scholarly journals In vitro Release Kinetics of Progesterone from Biodegradable In situ Implant System

1970 ◽  
Vol 6 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Irin Dewan ◽  
Md Elias-Al-Mamun ◽  
Reza-ul Jalil
Keyword(s):  
Release Kinetics ◽  
Drug Loading ◽  
Static Condition ◽  
Surrounding Tissue ◽  
In Vitro Dissolution ◽  
Release Mechanism ◽  
Water Mixture ◽  
Biodegradable Implant

In situ implants containing Progesterone (PRG) were prepared by using biodegradable Poly (DLlactide- co-glycolide) polymer. Dimethyl sulfoxide (DMSO) was used as an aprotic solvent in this implant formulation. This system was prepared by dissolving a water insoluble and biodegradable polymer (PLGA) in a biocompatible organic solvent (DMSO) and then the drug progesterone was added to the polymer solution to produce the drug solution. When the PLGA-PRG solution (0.5 ml) was injected subcutaneously into rat (weight 130g), the solvent dissipated into the surrounding tissue leading phase separation and subsequent coagulation of the polymer & drug to form an implant in situ. The implants were removed from the rat after one hour and stored in freezing condition. The digital photographs of the in-situ formed implants obtained after 1hour shows the evidence of the formation of the implants. Two formulations of implants were made. One contained 10% of progesterone and the other 20%. In vitro dissolution studies of progesterone was performed at static condition in ethanol-water mixture (30:70) at 37°C for 30 days. The implants of 20% progesterone loading showed about 65% release and the implants of 10% loading showed 56% release within 30 days. The release mechanism from these implants resembles closely to Higuchian pattern and first order. The release rate was found faster from the implants with higher drug loading of 20% progesterone, compared to implants of 10% drug loading. Key words: Biodegradable; Implant; Biocompatible; Sustained Release Dhaka Univ. J. Pharm. Sci. 6(2): 99-103, 2007 (December)

scholarly journals Comparative Evaluation of Bromhexine HCl Mucoadhesive Microspheres Prepared by Anionic, Cationic and Nonionic Polymers

2020 ◽  
Vol 23 (2) ◽  
pp. 117-124
Author(s):  
Sabirah Ishaque Limpa ◽  
Zahirul Islam ◽  
Md Selim Reza
Keyword(s):  
Surface Morphology ◽  
Release Kinetics ◽  
Drug Loading ◽  
Entrapment Efficiency ◽  
Pharmaceutical Journal ◽  
In Vitro Dissolution ◽  
Release Mechanism ◽  
Drug Entrapment Efficiency ◽  
Ph Range

The purpose of this study was to formulate and assess the mucoadhesive microspheres of bromhexine hydrochloride, a mucolytic agent, using three different types of polymers to achieve gastric retention for improved solubility and bioavailability of the drug. The mucoadhesive formulation was prepared because it dissolved in the pH range of 1 to 4. The characteristics of the prepared microspheres were evaluated by determining the particle size, percent drug loading, surface morphology, swelling behavior, mucoadhesive bond strength and drug entrapment efficiency. The in vitro dissolution was studied using the USP dissolution apparatus I in 0.1N HCl (pH 1.2) media for 8 hours. The release kinetics were analyzed by using zero order, first order, Higuchi, Korsmeyer-Peppas and Hixon-crowell equations to explain the release mechanism from the microspheres. The microspheres exhibited good swelling index and the drug entrapment efficiency was above 79 % for all the formulations. All the formulations showed drug release above 25%, 35%, 50% and 75% after 2 hrs, 4 hrs, 6 hrs and 8 hrs of dissolution respectively. The mucoadhesive bond was observed up to 8 hrs in acidic media. The surface morphology of the prepared microspheres was studied by Scanning Electron Microscope (SEM) and no interaction was found between drug and polymer from the FTIR study. Bangladesh Pharmaceutical Journal 23(2): 117-124, 2020

DEVELOPMENT AND CHARACTERIZATION OF GASTRO RETENTIVE MUCOADHESIVE MICROBEADS CONTAINING SIMVASTATIN WITH DIFFERENT CROSS LINKING AGENTS

2020 ◽  
pp. 118-126
Author(s):  
VENKATA RAMANA REDDY K. ◽  
NAGABHUSHANAM M. V. ◽  
PAMULA REDDY B. ◽  
RAVINDAR NAIK E.
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
Drug Loading ◽  
Aluminium Chloride ◽  
In Vitro Dissolution ◽  
Cross Linking ◽  
Stability Studies ◽  
Study Results ◽  
Curing Agents

Objective: The aim of the present work was to prepare and examine drug release of the oral controlled release microbeads using different curing agents by emulsification internal ionic gelation technique. Methods: Cross-linked alginate microbeads were prepared with different cross linking agents by using mucoadhesive properties. The formation and compatibility of microbeads were confirmed by compatibility studies. Prepared microbeads evaluated for encapsulated efficiency, micromeritic properties, drug loading, in vitro wash off studies, in vitro dissolution studies, drug release kinetics and stability studies Results: The in vitro drug release was influenced by both type of curing agents and type of polymers and no significant changes in characterization parameters was observed after 3 mo stability studies. The sustained release profile of optimized batch was found to be 99.66±0.18% in comparison to pure drug profile of 28.64±0.02% at 12 h release study. Results of both wash-off and in vitro studies suggests that batch (SF2) prepared with aluminium chloride has shown better mucoadhesive property. Drug release of optimized batch follows zero order with non fickian mechanism according to Korsmeyer-Peppas equation. Conclusion: The data suggest the use of simvastatin mucoadhesive cross linked microbeads to offer the potential for oral controlled drug delivery with improved gastric retention and capable to provide sustained drug release by using cross linking agents.

scholarly journals Porous nanoparticles of metoprolol tartrate produced by spray-drying: development, characterization and in vitro evaluation

2012 ◽  
Vol 62 (3) ◽  
pp. 383-394 ◽  
Author(s):  
Mohammed S. Khan ◽  
Gowda D. Vishakante ◽  
H. G. Shivakumar
Keyword(s):  
Drug Release ◽  
Spray Drying ◽  
Release Kinetics ◽  
Drug Loading ◽  
Release Mechanism ◽  
Metoprolol Tartrate ◽  
Pore Former ◽  
Porous Nanoparticles ◽  
Zero Order Release

The present investigation was undertaken to fabricate porous nanoparticles of metoprolol tartrate by spray-drying using ammonium carbonate as pore former. Prepared nanoparticles were coated with Eudragit S100 polymer in order to prevent the release of metoprolol tartrate in the upper GI tract. It was shown that nanoparticles with low size ranges can be obtained with a low feed inlet rate. Micromeritic studies confirmed that nanoparticle batches are discrete and free flowing. Effects of the pore former on drug loading, porosity and in vitro release were studied. It was found that there was an increase in drug loading and porosity with increasing the amount of pore former. In vitro drug release studies showed that an increase in pore former made drug release faster. Release kinetics proved that nanoparticles follow a zero-order release mechanism.

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

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.

scholarly journals Formulation and In vitro Evaluation of Eudragit RL 100 Loaded Fexofenadine HCl Microspheres

2016 ◽  
Vol 19 (1) ◽  
pp. 58-67
Author(s):  
Paroma Arefin ◽  
Ikramul Hasan ◽  
Md Shfiqul Islam ◽  
Md Selim Reza
Keyword(s):  
Drug Release ◽  
Release Rate ◽  
Encapsulation Efficiency ◽  
Release Kinetics ◽  
Drug Loading ◽  
Release Mechanism ◽  
Order Release ◽  
Eudragit Rl ◽  
Fexofenadine Hcl

The present study deals with the formulation and evaluation of Fexofenadine hydrochloride (HCl) loaded sustained release microspheres by emulsion solvent evaporation method with Eudragit RL 100. The effects of percent drug loading on drug encapsulation efficiency, drug content and drug release rate were assessed. In vitro dissolution study was performed spectrophotometrically according to USP paddle method using phosphate buffer (pH 6.8) for 10 hours. The release rate of Fexofenadine HCl from the microspheres was significantly increased with the increase of drug loading. The drug release patterns were simulated in different kinetic orders such as zero order release kinetics, first order release kinetics, Higuchi release kinetics, Korsmeyer-Peppas release kinetics and Hixson-Crowell release kinetics to assess the release mechanism and Higuchi release kinetics was found to be the predominant release mechanism. Morphological changes due to different drug loading were assessed by scanning electron microscopic (SEM) technique. Differential scanning calorimetry and fourier transform infra-red (FT-IR) spectroscopy was performed to evaluate compatibility of drug with the polymer. A statistically significant variation indrug encapsulation efficiency and release rate was observed for variation in drug loading.Bangladesh Pharmaceutical Journal 19(1): 58-67, 2016

scholarly journals Fixed Bed Adsorption of Drugs on Silica Aerogel from Supercritical Carbon Dioxide Solutions

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Giuseppe Caputo
Keyword(s):  
Silica Aerogel ◽  
Release Kinetics ◽  
Drug Loading ◽  
Fixed Bed ◽  
Fluid Phase ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Fixed Bed Adsorption ◽  
Supercritical Adsorption

Supercritical adsorption coupled with the high adsorption capacity of silica aerogel allows the preparation of a new kind of delivery systems of poor water soluble drugs. In order to overcome drawbacks of conventional techniques where the use of liquid solvents can cause the fracture of aerogel porous structure, in this work a new adsorption process of drugs from a supercritical mixture is proposed. Adsorption takes place from a fluid solution of the drug in supercritical CO2and ethanol as cosolvent. A fixed bed adsorption plant has been developed to allow fast mixing of fluid phase and effective contact in the adsorption column. The use of ethanol as cosolvent allows to overcome the limitation of supercritical adsorption due to low solubility of many drugs in supercritical CO2. Adsorption isotherms were measured for one-model substance, nimesulide, at 40°C, and breakthrough curve was experimentally obtained. The drug loading of the drug into silica aerogel was up to 9 wt%. The drug composite was characterized using scanning electron microscopy, and release kinetics of the adsorbed drug were also evaluated by in vitro dissolution tests. The dissolution of nimesulide from loaded aerogel is much faster than dissolution of crystalline nimesulide. Around 80% of nimesulide dissolves from the aerogel within 6 minutes, whereas dissolving 80% of the crystalline drug takes about 90 min.

scholarly journals In vitro Release Kinetic Study of Theophylline from Kollidon SR Polymer Based Matrix Tablet

2015 ◽  
Vol 14 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Abul Kalam Lutful Kabir ◽  
Shimul Halder ◽  
Abu Shara Shamsur Rouf
Keyword(s):  
Release Rate ◽  
Release Kinetics ◽  
Zero Order ◽  
In Vitro Dissolution ◽  
Release Mechanism ◽  
Matrix Tablet ◽  
Medium Ph ◽  
First Order ◽  
Tablet Matrix

Controlled release tablet matrix of theophylline was prepared with kollidon SR, a spray dried powder grade polymer (polyvinyl acetate and povidone based matrix rate retarding hydrophobic materials) by utilizing direct compression technique. Different proportion of kollidon SR was used to develop the matrix builder in the five proposed formulations (F-1 to F-5) for the study of release rate retardant effect at 10, 12, 15, 18 and 21% of total weight of matrix tablet, respectively. The in vitro dissolution study of the matrices of those proposed tablet formulations were carried out in simulated gastric medium (pH 1.3) for first two hours and then in simulated intestinal medium (pH 6.8) for 6 hours using USP dissolution apparatus II (paddle method). The formulation F-3 (using 15% polymer) and F-4 (using 18 % polymer) met the optimum release profiles of active ingredient for 8 hr period of total study. The release kinetics for theophylline was plotted against zero order, first order and Higuchi release rate kinetics to evaluate the release mechanism of drug from the formulated tablet matrix. The release kinetics of formulation F-3 and F-4 was followed very closely by Higuchi release rate kinetic order than other kinetics such as zero order and first order kinetics which has been reflected the type of drug release from the tablet matrix by diffusion as well as erosion mechanism.Dhaka Univ. J. Pharm. Sci. 14(1): 43-48, 2015 (June)

scholarly journals Enhancement of the dissolution profile of the diuretic hydrochlorothiazide by elaboration of microspheres

2018 ◽  
Vol 83 (11) ◽  
pp. 1243-1259
Author(s):  
Oum Larbi ◽  
Haouaria Merine ◽  
Youssef Ramli ◽  
Fawzia Toumi ◽  
Kaddour Guemra ◽  
...  
Keyword(s):  
Ftir Spectroscopy ◽  
Release Kinetics ◽  
Drug Loading ◽  
In Vitro Release ◽  
Aqueous Solubility ◽  
Xrd Analysis ◽  
In Vitro Dissolution ◽  
Dissolution Profile ◽  
Scanning Calorimetry

Hydrochlorothiazide (HCTZ), which was developed and introduced in the late 1950s, is still one of the most frequently employed drugs in antihypertensive treatments. Its poor aqueous solubility is one of the reasons for its limited bioavailability after oral administration. The present paper provides details of the preparation of HCTZ-loaded microspheres by the solvent evaporation technique. A total of seven formulations were prepared using ethyl cellulose, poly(?-caprolactone) (PCL), ?-cyclodextrin (?-CD) and synthesized poly-(methyl methacrylate) (PMMA) of different molecular weights in different drug-to-carrier ratios in order to investigate their effect on the encapsulation efficiency and drug release kinetics. The prepared formulations were characterized by Fourier transform-infrared (FTIR) spectroscopy, powder X-ray diffractometry, differential scanning calorimetry, yield, drug loading, optical microscopy, surface morphology by scanning electron microscopy (SEM), and in vitro release studies in simulated gastrointestinal tract fluid. The loading efficiency was found in the range from 18?0.34 to 39?0.95 %. The microspheres were spherical, and the mean Sauter diameter (d32) of the obtained microparticles ranged from 26?0.16 to 107?0.58 ?m. The presence of the drug and polymer carriers in the microparticles was confirmed by FTIR spectroscopy and XRD analysis. In vitro dissolution studies showed that the release rate was largely affected by the characteristics of the microparticles, namely the particle size and the nature of the matrix. The release data are best fitted to the Higuchi model with high correlation coefficients (r?).

Gastroretentive System of Fluvastatin Sodium by Using Natural Mucilage and Synthetic Polymer

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Umamaheswara G. ◽  
Anudeep D.
Keyword(s):  
Half Life ◽  
Release Kinetics ◽  
Kinetic Studies ◽  
Diffusion Path ◽  
Synthetic Polymer ◽  
In Vitro Dissolution ◽  
Direct Compression ◽  
Drug Content ◽  
Biological Half Life

Fluvastatin sodium is a novel compound used as cholesterol lowering agent which acts through the inhibition of 3- hydroxyl-3- methyl glutaryl- coenzyme A (HMG-Co A) reductase. It has short biological half life (1-3h) in humans required a dosing frequency of 20 to 40mg twice a day. Due to its short variable biological half life it has been developed to a sustained gastroretentive system with a natural and synthetic polymer and to study how far the natural mucilage improves the sustained activity. Floating tablets were prepared by direct compression method using in combination of natural mucilage and synthetic polymer. Prior to the preparation of tablets the physical mixtures were subjected to FT IR studies and pre compression parameters. After preparation of tablets they were subjected to various tests like swollen index, drug content, In vitro dissolution and release kinetics with pcp disso software etc. The tablets prepared by direct compression shown good in thickness, hardness and uniformity in drug content, the prepared tablets floated more than 12h except FS1 and FS2 shows 9 and 11h. Swollen index studies shows with increase in concentration of polymer the swelling increases the diffusion path length by which the drug molecule may have to travel and cause lag time. In vitro results shows that on increasing the amount of hibiscus polymer the sustain activity is increased because of its integrity and forms a thick swollen mass and reduces the erosion property of the HypromelloseK100M, kinetic studies shows that FS 1, FS2, FS3 followed the Korsmeyer peppas model and the rest FS 4, FS 5, FS6 follows the zero order respectively. Based on n value indicating that the drug release followed super case II transport mechanism due to the erosion of the polymer.

scholarly journals Long-Acting Risperidone Dual Control System: Preparation, Characterization and Evaluation In Vitro and In Vivo

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1210
Author(s):  
Xieguo Yan ◽  
Shiqiang Wang ◽  
Kaoxiang Sun
Keyword(s):  
Drug Loading ◽  
Entrapment Efficiency ◽  
In Vitro Dissolution ◽  
Dissolution Behavior ◽  
In Vivo Evaluation ◽  
Long Term Treatment ◽  
Long Acting

Schizophrenia, a psychiatric disorder, requires long-term treatment; however, large fluctuations in blood drug concentration increase the risk of adverse reactions. We prepared a long-term risperidone (RIS) implantation system that can stabilize RIS release and established in-vitro and in-vivo evaluation systems. Cumulative release, drug loading, and entrapment efficiency were used as evaluation indicators to evaluate the effects of different pore formers, polymer ratios, porogen concentrations, and oil–water ratios on a RIS implant (RIS-IM). We also built a mathematical model to identify the optimized formulation by stepwise regression. We also assessed the crystalline changes, residual solvents, solubility and stability after sterilization, in-vivo polymer degradation, pharmacokinetics, and tissue inflammation in the case of the optimized formulation. The surface of the optimized RIS microspheres was small and hollow with 134.4 ± 3.5 µm particle size, 1.60 SPAN, 46.7% ± 2.3% implant drug loading, and 93.4% entrapment efficiency. The in-vitro dissolution behavior of RIS-IM had zero-order kinetics and stable blood concentration; no lag time was released for over three months. Furthermore, the RIS-IM was not only non-irritating to tissues but also had good biocompatibility and product stability. Long-acting RIS-IMs with microspheres and film coatings can provide a new avenue for treating schizophrenia.

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