scholarly journals Preparation of a Sustained Release Drug Delivery System for Dexamethasone by a Thermosensitive, In Situ Forming Hydrogel for Use in Differentiation of Dental Pulp

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Elham Khodaverdi ◽  
Fatemeh Kheirandish ◽  
Farnaz Sadat Mirzazadeh Tekie ◽  
Bibi Zahra Khashyarmanesh ◽  
Farzin Hadizadeh ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Delivery System ◽  
In Vitro Release ◽  
In Situ Forming ◽  
Release Study ◽  
Vitro Release

In situ forming delivery systems composed of block copolymers are attracting substantial attention due to their ease of use, biocompatibility, and biodegradability. In this study, the thermoresponsive triblock copolymer PLGA-PEG-PLGA was studied as a dexamethasone delivery system. Dexamethasone, a synthetic glucocorticoid, is used clinically to improve inflammation, pain, and the hyperemesis of chemotherapy, and it is applied experimentally as a differentiation factor in tissue engineering. PLGA-PEG-PLGA was synthesised under microwave irradiation for 5 min. The obtained copolymer was characterised to determine its structure and phase transition temperature. An in vitro release study was conducted for various copolymer structures and drug concentrations. The yield of the reaction and HNMR analysis confirmed the appropriateness of the microwave-assisted method for PLGA-PEG-PLGA synthesis. Phase transition temperature was affected by the drug molecule as well as by the copolymer concentration and structure. An in vitro release study demonstrated that release occurs mainly by diffusion and does not depend on the copolymer structure or dexamethasone concentration.

scholarly journals In Situ-Forming Microparticles for Controlled Release of Rivastigmine: In Vitro Optimization and In Vivo Evaluation

2021 ◽  
Vol 14 (1) ◽  
pp. 66
Author(s):  
Mohamed Haider ◽  
Ibrahim Elsayed ◽  
Iman S. Ahmed ◽  
Ahmed R. Fares
Keyword(s):  
Drug Release ◽  
In Vitro Release ◽  
Flip Flop ◽  
In Situ Forming ◽  
Internal Phase ◽  
The Matrix ◽  
Vitro Release

In this work, sucrose acetate isobutyrate (SAIB) and polylactic co-glycolic acid (PLGA) were used alone or in combination as a matrix-former (MF) to prepare long-acting injectable rivastigmine (RV) in situ-forming microparticles (ISM). RV-ISM were prepared by the emulsification of an internal phase, containing the drug and the matrix former(s), into an external oily phase containing a stabilizer. The statistical design, Central Composite Design (CCD), was adopted as a quality by design (QbD) approach to optimize the formulation of RV-ISM systems. The fabricated RV-ISM systems was designed to minimize the initial burst drug release and maximize the sustainment of RV release from the ISM and ease of injection. The influence of critical formulation variables such as the matrix-former to drug (MF/D) ratio and SAIB to PLGA (S/P) ratio in the internal phase with respect to critical quality attributes (CQAs), such as the percentage drug release within the first day (Q1), the time required for 50% drug release (T50%) and the rate of injection, were studied using the CCD. The optimal RV-ISM system with the highest desirability value (0.74) was predicted to have an MF/D ratio of 11.7:1 (w/w) and an S/P ratio of 1.64:1 (w/w). The optimal RV-ISM system was assessed for its release profile, injectability, rheological properties, morphology, effect on cell viability, tolerance to γ-sterilization and in vivo performance in male albino rabbits. In vitro release studies revealed that the optimal RV-ISM system released 100% of its drug content throughout a release period of 30 days with only 15.5% drug release within the first day (Q1) and T50% of 13.09 days. Moreover, the optimal system showed a high injection rate of 1.012 mL/min, pseudoplastic flow, uniform spherical globules with homogenous particle size, minimal cytotoxicity and high tolerability to γ-sterilization. In vivo pharmacokinetic (PK) studies revealed that the rate of absorption of RV from the optimal RV-ISM system was controlled compared to a drug solution following either intramuscular (IM) or subcutaneous (SC) injection. Furthermore, the optimal RV-ISM was found to follow flip-flop PK with poor correlation between in vitro release and in vivo findings. These findings suggest that the optimal RV-ISM is a promising tool to achieve a sustained release therapy for RV; however, further investigation is still required to optimize the in vivo performance of RV-ISM.

In-vitro Release Evaluation of Growth Hormone from an Injectable In-Situ Forming Gel Using PCL-PEG-PCL Thermosensitive Triblock

2020 ◽  
Vol 17 (2) ◽  
pp. 174-183
Author(s):  
Elham Khodaverdi ◽  
Khadijeh Delroba ◽  
Fatemeh Mohammadpour ◽  
Bahman Khameneh ◽  
Sayyed A. Sajadi Tabassi ◽  
...  
Keyword(s):  
Growth Hormone ◽  
In Vitro Release ◽  
Cd Spectrum ◽  
In Situ Forming ◽  
Sds Page ◽  
In Situ Forming Gel ◽  
The Stability ◽  
Vitro Release

Objective: An injectable long acting In-Situ Forming Gel (ISFG) of human Growth Hormone (hGH) was prepared by using triblock PCL-­‐PEG-­‐PCL (Mw 1500-1500-1500). Ring-Opening Polymerization (ROP) of triblock using microwave was applied. Methods: The BCA protein assay Kit was used to determine the concentration of hGH in the in-vitro release medium. Finally, Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) tests and Circular Dichroism (CD) spectrum were done to approve the stability of released hGH. The result of ROP demonstrated that the proportion of PCL to PEG accorded with the initial molar ratio of the monomers. The cross-section of the Surface Electron Microscopy (SEM) indicated the porous framework of the hydrogel could load the drug into its tridimensional matrixes structure. There is the low initial burst release of hGH from the supramolecular hydrogel. Results: The maximum in-vitro release of hGH was 71.2 % ± 1.5 that were due to hGH degrading after this time (21 days). The CD spectrum and SDS-PAGE results confirmed the stability of hGH during invitro release evaluation. Conclusion: The results suggest that the sustained-release formulation using PCL-PEG-PCL can be applied to control the release of hGH.

scholarly journals ORAL GENTAMICIN PREPARATION USING SOLIDIFIED LIPID PARTICULATE DELIVERY SYSTEM

2017 ◽  
Vol 9 (9) ◽  
pp. 22
Author(s):  
Musiliu Adedokun ◽  
Tenderwealth Jackson ◽  
Kelechi Uchegbu ◽  
Anthony Attama
Keyword(s):  
Particle Size ◽  
Sustained Release ◽  
Delivery System ◽  
In Vitro Release ◽  
Zero Order ◽  
Lipid Matrix ◽  
Mean Particle Size ◽  
Release Study ◽  
Vitro Release

Objective: Despite the broad pharmacological activity of gentamicin against a number of bacteria, it's very inadequate oral bioavailability due to poor intestinal membrane permeability has limited its formulation into oral dosage delivery system. This work was thus aimed at formulation and evaluation of gentamicin-loaded microemulsions based on preparation of lipid matrix for sustained release delivery.Methods: Oral gentamicin suspensions were prepared by emulsification method using Tween 80 as a mobile surfactant in the lipid matrix dispersion. The resultant oral suspensions were evaluated for mean particle size and morphology using a photomicrograph, encapsulation efficiency/entrapment, EE (%), dispersibility, pH and absolute drug content. Release study as a function of inhibition zone diameter (IZD) and in vitro release study was also carried out. The in vitro release study was performed in both simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 7.2) respectively. The release data were analyzed mathematically according to zero order, first order and Higuchi equations.Results: The prepared suspensions were cream-white in colour, easily dispersed and well homogenized. Batch D, which had least amount of excipients incorporated into the lipid matrix showed clumped irregular-shaped and less free-flowing particles. The particle size was significantly influenced by lipid matrix combination ratio in the presence of a surfactant (p<0.05). The mean particle size diameters of the samples were 15.44 mm, 10.64 mm, 4.12 mm, and 2.70 mm for batches A, B, C and D respectively. The values of EE obtained varied between 47% and 59% with Batch B exhibiting the highest value. The Higuchi model gave the best release kinetics result followed by zero order kinetics.Conclusion: Oral gentamicin prepared exhibited antibacterial properties against Klebsiella spp., Escherchia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. The results suggest that a lipid matrix system could be useful as a sustained release oral delivery system of a poorly absorbable drug such as gentamicin.

Nanocapsulation of Nitazoxanide in Solid Lipid Nanoparticles as a New Drug Delivery System and in vitro Release Study

2016 ◽  
Vol 16 (4) ◽  
pp. 120-127 ◽  
Author(s):  
Roghayeh Abbasalipo ◽  
Mohammad Fallah ◽  
Fruzan Sedighi ◽  
Amir Hossein Maghsood ◽  
Saman Javid
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Solid Lipid Nanoparticles ◽  
In Vitro Release ◽  
Lipid Nanoparticles ◽  
Solid Lipid ◽  
Release Study ◽  
Vitro Release

scholarly journals FORMULATION AND EVALUATION OF IMPLANTABLE DRUG DELIVERY SYSTEM OF TEMOZOLOMIDE BY USING HYDROPHILIC POLYMER

2017 ◽  
Vol 10 (11) ◽  
pp. 239
Author(s):  
Sindhu Vemula ◽  
Bhavya S ◽  
Suresh Kumar P ◽  
Jeyabaskaran M ◽  
Praveenkumar T ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
In Vitro Release ◽  
Hydrophilic Polymer ◽  
Short Term ◽  
Drug Content ◽  
Release Study ◽  
Vitro Release

  Objective: The present research study was carried out to formulate and evaluate the implants of temozolomide using hydrophilic polymer.Methods: Temozolomide implants were formulated using extrusion method with different grades of carbopol. The powdered blend was evaluated for micromeritic properties such as angle of repose, bulk density, tapped density, Carr’s index, and Hausner’s ratio. The formulated implants were analyzed for drug content uniformity, thickness, weight variation, and short-term stability study. In vitro release study of implants was performed using 0.1N hydrochloric acid, and it is maintained at 37°C±0.5°C.Results: In vitro release study demonstrated that the release rate of temozolomide from the implant matrix was a function of concentration of the polymer. As the concentration of polymer was increased, drug release from the matrix was extended. The release of drug from all implant formulations was found to be uniform and was extended over a period of 12 hrs. The implant formulations were found sterile, uniform in weight and size. The drug content was found to be in the range of 97.2-101.33%.Conclusion: Drug interaction studies revealed that there were no chemical interactions between temozolomide and polymers used in the study. Short-term stability studies of implants revealed that implants were stable, and there were no significant changes in the physical appearance and drug content of the implant formulations. The results of the study demonstrated that implantable drug delivery system of temozolomide can be formulated using hydrophilic polymer.

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