Hydrogel-Forming Microneedle Arrays for Sustained and Controlled Ocular Drug Delivery

2020 ◽  
Vol 3 (4) ◽  
Author(s):  
Maher Amer ◽  
Roland K. Chen
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Release Kinetics ◽  
Therapeutic Index ◽  
Ocular Drug Delivery ◽  
Release Profile ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
Sustained Drug Delivery ◽  
Kinetics Of

Abstract Microneedles (MNs) provide a minimally invasive alternative to intravitreal injections and a promising means to sustainable ocular drug delivery. To optimize the sustained drug release profile and to ease the administration of the MN array to the eye, the number of MNs in an MN array and their layout need to be carefully selected. In this study, the drug release kinetics of MN arrays with varying numbers of MNs (8, 12, and 16) is studied over a four-week period. The MN arrays show a much more uniform drug release profile than the single injections. Only the 16-needle MN array fully released all the amount of loaded drug at the end of the 4-week period. Both 8- and 12-needle arrays showed a steady release rate over the 4-week period, which is the longest sustained release duration that has been reported. Zero-order models are created to predict drug release profiles for the three MN arrays. It is estimated that the MN array with 8 needles can deliver the drug for up to 6 weeks. The models can be used to design MN arrays with a given targeted therapeutic index for sustained drug delivery.

scholarly journals Application of Mathematical Models in Drug Release Kinetics of Cyanocobalamine Fast Dissolving Sublingual Film

2021 ◽  
pp. 72-81
Author(s):  
Adil Patel ◽  
Ami Kalsariya ◽  
Srushti Patel ◽  
Chandni Patel ◽  
Shreya Patel
Keyword(s):  
Drug Release ◽  
Mathematical Models ◽  
Release Kinetics ◽  
Release Profile ◽  
Suitable Model ◽  
Order Model ◽  
Drug Release Profile ◽  
Casting Technique ◽  
Kinetics Of

The aim of present work is to determine and analyse the kinetics of drug release from the fast dissolving sublingual by employing various mathematical models. A study was done with Cyanocobalamine fast dissolving sublingual films, 1.5 mg/film by employing solvent casting technique using dehydrated banana starch and Gelatin. The in-vitro drug release profile was carried out in pH 6.8 phosphate buffer (900 mL) using USP dissolution apparatus I (Basket) at 50 rpm for 20 mins. The drug release data was obtained, quantitatively correlated and interpreted with various mathematical models viz. Zero order model, first order model, Higuchi model, Hixson-Crowell model and Korsmeyer-Peppas model and evaluated to understand the kinetics of drug release. The criterion for the most suitable model was based on the high degree of coefficient of correlation of drug release profile of Cyanocobalamine fast dissolving sublingual films.

scholarly journals Polymers Blending as Release Modulating Tool in Drug Delivery

2021 ◽  
Vol 8 ◽  
Author(s):  
Parisa Ghasemiyeh ◽  
Soliman Mohammadi-Samani
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery Systems ◽  
Release Profile ◽  
Core Shell ◽  
Drug Release Profile ◽  
Polymer Blending ◽  
Different Types ◽  
Kinetics Of ◽  
Physical Mixtures

Different polymeric materials have been used as drug delivery vehicles for decades. Natural, semisynthetic, and synthetic polymers each have their own specific characteristics and, due to the physicochemical limitations of each polymer, tuning the release rate and targeting the active ingredient to a specific organ or site of action is a complicated task for pharmaceutical scientists. In this regard, polymer blending has been considered as an attractive approach to fabricate novel and unique drug delivery systems with modified physical and/or chemical characteristics. There are three major polymer blending approaches that are used for drug delivery purposes: physical mixtures, core-shell model, and block copolymer model. Each of these types of polymer blends could significantly affect the loading capacities and the kinetics of drug release from the relevant formulations. Drug release from these blended polymers can be tuned through the changes in temperature and pH of the environment, and physiochemical properties of the target organs. Furthermore, the possible molecular interactions among polymers and drug molecules can significantly affect the drug release profile from these blended polymeric micro- and nanocarriers. In this review, first of all, different types of polymers and their various applications in biomedical sciences have been discussed and smart or stimuli responsive polymers are introduced and categorized based on their nature. Then, the purpose of polymer blending in drug delivery systems has been discussed. Different types of polymer blends including physical mixtures, core-shell polymeric carriers, and block copolymers have been summarized with focus on the effect of polymer blending on encapsulated drug release profiles. Finally, the consequence of each blending approach on drug release profile and kinetics of drug release have been mentioned in tabular format.

Synthesis, characterization and formulation of sodium calcium silicate bioceramic for drug delivery applications

2016 ◽  
Vol 23 (4) ◽  
pp. 375-380
Author(s):  
P. Manohar Reddy ◽  
Ravy Lakshmi ◽  
Febin Prabhu Dass ◽  
Swamiappan Sasikumar
Keyword(s):  
Drug Delivery ◽  
Calcium Silicate ◽  
Release Kinetics ◽  
Release Profile ◽  
Apatite Formation ◽  
X Ray Diffraction ◽  
Drug Release Profile ◽  
Sodium Calcium ◽  
Calcium Magnesium ◽  
Model Drug

AbstractSodium calcium silicate (Na2CaSiO4) is a bioactive silicate with Na2O, CaO and SiO2 as its basic components, which is similar to that of the composition of bioactive glasses. In the present study, pure sodium calcium silicate was synthesized by rapid combustion technique, and the synthesized sample was characterized by powder X-ray diffraction to check the phase purity. The scaffolds were prepared by varying the ratio of sodium calcium silicate and polyvinyl alcohol, and the apatite-formation ability of the scaffolds was examined by soaking them in a simulated body fluid. The results revealed the formation of hydroxyapatite on the surface of the scaffold after 5 days, which is found to be rapid when compared with the bioactivity of the calcium silicates and calcium magnesium silicates. The scaffolds were also loaded with ciprofloxacin as a model drug and analyzed for its drug release profile using UV spectrophotometer. The release profile did not vary with the change in bioceramic-to-biopolymer ratio, and 60% of the drug was released in 10 days, which is within the appreciable range for a targeted drug delivery system. Moreover, the experimental and simulated values of the release kinetics were compared by applying the existing mathematical model.

scholarly journals Ranitidine Loaded Biopolymer Floats: Designing, Characterization, and Evaluation

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Abdul Karim ◽  
Muhammad Ashraf Shaheen ◽  
Tahir Mehmood ◽  
Abdul Rauf Raza ◽  
Musadiq Aziz ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Lag Time ◽  
Zero Order ◽  
Release Profile ◽  
Drug Release Profile ◽  
Independent Variables ◽  
Zero Order Kinetics ◽  
Model Drug ◽  
Predicted Values

The float formulation is a strategy to improve the bioavailability of drugs by gastroretentive drug delivery system (GRDDS). A drug delivery model based on swellable and reswellable low density biopolymers has been designed to evaluate its drug release profile using ranitidine (RNT) as a model drug and formulations have been prepared utilizing 32factorial designs. The drug release (DR) data has been subjected to various kinetic models to investigate the DR mechanism. A reduction in rate has been observed by expanding the amounts of PSG and LSG parts, while an expansion has been noted by increasing the concentration of tragacanth (TG) and citric acid (CA) with an increment in floating time. The stearic acid (SA) has been used to decrease the lag time because a decrease in density of system was observed. The kinetic analysis showed that the optimized formulation (S4F3) followed zero-order kinetics and power law was found to be best fitted due to its minimum lag time and maximum floating ability. The resemblance of observed and predicted values indicated the validity of derived equations for evaluating the effect of independent variables while kinetic study demonstrated that the applied models are feasible for evaluating and developing float for RNT.

scholarly journals A Review of Sustained Drug Release Studies from Nanofiber Hydrogels

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1612
Author(s):  
Ilker S. Bayer
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Cell Function ◽  
High Surface ◽  
Polymer Networks ◽  
Cellular Interactions ◽  
Sustained Drug Release ◽  
Sustained Drug Delivery ◽  
Recent Advances ◽  
Release Studies

Polymer nanofibers have exceptionally high surface area. This is advantageous compared to bulk polymeric structures, as nanofibrils increase the area over which materials can be transported into and out of a system, via diffusion and active transport. On the other hand, since hydrogels possess a degree of flexibility very similar to natural tissue, due to their significant water content, hydrogels made from natural or biodegradable macromolecular systems can even be injectable into the human body. Due to unique interactions with water, hydrogel transport properties can be easily modified and tailored. As a result, combining nanofibers with hydrogels would truly advance biomedical applications of hydrogels, particularly in the area of sustained drug delivery. In fact, certain nanofiber networks can be transformed into hydrogels directly without the need for a hydrogel enclosure. This review discusses recent advances in the fabrication and application of biomedical nanofiber hydrogels with a strong emphasis on drug release. Most of the drug release studies and recent advances have so far focused on self-gelling nanofiber systems made from peptides or other natural proteins loaded with cancer drugs. Secondly, polysaccharide nanofiber hydrogels are being investigated, and thirdly, electrospun biodegradable polymer networks embedded in polysaccharide-based hydrogels are becoming increasingly popular. This review shows that a major outcome from these works is that nanofiber hydrogels can maintain drug release rates exceeding a few days, even extending into months, which is an extremely difficult task to achieve without the nanofiber texture. This review also demonstrates that some publications still lack careful rheological studies on nanofiber hydrogels; however, rheological properties of hydrogels can influence cell function, mechano-transduction, and cellular interactions such as growth, migration, adhesion, proliferation, differentiation, and morphology. Nanofiber hydrogel rheology becomes even more critical for 3D or 4D printable systems that should maintain sustained drug delivery rates.

scholarly journals Preparation and characterization of azathioprine microspheres for colon specific delivery

2019 ◽  
Vol 9 (2) ◽  
pp. 97-101
Author(s):  
Rinku Gonekar ◽  
Mohan Lal Kori
Keyword(s):  
Drug Delivery ◽  
Particle Size ◽  
Drug Release ◽  
Study Drug ◽  
Entrapment Efficiency ◽  
Release Profile ◽  
Intestinal Fluid ◽  
Drug Release Profile ◽  
Fecal Matter

The objective of the present study is to develop colon targeted drug delivery system using dextrin (polysaccharide) as a carrier for Azathioprine.  Microspheres containing azathioprine, dextrin and various excipients were prepared by solvent evaporation technique. The prepared microsphere were evaluated by different methods parameters like particle size,  drug entrapment efficiency, percentage yield, shape and surface morphology  and in vitro drug release study. Drug release profile was evaluated in simulated gastric, intestinal fluid and simulated colonic fluid. Best formulation was decided on the basis drug release profile in simulated gastric, intestinal fluid and simulated colonic fluid. In dextrin based microspheres, dextrin as a carrier was found to be suitable for targeting of Azathioprine for local action in the site of colon. Dextrin microspheres released 95-99% of azathioprine in simulated colonic fluid with 4% human fecal matter solution. The results of in-vitro studies of the azathioprine microspheres indicate that for colon targeting dextrin are suitable carriers to deliver the drug specifically in the colonic region. Dextrin based azathoprine microspheres showed no significance change in particle size and % residual upon storage at 5 ± 3ºC, 25 ± 2ºC/60 ± 5% RH (room temperature) and 40 ± 2ºC/75 ±5%RH humidity for three months. Keywords: azathioprine, microsphere, dextrin, colon specific drug delivery.

scholarly journals FORMULATION AND EVALUATION OF FLOATING MATRIX TABLETS OF LEVOFLOXACIN HEMIHYDRATE USING HYDROXYPROPYL METHYLCELLULOSE K4M TO TREAT HELICOBACTER PYLORI INFECTION

2018 ◽  
Vol 11 (6) ◽  
pp. 148
Author(s):  
Srinivasa Rao Baratam ◽  
Vijayaratna J
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Release Kinetics ◽  
Hydroxypropyl Methylcellulose ◽  
Matrix Tablets ◽  
In Vitro Dissolution ◽  
Linear Regression Method ◽  
In Vitro Drug Release ◽  
Sustained Drug Delivery

Objective: The aim of the study was to develop a floating drug delivery system of levofloxacin (LVF) hemihydrate for sustained drug delivery to improve the extended retention in the stomach, oral bioavailability, and local site-specific action in the stomach. Methods: Preparation of LVF tablets using melt granulation method using hydroxypropyl methylcellulose (HPMC) K4M with sodium bicarbonate as gas generating agent. From LFTA1 to LFTA5, formulations were developed and evaluated for floating properties for swelling characteristics and in vitro drug release studies. In vitro dissolution was carried out using USP II paddle method using 0.1N HCI pH buffer at 50 rpm and samples were measured at 294 nm using ultraviolet-visible spectroscopy. Results: Obtained Fourier-transform infrared charts indicated that there is no positive evidence for the interaction between LVF and ingredients of the optimized formula. In vitro drug release was performed and drug release kinetics were evaluated using the linear regression method and were found to be followed the zero-order release by diffusion controlled release. Optimized formula was found to be LFTA4 with 20% of a polymer with 99.03% of drug release with 12 h of floating time and 32 s floating lag time. Conclusion: Matrix tablets (LFTA4) formulated employing 20% HPMC K4M are best suited to be used for gastroretentive dosage form of LVF.

Hydrodynamically Balanced Capsule of Famotidine: An Improved Delivery via Gastroretentive Hydrogels

2021 ◽  
pp. 4573-4579
Author(s):  
Ritesh Kumar ◽  
Kashmira J. Gohil
Keyword(s):  
Drug Release ◽  
Patient Compliance ◽  
Release Kinetics ◽  
Mixing Time ◽  
Fickian Diffusion ◽  
Absolute Bioavailability ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
In Vitro Drug Release

Objective: The aim of the present study was to increase the absolute bioavailability of famotidine, enhanced patient compliance in the treatment of peptic ulcer by increasing its gastric residence time and controlled local release of drug upto 12 hours. Materials and Methods: Hydrodynamically balanced capsules of famotidine were prepared, consisting of floating matrix granules, which formed hydrogels. Effects of different formulation variables namely hypromellose (HPMC 4000 cps, HPMC 5600 cps, HPMC 15000 cps), effervescent agent (potassium bicarbonate) and mixing time were studied. Optimization study included 23 full factorial design with t50% and t80% as the kinetic parameters (response variable). Matrix characterization included scanning electron microscopy. All prepared formulations were evaluated to various parameters such as micromeritics properties, % buoyancy and in vitro drug release studies. Results and Discussion: The optimized formulation (F4) remains buoyant for more than 12 hrs. The in-vitro drug release study indicated that increasing the viscosity of HPMC resulted in sustained drug release with long floating duration. SEM studies showed definite entrapment of the drug in the matrix and hydrogel formation. Results showed a pH independent but polymer viscosity dependent drug release profile. The release kinetics followed Higuchi model and mechanism of release was found to be non-Fickian diffusion. Conclusion: Famotidine-loaded hydrodynamically balanced capsules were successfully prepared and prove to be useful for prolonged gastric residence of the drug, better bioavailability, patient compliance and improve delivery for enhanced anti-ulcer activity.

Sign in / Sign up

Export Citation Format

Share Document