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Fulltext Carbamazepine Gel Formulation as a Sustained Release Epilepsy Medication for Pediatric Use

Mawazi SM, Al-Mahmood SMA, Chatterjee B, Hadi HA, Doolaanea AA

Pharmaceutics, 2019 Sep 20;11(10).
PMID: 31547112 DOI: 10.3390/pharmaceutics11100488

This study aimed to develop a carbamazepine (CBZ) sustained release formulation suitable for pediatric use with a lower risk of precipitation. The CBZ was first prepared as sustained release microparticles, and then the microparticles were embedded in alginate beads, and finally, the beads were suspended in a gel vehicle. The microparticles were prepared by a solvent evaporation method utilizing ethyl cellulose as a sustained release polymer and were evaluated for particle size, encapsulation efficiency, and release profile. The beads were fabricated by the dropwise addition of sodium alginate in calcium chloride solution and characterized for size, shape, and release properties. The gel was prepared using iota carrageenan as the gelling agent and evaluated for appearance, syneresis, drug content uniformity, rheology, release profile, and stability. The microparticles exhibited a particle size of 135.01 ± 0.61 µm with a monodisperse distribution and an encapsulation efficiency of 83.89 ± 3.98%. The beads were monodispersed with an average size of 1.4 ± 0.05 mm and a sphericity factor of less than 0.05. The gel was prepared using a 1:1 ratio (gel vehicle to beads) and exhibited no syneresis, good homogeneity, and good shear-thinning properties. The release profile from the beads and from the gel was not significantly affected, maintaining similarity to the tablet form. The gel properties were maintained for one month real time stability, but the accelerated stability showed reduced viscosity and pH with time. In conclusion, CBZ in a gel sustained release dosage form combines the advantages of the suspension form in terms of dosing flexibility, and the advantages of the tablet form in regards to the sustained release profile. This dosage form should be further investigated in vivo in animal models before being considered in clinical trials.

Matched MeSH terms: Delayed-Action Preparations
Fulltext PEGylated Lipid Polymeric Nanoparticle-Encapsulated Acyclovir for In Vitro Controlled Release and Ex Vivo Gut Sac Permeation

Mahmood S, Kiong KC, Tham CS, Chien TC, Hilles AR, Venugopal JR

AAPS PharmSciTech, 2020 Oct 14;21(7):285.
PMID: 33057878 DOI: 10.1208/s12249-020-01810-0

Currently, pharmaceutical research is directed wide range for developing new drugs for oral administration to target disease. Acyclovir formulation is having common issues of short half-life and poor permeability, causing messy treatment which results in patient incompliance. The present study formulates a lipid polymeric hybrid nanoparticles for antiviral acyclovir (ACV) agent with Phospholipon® 90G (lecithin), chitosan, and polyethylene glycol (PEG) to improve controlled release of the drugs. The study focused on the encapsulation of the ACV in lipid polymeric particle and their sustained delivery. The formulation developed for the self-assembly of chitosan and lecithin to form a shell encapsulating acyclovir, followed by PEGylation. Optimisation was performed via Box-Behnken Design (BBD), forming nanoparticles with size of 187.7 ± 3.75 nm, 83.81 ± 1.93% drug-entrapped efficiency (EE), and + 37.7 ± 1.16 mV zeta potential. Scanning electron microscopy and transmission electron microscopy images displayed spherical nanoparticles formation. Encapsulation of ACV and complexity with other physical parameters are confirmed through analysis using Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. Nanoparticle produced was capable of achieving 24-h sustained release in vitro on gastric and intestinal environments. Ex vivo study proved the improvement of acyclovir's apparent permeability from 2 × 10-6 to 6.46 × 10-6 cm s-1. Acyclovir new formulation was achieved to be stable up to 60 days for controlled release of the drugs. Graphical abstract.

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Fulltext A Statistical Study on the Development of Metronidazole-Chitosan-Alginate Nanocomposite Formulation Using the Full Factorial Design

Sabbagh HAK, Hussein-Al-Ali SH, Hussein MZ, Abudayeh Z, Ayoub R, Abudoleh SM

Polymers (Basel), 2020 Apr 01;12(4).
PMID: 32244671 DOI: 10.3390/polym12040772

The goal of this study was to develop and statistically optimize the metronidazole (MET), chitosan (CS) and alginate (Alg) nanoparticles (NP) nanocomposites (MET-CS-AlgNPs) using a (21 × 31 × 21) × 3 = 36 full factorial design (FFD) to investigate the effect of chitosan and alginate polymer concentrations and calcium chloride (CaCl2) concentration ondrug loading efficiency(LE), particle size and zeta potential. The concentration of CS, Alg and CaCl2 were taken as independent variables, while drug loading, particle size and zeta potential were taken as dependent variables. The study showed that the loading efficiency and particle size depend on the CS, Alg and CaCl2 concentrations, whereas zeta potential depends only on the Alg and CaCl2 concentrations. The MET-CS-AlgNPs nanocomposites were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM) and in vitro drug release studies. XRD datashowed that the crystalline properties of MET changed to an amorphous-like pattern when the nanocomposites were formed.The XRD pattern of MET-CS-AlgNPs showed reflections at 2θ = 14.2° and 22.1°, indicating that the formation of the nanocompositesprepared at the optimum conditions havea mean diameter of (165±20) nm, with a MET loading of (46.0 ± 2.1)% and a zeta potential of (-9.2 ± 0.5) mV.The FTIR data of MET-CS-AlgNPs showed some bands of MET, such as 3283, 1585 and 1413 cm-1, confirming the presence of the drug in the MET-CS-AlgNPs nanocomposites. The TGA for the optimized sample of MET-CS-AlgNPs showed a 70.2% weight loss compared to 55.3% for CS-AlgNPs, and the difference is due to the incorporation of MET in the CS-AlgNPs for the formation of MET-CS-AlgNPs nanocomposites. The release of MET from the nanocomposite showed sustained-release properties, indicating the presence of an interaction between MET and the polymer. The nanocomposite shows a smooth surface and spherical shape. The release profile of MET from its MET-CS-AlgNPs nanocomposites was found to be governed by the second kinetic model (R2 between 0.956-0.990) with more than 90% release during the first 50 h, which suggests that the release of the MET drug can be extended or prolonged via the nanocomposite formulation.

Matched MeSH terms: Delayed-Action Preparations
Use of artificial neural networks to predict drug dissolution profiles and evaluation of network performance using similarity factor

Peh KK, Lim CP, Quek SS, Khoh KH

Pharm Res, 2000 Nov;17(11):1384-8.
PMID: 11205731

PURPOSE: To use artificial neural networks for predicting dissolution profiles of matrix-controlled release theophylline pellet preparation, and to evaluate the network performance by comparing the predicted dissolution profiles with those obtained from physical experiments using similarity factor.
METHODS: The Multi-Layered Perceptron (MLP) neural network was used to predict the dissolution profiles of theophylline pellets containing different ratios of microcrystalline cellulose (MCC) and glyceryl monostearate (GMS). The concepts of leave-one-out as well as a time-point by time-point estimation basis were used to predict the rate of drug release for each matrix ratio. All the data were used for training, except for one set which was selected to compare with the predicted output. The closeness between the predicted and the reference dissolution profiles was investigated using similarity factor (f2).
RESULTS: The f2 values were all above 60, indicating that the predicted dissolution profiles were closely similar to the dissolution profiles obtained from physical experiments.
CONCLUSION: The MLP network could be used as a model for predicting the dissolution profiles of matrix-controlled release theophylline pellet preparation in product development.

Matched MeSH terms: Delayed-Action Preparations
Encapsulation of Ethylene Gas into Granular Cold-Water-Soluble Starch: Structure and Release Kinetics

Shi L, Fu X, Tan CP, Huang Q, Zhang B

J Agric Food Chem, 2017 Mar 15;65(10):2189-2197.
PMID: 28215072 DOI: 10.1021/acs.jafc.6b05749

Ethylene gas was introduced into granular cold-water-soluble (GCWS) starches using a solid encapsulation method. The morphological and structural properties of the novel inclusion complexes (ICs) were characterized using scanning electron microscopy, X-ray diffractometry, and Raman spectroscopy. The V-type single helix of GCWS starches was formed through controlled gelatinization and ethanol precipitation and was approved to host ethylene gas. The controlled release characteristics of ICs were also investigated at various temperature and relative humidity conditions. Avrami's equation was fitted to understand the release kinetics and showed that the release of ethylene from the ICs was accelerated by increasing temperature or RH and was decelerated by increased degree of amylose polymerization. The IC of Hylon-7 had the highest ethylene concentration (31.8%, w/w) among the five starches, and the IC of normal potato starch showed the best controlled release characteristics. As a renewable and inexpensive material, GCWS starch is a desirable solid encapsulation matrix with potential in agricultural and food applications.

Matched MeSH terms: Delayed-Action Preparations
In vitro and in vivo evaluation of a nanofiber wound dressing loaded with melatonin

Mirmajidi T, Chogan F, Rezayan AH, Sharifi AM

Int J Pharm, 2021 Mar 01;596:120213.
PMID: 33493599 DOI: 10.1016/j.ijpharm.2021.120213

Wound healing is a complicated process that takes a long time to complete. The three-layer nanofiber wound dressing containing melatonin is highly expected to show remarkable wound repair by reducing the wound healing time. In this study, chitosan (Cs)-polycaprolactone (PCL)/ polyvinylalcohol (PVA)-melatonin (MEL)/ chitosan-polycaprolactone three-layer nanofiber wound dressing was prepared by electrospinning for melatonin sustained release. The characteristics of the wound dressing were further evaluated. The wound dressing had a high water uptake after 24 h (401%), and the water contact angle results showed that it had hydrophilicity effect that supported the cell attachment. The wound healing effect of wound dressing was examined using a full-thickness excisional model of rat skin by the local administration of MEL. The gene expressions of transforming growth factor-beta (TGF-β1), alpha-smooth muscle actin (α-SMA), collagen type I (COL1A1), and collagen type III (COL3A1) were further studied. The histopathological evaluation showed the complete regeneration of the epithelial layer, remodeling of wounds, collagen synthesis, and reduction in inflammatory cells. The NF + 20% MEL significantly increased TGF-β1, COL1A1, COL3A1, and α-SMA mRNA expressions. This wound dressing may have a considerable potential as a wound dressing to accelerate the wound healing.

Matched MeSH terms: Delayed-Action Preparations
Fulltext Pharmaco-Technical Evaluation of Statistically Formulated and Optimized Dual Drug-Loaded Silica Nanoparticles for Improved Antifungal Efficacy and Wound Healing

Masood A, Maheen S, Khan HU, Shafqat SS, Irshad M, Aslam I, et al.

ACS Omega, 2021 Mar 30;6(12):8210-8225.
PMID: 33817480 DOI: 10.1021/acsomega.0c06242

The current research aimed at designing mesoporous silica nanoparticles (MSNs) for a controlled coadministration of salicylic acid (SA) and ketoconazole (KCZ) to effectively treat highly resistant fungal infections. The sol-gel method was used to formulate MSNs, which were further optimized using central composite rotatable design (CCRD) by investigating mathematical impact of independent formulation variables such as pH, stirring time, and stirring speed on dependent variables entrapment efficiency (EE) and drug release. The selected optimized MSNs and pure drugs were subjected to comparative in vitro/in vivo antifungal studies, skin irritation, cytotoxicity, and histopathological evaluations. The obtained negatively charged (-23.1), free flowing spherical, highly porous structured MSNs having a size distribution of 300-500 nm were suggestive of high storage stability and improved cell proliferation due to enhanced oxygen supply to cells. The physico-chemical evaluation of SA/KCZ-loaded MSNs performed through powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA) indicates absolute lack of any interaction between formulation components and successful encapsulation of both drugs in MSNs. The EESA, EEKCZ, SA release, and KCZ release varied significantly from 34 to 89%, 36 to 85%, 39 to 88%, and 43 to 90%, respectively, indicating the quadratic impact of formulation variables on obtained MSNs. For MSNs, the skin tolerability and cell viability percentage rate were also having an extraordinary advantage over suspension of pure drugs. The optimized SA/KCZ-loaded MSNs demonstrated comparatively enhanced in vitro/in vivo antifungal activities and rapid wound healing efficacy in histopathological evaluation without any skin irritation impact, suggesting the MSNs potential for the simultaneous codelivery of antifungal and keratolyic agents in sustained release fashion.

Matched MeSH terms: Delayed-Action Preparations
Fulltext Budesonide-Loaded Pectin/Polyacrylamide Hydrogel for Sustained Delivery: Fabrication, Characterization and In Vitro Release Kinetics

Pandey M, Choudhury H, D/O Segar Singh SK, Chetty Annan N, Bhattamisra SK, Gorain B, et al.

Molecules, 2021 May 05;26(9).
PMID: 34062995 DOI: 10.3390/molecules26092704

A single ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that causes inflammation of the colonic mucosa at the distal colon and rectum. The mainstay therapy involves anti-inflammatory immunosuppression based on the disease location and severity. The disadvantages of using systemic corticosteroids for UC treatment is the amplified risk of malignancies and infections. Therefore, topical treatments are safer as they have fewer systemic side effects due to less systemic exposure. In this context, pH sensitive and enzymatically triggered hydrogel of pectin (PC) and polyacrylamide (PAM) has been developed to facilitate colon-targeted delivery of budesonide (BUD) for the treatment of UC. The hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), swelling ratio, and drug release. FT-IR spectroscopy confirmed the grafting as well loading of BUD in hydrogel. XRD showed the amorphous nature of hydrogel and increment in crystallinity after drug loading. On the other hand, SEM showed that the hydrogels exhibited a highly porous morphology, which is suitable for drug loading and also demonstrated a pH-responsive swelling behaviour, with decreased swelling in acidic media. The in-vitro release of BUD from the hydrogel exhibited a sustained release behaviour with non-ficken diffusion mechanism. The model that fitted best for BUD released was the Higuchi kinetic model. It was concluded that enzyme/pH dual-sensitive hydrogels are an effective colon-targeted delivery system for UC.

Matched MeSH terms: Delayed-Action Preparations
Controlled release formulation of agrochemical pesticide based on 4-(2,4-dichlorophenoxy)butyrate nanohybrid

Hussein MZ, Hashim N, Yahaya AH, Zainal Z

J Nanosci Nanotechnol, 2009 Mar;9(3):2140-7.
PMID: 19435093

Hybridization of beneficial organic guest with inorganic host affords scientists an opportunity to synthesize various combinations of new organic-inorganic nanohybrids with various potential applications, especially for controlled delivery of beneficial agent and storage. A new layered organic-inorganic nanohybrid material containing an agrochemical, 4-(2,4-dichlorophenoxy)butyrate (DPBA) in Zn-Al-layered double hydroxide inorganic interlayer was synthesised by direct and indirect methods. Both methods yielded mesoporous-type, phase pure, well-ordered layered nanohybrids with similar basal spacing of 28.5-28.7 angstroms and organic loading of around 54.3%. Compared to the material prepared by direct method, the ion exchanged product inherited more of the host's properties especially the pore structure and the organic moiety is also more easily released. This shows that the method of preparation plays an important role in determining the resulting physicochemical properties, in particular the release property and therefore can be used as a means to tune up the release property of the beneficial agent.

Matched MeSH terms: Delayed-Action Preparations
Fulltext Exploring the potential of a highly compressible microcrystalline cellulose as novel tabletting excipient in the compaction of extended-release coated pellets containing an extremely water-soluble model drug

Zeeshan F, Peh KK, Tan YT

AAPS PharmSciTech, 2009;10(3):850-7.
PMID: 19554454 DOI: 10.1208/s12249-009-9278-2

Compaction of controlled-release coated pellets into tablets is challenging because of the fusion of pellets and the rupturing of coated film. The difficulty in compaction intensifies with the use of extremely water-soluble drugs. Therefore, the present study was conducted to prepare and compact pellets containing pseudoephedrine hydrochloride as an extremely water-soluble model drug. The pellets were produced using an extrusion-spheronization technique. The drug-loaded pellets were coated to extend the drug release up to 12-h employing various polymers, and then they were compressed into tablets using microcrystalline cellulose Ceolus KG-801 as a novel tabletting excipient. The in vitro drug release studies of coated pellets and tablets were undertaken using the USP basket method in dissolution test apparatus I. The amount of drug released was analyzed at a wavelength of 215 nm. The combined coatings of hydroxypropyl methylcellulose and Kollicoat SR-30D yielded 12-h extended-release pellets with drug release independent of pH of dissolution medium following zero-order kinetics. The drug release from the tablets prepared using inert Celous KG-801 granules as tabletting excipient was found faster than that of coated pellets. However, a modification in drug release rate occurred with the incorporation of inert Ceolus KG-801 pellets. The drug dissolution profile from tablets containing 40% w/w each of coated pellets and inert granules along with 20% w/w inert pellets was found to be closely similar to that of coated pellets. Furthermore, the friability, tensile strength, and disintegration time of the tablets were within the USP specifications.

Matched MeSH terms: Delayed-Action Preparations
In vitro and in vivo evaluation of hydrophilic and hydrophobic polymers-based nicorandil-loaded peroral tablet compared with its once-daily commercial sustained-release tablet

Tamilvanan S, Venkatesh Babu R, Nappinai A, Sivaramakrishnan G

Drug Dev Ind Pharm, 2011 Apr;37(4):436-45.
PMID: 20923389 DOI: 10.3109/03639045.2010.521161

Hydrophilic and hydrophobic polymer-based nicorandil (10 mg)-loaded peroral tablets were prepared using the wet granulation technique. The influence of varying amounts of hydroxypropyl methylcellulose (HPMC) (30-50 mg), ethylcellulose (2-4 mg), microcrystalline cellulose (5-20 mg) and Aerosil® (5-12 mg) in conjunction with the constant amounts (3 mg) of glidant and lubricant (magnesium stearate and talc) on the in vitro performances of the tablets (hardness, friability, weight variation, thickness uniformity, drug content, and drug release behavior) were investigated.

Matched MeSH terms: Delayed-Action Preparations
Design of a 24-hour controlled porosity osmotic pump system containing PVP: formulation variables

Yakubu R, Peh KK, Tan YT

Drug Dev Ind Pharm, 2009 Dec;35(12):1430-8.
PMID: 19929202 DOI: 10.3109/03639040902988566

The purpose of this study was to design a 24-hour controlled porosity osmotic pump system that utilizes polyvinyl pyrrolidone (PVP) as an osmotic-suspending/release retarding agent of drugs.

Matched MeSH terms: Delayed-Action Preparations
In vitro controlled release of alfuzosin hydrochloride using HPMC-based matrix tablets and its comparison with marketed product

Nair A, Gupta R, Vasanti S

Pharm Dev Technol, 2007;12(6):621-5.
PMID: 18161635

The present study is an attempt to formulate a controlled-release matrix tablet formulation for alfuzosin hydrochloride by using low viscous hydroxy propyl methyl cellulose (HPMC K-100 and HPMC 15cps) and its comparison with marketed product. Different batches of tablets containing 10 mg of alfuzosin were prepared by direct compression technique and evaluated for their physical properties, drug content, and in vitro drug release. All the formulations had a good physical integrity, and the drug content between the batches did not vary by more than 1%. Drug release from the matrix tablets was carried out for 12 hr and showed that the release rate was not highly significant with different ratios of HPMC K-100 and HPMC15cps. Similar dissolution profiles were observed between formulation F3 and the marketed product throughout the study period. The calculated regression coefficients showed a higher r2 value with zero-order kinetics and Higuchi model in all the cases. Although both the models could be applicable, zero-order kinetics seems to be better. Hence, it can be concluded that the use of low viscous hydrophilic polymer of different grades (HPMC K-100 and HPMC 15cps) can control the alfuzosin release for a period of 12 hr and was comparable to the marketed product.

Matched MeSH terms: Delayed-Action Preparations
Fulltext Comparative bioavailability study of a generic sustained release diclofenac sodium tablet

Magosso E, Yuen KH, Choy WP, Ling SSN, Ng BH, Ur-Rahman N, et al.

Med J Malaysia, 2004 Aug;59(3):352-6.
PMID: 15727381

The bioavailability of a generic diclofenac sodium sustained release tablet preparation (Zolterol, SR) was compared with the innovator product, Voltaren, SR. Twelve healthy adult male volunteers participated in the study, which was conducted according to a randomized, two-way crossover design with a wash out period of one week. The bioavailability of diclofenac was compared using the parameters area under the plasma concentration-time curve (AUC(0-infinity)), peak plasma concentration (Cmax) and time to reach peak plasma concentration (Tmax). No statistically significant difference was observed for both logarithmically transformed AUC(0-infinity), Cmax values and Tmax value of the two preparations.

Matched MeSH terms: Delayed-Action Preparations
Synthesis of 4-chlorophenoxyacetate-zinc-aluminium-layered double hydroxide nanocomposite: physico-chemical and controlled release properties

Hussein MZ, Sarijo SH, Yahaya AH, Zainal Z

J Nanosci Nanotechnol, 2007 Aug;7(8):2852-62.
PMID: 17685307

Layered organic-inorganic hybrid nanocomposite material was synthesised using 4-chlorophenoxyacetate (4CPA) as guest anion intercalated into the Zn-Al layered double hydroxide inorganic host by direct co-precipitation method at pH = 7.5 and Zn to Al molar ratio of 4. Both PXRD and FTIR results confirmed that the 4CPA was successfully intercalated into the Zn-AI-LDH interlayer. As a result, a well-ordered nanolayered organic-inorganic hybrid nanocomposite, with the expansion of the basal spacing from 8.9 angstroms in the layered double hydroxide to 20.1 angstroms in the resulting nanocomposite was observed. The FTIR spectrum of the nanocomposite (ZAC) showed that it composed spectral features of Zn-AI-LDH (ZAL) and 4CPA. The nanocomposites synthesized in this work are of mesoporous-type containing 39.8% (w/w) of 4CPA with mole fraction of Al3+ in the inorganic brucite-like layers (xAI) of 0.224. The release studies showed a rapid release of the 4CPA for the first 600 min, and more sustained thereafter. The total amount of 4CPA released from the nanocomposite interlayer into the aqueous solution were 21%, 66%, and 72% in 0.0001, 0.00025, and 0.0005 M sodium carbonate, respectively. In distilled water, about 75, 35, and 57% of 4CPA could be released in 1000 min, when the pH of the release media was set at 3, 6.25, and 12, respectively. In comparison with a structurally similar organic moiety with one more chlorine atom at the 2-position of the aromatic ring, namely 2,4-dichlorophenoxyacetate (24D), the 4CPA showed a slower release rate. The slightly bulkier organic moiety of 24D together with the presence of chlorine atom at the 2-position presumably had contributed to its higher release rate, and it seems that these factors may be exploited for tuning the release rate of intercalated guest anions with similar properties. This study suggests that layered double hydroxide can be used as a carrier for an active agent and the chemical structure of the intercalated moiety can be used to tune the desired release kinetics of the beneficial agent.

Matched MeSH terms: Delayed-Action Preparations
Effects of microwave on drug release property of poly(methyl vinyl ether-co-maleic acid) matrix

Wong TW, Wahab S, Anthony Y

Drug Dev Ind Pharm, 2007 Jul;33(7):737-46.
PMID: 17654022

The drug release behavior of beads made of poly(methyl vinyl ether-co-maleic acid) was investigated with respect to the influence of microwave irradiation. The beads were prepared by an extrusion method with sodium diclofenac as a model water-soluble drug. The beads were subjected to microwave irradiation at 80 W for 5 and 20 min, and at 300 W for 1 min 20 s and 5 min 20 s. The profiles of drug dissolution, drug content, drug-polymer interaction, and polymer-polymer interaction were determined by using dissolution testing, drug content assay, differential scanning calorimetry, and Fourier transform infra-red spectroscopy. Keeping the level of supplied irradiation energy identical, treatment of beads by microwave at varying intensities of irradiation did not bring about similar drug release profiles. The extent and rate of drug released from beads were markedly enhanced through treating the samples by microwave at 80 W as a result of loss of polymer-polymer interaction via the (CH(2))(n) moiety, but decreased upon treating the beads by microwave at 300 W following polymer-polymer interaction via the O-H, COOH, and COO(-) moieties as well as drug-polymer interaction via the N-H, O-H, COO(-), and C-O moieties. The beads treated by microwave at 300 W exhibited a higher level of drug release retardation capacity than those that were treated by microwave at 80 W in spite of polymer-polymer interaction via the (CH(2))(n) moiety was similarly reduced in the matrix. The mechanism of drug release of both microwave-treated and untreated beads tended to follow zero order kinetics. The drug release was markedly governed by the state of polymer relaxation of the matrix and was in turn affected by the state of polymer-polymer and/or drug-polymer interaction in beads.

Matched MeSH terms: Delayed-Action Preparations
Fulltext Applications of calixarenes in cancer chemotherapy: facts and perspectives

Yousaf A, Hamid SA, Bunnori NM, Ishola AA

Drug Des Devel Ther, 2015;9:2831-8.
PMID: 26082613 DOI: 10.2147/DDDT.S83213

Research on the therapeutic applications of calixarene derivatives is an emerging area of interest. The anticancer activity of various functionalized calixarenes has been reported by several research groups. Due to their superior geometric shape, calixarenes can accommodate drug molecules by forming inclusion complexes. Controlled release of anticancer drugs by calixarenes might help in targeted chemotherapy. This review summarizes the anticancer potential of the calixarenes and their drug loading properties. The potential use of calixarenes in chemoradiotherapy is also highlighted in brief.

Matched MeSH terms: Delayed-Action Preparations
Triggering Mechanisms of Thermosensitive Nanoparticles Under Hyperthermia Condition

Dabbagh A, Abdullah BJ, Abdullah H, Hamdi M, Kasim NH

J Pharm Sci, 2015 Aug;104(8):2414-28.
PMID: 26073304 DOI: 10.1002/jps.24536

Nanoparticle-based hyperthermia is an effective therapeutic approach that allows time- and site-specific treatment with minimized off-site effects. The recent advances in materials science have led to design a diversity of thermosensitive nanostructures that exhibit different mechanisms of thermal response to the external stimuli. This article aims to provide an extensive review of the various triggering mechanisms in the nanostructures used as adjuvants to hyperthermia modalities. Understanding the differences between various mechanisms of thermal response in these nanostructures could help researchers in the selection of appropriate materials for each experimental and clinical condition as well as to address the current shortcomings of these mechanisms with improved material design.

Matched MeSH terms: Delayed-Action Preparations
Controlled release of doxorubicin from electrospun PEO/chitosan/graphene oxide nanocomposite nanofibrous scaffolds

Ardeshirzadeh B, Anaraki NA, Irani M, Rad LR, Shamshiri S

Mater Sci Eng C Mater Biol Appl, 2015 Mar;48:384-90.
PMID: 25579938 DOI: 10.1016/j.msec.2014.12.039

Polyethylene oxide (PEO)/chitosan (CS)/graphene oxide (GO) electrospun nanofibrous scaffolds were successfully developed via electrospinning process for controlled release of doxorubicin (DOX). The SEM analysis of nanofibrous scaffolds with different contents of GO (0.1, 0.2, 0.5 and 0.7wt.%) indicated that the minimum diameter of nanofibers was found to be 85nm for PEO/CS/GO 0.5% nanofibers. The π-π stacking interaction between DOX and GO with fine pores of nanofibrous scaffolds exhibited higher drug loading (98%) and controlled release of the DOX loaded PEO/CS/GO nanofibers. The results of DOX release from nanofibrous scaffolds at pH5.3 and 7.4 indicated strong pH dependence. The hydrogen bonding interaction between GO and DOX could be unstable under acidic conditions which resulted in faster drug release rate in pH5.3. The cell viability results indicated that DOX loaded PEO/CS/GO/DOX nanofibrous scaffold could be used as an alternative source of DOX compared with free DOX to avoid the side effects of free DOX. Thus, the prepared nanofibrous scaffold offers as a novel formulation for treatment of lung cancer.

Matched MeSH terms: Delayed-Action Preparations
Fulltext Development of a controlled release of salicylic acid loaded stearic acid-oleic acid nanoparticles in cream for topical delivery

Woo JO, Misran M, Lee PF, Tan LP

ScientificWorldJournal, 2014;2014:205703.
PMID: 24578624 DOI: 10.1155/2014/205703

Lipid nanoparticles are colloidal carrier systems that have extensively been investigated for controlled drug delivery, cosmetic and pharmaceutical applications. In this work, a cost effective stearic acid-oleic acid nanoparticles (SONs) with high loading of salicylic acid, was prepared by melt emulsification method combined with ultrasonication technique. The physicochemical properties, thermal analysis and encapsulation efficiency of SONs were studied. TEM micrographs revealed that incorporation of oleic acid induces the formation of elongated spherical particles. This observation is in agreement with particle size analysis which also showed that the mean particle size of SONs varied with the amount of OA in the mixture but with no effect on their zeta potential values. Differential scanning calorimetry analysis showed that the SONs prepared in this method have lower crystallinity as compared to pure stearic acid. Different amount of oleic acid incorporated gave different degree of perturbation to the crystalline matrix of SONs and hence resulted in lower degrees of crystallinity, thereby improving their encapsulation efficiencies. The optimized SON was further incorporated in cream and its in vitro release study showed a gradual release for 24 hours, denoting the incorporation of salicylic acid in solid matrix of SON and prolonging the in vitro release.

Matched MeSH terms: Delayed-Action Preparations

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