Preparation and characterization of microcapsules of Pterodon pubescens Benth. by using natural polymers

An oleaginous fraction obtained from an alcohol extract of the fruit of Pterodon pubescensBenth. (FHPp) was microencapsulated in polymeric systems. These systems were developed using a complex coacervation method and consisted of alginate/medium-molecular-weight chitosan (F1-MC), alginate/chitosan with greater than 75% deacetylation (F2-MC), and alginate/low-molecular-weight chitosan (F3-MC). These developed systems have the potential to both mask the taste of the extract, and to protect its constituents against possible chemical degradation. The influence of the formulation parameters and process were determined by chemical profiling and measurement of the microencapsulation efficiency of the oleaginous fraction, and by assessment of microcapsule morphology. The obtained formulations were slightly yellow, odorless, and had a pleasant taste. The average diameters of the microcapsules were 0.4679 µm (F2-MC), 0.5885 µm (F3-MC), and 0.9033 µm (F1-MC). The best formulation was F3-MC, with FHPp microencapsulation efficiency of 61.01 ± 2.00% and an in vitro release profile of 75.88 ± 0.45%; the content of vouacapans 3-4 was 99.49 ± 2.80%. The best model to describe the release kinetics for F1-MC and F3-MC was that proposed by Higuchi; however, F2-MC release displayed first-order kinetics; the release mechanism was of the supercase II type for all formulations.

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DESIGN AND IN VITRO/IN VIVO EVALUATION OF EXTENDED RELEASE MATRIX TABLETS OF NATEGLINIDE

Journal of Biomedical and Pharmaceutical Research ◽

10.32553/jbpr.v7i6.559 ◽

2018 ◽

Vol 7 (6) ◽

Author(s):

Mohini Sihare ◽

Rajendra Chouksey

Keyword(s):

Drug Release ◽

Release Kinetics ◽

In Vitro Release ◽

Release Profile ◽

Matrix Tablets ◽

In Vivo Studies ◽

Release Mechanism ◽

In Vivo Evaluation

Aim: Nateglinide is a quick acting anti-diabetic medication whose potent activity lasts for a short duration. One of the dangerous side effects of nateglinide administration is rapid hypoglycemia, a condition that needs to be monitored carefully to prevent unnecessary fatalities. The aim of the study was to develop a longer lasting and slower releasing formulation of nateglinide that could be administered just once daily. Methods: Matrix tablets of nateglinide were prepared in combination with the polymers hydroxypropylmethylcellulose (HPMC), eudragits, ethyl cellulose and polyethylene oxide and the formulated drug release patterns were evaluated using in vitro and in vivo studies. Conclusion: Of the seventeen formulated matrix tablets tested, only one formulation labelled HA-2 that contained 15% HPMC K4M demonstrated release profile we had aimed for. Further, swelling studies and scanning electron microscopic analysis confirmed the drug release mechanism of HA-2. The optimized formulation HA-2 was found to be stable at accelerated storage conditions for 3 months with respect to drug content and physical appearance. Mathematical analysis of the release kinetics of HA-2 indicated a coupling of diffusion and erosion mechanisms. In-vitro release studies and pharmacokinetic in vivo studies of HA-2 in rabbits confirmed the sustained drug release profile we had aimed for. Keywords: Hydroxypropylmethylcellulose, Matrix tablets, Nateglinide, Sustained release

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Release Kinetics Study of Azithromycin from Bi-layered Tablets

Bangladesh Pharmaceutical Journal ◽

10.3329/bpj.v20i1.32094 ◽

2017 ◽

Vol 20 (1) ◽

pp. 54-63

Author(s):

FM Shah Noman Ul Bari ◽

Muhammad Rashedul Islam ◽

Md Mizanur Rahman Moghal ◽

Israt Jahan Ira

Keyword(s):

Release Kinetics ◽

In Vitro Release ◽

Methyl Cellulose ◽

Pharmaceutical Journal ◽

High Viscosity ◽

Release Mechanism ◽

Low Viscosity ◽

Release Studies ◽

Vitro Release

The objective of this study was to analysis in vitro release kinetics of Azithromycin from bi-layer tablets prepared by direct compression using high viscosity to low viscosity grades of hydroxypropyl methyl cellulose (HPMC K15M, HPMC K4M, HPMC 50 cps), Carbopol 934p and Carbopol 974p. In addition, it also includes evaluating the effect of formulation variables like polymer proportion and polymer viscosity on the release of Azithromycin. In vitro release studies were performed using USP Type-II (Rotating paddle method) at 100 rpm. The dissolution medium consisted of 0.1N HCl (900 ml) for the first 2 hr and the phosphate buffer (pH 6.0) from 3rd to 10th hour. From twenty five different formulations (F-1 to F-25) based on polymer variation, model-dependent and independent methods were used for data analysis and the best results were observed for HPMC 50cps in Korsmeyer- Peppas (R2=0.995 on F-23) kinetic model. The release mechanism of all formulations was Fickian.Bangladesh Pharmaceutical Journal 20(1): 54-63, 2017

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Effect of Polymers nature and Stirring Speeds on Physicochemical Properties and the Controlled Release of Allopurinol-loaded Microspheres

Journal of the Mexican Chemical Society ◽

10.29356/jmcs.v66i1.1583 ◽

2021 ◽

Vol 66 (1) ◽

Author(s):

Karima Badis ◽

Haouaria Merine ◽

Youssef Ramli ◽

OumCheikh Larbi ◽

Cherifa Hakima Memou

Keyword(s):

Fourier Transforms ◽

Release Kinetics ◽

Drug Loading ◽

In Vitro Release ◽

Release Mechanism ◽

Release Studies ◽

Fourier Transforms Infrared Spectroscopy ◽

The Mean ◽

Solvent Evaporation Process

Abstract. Allopurinol is an antigout drug therapy, commonly used in the treatment of chronic gout or hyperuricaemia associated with treatment of diuretic conditions. In the present study, new formulations based on Allopurinol, have been prepared with the microencapsulation by solvent evaporation process. Microspheres were prepared using pure Allopurinol and polymeric matrices (ethylcellulose EC, poly (ε-caprolactone) PCL, β-cyclodextrin CD and hydroxypropylmethylcellulose HPMC) at different compositions and stirring speeds to investigate the effect of these parameters on loading efficiency and drug release kinetics. The formulations produced were characterized by various methods : Fourier transforms infrared spectroscopy (FTIR), X-ray powder diffractometry, optical microscopy, surface morphology by scanning electron microscopy (SEM) and drug loading, as well as in vitro release studies in the simulated stomach tract. Depending on the stirring speed and the composition of the microparticles, the active ingredient loading is in a range from 10.46 ± 1.45 to 46.40 ± 0.5%. The microspheres are spherical and the mean Sauter diameter (d32) of the microparticles obtained is smaller and is in the range of 47.71 to 151.01 µm. Different release profiles were obtained and show that the release rate is strongly influenced by the characteristics of the microparticles ; namely, the stirring rates and the composition of the microparticles. The release mechanism was identified by modelling using Higuchi and Korsmeyer-Peppas models. Resumen. Alopurinol es una droga terapéutica para tratar la gota, y se utiliza en el tratamiento de gota crónica o hiperuricemia asociada con el tratamiento de condiciones diuréticas. En este estudio, nuevas formulaciones basadas en Alopurinol se prepararon mediante microencapsulación por el proceso de evaporación de disolvente. Microesferas se prepararon usando Alopurinol puro y diferentes matrices poliméricas (etil-celulosa EC, poli(-caprolactona) PCL, β-cyclodextrina CD e hidroxipropil-metil-celulose HPMC) en diferentes composiciones y velocidades de agitación, para investigar el efecto de estos parámetros en la eficiencia de carga y en la cinética de liberación del fármaco. Las formulaciones obtenidas fueron caracterizadas por diferentes técnicas : Espectroscopía infrarroja de transformadas de Fourier (FTIR), difractometría de rayos X de polvos, microscopía óptica, morfología de superficies mediante microscopía electrónica de barrido electrónico, y la eficiencia de carga del fármaco, así como estudios de liberación in vitro en tracto estomacal simulado. Dependiendo de la velocidad de agitación y la composición de las micropartículas, la carga del ingrediente activo se encuentra en el rango de 10.46 ± 1.45 a 46.40 ± 0.5%. Las microesferas son esféricas y el diámetro medio de Sauter (d32) de las micropartículas obtenidas es menor, y se encuentra en el rango de 47.71 a 151.01 µm. Se obtuvieron diferentes perfiles de liberación y se observa que la velocidad de liberación está influenciada principalmente por las características propias de la producción de las micropartículas ; en particualr, las velocidades de agitación y las composición de las micropartículas. El mecanismo de liberación se ajusta mejor a los modelos matemáticos de Higuchi and Korsmeyer-Peppas.

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Formulation and Ex-vivo Evaluation of Glipizide Buccal Tablets

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2014.7.2.10 ◽

2014 ◽

Vol 7 (2) ◽

pp. 2487-2493

Author(s):

Sudarshan Singh ◽

Sandip G Maru ◽

Sunil Bothara B

Keyword(s):

Guar Gum ◽

Chemical Interaction ◽

Ex Vivo ◽

Release Kinetics ◽

In Vitro Release ◽

Aloe Vera ◽

Release Mechanism ◽

Drug Release Profile ◽

Buccal Tablets

Bioadhesive materials are agents which adhere to the mucous membrane due to specific properties and release the drug at the site of action in controlled manner. Since the biodegradability of the synthetic polymer is at some instance hesitant. In this exploration, a bioadhesive polymer has been developed which was isolated from leaves of Aloe vera (L.) Burm. f. The mucilage isolated from A. vera were used as a bioadhesive polymer in tablet formulation and evaluated for the parameters such as swelling, pH, and bioadhesive property like bioadhesive strength, record of adherence and ex-vivo residence time. The buccal bioadhesive tablet was prepared using glipizide as model drug. The prepared tablet was evaluated against existing bioadhesive polymer such as guar gum and hydroxyl propyl cellulose. Swelling index and surface pH was found to be 13.12-18.06% and 6.5-6.9 respectively. The drug permeation through goat buccal mucosa was found to be 60.21 ± 0.06 % in the end of 7 h with a Jss of 0.24 mg h-1 cm-2. The stability studies were performed on optimized formulation as per ICH guideline, result showed that there was no significant change in physical characteristic, adhesive strength and in vitro release. It was observed that as the concentration of mucilage increases swelling index also increases. Results of pH showed that mucilage is slightly near to neutral in nature. Formulations were evaluated for preformulation parameters, in vitro drug release profile and release kinetics. The formulations were found to have good preformulation characteristics. FTIR spectroscopy showed no significant chemical interaction within drug and excipients. The release mechanism of glipizide from buccal tablets indicated anomalous (non-fickian) transport mechanism and followed zero order kinetics. It was concluded that the mucilage of A. vera can be used as a pharmaceutical excipient in buccal bioadhesive drug delivery systems.

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Preparation and in vitro release kinetics of ivermectin sustained-release bolus optimized by response surface methodology

PeerJ ◽

10.7717/peerj.5418 ◽

2018 ◽

Vol 6 ◽

pp. e5418 ◽

Cited By ~ 1

Author(s):

Xiangchun Ruan ◽

Xiuge Gao ◽

Ying Gao ◽

Lin Peng ◽

Hui Ji ◽

...

Keyword(s):

Response Surface Methodology ◽

Sustained Release ◽

Response Surface ◽

Release Kinetics ◽

In Vitro Release ◽

Information Criterion ◽

Quadratic Model ◽

Dissolution Time ◽

Release Mechanism

Sustained-release formulations of ivermectin (IVM) are useful for controlling parasitic diseases in animals. In this work, an IVM bolus made from microcrystalline cellulose (MCC), starch and low-substituted hydroxypropyl cellulose (LS-HPC) was optimized by response surface methodology. The bolus was dissolved in a cup containing 900 mL of dissolution medium at 39.5 °C, under with stirring at 100 rpm. A quadratic model was formulated using analysis of variance according to the dissolution time. The optimized formulation of the bolus contained 8% MCC, 0.5% starch, and 0.25% LS-HPC. The length, width, and height of the prepared IVM bolus were 28.12 ± 0.14, 16.1 ± 0.13, and 13.03 ± 0.05 mm, respectively. The bolus weighed 11.4842 ± 0.1675 g (with a density of 1.95 g/cm3) and contained 458.26 ± 6.68 mg of IVM. It exhibited in vitro sustained-release for over 60 days, with a cumulative amount and percentage of released IVM of 423.72 ± 5.48 mg and 92.52 ± 1.20%, respectively. The Korsmeyer–Peppas model provided the best fit to the dissolution release kinetics, exhibiting anR2value close to 1 and the lowest Akaike Information Criterion among different models. The parametern(0.5180) of the Korsmeyer–Peppas model was between 0.45 and 0.89. It was demonstrated that the release mechanism of the IVM bolus followed a diffusive erosion style.

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FORMULATION AND EVALUATION OF GASTRORETENTIVE FLOATING TABLET USING HIBISCUS ROSA-SINENSIS MUCILAGE

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2017.v10i3.16494 ◽

2017 ◽

Vol 10 (3) ◽

pp. 444

Author(s):

Rohini Sachin More ◽

Kharwade Rs ◽

Mahajan Un

Keyword(s):

Dopamine D2 Receptor ◽

Release Kinetics ◽

In Vitro Release ◽

D2 Receptor ◽

Zero Order ◽

Release Mechanism ◽

Floating Tablets ◽

Hibiscus Rosa Sinensis ◽

Weight Variation

ABSTRACTObjective: Domperidone is a synthetic benzimidazole compound that acts as a dopamine D2 receptor antagonist. The main aim of this study was tooptimize and evaluate the floating tablets of domperidone that prolongs the gastric residence time using Hibiscus rosa-sinensis mucilage.Methods: The directly compressible floating tablets of domperidone were formulated using varying amount of hydroxypropyl methylcelluloseK100 M, carbopol 934P and H. rosa-sinensis mucilage. The effervescent components sodium bicarbonate is used for the generation of CO2 gas. Theprepared tablets were evaluated for physicochemical parameters and found to be within range, viz., hardness, swelling index, floating capacity,thickness, and weight variation. Further, tablets were evaluated for in vitro release characteristics. The concentration of H. rosa-sinensis mucilage witha gas-generating agent was optimized to get the sustained release of domperidone.Result: The % cumulative drug release of all formulation from F1 to F6 was within the range of 81.37% to 98.62% for 18 hrs. The release kinetics ofall the dosage forms was calculated using zero order, first order, Higuchi, and Korsmeyer–Peppas. It concludes that the release followed zero orderrelease, whereas the correlation coefficient (r2 value) was higher for zero order release. The release mechanism follows Higuchi model, Korsmeyer-Peppas model, and non-Fickian diffusion.Conclusion: As a result of this study, it may be concluded that the floating tablets using H. rosa-sinensis mucilage in optimized concentrations canbe used to increase the gastric retention time of the dissolution fluid in the stomach to deliver the drug in a sustained manner. Furthermore, from1 month stability data shows no significant change compared to initial result.Keywords: Floating drug delivery, Hibiscus rosa-sinensis mucilage, Domperidone.

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Formulation of Nano/Micro-Carriers Loaded with an Enriched Extract of Coffee Silverskin: Physicochemical Properties, In Vitro Release Mechanism and In Silico Molecular Modeling

Pharmaceutics ◽

10.3390/pharmaceutics14010112 ◽

2022 ◽

Vol 14 (1) ◽

pp. 112

Author(s):

Faezeh Fathi ◽

Samad N. Ebrahimi ◽

João A. V. Prior ◽

Susana M. L. Machado ◽

Reza Mohsenian Kouchaksaraee ◽

...

Keyword(s):

Surface Charge ◽

Chlorogenic Acid ◽

In Vitro Release ◽

Release Mechanism ◽

Natural Polymers ◽

Hydrogen Binding ◽

Coffee Silverskin ◽

Coating Layers ◽

Vitro Release

Designing strategies for an effective transformation of food waste into high-value products is a priority to address environmental sustainability concerns. Coffee silverskin is the major by-product of the coffee roasting industry, being rich in compounds with health benefits. Such composition gives it the potential to be transformed into high-value products. In this study, coffee silverskin extracts were enriched, regarding caffeine and chlorogenic acid contents, by adsorbent column chromatography. The compounds content increased 3.08- and 2.75-fold, respectively, compared to the original extract. The enriched fractions were loaded into nano-phytosomes or cholesterol-incorporated nano-phytosomes (first coating layers) to improve the physiochemical properties and permeation rate. These nano-lipid carriers were also subjected to a secondary coating with different natural polymers to improve protection and stability against degradation. In parallel, and for comparison, different natural polymers were also used as first coating layers. The produced particles were evaluated regarding product yield, encapsulation efficiency, loading capacity, particle size, surface charge, and in vitro release simulating gastrointestinal conditions. All samples exhibited anionic surface charge. FTIR and molecular docking confirmed interactions between the phytoconstituents and lipid bilayers. The best docking score was observed for 5-caffeoylquinic acid (chlorogenic acid) exhibiting a stronger hydrogen binding to the lipid bilayer. Among several kinetic models tested, the particle release mechanism fitted well with the First-order, Korsmeyer–Peppas, and Higuchi models. Moreover, most of the formulated particles followed the diffusion-Fick law and anomalous transport.

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Preparation, characterization, and in vitro release kinetics of doxorubicin-loaded magnetosomes

Journal of Biomaterials Applications ◽

10.1177/08853282211060544 ◽

2021 ◽

pp. 088532822110605

Author(s):

Shuang Zhang ◽

Xinxin Fan ◽

Guojing Zhang ◽

Weidong Wang ◽

Lei Yan

Keyword(s):

Particle Size ◽

Physical Adsorption ◽

Release Kinetics ◽

In Vitro Release ◽

Release Mechanism ◽

Target Drug Delivery ◽

Target Drug ◽

Potential Applications ◽

Release Data

The doxorubicin (DOX) was successfully coupled to the magnetosomes from Acidithiobacillus ferrooxidans ( At. ferrooxidans) by genipin bridging. The parameters (magnetosome concentration, DOX concentration, genipin concentration-, and cross-link time) expected for temperature significantly influenced the coupling rate. Bacterial magnetosome-doxorubicin complexes (BMDCs) were characterized by transmission electron microscope (TEM), particle size analyzer and Fourier transform infrared spectroscopy. Results indicated that BMDCs exhibited a mean particle size of 83.98 mm and displayed a negative charge. The chemical reaction occurring between CO and NH group and the physical adsorption predominated by electrostatic interaction were found to involve in coupling. BMDCs can release 40% of DOX in simulated gastrointestinal conditions within 38 h. Kinetic models including Higuchi, Korsmeyer–Peppas, Zero order, First order, Hixon-Crowell, Baker-Lonsdale, and Weibull and Gompertz were utilized to explore the release mechanism of DOX from BMDCs. All models were found to fit well (r2 ≥ 0.8144) with the release data and the Gompertz was the best fit model (r2 = 0.9742), implying that the complex mechanisms involving Fickian and Gompertz diffusion contributed to the release. These findings suggested that magnetosomes from At. ferrooxidans have great potential applications in biomedical and clinical fields as the carrier of target drug delivery systems in the future.

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Design, Synthesis and Studies on Novel Polymeric Prodrugs of Erlotinib for Colon Drug Delivery

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520620666200811124013 ◽

2020 ◽

Vol 20 ◽

Author(s):

Sahil Kumar ◽

Bandna Sharma ◽

Tilak R. Bhardwaj ◽

Rajesh K. Singh

Keyword(s):

Drug Delivery ◽

Colon Cancer ◽

Drug Release ◽

Anticancer Agents ◽

Release Kinetics ◽

In Vitro Release ◽

Specific Treatment ◽

Drug Conjugates ◽

Polymer Drug Conjugates

Aims: In the present study, polymer-drug conjugates were synthesized based on azo-bond cleavage drug delivery approach for targeting erlotinib as anticancer drug specifically to the colon for the proficient treatment of colon cancer. Background: Colon cancer (CC) is the third commonly detected tumor worldwide and it make up about 10 % of all cases of cancers. Most of the chemotherapeutic drugs available for treating colon cancer are not only toxic to cancerous cells but also to the normal healthy cells. Among the various approaches to get rid of the adverse effects of anticancer agents, prodrugs are one of the most imperative approaches. Objective: The objective of the study is to chemically modify the erlotinib drug through azo-bond linkage and suitable spacer which will be finally linked to polymeric backbone to give desired polymer linked prodrug. The azo reductase enzyme present in colon is supposed to cleave the azo-bond specifically and augment the drug release at the colon. Methods: The synthesized conjugates were characterized by IR and 1H-NMR spectroscopy. The cleavage of aromatic azobond resulted in a potential colon-specific liberation of drug from conjugate studied in rat fecal contents. In vitro release profiles of polyphosphazene-linked conjugates of erlotinib have been studied at pH 1.2, pH 6.8 and pH 7.4. The stability study was designed to exhibit that free drug was released proficiently and unmodified from polyphosphazene-erlotinib conjugates having aromatic azo-bond in artificial colon conditions. Results: The synthesized conjugates were demonstrated to be stable in simulated upper gastro-intestinal tract conditions. The drug release kinetics shows that all the polymer-drug conjugates of erlotinib follow zero-order release kinetics which indicates that the drug release from the polymeric backbone is independent of its concentration. Kinetic study of conjugates with slope (n) shows the anomalous type of release with an exponent (n) > 0.89 indicating a super case II type of release. Conclusion: These studies indicate that polyphosphazene linked drug conjugates of erlotinib could be the promising candidates for the site-specific treatment of colon cancer with least detrimental side-effects.

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Clinoptilolite Microparticles as Carriers of Catechin-Rich Acacia Catechu Extracts: Microencapsulation and In Vitro Release Study

Molecules ◽

10.3390/molecules26061655 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1655

Author(s):

Zvezdelina Yaneva ◽

Donika Ivanova ◽

Nikolay Popov

Keyword(s):

Composite System ◽

Release Kinetics ◽

Spectral Characteristics ◽

In Vitro Release ◽

Medium Ph ◽

Release Capacity ◽

Bioactive Substance ◽

Acacia Catechu ◽

Vitro Release

The main goal of the present study was to investigate the microencapsulation, in vitro release capacity and efficiency of catechin-rich Acacia catechu extract by Clinosorbent-5 (CLS-5) microparticles by in-depth detailed analyses and mathematical modelling of the encapsulation and in vitro release kinetics behaviour of the polyphenol-mineral composite system. The bioflavanol encapsulation and release efficiency on/from the mineral matrix were assessed by sorption experiments and interpretative modelling of the experimental data. The surface and spectral characteristics of the natural bioactive substance and the inorganic microcarrier were determined by Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet/Visible (UV/Vis) spectrophotometric analyses. The maximum extent of catechin microencapsulation in acidic medium was 32%. The in vitro release kinetics study in simulated enzyme-free gastric medium (pH = 1.2) approved 88% maximum release efficiency achieved after 24 h. The in vitro release profile displayed that the developed bioflavanol/clinoptilolite microcarrier system provided sustained catechin in vitro release behaviour without an initial burst effect. Thus, the results from the present study are essential for the design and development of innovative catechin-CLS-5 microcarrier systems for application in human and veterinary medicine.

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