompatible, biodegradable systems. Fabrication methods such as electrospinning, freeze-drying, molding, and 3D printing can be used with the hydrogel solution to form 3D structures. In this review, natural, semi-synthetic, synthetic, and composite hydrogels for skeletal muscle regeneration are discussed. It was ascertained that the majority of the current research focused on natural polymeric hydrogels including collagen, gelatin, agarose, alginate, fibrin, chitosan, keratin, and combinations of the aforementioned. This category was followed by a discussion of composite hydrogels, defined in this review as at least one synthetic and one natural polymer combined to form a hydrogel, and these are the next most favored materials. Synthetic polymer hydrogels came in third with semi-synthetic polymers, chemically modified natural polymers, being the least common. While many of the hydrogels show promise for skeletal muscle regeneration, continued investigation is needed in order to regenerate a functional muscle tissue replacement. Skeletal muscle tissue engineering focuses on regenerating large amounts of skeletal muscle tissue lost due to tumor removal, traumatic injuries, and/or disease. Neither natural repair processes by the body nor current medical interventions are able to completely restore function after volumetric muscle loss. Thus, scientists are investigating alternative approaches to regenerate the lost muscle, restore function, and increase patient quality of life. This review paper summarizes the research from 2013 to early 2018 using hydrogels, a soft material with a high water content, as a tool to regenerate muscle. The review is categorized into hydrogels made from natural materials, semi-synthetic materials, synthetic materials, and composite materials (at least one natural and one synthetic material combined).

Formulation Development and Evaluation of Gastro Retentive Floating Drug Delivery System for Novel Fluoroquinolone using Natural and Semisynthetic Polymers

The purpose of present research work is to develop gastro retentive formulation for Moxifloxacin using various release retardants. Moxifloxacin, novel synthetic fluoro quinolone, antibacterial agent. Floating tablets of Moxifloxacin. HCl were prepared using variable amounts of HPMCK4M, HPMCK15M and HPMCK100M with effervescent mixtures by direct compression technique. Totally 9 formulations were designed, prepared and are evaluated for various pharmacopoeial tests like uniformity of weight, thickness, Hardness, friability, floating lag time, Total floating time. Drug release profiles of formulation trails subjected to kinetic modeling. Parameters like correlation coefficient(r), slope(b), intercept(a) were determined. The results reveals that floating lag time decreases with decreased viscosity of polymer composites. According to SUPAC guidelines formulation (F4) containing 12.5% HPMCK15M was found to be most identical formulation (similarity factor f2= 70.997, dissimilarity factor f1= 6.007 to marketed product (AVELOX) . Trail F4 drug release found to be First order kinetics, Non-Fickian Diffusion Anomalous Transport. (n= 1.065).

An Overview: Natural Polymers and their Applications

Active ingredient and excipients are two main ingredients of any pharmaceutical formulation. Excipients help in the manufacturing of dosage form as well as improve physicochemical parameters of the dosage form. Polymers play a vital role in any dosage form as excipients. The influencing capacity of polymers towards the drug release and should be compatible, non-toxic, and stable and economic etc. They are broadly classified in three categories viz. natural polymers, semi-synthetic and synthetic polymers. Natural polymers are generally used as rate controlling agents, taste masking agents, protective and stabilizing agents in the oral drug delivery system. To provide uniform drug delivery certain polymers are used to reduce the frequency of dosing and to increase effectiveness of the drug by localization at the site of action. Nowadays, due to many problems associated with drug release and side effects of synthetic polymers manufacturers are inclined towards using natural polymers. Natural polymers being polysaccharides are biocompatible and without any side effects. Applications of natural polymers in pharmacy are large in comparison to the synthetic polymers and have wide scope in food and the cosmetic industry.

AlCl<sub>3</sub> Cross-Linked and Spray Dried Carboxymethyl Sago Cellulose Microspheres as Potential Carriers for the Enteric Delivery

A semisynthetic polymer of carboxymethyl sago cellulose (CMSC) was synthesized from Malaysian sago biomass and further used in the development of drug delivery system. Recently, we have reported spray-dried carboxymethyl sago cellulose (CMSC) microspheres for enteric release and dissolution enhancement of piroxicam. In the present investigation, an attempt has been made to improve the enteric release property of CMSC microspheres using aluminium chloride as a cross-linker in the spray drying process and prednisolone as a model drug. CMSC microspheres loaded with prednisolone were prepared using a cross-linker concentration of 0%, 0.01%, 0.025% and 0.05%. All the drug-loaded microspheres were found to have high drug entrapment efficiencies (DEE) ranging from 99% to 106.1%. FT-IR spectroscopy has confirmed the cross-linking in CMSC microspheres as well as intact and amorphous nature of the entrapped drug. Field Emission Scanning Electron Microscope (FESEM) results have shown agglomeration of microspheres and the presence of drugs on the surface. Cross-linked microspheres have shown better efficiency than the uncross-linked microspheres in restricting drug release in stomach pH. Only about 5% of the loaded drug was released from cross-linked microspheres at pH 1.2 while 10% of the drug was released from uncross-linked microspheres. Also, cross-linked microspheres have exhibited faster drug release in pH 6.8 than the uncross-linked microspheres. Spray-dried and AlCl3 cross-linked CMSC microspheres have shown promising results in enteric drug delivery as well as dissolution enhancement.

Formulation development using different natural and semi synthetic polymers, in vitro evaluation of colon targeted Sulfasalazine tablets for ulcerative colitis

Formulation development using different natural and semi synthetic polymers, in vitro evaluation of colon targeted Sulfasalazine tablets for ulcerative colitis

Microencapsulation of 2-phenyl ethanol with methylcellulose/alginate/methylcellulose as the wall material and stability of the microcapsules

In this study, 2-phenyl ethanol (2-PEA) was microencapsulated with natural and semisynthetic carbohydrate polymers as the wall material. The wall material components methylcellulose (MC), alginate sodium (ALG), and carboxymethyl chitosan were optimized according to the results of microscopy images, zeta potential, and 2-PEA content. The combination of MC/ALG/MC was selected as the best wall components. Cobalt chloride (CoCl2) was used as the core material to prepare microcapsules whose color was measured with a colorimeter to intuitively express the water absorption of the microcapsules. The absorbed water mass and b* were related to one variable quadratic equation. The rapid release properties and the natural long-term release properties of 2-PEA microcapsules were measured.

Recent insights on nanomedicine for augmented infection control.

Antimicrobial agents have been widely investigated for protecting against microbial infections in modern health. Drug-related limitations, poor bioavailability, toxicity to mammalian cells, and frequent bacteria drug resistance are major challenges faced when exploited in nanomedicine forms. Specific attention has been paid to control nanomaterial-based infection against numerous challenging pathogens in addition to improved drug delivery, targeting, and pharmacokinetic (PK) profiles, and thus, efficient antimicrobials have been fabricated using diverse components (metals, metal oxides, synthetic and semisynthetic polymers, natural or biodegradable polymers, etc). The present review covers several nanocarriers delivered through various routes of administration, highlighting major findings to control microbial infection as compared to using the free drug. Results over the past decade support the consistent development of various nanomedicines capable of improving biological significance and therapeutic benefits against an array of microbial strains. Depending on the intended application of nanomedicine, infection control will be challenged by various factors such as weighing the risk–benefits in healthcare settings, nanomaterial-induced (eco)toxicological hazards, frequent development of antibiotic resistance, scarcity of in vivo toxicity data, and a poor understanding of microbial interactions with nanomedicine at the molecular level. This review summarizes well-established informative data for nanomaterials used for infection control and safety concerns of nanomedicines to healthcare sectors followed by the significance of a unique “safe-by-design” approach.

FORMULATION AND EVALUATION OF EXTENDED RELEASE PELLETS OF PIOGLITAZONE HYDROCHLORIDE USING NATURAL AND SYNTHETIC POLYMERS BY FLUIDIZED BED COATING TECHNIQUE

Objective: The objective of the current work was to develop Pioglitazone hydrochloride (HCl) pellets coated with natural polymer extracted from peas gum and also to compare the drug release profile with coatings containing semi-synthetic and synthetic polymers.
 Methods: Fluidized bed coating technique was used to develop pellets. A 22 factorial design was employed to study the effect of independent variables (inlet air temperature and spray rate), on dependent variables (percentage entrapment efficiency, percentage friability, and average particle size). Optimization was done by fitting experimental data to the software program. Obtained pellets were subjected to different evaluation parameters which are critical in the development of the dosage form. An in vitro lag phase study was carried out for all batches in simulated gastric fluid (0.1N HCl) for 5 h and in vitro drug release study was carried out for optimized batch (E-2 and P-3) in simulated intestinal fluid (pH 7.4 phosphate buffer).
 Results: The optimized batches E-2 and P-3 showed satisfactory percentage entrapment efficiency of 92.66±1.52, percentage friability of 0.57±0.03, and average particle size of 1424±16 μm. All batches maintained lag phase for 5 h in 0.1N HCl. An optimized batch of two different sizes exhibited a burst release within 30 min in a simulated intestinal fluid with no significant difference in release rate constant (*p>0.05) and followed first-order kinetics.
 Conclusion: Thus, Pioglitazone HCl pulsatile pellets were successfully developed for treating diabetes mellitus by fluidized bed coating technique employing factorial design.

Natural and semisynthetic polymers blended orodispersible films of citalopram

This study was aimed at developing orodispersible films of citalopram using combination of natural and semisynthetic polymers for patients with swallowing problem. Okra biopolymer and moringa gum were utilized in combination with hydroxypropyl methylcellulose (HPMC) and pullulan. The disintegration time was less than 30 seconds and the drug content uniformity was 97.89–102.05% for all film formulations. Films formulated with HPMC (K15 and K4M) combination (F1) and combination of okra and HPMC K15 (F2) had superior mechanical properties as compared with F3 (okra and pullulan) and F4 (moringa gum and HPMC). Thermal analysis revealed stable formulations over the studied temperature range and the crystalline citalopram was completely or partially transformed into amorphous form as revealed by the differential thermal analysis, X-ray diffraction and scanning electron microscopy images. In conclusion, okra biopolymer could be used in combination with HPMC for the development of orodispersible films.

Nano-encapsulation and characterization of baricitinib using poly-lactic-glycolic acid co-polymer

Baricitinib is a recently approved anti-rheumatic drug having very poor aqueous solubility and hence its performance suffers from low or inconsistent oral bioavailability. The purpose of the study was to develop and evaluate poly lactic-co-glycolic acid (PLGA) nanoparticles of baricitinib in order to enhance in vitro dissolution and performance. Nano-suspension of baricitinib with or without PLGA, a biodegradable, FDA approved semi-synthetic polymer, was developed by nanoprecipitation method. Research methodology employed a quantitative research utilizing experimental design wherein effect of independent variables such as amount of polymer, drug: polymer ratio, types of solvent, and solvent: anti-solvent ratio were evaluated over the size and size distribution of nanoparticles along with entrapment efficiencies. Among the several organic phases evaluated, acetone was found to be suitable solvent for drug and polymer. The aqueous phase (anti-solvent) was deionized water containing 1% w/v pluronic 127 as the stabilizer of nanoparticle suspension. The optimized nanoparticles had particle size less than 100 nm (91 nm ± 6.23) with a very narrow size distribution (0.169 ± 0.003), high zeta potential (−12.5 mV ± 5.46) and entrapment efficiency (88.0%). The optimized nanoparticles were characterized by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, infrared spectroscopy and in vitro dissolution studies. In-vitro dissolution study of PLGA nanoparticles exhibited sustained release with approximately 93% release of baricitinib during 24-h period.