scholarly journals The EyeFlowCell: Development of a 3D-Printed Dissolution Test Setup for Intravitreal Dosage Forms

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1394
Author(s):  
Tobias Auel ◽  
Linus Großmann ◽  
Lukas Schulig ◽  
Werner Weitschies ◽  
Anne Seidlitz

An in vitro dissolution model, the so-called EyeFlowCell (EFC), was developed to test intravitreal dosage forms, simulating parameters such as the gel-like consistency of the vitreous body. The developed model consists of a stereolithography 3D-printed flow-through cell with a polyacrylamide (PAA) gel as its core. This gel needed to be coated with an agarose sheath because of its low viscosity. Drug release from hydroxypropyl methylcellulose-based implants containing either triamcinolone acetonide or fluorescein sodium was studied in the EFC using a schematic eye movement by the EyeMovementSystem (EyeMoS). For comparison, studies were performed in USP apparatus 4 and USP apparatus 7. Significantly slower drug release was observed in the PAA gel for both model drugs compared with the compendial methods. Drug release from fluorescein sodium-containing model implants was completed after 40 min in USP apparatus 4, whereas drug release in the gel-based EFC lasted 72 h. Drug release from triamcinolone acetonide-containing model implants was completed after 35 min in USP apparatus 4 and after 150 min in USP apparatus 7, whereas this was delayed until 96 h in the EFC. These results suggest that compendial release methods may overestimate the drug release rate in the human vitreous body. Using a gel-based in vitro release system such as the EFC may better predict drug release.

2019 ◽  
Vol 64 (02) ◽  
pp. 61-72
Author(s):  
Elena Kazandjievska ◽  
Iva Antova ◽  
Slavica Mitrevska ◽  
Aleksandar Dimkovski ◽  
Elena Dimov ◽  
...  

In vitro dissolution profiles are increasingly used to evaluate drug release characteristics of pharmaceutical products. The dissolution methods is expected to be an appropriate tool for checking consistency of the pharmaceutical attributes by discriminating similarities and dissimilarities between different drug formulations. Expansion in development of novel “special” dosage forms, due to the manner in which these dosage forms release the active pharmaceutical ingredient, usually requires applying non-compendial dissolution strategy that differs from the traditional compendial recommendations. For demonstrating sameness in the dissolution profile, in vitro drug release comparison between test and reference product of highly viscous oral suspension by applying non-compendial peak vessel against conventional hemispheric vessel was demonstrated in this study. All reference batches exhibited high variability in dissolution data when using hemispheric vessel due to forming mound compact mass at the bottom of the vessel. Different strategies for samples manipulation, before and during dissolution period, were performed in order to eliminate additional variabilities. Modifications of conventional USP 2 apparatus such as using peak vessel provided with more reproducible and reliable result for distinguishing in vitro similarities between different formulations of oral suspensions. Misinterpretation of dissolution data can lead to negative impact on product development. Taking time to observe and evaluate what is happening to the product in the vessel during dissolution is of curtail consideration for proper selection of the dissolution strategy. Keywords: oral suspensions; in-vitro release; hydrodynamic variability; USP apparatus 2/ Paddle apparatus; peak vessel


2017 ◽  
Vol 15 (2) ◽  
pp. 203-208
Author(s):  
Md Haider Ali ◽  
Mohiuddin Ahmed Bhuiyan ◽  
Md Selim Reza ◽  
Samira Karim

The aim of this research was to develop and evaluate gastric floating tablets of salbutamol sulphate. The oral delivery of anti-asthmatic salbutamol sulphate tablets were facilitated by preparing floating dosage form which could increase its absorption in the stomach by increasing the gastric residence time of the drug. Floating tablets were formulated by using different polymers like carbopol, xanthan gum, HPMC-K4 MCR and HPMC- K100 MCR with different proportions. A comparative study of normal effervescent tablets of salbutamol sulphate had also been done. The prepared tablets were evaluated for all their physicochemical properties and in vitro buoyancy study. In vitro dissolution studies of the formulations were done in pH 6.8 phosphate buffer using USP apparatus 2 (paddle method) at 50 rpm. Percent drug release of the formulations (F-1 to F-11) was from 87.34%- 99.12% after 12 hours. From the results, F-11 was selected as an optimized formulation based on 12 h drug release which showed minimal floating lag time and maximum floating time. On the other hand, 100% drug was released within 2 hours from the F-12 of effervescent salbutamol sulphate tablets in which polymer was absent while gas generating sodium bicarbonate and citric acid were present. The results of the study were consistent and may encourage formulating similar dosage form with other drugs.Dhaka Univ. J. Pharm. Sci. 15(2): 203-208, 2016 (December)


2016 ◽  
Vol 19 (2) ◽  
pp. 219-225 ◽  
Author(s):  
Muhammad Rashedul Islam ◽  
Md Elias Al Mamun ◽  
Md Mizanur Rahman Moghal

The study was carried out to evaluate the release modification of indomethacin press coated tablets through different polymers. Several batches of press coated tablets were prepared with indomethacin and Avicel PH 102. The core tablet was compression coated with minimal compression pressure. Formulation IX was modified by incorporating PEG 6000, sodium chloride and sodium lauryl sulphate (SLS). In vitro dissolution studies of the formulations of different excipients were done at pH 7.2 in phosphate buffer using USP apparatus 2 (paddle method) at 50 rpm and 37 ± 0.5 °C temperature. The drug release data was treated in different mathematical fashion to identify the kinetic behaviour. It was found that, drug release which was inversely proportional to the amount of xanthan gum in the coating formulations was significantly changed by the polymers used in the study. Incorporation of SLS caused the drug to be released in near zero order fashion. Drug release was found to follow Higuchi mechanism for all the formulations. The study reveals that the polymers used may be a significant factor for the discrepancy in release rate of indomethacin.Bangladesh Pharmaceutical Journal 19(2): 219-225, 2016


ADMET & DMPK ◽  
2020 ◽  
Author(s):  
Raúl Medina-López ◽  
Sergio Guillén-Moedano ◽  
Marcela Hurtado

<p class="ADMETabstracttext">Furosemide is a diuretic drug widely used in chronic renal failure. The drug has low solubility and permeability, which cause clinical problems. Studying the in vitro release performance elucidates the rate and extent of drug dissolved from dosage forms under different conditions. Furosemide reference tablets were tested using USP Apparatuses 1 and 2 as well as the flow-through cell method (USP Apparatus 4), a dissolution apparatus that simulates the human gastrointestinal tract better than the other methods. Dissolution profiles were created with USP Apparatuses 1 and 2 at 25, 50, and 75 rpm and 900 mL of 0.1 M hydrochloric acid, acetate buffer (pH 4.5), and phosphate buffer (pH 6.8). USP Apparatus 4 with a laminar flow of 16 mL/min and 22.6 mm cells was used. Drug dissolution was quantified at 274 nm for 60 min. Mean dissolution time, dissolution efficiency, time to 50 % dissolution, and time to 80 % dissolution data were used to compare dissolution profiles. Additionally, zero-order, first-order, Higuchi, Hixson-Crowell, Makoid-Banakar, and Weibull models were used to adjust furosemide dissolution data. Between USP Apparatus 1 and 2, significant differences were observed in almost all parameters at 50 and 75 rpm (p &lt; 0.05). A similar dissolution profile (f<sub>2</sub> &gt; 50) with a pharmacopoeial dissolution method (USP Apparatus 2 at 50 rpm and 900 mL of phosphate buffer pH 5.8) and USP Apparatus 4 (laminar flow of 16 mL/min, 22.6 mm cells, and pH 6.8) was observed. The Weibull function was the best mathematical model to describe the in vitro release performance of furosemide in the three USP dissolution apparatuses. These results could be used to manufacture better furosemide dosage forms and decrease the negative clinical impact of current furosemide formulations.</p>


2019 ◽  
Vol 3 (2) ◽  
pp. 18-22
Author(s):  
Letícia Lenz Sfair ◽  
Caren Gobetti ◽  
Martin Steppe ◽  
Elfrides Schapoval

A dissolution test for mianserin hydrochloride in coated tablets containing 30 mg was developed and validated using a fast ultraviolet spectrophotometric method. The appropriate conditions were determinate after testing sink conditions, agitation spped and dissolution medium. The sink conditions tested showed that mianserin hydrochloride was soluble in 0.01 and 0.1 M hydrochloric acid (HCl), acetate buffer pH 4.1 and 5.0 and phosphate buffer pH 6.8. Then, dissolution tests were performed to investigate the drug release in each medium. Optimal conditions to carry out the dissolution test were 900 mL 0.1 M HCl and USP apparatus 2 (paddle) at 50 rpm stirring speed. The quantification method was also adapted and validated. The UV method showed specificity, linearity, precision and accuracy. The in vitro dissolution test can be used to evaluate the drug release profile and the data was used as an aid to establish a possible correlation with in vivo data.


Author(s):  
R. Nagaraju ◽  
Rajesh Kaza

Salbutamol and theophylline are available in conventional dosage forms, administered four times a day, leading to saw tooth kinetics and resulting in ineffective therapy. The combination of these two drugs in a single dosage form will enhance the patient compliance and prolong bronchodilation. Various polymers, such as hydroxy propyl methylcellulose K4M (HPMC- K4M), hydroxy propyl methylcellulose K100M (HPMC- K100M), xanthan gum, ethyl cellulose and hydroxy propyl methylcellulose phthalate (HPMC-P) were studied. HPMC-P and HPMC- K4M were found to be best in controlling the release. In-vitro dissolution studies were carried out for all the bi-layered tablets developed using USP dissolution apparatus type 2 (paddle). It was found that the tablet FB15-FW3 showed 50% release of salbutamol in first hour and the remaining was released for eight hours. However, theophylline was found to be released as per the USP specifications. The IR spectrum was taken for FB15-FW3 formulation and it revealed that there is no disturbance in the principal peaks of pure drugs salbutamol and theophylline. This further confirms the integrity of pure drugs and no incompatibility of them with excipients. Also, formulation of FB15-FW3 has shown required release pattern and complies with all the evaluated parameters and comparable to the marketed formulation.


Author(s):  
Sudarshan Singh ◽  
S S Shyale ◽  
P Karade

The aim of this study was to design orally disintegrating tablet (ODT) of Lamotrigine. It is an Antiepileptic drug which is widely used in epilepsy. It is also used in simple and complex partial seizures and secondary generalized tonic-clonic seizures. It is poorly water soluble drug (0.46 mg/ml). Thus, an attempt was made to enhance the water solubility by complexation with β-cyclodextrin (1:1 molar ratios). The orally disintegrating tablet of lamotrigine was prepared by direct compression method using different concentration of superdisintegrants such as Sodium starch glycollate, croscarmellose sodium by sublimating agent such as camphor. The formulations were evaluated for weight variation, hardness, friability, drug content, wetting time, in vitro disintegration time and in vitro dissolution studies. The prepared tablets were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The disintegration time for the complexed tablets prepared by different concentration of superdisintegrants was found to be in range of 32.54 ± 0.50 to 55.12 ± 0.57 sec and wetting time of the formulations was found to be in range of 28.47 ± 0.67 to 52.19 ± 0.72 sec. All the formulation showed almost 100 percent of drug release within 15 min. Among all the formulation F6 and F7 prepared with 18% croscarmellose sodium and camphor shows faster drug release, respectively 10 min, F6 gives good result for disintegration time, drug release, wetting time and friability. Further formulations were subjected to stability testing for 30 days at temperature of 40 ± 5 ºC/75 ± 5 %RH. Tablets showed no appreciable changes with respect to physical appearance, drug content, disintegration time and dissolution profiles. Results were statistically analyzed by one-way ANOVA at a p < 0.05. It was found that, the data at any point of time are significant at p < 0.05.


Author(s):  
Muhammad Faris Adrianto ◽  
Febri Annuryanti ◽  
Clive G. Wilson ◽  
Ravi Sheshala ◽  
Raghu Raj Singh Thakur

AbstractThe delivery of drugs to the posterior segment of the eye remains a tremendously difficult task. Prolonged treatment in conventional intravitreal therapy requires injections that are administered frequently due to the rapid clearance of the drug molecules. As an alternative, intraocular implants can offer drug release for long-term therapy. However, one of the several challenges in developing intraocular implants is selecting an appropriate in vitro dissolution testing model. In order to determine the efficacy of ocular implants in drug release, multiple in vitro test models were emerging. While these in vitro models may be used to analyse drug release profiles, the findings may not predict in vivo retinal drug exposure as this is influenced by metabolic and physiological factors. This review considers various types of in vitro test methods used to test drug release of ocular implants. Importantly, it discusses the challenges and factors that must be considered in the development and testing of the implants in an in vitro setup. Graphical abstract


Author(s):  
Mahima Singh ◽  
Sriramakamal Jonnalagadda

AbstractThis study evaluates the suitability of 3D printed biodegradable mats to load and deliver the topical antibiotic, neomycin, for up to 3 weeks in vitro. A 3D printer equipped with a hot melt extruder was used to print bandage-like wound coverings with porous sizes appropriate for cellular attachment and viability. The semicrystalline polyester, poly-l-lactic acid (PLLA) was used as the base polymer, coated (post-printing) with polyethylene glycols (PEGs) of MWs 400 Da, 6 kDa, or 20 kDa to enable manipulation of physicochemical and biological properties to suit intended applications. The mats were further loaded with a topical antibiotic (neomycin sulfate), and cumulative drug-release monitored for 3 weeks in vitro. Microscopic imaging as well as Scanning Electron Microscopy (SEM) studies showed pore dimensions of 100 × 400 µm. These pore dimensions were achieved without compromising mechanical strength; because of the “tough” individual fibers constituting the mat (Young’s Moduli of 50 ± 20 MPa and Elastic Elongation of 10 ± 5%). The in vitro dissolution study showed first-order release kinetics for neomycin during the first 20 h, followed by diffusion-controlled (Fickian) release for the remaining duration of the study. The release of neomycin suggested that the ability to load neomycin on to PLLA mats increases threefold, as the MW of the applied PEG coating is lowered from 20 kDa to 400 Da. Overall, this study demonstrates a successful approach to using a 3D printer to prepare porous degradable mats for antibiotic delivery with potential applications to dermal regeneration and tissue engineering.


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