scholarly journals Critical Factors for Metformin Osmotic Controlled Release Pump

2020 ◽  
pp. 1-12
Author(s):  
García-Flores Mirna ◽  
Melgoza-Contreras Luz María ◽  
Hernández-Baltazar Efrén
Keyword(s):  
Drug Release ◽  
Release Rate ◽  
Osmotic Pump ◽  
Critical Factors ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Drug Release Profile ◽  
Osmotic Pumps ◽  
The Impact

Aim: Studied the critical factors in the design of an osmotic pump with metformin release rate constant at 4%/hr in diabetes mellitus within 24 hr. with the goal to reduce daily medications. Study Design: Experimental design 32 Methodology: In vitro drug release profiles for 24h. The effects of different formulation variables, that is, concentration of hydrophilic polymer, diameter of drug releasing orifice and coating thickness, on the drug release profile were investigated. Also, the impact of pH, osmotic pressure and morphology with stereo microscopy and scanning electronic microscopy of the osmotic pumps were investigated. At last, osmotic pumps surface was analyze with scanning electronic microscopy. Results: Metformin osmotic pump were successfully prepared in this study to overcome the weak point of multiple doses and great concentration fluctuation of metformin. The formulation determined finally have a release orifice of 700 mm and 3.0% of weight gain, achieved the desired effect which can realize the constant drug release rate at the first 24 hr. Conclusion: The developed osmotic systems have a linear release near 4%/hr. and demonstrated that the behavior was independent of the agitation intensity and the pH of the gastrointestinal apparatus.

scholarly journals Preparation and In vitro Evaluation of Theophylline Loaded Gastroretentive Floating Tablets of METHOCEL K4M

1970 ◽  
Vol 7 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Ferdous Khan ◽  
Md Shaikhul Millat Ibn Razzak ◽  
Md Ziaur Rahman Khan ◽  
Kazi Rashidul Azam ◽  
Sams Mohammad Anowar Sadat ◽  
...  
Keyword(s):  
Citric Acid ◽  
Drug Release ◽  
Sodium Bicarbonate ◽  
Release Rate ◽  
Lag Time ◽  
Release Mechanism ◽  
Drug Release Profile ◽  
Floating Tablets ◽  
Time Required

This investigation describes the preparation and in vitro evaluation of gastroretentive floating tablets of theophylline. Hydrophilic polymer METHOCEL K4M was used for its gel forming and release controlling properties. Sodium bicarbonate and citric acid were incorporated as gas generating agents. The effects of soluble components (sodium bicarbonate and citric acid), gel forming agent (METHOCEL K4M) and dose variation on drug release profile and floating properties were investigated. It has been observed that in all cases increase of the amount of floating agent caused a decrease of the floating lag time. Increase of theophylline load showed an increase of the floating lag time, which was independent of floating agent content. The release mechanisms were explored and explained with zero order, first order, Higuchi, Korsmeyer and Hixon-Crowell equations. The release rate, extent and mechanisms were found to be governed by the content of polymer and floating agent. The content of active ingredient was also a vital factor in controlling drug release pattern. It was found that polymer content and amount of floating agent significantly affected the time required for 50% of drug release (T50%), percentage drug release after 8 hours, release rate constant, and diffusion exponent (n). Kinetic modeling of dissolution profiles revealed that the drug release mechanism could range from diffusion controlled to case II transport, which was mainly dependent on presence of relative amount of theophylline, polymer and floating agent. Key words: Gastroretention, Floating tablet, Theophylline  DOI = 10.3329/dujps.v7i1.1220 Dhaka Univ. J. Pharm. Sci. 7(1): 65-70, 2008 (June)

scholarly journals Formulation and Evaluation of Gastro Retentive Floating Tablets of Simvastatin using Hydrophilic Rate Retardant

2012 ◽  
Vol 15 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Md Nazmul Hussain ◽  
Md Abdullah Al Masum ◽  
Sharmin Akhter ◽  
Florida Sharmin ◽  
Md Selim Reza
Keyword(s):  
Citric Acid ◽  
Drug Release ◽  
Sodium Bicarbonate ◽  
Release Rate ◽  
Dissolution Time ◽  
Drug Release Profile ◽  
Compression Technique ◽  
Weight Variation ◽  
Gastro Retentive

Gastro retentive floating tablet of Simvastatin was prepared by direct compression technique using Methocel K4M as the rate controlling polymer. The hydrophilic cellulose derivative, Methocel K4M was evaluated for its gel forming and release controlling properties. Sodium bicarbonate and citric acid were incorporated as gas generating agents. The effects of soluble components (sodium bicarbonate and citric acid) and gel forming agents on drug release profile and floating properties were investigated. The tablets from all formulations were evaluated for thickness, diameter, weight variation, hardness, and friability. The tablets were also tested for the buoyancy studies and in vitro drug release studies. The drug release study was evaluated for eight hours using USP XXII paddle-type dissolution apparatus using 0.1N HCl with 1% Sodium Lauryl Sulphate as dissolution medium. The release mechanisms were explored and explained with zero order, first order, Higuchi, Hixon Crowell and Korsmeyer equations. The release rate, extent and mechanisms were found to be governed by the polymer content. It was found that the mean dissolution time, percentage drug release, release rate constant and diffusion exponent were influenced significantly by the amount of polymer incorporation. DOI: http://dx.doi.org/10.3329/bpj.v15i2.12575 Bangladesh Pharmaceutical Journal 15(2): 119-126, 2012

Pharmacokinetics of an Implanted Osmotic Pump Delivering Sufentanil for the Treatment of Chronic Pain

2003 ◽  
Vol 99 (4) ◽  
pp. 929-937 ◽  
Author(s):  
Dennis M. Fisher ◽  
Norma Kellett ◽  
Rainer Lenhardt
Keyword(s):  
Chronic Pain ◽  
Release Rate ◽  
Half Life ◽  
Local Heating ◽  
Osmotic Pump ◽  
Population Pharmacokinetic ◽  
Systematic Effect ◽  
The Impact

Background A matchstick-sized implanted osmotic pump (Chronogesic) that delivers sufentanil subcutaneously for more than 90 days is being developed to treat chronic pain. This study evaluates pharmacokinetic characteristics related to the absorption of sufentanil using a prototype 60-day system. Methods Twelve opioid-naive volunteers were given naltrexone to prevent opioid effects. Sufentanil, 60 microg, was infused intravenously over 6 h, then 48 h later, the pump was implanted subcutaneously in the upper arm under local anesthesia. Pumps were removed 9 days later. In six volunteers, fever (1.6-3.3 degrees C) was induced with interleukin-2. Plasma was sampled and population pharmacokinetic modeling was performed to estimate in vivo release rate and absorption half-life. Bioavailability was calculated by comparing in vivo to in vitro release rates. The impact of perturbations in release rate on sufentanil plasma concentration (Cp) was simulated. Results Fever had no systematic effect on Cp. Release rate estimated in vivo was similar to that measured in vitro; bioavailability did not differ from 100%. Absorption half-life was 16.2 h. Simulation demonstrated that supplemental release of sufentanil from the implant (as might occur with local heating) increases Cp an average of 2.5-2.8% per hours supplemental dose. Conclusions An implantable osmotic pump delivered sufentanil in vivo at the rate predicted from in vitro experiments. The rate at which sufentanil was absorbed from the subcutaneous space (half-life > 16 h) was markedly slower than reported with subcutaneous or intramuscular administration of large volumes of dilute opioids; this slow absorption dampens potential changes in Cp if release rate is perturbed.

scholarly journals The Impact of the Ionic Cross-Linking Mode on the Physical and In Vitro Dexamethasone Release Properties of Chitosan/Hydroxyapatite Beads

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4510 ◽  
Author(s):  
Maria Jucélia L. Dantas ◽  
Bárbara Fernanda F. dos Santos ◽  
Albaniza A. Tavares ◽  
Matheus A. Maciel ◽  
Breno de Medeiros Lucena ◽  
...  
Keyword(s):  
Drug Release ◽  
Release Rate ◽  
Sodium Tripolyphosphate ◽  
In Vitro Release ◽  
Surface Topology ◽  
Cartilage Tissue ◽  
Cross Linking ◽  
Release Process ◽  
The Impact

In this study, the effect of the ionic cross-linking mode on the ability to control physical properties and in vitro release behavior of the dexamethasone (DEX) drug from chitosan (CS) and chitosan/hydroxyapatite (CS/HA) beads was investigated. CS solutions without and with HA and DEX were dripped into two coagulation solutions, prepared with a non-toxic ionic crosslinker (sodium tripolyphosphate, TPP) and distilled water, one at pH = 9.0 and other at pH = 6.0. Optical microscopy (OM) and scanning electron microscopy (SEM) results showed changes on the surface topology of the beads, with a reduction of roughness for beads prepared at pH = 6.0 and an increase for the one prepared at pH = 9.0. The diameter and sphericity of the beads prepared at pH = 6.0 proved more uniform and had a larger pore size with a good interconnectivity framework. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) suggested a higher crosslinking degree for beads prepared at pH = 6.0, corroborated by X-ray diffraction profiles (XRD) analysis that indicated a decrease in the crystalline structure for such beads. In in vitro drug release data, all beads presented a sustained release during the studied period (24 h). The drug release rate was affected by the pH of the coagulation solution used in the preparation of the beads. The in vitro kinetics of the release process was of the Peppas–Sahlin model, controlled by both diffusion and relaxation of polymer chains or swelling (anomalous transport mechanism). Our results suggest that DEX-loaded CS/HA beads, crosslinked in TPP coagulation solution at pH = 9.0, led to a decrease in the DEX release rate and prolonged the release period. Thus, this composition might have prospective as a functional material for bone and cartilage tissue engineering.

Synthesis, Characterization and in-vitro drug release studies of a macromolecular prodrug of Didanosine.

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Neeraj Agrawal ◽  
M.J. Chandrasekar ◽  
U.V. Sara ◽  
Rohini A.
Keyword(s):  
Drug Release ◽  
Drug Level ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
Alkaline Environment ◽  
Stomach Acid ◽  
Release Studies ◽  
Macromolecular Prodrug

A macromolecular prodrug of didanosine (ddI) for oral administration was synthesized and evaluated for in-vitro drug release profile. Didanosine was first coupled to 2-hydroxy ethyl methacrylate (HEMA) through a succinic spacer to form HEMA-Suc-ddI monomeric conjugate which was subsequently polymerized to yield Poly(HEMA-Suc-ddI) conjugate. The structures of the synthesized compounds were characterized by FT-IR, Mass and 1H-NMR spectroscopy. The prodrug was subjected for in-vitro drug release studies in buffers of pH 1.2 and 7.4 mimicking the upper and lower GIT. The results showed that the drug release from the polymeric backbone takes place in a sustained manner over a period of 24 h and the amount of drug released was comparatively higher at pH 7.4 indicating that the drug release takes place predominantly at the alkaline environment of the lower GIT rather than at the acidic environment of the upper GIT. This pH dependent sustained drug release behavior of the prodrug may be capable of reducing the dose limiting toxicities by maintaining the plasma drug level within the therapeutic range and increasing t1/2 of ddI. Moreover, the bioavailability of the drug should be improved as the prodrug releases ddI predominantly in the alkaline environment which will reduce the degradation of ddI in the stomach acid.

Formulation Development and Characterization of controlled release core in cup matrix tablets of venlafaxine HCl

2020 ◽  
Vol 15 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Vikas Jhawat ◽  
Gandhi Sivaraman ◽  
Om Prakash Sunnapu ◽  
Ramya Krishna Nakkala ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Zero Order ◽  
Water Soluble ◽  
Matrix Tablets ◽  
Drug Dissolution ◽  
Crystalline Cellulose ◽  
Hydrophobic Polymers

Background: Venlafaxine HCl is a selective serotonin reuptake inhibitor which is given in the treatment of depression. The delivery of the drug at a controlled rate can be of great importance for prolonged effect. Objective: The objective was to prepare and optimize the controlled release core in cup matrix tablet of venlafaxine HCl using the combination of hydrophilic and hydrophobic polymers to prolong the effect with rate controlled drug release. Methods: The controlled release core in cup matrix tablets of venlafaxine HCl were prepared using HPMC K5, K4, K15, HCO, IPA, aerosol, magnesium sterate, hydrogenated castor oil and micro crystalline cellulose PVOK-900 using wet granulation technique. Total ten formulations with varying concentrations of polymers were prepared and evaluated for different physicochemical parameters such FTIR analysis for drug identification, In-vitro drug dissolution study was performed to evaluate the amount of drug release in 24 hrs, drug release kinetics study was performed to fit the data in zero order, first order, Hixson–crowell and Higuchi equation to determine the mechanism of drug release and stability studies for 3 months as observed. Results: The results of hardness, thickness, weight variation, friability and drug content study were in acceptable range for all formulations. Based on the In vitro dissolution profile, formulation F-9 was considered to be the optimized extending the release of 98.32% of drug up to 24 hrs. The data fitting study showed that the optimized formulation followed the zero order release rate kinetics and also compared with innovator product (flavix XR) showed better drug release profile. Conclusion: The core-in-cup technology has a potential to control the release rate of freely water soluble drugs for single administration per day by optimization with combined use of hydrophilic and hydrophobic polymers.

Development and Optimization of Sustained Release Moxifloxacin Hydrochloride Loaded Nanoemulsion for Ophthalmic Drug Delivery: A 32 Factorial Design Approach

2020 ◽  
Vol 12 ◽  
Author(s):  
Sagar R. Pardeshi ◽  
Harshal A. Mistari ◽  
Rakhi S. Jain ◽  
Pankaj R. Pardeshi ◽  
Rahul L. Rajput ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Factorial Design ◽  
Water Solubility ◽  
Tween 80 ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
Bacterial Conjunctivitis ◽  
Promising Alternative

Background: Moxifloxacin is a BCS class I drug used in the treatment of bacterial conjunctivitis and keratitis. Despite its high water solubility, it possesses limited bioavailability due to anatomical and physiological constraints associated with the eyes which required multiple administrations to achieve a therapeutic effect. Objective: In order to prolong drug release and to improve antibacterial efficacy for the treatment of bacterial keratitis and conjunctivitis, moxifloxacin loaded nanoemulsion was developed. Methods: The concentration of oil (oleic acid), surfactant (tween 80), and cosurfactant (propylene glycol) were optimized by employing a 3-level 2-factorial design of experiment for the development of nanoemulsion. The developed nanoemulsion was characterized by particle size distribution, viscosity, refractive index, pH, drug content and release, transmission electron microscopy (TEM), and antibacterial study. The compatibility of the drug with the excipients was accessed by Fourier transform infrared spectroscopy (FTIR). Result: The average globule size was found to be 198.20 nm. The TEM study reveals the globules were nearly spherical and are well distributed. In vitro drug release profile for nanoemulsion shown sustained drug release (60.12% at the end of 6 h) compared to drug solution, where complete drug released within 2 h. The antibacterial effectiveness of the drug-loaded nanoemulsion was improved against S. aureus compared with the marketed formulation. Conclusion: The formulated sustained release nanoemulsion could be a promising alternative to eye drop with improved patient compliance by minimizing dosing frequency with improved antibacterial activity.

scholarly journals Development and In Vitro-In Vivo Evaluation of a Novel Sustained-Release Loxoprofen Pellet with Double Coating Layer

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 260 ◽  
Author(s):  
Dongwei Wan ◽  
Min Zhao ◽  
Jingjing Zhang ◽  
Libiao Luan
Keyword(s):  
Citric Acid ◽  
Drug Release ◽  
Sustained Release ◽  
Release Rate ◽  
Diffusion Rate ◽  
Immediate Release ◽  
Pharmacokinetic Studies ◽  
Release Tablet

This study aimed to develop a novel sustained release pellet of loxoprofen sodium (LXP) by coating a dissolution-rate controlling sub-layer containing hydroxypropyl methyl cellulose (HPMC) and citric acid, and a second diffusion-rate controlling layer containing aqueous dispersion of ethyl cellulose (ADEC) on the surface of a LXP conventional pellet, and to compare its performance in vivo with an immediate release tablet (Loxinon®). A three-level, three-factor Box-Behnken design and the response surface model (RSM) were used to investigate and optimize the effects of the citric acid content in the sub-layer, the sub-layer coating level, and the outer ADEC coating level on the in vitro release profiles of LXP sustained release pellets. The pharmacokinetic studies of the optimal sustained release pellets were performed in fasted beagle dogs using an immediate release tablet as a reference. The results illustrated that both the citric acid (CA) and ADEC as the dissolution- and diffusion-rate controlling materials significantly decreased the drug release rate. The optimal formulation showed a pH-independent drug release in media at pH above 4.5 and a slightly slow release in acid medium. The pharmacokinetic studies revealed that a more stable and prolonged plasma drug concentration profile of the optimal pellets was achieved, with a relative bioavaibility of 87.16% compared with the conventional tablets. This article provided a novel concept of two-step control of the release rate of LXP, which showed a sustained release both in vitro and in vivo.

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.

Formulation and Evaluation of Solid Self-Nanoemulsifying Drug Delivery System for Enhancing the Solubility and Dissolution Rate of Budesonide

2021 ◽  
pp. 5755-5763
Author(s):  
Kanuri Lakshmi Prasad ◽  
Kuralla Hari
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Dissolution Rate ◽  
Drug Delivery System ◽  
Delivery System ◽  
Ternary Phase Diagram ◽  
Water Soluble ◽  
Drug Release Profile ◽  
Water Soluble Drug

Objective: To enhance solubility and dissolution rate of budesonide through development of solid self-nanoemulsifying drug delivery system (S-SNEDDS). Methods: Liquid self-nanoemulsifying drug delivery systems (L-SNEDDS) were prepared and ternary phase diagram was constructed using Origin pro 8. Liquid self-nanoemulsifying formulation LF2 having 20% oil and 80% of surfactant/co-surfactant was optimized from the three formulations (LF1-LF3) to convert in to solid, through various characterization techniques like self-emulsification, in vitro drug release profile and drug content estimation. The prepared L-SNEDDS converted into S-SNEDDS, SF1-SF6 by adsorption technique using Aerosil 200, Neusilin US2, and Neusilin UFL2 to improve flowability, compressibility and stability. Results: Formulation LF2 exhibited globule size of 82.4 nm, PDI 0.349 and Zeta potential -28.6 mV with drug indicating the stability and homogeneity of particles. The optimized formulation SF4 containing Neusilin UFL2 was characterized by DSC, FTIR, X-Ray diffraction studies and found no incompatibility and no major shifts were noticed. Formulation SF4 released 100 % drug in 20 min against pure drug release of 47 % in 60 min. Regardless of the form (i.e. liquid or solid) similar performance of emulsification efficiency is observed. Conclusion: The results demonstrated that the technique of novel solid self-nanoemulsifying drug delivery system can be employed to enhance the solubility and dissolution rate of poorly water-soluble drug budesonide.

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