5-Fluorouracil Release from Chitosan-Based Matrix.Experimental and Theoretical Aspects

A series of four drug release formulations based on 5-fluorouracil encapsulated into a chitosan-based matrix were prepared by in situ hydrogelation with 3,7-dimethyl-2,6-octadienal. The formulations were investigated from structural and morphological aspects by FTIR spectroscopy, polarized light microscopy and scanning electron microscopy. It was established that 5-fluorouracil was anchored into the matrix as crystals, whose dimension varied as a function of the crosslinking density. The in vitro drug release simulated into a media mimicking the physiological environment revealed a progressive release of the 5-fluorouracil, in close interdependence with the crosslinking density. In the context of Pharmacokinetics behavioral analysis, a new mathematical procedure for describing drug release dynamics in polymer-drug complex system is proposed. Assuming that the dynamics of polymer-drug system�s structural units take place on continuous and nondifferentiable curves (multifractal curves), we show that in a one-dimensional hydrodynamic formalism of multifractal variables the drug release mechanism (Fickian diffusion, non-Fickian diffusion, etc) are given through synchronous dynamics at a differentiable and non-differentiable scale resolutions. Finally, the model is confirmed by the empirical data.

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DESIGN AND CHARACTERIZATION OF ALFUZOSIN HCL GASTRORETENTIVE FLOATING MATRIX TABLETS EMPLOYING HPMC K 100M

INDIAN DRUGS ◽

10.53879/id.55.11.10741 ◽

2018 ◽

Vol 55 (11) ◽

pp. 71-73

Author(s):

Ch. Taraka Ramarao ◽

◽

J Vijaya Ratna ◽

R. B. Srinivasa

Keyword(s):

Drug Release ◽

Dosage Forms ◽

Matrix Tablets ◽

Fickian Diffusion ◽

Release Mechanism ◽

Gastric Residence Time ◽

Drug Release Mechanism ◽

The Matrix ◽

Gastro Retentive

The present investigation involves developing gastro retentive drug delivery systems (GFDDS) of alfuzosin HCl using HPMCK100M a is the matrixing agent and floating enhancer. Sodium bicarbonate in the acidic environment reacts with the acid and produces carbon dioxide. The gastro retentive tablets can be formulated to increase the gastric residence time and thereby increase the oral bioavailability. From the drug release study, it was concluded that the AFTB4 formula of HPMC K 100 M matrix tablets gives the controlled release up to 12 hours by showing increased release with floating lag time 24 seconds. Non – Fickian diffusion was the drug release mechanism from the matrix tablets formulated employing HPMC K 100 M. The matrix tablets (AFTB4) formulated employing 40 % HPMC K 100 M are best suited to be used for gastro retentive dosage form of alfuzosin HCl. Finally, it can be concluded that good candidates for the preparation of gastro retentive dosage forms due its gastric stability, gastric absorption and better bioavailability.

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Formulation and invitro evaluation of oral extended release microspheres of aceclofenac using various natural polymers

International Journal of Research in Pharmaceutical Sciences and Technology ◽

10.33974/ijrpst.v1i2.69 ◽

2019 ◽

Vol 1 (2) ◽

pp. 58-66

Author(s):

Syed abid ali ◽

Syed mujtaba pasha ◽

Omair sohail ahmed ◽

Omer wasiq ◽

Mohammed mukaram ◽

...

Keyword(s):

Drug Release ◽

Sodium Alginate ◽

Oral Route ◽

Aqueous System ◽

Fickian Diffusion ◽

Release Mechanism ◽

Natural Polymers ◽

Drug Release Mechanism ◽

Microsphere Method

In the present work, bioadhesive microspheres of Aceclofenac using Sodium alginate along with Carbopol 934, Carbopol 971, HPMC K4M as copolymers were formulated to deliver Aceclofenac via oral route. The results of this investigation indicate that ionic cross-linking technique Ionotropic gelation method can be successfully employed to fabricate Aceclofenac microspheres. The technique provides characteristic advantage over conventional microsphere method, which involves an “all-aqueous” system, avoids residual solvents in microspheres. FT-IR spectra of the physical mixture revealed that the drug is compatible with the polymers and copolymers used. Micromeritic studies revealed that the mean particle size of the prepared microspheres was in the size range of 512-903µm and are suitable for bioadhesive microspheres for oral administration. The in-vitro mucoadhesive study demonstrated that microspheres of Aceclofenac using sodium alginate along with Carbopol934 as copolymer adhered to the mucus to a greater extent than the microspheres of Aceclofenac using sodium alginate along with Carbopol 971 and HPMC K4M as copolymers. The invitro drug release decreased with increase in the polymer and copolymer concentration. Analysis of drug release mechanism showed that the drug release from the formulations followed non-Fickian diffusion and the best fit model was found to be Korsmeyer-Peppas. Based on the results of evaluation tests formulation coded T4 was concluded as best formulation.

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Doxycycline and Monocaprin In Situ Hydrogel: Effect on Stability, Mucoadhesion and Texture Analysis and In Vitro Release

Gels ◽

10.3390/gels5040047 ◽

2019 ◽

Vol 5 (4) ◽

pp. 47 ◽

Cited By ~ 1

Author(s):

Venu Gopal Reddy Patlolla ◽

William Peter Holbrook ◽

Sveinbjorn Gizurarson ◽

Thordis Kristmundsdottir

Keyword(s):

Drug Release ◽

In Vitro Release ◽

Fickian Diffusion ◽

Release Time ◽

Release Mechanism ◽

Oral Diseases ◽

Zero Order Kinetics ◽

In Situ Hydrogel

The aim of this study was to develop a stable aqueous formulation containing a combination of doxycycline and monocaprin in clinically relevant concentrations. Increase in expression of Matrix metalloproteinases (MMPs) and microbial role in oral diseases is well established and the combination of above active ingredients could be potentially beneficial in treatment of oral mucosal conditions. The hydrogels containing different concentrations of doxycycline and monocaprin in the presence and absence of stabilizing excipients were developed and their stabilities were studied at 4 °C for up to 1 year. The drug–drug interaction was evaluated using Fourier-transform infrared spectroscopy (FTIR). The addition of monocaprin on doxycycline in situ hydrogel’s mucoadhesiveness, texture properties and drug release mechanism was studied. The addition of monocaprin negatively affected the doxycycline stability and was concentration dependent, whereas monocaprin was stable up to 1 year. Doxycycline did not interfere with the anti-Candidal activity of monocaprin. Furthermore, the presence of monocaprin significantly affected the formulation hardness, compressibility and adhesiveness. Monocaprin and doxycycline release followed zero order kinetics and the release mechanism was, by anomalous (non-Fickian) diffusion. The addition of monocaprin increased the drug release time and altered the release mechanism. It is possible to stabilize doxycycline in the presence of monocaprin up to 1 year at 4 °C.

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Relevancy of Nizatidine Release from Floating Tablets with Viscosity of Various Cellulose Ethers

Sci ◽

10.3390/sci1010022 ◽

2019 ◽

Vol 1 (1) ◽

pp. 22 ◽

Cited By ~ 1

Author(s):

Yasser Shahzad ◽

Namra Ibrar ◽

Talib Hussain ◽

Abid Mehmood Yousaf ◽

Ikram Ullah Khan ◽

...

Keyword(s):

Drug Release ◽

Fickian Diffusion ◽

In Vitro Dissolution ◽

Release Mechanism ◽

Cellulose Ethers ◽

Polymer Backbone ◽

Floating Tablets ◽

The Matrix ◽

The Difference

Nizatidine is a gastroprotective drug with a short biological half-life and narrow absorption window. This study aimed at developing floating tablets of nizatidine using various HPMC viscosity grades, namely K4M, E4M, K15 and K200M. Directly compressed tablets revealed an excellent uniformity in hardness, thickness and weight and nizatidine was evenly distributed within the matrix floating tablets. Buoyancy study revealed floating lag time as low as 18–38 s, and tablets remain buoyant for upto 24 h. However, the later depended upon viscosity grade of HPMC and that the higher the viscosity, the less was the total floating time. In vitro dissolution indicated viscosity dependent nizatidine release from the floating tablets. HPMC K4M and E4M based floating tablets released almost 100% drug in 12 h, whilst higher viscosity polymers such as K15 and K200M only released 81.88% and 75.81% drug, respectively. The drug release followed non-Fickian diffusion from tablets formulated with K4M, K15 and K200M, whilst super case II transport was observed with E4M based tablets. More interestingly, K4M and E4M polymers have similar viscosity yet exhibited different drug release mechanism. This was attributed to the difference in degree of substitution of methoxyl- and hydroxypropoxyl- groups on polymer backbone.

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Relevancy of Nizatidine’s Release from Floating Tablets with Viscosity of Various Cellulose Ethers

Sci ◽

10.3390/sci3020022 ◽

2021 ◽

Vol 3 (2) ◽

pp. 22

Author(s):

Yasser Shahzad ◽

Namra Ibrar ◽

Talib Hussain ◽

Abid Mehmood Yousaf ◽

Ikram Ullah Khan ◽

...

Keyword(s):

Drug Release ◽

Fickian Diffusion ◽

In Vitro Dissolution ◽

Release Mechanism ◽

Cellulose Ethers ◽

Polymer Backbone ◽

Floating Tablets ◽

The Matrix ◽

The Difference

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

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2021v13i1.39965 ◽

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.

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Novel Gliclazide Electrosprayed Nano-Solid Dispersions: Physicochemical Characterization and Dissolution Evaluation

Advanced Pharmaceutical Bulletin ◽

10.15171/apb.2019.026 ◽

2019 ◽

Vol 9 (2) ◽

pp. 231-240

Author(s):

Khosro Adibkia ◽

Solmaz Ghajar ◽

Karim Osouli-Bostanabad ◽

Niloufar Balaei ◽

Shahram Emami ◽

...

Keyword(s):

Drug Release ◽

Solid Dispersions ◽

In Vitro Release ◽

Physicochemical Characterization ◽

Amorphous State ◽

Water Soluble ◽

Fickian Diffusion ◽

Release Mechanism ◽

Peg 6000

Purpose: In the current study, electrospraying was directed as a novel alternative approach to improve the physicochemical attributes of gliclazide (GLC), as a poorly water-soluble drug, by creating nanocrystalline/amorphous solid dispersions (ESSs). Methods: ESSs were formulated using Eudragit® RS100 and polyethylene glycol (PEG) 6000 as polymeric carriers at various drug: polymer ratios (i.e. 1:5 and 1:10) with different total solution concentrations of 10, 15, and 20% w/v. Morphological, physicochemical, and in-vitro release characteristics of the developed formulations were assessed. Furthermore, GLC dissolution behaviors from ESSs were fitted to various models in order to realize the drug release mechanism. Results: Field emission scanning electron microscopy analyses revealed that the size and morphology of the ESSs were affected by the drug: polymer ratios and solution concentrations. The polymer ratio augmentation led to increase in the particle size while the solution concentration enhancement yielded in a fiber establishment. Differential scanning calorimetry and powder X-ray diffraction investigations demonstrated that the ESSs were present in an amorphous state. Furthermore, the in vitro drug release studies depicted that the samples prepared employing PEG 6000 as carrier enhanced the dissolution rate and the model that appropriately fitted the release behavior of ESSs was Weibull model, where demonstrating a Fickian diffusion as the leading release mechanism. Fourier-transform infrared spectroscopy results showed a probability of complexation or hydrogen bonding, development between GLC and the polymers in the solid state. Conclusion: Hence the electrospraying system avails the both nanosizing and amorphization advantages, therefore, it can be efficiently applied to formulating of ESSs of BCS Class II drugs.

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DESIGN AND CHARACTERISATION OF TRANSDERMAL PATCHES OF PHENFORMIN HYDROCHLORIDE

International Journal of Current Pharmaceutical Research ◽

10.22159/ijcpr.2017v9i6.23437 ◽

2017 ◽

Vol 9 (6) ◽

pp. 90

Author(s):

Pratik Swarup Das ◽

Puja Saha

Keyword(s):

Drug Release ◽

Diffusion Mechanism ◽

Skin Irritation ◽

In Vitro Release ◽

Chemical Properties ◽

In Vitro Dissolution ◽

Release Mechanism ◽

Transdermal Patches ◽

The Matrix

Objective: In present work was designed to develop suitable transdermal matrix patches of Phenformin hydrochloride using various hydrophilic (HPMC) and hydrophobic (EUDRAGID) polymers as matrix formers.Methods: Transdermal patches containing Phenformin hydrochloride were prepared by the solvent casting evaporation technique.Results: Revealed that prepared patches showed good physical characteristics, no drug-polymer interaction and no skin irritation was observed. The in vitro release study revealed that F3 formulation showed maximum release in 24 h. Formulation F3 was subjected for accelerated stability studies. The F3 formulation was found to be stable as there was no drastic change in the Physico-chemical properties of the patches, which was also confirmed by FTIR.Conclusion: Thus conclusion can be made that stable transdermal patches of Phenformin hydrochloride has been developed. F1, F2, F3, F4 formulations showed highest cumulative percentage drug release of 98.13%, 95.50%, 98.65%, 97.21% were obtained during in vitro drug release studies after 24 h. The release of Phenformin hydrochloride appears to be dependent on lipophilicity of the matrix. Moderately lipophillic matrices showed best release. The predominant release mechanism of drug through the fabricated matrices was believed to be by diffusion mechanism. Based upon the in vitro dissolution data the F3 formulation was concluded as optimized formulation.

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FORMULATION AND EVALUATION OF RAMIPRIL MOUTH DISSOLVING FILMS

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2019v11i3.32361 ◽

2019 ◽

pp. 124-129

Author(s):

Jasvanth E ◽

Teja D ◽

Mounika B ◽

Buchi N Nalluri

Keyword(s):

Drug Release ◽

Release Kinetics ◽

Hydroxypropyl Methylcellulose ◽

Release Mechanism ◽

Onset Of Action ◽

In Vitro Drug Release ◽

Drug Release Mechanism ◽

Preparation And Evaluation ◽

Pvp K30

Objective: The present investigation was aimed at preparation and evaluation of mouth dissolving films (MDFs) of Ramipril to enhance patient convenience, compliance and to improve bioavailability. Methods: MDFs with 0.5% w/w Ramipril were prepared by a solvent casting method using a wet film applicator. The effects of film formers, wetting/solubilizing, saliva stimulating agents and film modifiers on the physicomechanical and in vitro Ramipril release from MDFs were evaluated. Results: The MDFs prepared were transparent, smooth and showed no re-crystallization upon storage. MDFs casted with hydroxypropyl methylcellulose (HPMC) E3 as film former and polyethylene glycol (PEG-400) as plasticizer showed superior Ramipril release rates and good physicomechanical properties when compared to MDFs with E5 and E15 as film formers. HPMC E3 MDFs with polyvinyl pyrrolidone K30 (PVP K30) and sodium lauryl sulphate (SLS) gave superior drug release properties than MDFs without PVP K30 and SLS. The HPMC E3 MDFs with citric acid (CA) as saliva stimulating and xylitol as soothing agent gave significantly superior in vitro drug release than the MDFs without CA and xylitol. Release kinetics data reveals diffusion as a drug release mechanism. Conclusion: From the obtained results, it can be concluded that the administration of Ramipril as MDF may provide a quick onset of action with enhanced oral bioavailability and therapeutic efficacy.

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Techniques of Mucilage and Gum Modification and their Effect on Hydrophilicity and Drug Release

Recent Patents on Drug Delivery & Formulation ◽

10.2174/1872211314666201204160641 ◽

2020 ◽

Vol 14 ◽

Author(s):

Rishabha Malviya ◽

Vandana Tyagi ◽

Dharmendra Singh

Keyword(s):

Drug Release ◽

Dosage Form ◽

Extended Release ◽

Release Mechanism ◽

Release Agent ◽

Drug Release Mechanism ◽

Polymer Relaxation ◽

Hydrophilic Matrices ◽

The Matrix ◽

High Degree

Aim: The manuscript aims to describe the techniques of modification of gums and mucilages and their effect on hydrophilicity and drug release. Discussion: The interest is increased in the fields of polymers which is obtained from natural origin and used in the preparation of pharmaceuticals. Mucilage and gum are natural materials, widely used in the preparation of novel dosage form and conventional dosage form. They are used in the pharmaceutical industry for various purposes like suspending, emulsifying, bio-adhesive, binding, matrix-forming, extended release and controlled release agent. Gum and mucilage are biodegradable, less toxic, cheap and easily available. Moreover, mucilage and gum can be changed to acquire tailored materials for the delivery of drugs and allow them to compete with commercially available synthetic products. These polysaccharides have unique swellability in an aqueous medium that can exert a retardant effect on drug release or act as a super disintegrant, depending on the concentration utilized in the preparation. Drug release mechanism from hydrophilic matrices consisting of gums and mucilages is based on solvent penetration-induced polymer relaxation, diffusion of entrapped drug followed by degradation or erosion of the matrix. Conclusion: The present manuscript highlight the advantages, modifications of gum and mucilage, their effects on hydrophilicity and drug release as well as aspects of the natural gums which can be assumed to be bifunctional excipient because of their concentration-dependent effect on drug release and their high degree of swellability.

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