Fig. 12 Scanning electron micrograph of D.L-PLA nanoparticles loaded with CGP 57813. (Ref. 51.) scanning force microscopy (also called atomic force microscopy), enable the visualiza-tion of nanoparticles at atmospheric pressure without gold coating [12,64]. Neverthe-less, the resolution obtained with these new tools is still lower than that with SEM. For size determination, transmission electron microscopy is not as widely used as PCS and SEM, but it is still a powerful method for determining the morphology of particles. With this technique, Fessi et al. [42] estimated the wall thickness of PLA nanocapsules. Krause et al. [18] described the highly porous structure of PLA nano-spheres prepared by the emulsion-evaporation procedure. VIII. IN VITRO RELEASE STUDIES In vitro release studies should in principle be useful for quality control as well as for the prediction of in vivo kinetics. Unfortunately, due to the very small size of the par-ticles, the release rate observed in vivo can differ greatly from the release obtained in a buffer solution. However, in vitro release studies remain very useful for quality control as well as for evaluation of the influence of process parameters on the release rate of active compounds. In vitro drug release from microdispersed systems has been exten-sively reviewed by Washington [65]. Depending on the type of polyester, drug release from nanoparticles can take place through several processes, of which the following appear to be the most important: (1) The drug may diffuse out of the carrier through the solid matrix; to allow complete release from the carriers, (the concentration of drug in the release medium should re-main infinitely low, which condition is known as sink condition); (2) The solvent may penetrate the nanoparticles and dissolve the drug, which then diffuses out into the re-lease medium. Depending on the physico-chemical characteristics of the particles, wa-ter can enter the particles through narrow pores or by hydration. Once the drug is dis-solved, the drug diffuses out of the particles. Here again, since diffusion is driving the

1998 ◽  
pp. 204-216
Keyword(s):  
Quality Control ◽  
Drug Release ◽  
Release Rate ◽  
In Vitro Release ◽  
Scanning Force Microscopy ◽  
Force Microscopy ◽  
Release Studies ◽  
Vitro Release

Preparation, evaluation, and in vitro release of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules

2020 ◽  
pp. 1-9
Author(s):  
Yunhong Wang ◽  
Rong Hu ◽  
Yanlei Guo ◽  
Weihan Qin ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Release Rate ◽  
Orthogonal Design ◽  
Drug Loading ◽  
In Vitro Release ◽  
Core Material ◽  
Evaluation Indexes ◽  
Vitro Release

OBJECTIVE: In this study we explore the method to prepare tanshinone self-microemulsifying sustained-release microcapsules using tanshinone self-microemulsion as the core material, and chitosan and alginate as capsule materials. METHODS: The optimal preparation technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules was determined by using the orthogonal design experiment and single-factor analysis. The drug loading and entrapment rate were used as evaluation indexes to assess the quality of the drug, and the in vitro release rate was used to evaluate the drug release performance. RESULTS: The best technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules is as follows: the concentration of alginate is 1.5%, the ratio of tanshinone self-microemulsion volume to alginate volume to chitosan mass is 1:1:0.5 (ml: ml: g), and the best concentration of calcium chloride is 2.0%. To prepare the microcapsules using this technology, the drug loading will be 0.046%, the entrapment rate will be 80.23%, and the 24-hour in vitro cumulative release rate will be 97.4%. CONCLUSION: The release of the microcapsules conforms to the Higuchi equation and the first-order drug release model and has a good sustained-release performance.

scholarly journals In vitro Release Kinetics Study of Ranolazine from Swellable Hydrophilic Matrix Tablets

1970 ◽  
Vol 8 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Mohammad Nezab Uddin ◽  
Ishtiaq Ahmed ◽  
Monzurul Amin Roni ◽  
Muhammad Rashedul Islam ◽  
Mohammad Habibur Rahman ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Release Kinetics ◽  
In Vitro Release ◽  
High Viscosity ◽  
Matrix Tablets ◽  
Release Studies ◽  
The Matrix ◽  
Vitro Release

The objective of this study was to design oral sustained release matrix tablets of Ranolazine usinghydroxypropyl methylcellulose (HPMC) as the retardant polymer and to study the effect of formulation factors suchas polymer proportion and polymer viscosity on the release of drug. In vitro release studies were performed usingUSP type II apparatus (paddle method) in 900 mL of 0.1N HCl at 100 rpm for 12 hours. The release kinetics wasanalyzed using the zero-order, first order, Higuchi and Korsmeyer-Peppas equations to explore and explain themechanism of drug release from the matrix tablets. In vitro release studies revealed that the release rate decreasedwith increase in polymer proportion and viscosity grade. Mathematical analysis of the release kinetics indicated thatthe nature of drug release from the matrix tablets was dependent on drug diffusion and polymer relaxation andtherefore followed non-Fickian or anomalous release. The developed controlled release matrix tablets of Ranolazineprepared with high viscosity HPMC extended release up to 12 hours.Key words: Ranolazine; Sustained release; Methocel E50 Premium LV; Methocel K100LV CR; Methocel K4M CR;Methocel K15M CR.DOI: 10.3329/dujps.v8i1.5333Dhaka Univ. J. Pharm. Sci. 8(1): 31-38, 2009 (June)

scholarly journals FABRICATION OF NANO CLAY INTERCALATED POLYMERIC MICROBEADS FOR CONTROLLED RELEASE OF CURCUMIN

2021 ◽  
pp. 206-215
Author(s):  
DHARMENDER PALLERLA ◽  
SUMAN BANOTH ◽  
SUNKARI JYOTHI
Keyword(s):  
Drug Release ◽  
In Vitro Release ◽  
Controlled Drug Release ◽  
Fickian Diffusion ◽  
Simulated Gastric Fluid ◽  
Release Mechanism ◽  
Release Studies ◽  
Swelling Studies ◽  
Vitro Release

Objective: The objective of this study was to formulate and evaluate the Curcumin (CUR) encapsulated sodium alginate (SA)/badam gum (BG)/kaolin (KA) microbeads for controlled drug release studies. Methods: The fabricated microbeads were characterized by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (X-RD), and scanning electron microscopy (SEM). Dynamic swelling studies and in vitro release kinetics were performed in simulated intestinal fluid (pH 7.4) and simulated gastric fluid (pH 1.2) at 37 °C. Results: FTIR confirms the formation of microbeads. DSC studies confirm the polymorphism of CUR in drug loaded microbeads which indicate the molecular level dispersion of the drug in the microbeads. SEM studies confirmed the microbeads are spherical in shape with wrinkled and rough surfaces. XRD studies reveal the molecular dispersion of CUR and the presence of KA in the developed microbeads. In vitro release studies and swelling studies depend on the pH of test media, which might be suitable for intestinal drug delivery. The % of drug release values fit into the Korsmeyer-Peppas equation and n values are obtained in the range of 0.577-0.664, which indicates that the developed microbeads follow the non-Fickian diffusion drug release mechanism. Conclusion: The results concluded that the CUR encapsulated microbeads are potentially good carriers for controlled drug release studies.

scholarly journals DESIGN AND IN VITRO EVALUATION OF EXTENDED RELEASE TABLET OF NATEGLINIDE

2018 ◽  
Vol 8 (5-s) ◽  
pp. 235-239
Author(s):  
NILESH M MAHAJAN ◽  
Kalyanee Wanaskar ◽  
Yogesh Bhutada ◽  
Raju Thenge ◽  
Vaibhav Adhao
Keyword(s):  
Drug Release ◽  
Extended Release ◽  
In Vitro Release ◽  
Matrix Tablet ◽  
Direct Compression ◽  
In Vitro Drug Release ◽  
Release Studies ◽  
Tablet Properties ◽  
Vitro Release

The aim of present study is to formulate and evaluate extended release matrix tablet of Nateglinide by direct compression method using different polymer like HPMC K4 and HPMC K15. Matrix tablet of nateglidine were prepared in combination with the polymer HPMC K4, HPMC K15, along with the excipients and the formulations were evaluated for tablet properties and in vitro drug release studies. Nateglinide matrix tablet prepared by using polymer such as HPMC K4 and HPMC K15,  it was found that HPMC K15 having higher viscosity as compare to HPMC K4 therefore different concentration of polymer were studied to extend the drug release up to 12 h. The tablets of Nateglinide prepared by direct compression had acceptable physical characteristics and satisfactory drug release. The study demonstrated that as far as the formulations were concerned, the selected polymers proved to have an acceptable flexibility in terms of in-vitro release profile. In present the study the percent drug release for optimize batch was found to 94.62%.  Hence it can be conclude that Nateglinide extended release matrix tablet can prepared by using HPMC. The swollen tablet also maintains its physical integrity during the drug release study Keywords: Tablet, in-vitro drug release, Nateglinide, HPMC

scholarly journals Influence of sterilization on the drug release behaviour of drug coated silicone

2021 ◽  
Vol 7 (2) ◽  
pp. 672-675
Author(s):  
Katharina Wulf ◽  
Stefan Raggl ◽  
Thomas Eickner ◽  
Gerrit Paasche ◽  
Niels Grabow
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Polymer Coating ◽  
Drug Loading ◽  
In Vitro Release ◽  
Physical Chemical ◽  
Release Studies ◽  
Vitro Release ◽  
Dual Drug

Abstract Sterilization processes ensure sterility of drug delivery systems, but may negatively affect the properties of biomaterials and incorporated drugs by changing their physical, chemical, mechanical properties and drug release behaviour. Therefore, it is important to investigate their influence. In this study, the influence of ethylene oxide (EtO) sterilization on the drug loading and release behaviour of incorporated Diclofenac (DCF) in a Poly-L-lactide (PLLA) coating and Dexamethasone (DMS) in the silicone carrier is presented. Silicone samples containing DMS were coated with PLLA containing DCF varying in layer thickness (5, 10, and 20 μm). Half of the samples underwent EtO sterilization, the other half was not sterilized. All un-/sterilized sample surfaces were in view of the morphology and hydrophilicity examined. Furthermore, in vitro release studies of DMS and DCF were conducted. The sterilized sample surfaces showed no morphological and hydrophilicity changes. The DCF and DMS loadings were similar for the sterile and untreated samples. This also applied to the in vitro DMS release profiles apart from the end of the studies where slight differences were evident. The results indicate that both drugs loaded in the polymer coating and the silicone were not impaired by the sterilization process. Thus, EtO sterilization appears suitable for DMS containing silicone and DCF incorporated PLLA coatings as a dual drug delivery system.

Development of Mucoadhesive Patches for Buccal Administration of Prochlorperazine: Evaluation of In Vitro Release and Mechanical Properties

1970 ◽  
Vol 1 (1) ◽  
pp. 64-70
Author(s):  
Chandra Sekhar Kolli ◽  
Ramesh Gannu ◽  
Vamshi Vishnu Yamsani ◽  
Kishan V ◽  
Madhsudan Rao Yamsani
Keyword(s):  
Mechanical Properties ◽  
Drug Release ◽  
Moisture Absorption ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Work Of Adhesion ◽  
Casting Technique ◽  
Vitro Release

The aim of this investigation was to develop and evaluate mucoadhesive buccal patches of prochlorperazine (PCPZ). Permeation of PCPZ was calculated in vitro using porcine buccal membrane. Buccal formulations were developed by solvent-casting technique using hydroxy propylmethyl cellulose (HPMC) as mucoadhesive polymer. The patches were evaluated for in vitro release, moisture absorption and mechanical properties. The optimized formulation, based on in vitro release and moisture absorption studies, was subjected for bioadhesion studies using porcine buccal membrane. In vitro flux of PCPZ was calculated to be 2.14 ± 0.01 µg. h–1.cm–2 and buccal absorption was also demonstrated in vivo in human volunteers.             In vitro drug release and moisture absorbed was governed by HPMC content. Increasing concentration of HPMC delayed the drug release. All formulations followed Zero order release kinetics whereas the release pattern was non-Fickian. The mechanical properties, tensile strength (10.28 ± 2.27 kg mm–2 for formulation P3) and elongation at break reveal that the formulations were found to be strong but not brittle. The peak detachment force and work of adhesion for formulation P3 were 0.68 ± 0.15 N and 0.14 ± 0.08 mJ, respectively. The results indicate that suitable bioadhesive buccal patches of PCPZ with desired permeability and suitable mechanical properties could be prepared

scholarly journals Ligand Decorated Embelin Loaded PLGA Nanoparticles for Management of Alcohol Induced Hepatotoxicity

2020 ◽  
Vol 10 (1) ◽  
pp. 72-80
Author(s):  
Ajay Kumar ◽  
M. Nikhat Khan ◽  
Jovita Kanoujia ◽  
Amandeep Singh ◽  
Neeraj Mishra
Keyword(s):  
High Performance ◽  
In Vitro Release ◽  
Plga Nanoparticles ◽  
Hep G2 ◽  
Release Studies ◽  
Plga Nanoparticle ◽  
Surface Modified ◽  
Vitro Release

Preparation of surface modified Embelin loaded nanoparticles (GA-PEG-PLGA) for the management of hepatotoxicity. Surface modified Embelin loaded GA-PEG-PLGA NPs were evaluated by NMR, FTIR, TEM techniques and in vitro release studies. The biodistribution of the nanoparticles was assessed by High-performance liquid chromatography (HPLC), and the cellular uptake study was evaluated using Hep G2 cells (liver cells lines). The hepatoprotecttive effect of the surface modified Embelin loaded GA-PEG-PLGA NPs was investigated in-vitro and in-vivo. The surface modified Embelin loaded GA-PEG-PLGA nanoparticles significantly increases the uptake of drug in liver by 2.5 folds more than plain drug. Keywords: Glycyrrhetinic acid, Receptor mediated, Surface functionalization, Embelin, PLGA nanoparticle.

scholarly journals Evaluation of the Correlation between in Vivo and in Vitro Release. Effect of the Force of Contraction and Food on Drug Release.

1994 ◽  
Vol 17 (2) ◽  
pp. 291-295 ◽  
Author(s):  
Shigeru AOKI ◽  
Hidenobu ANDO ◽  
Masaaki ISHII ◽  
Katsumi IDA ◽  
Sumio WATANABE ◽  
...  
Keyword(s):  
Drug Release ◽  
In Vitro Release ◽  
Force Of Contraction ◽  
Vitro Release
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