scholarly journals Control of Drug Dissolution Rate from Film Dosage Forms Containing Valsartan

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Yoshifumi Murata ◽  
Kyoko Kofuji ◽  
Chieko Maida
Keyword(s):  
Dissolution Rate ◽  
Sodium Alginate ◽  
Antihypertensive Drug ◽  
Alginic Acid ◽  
Dosage Forms ◽  
The Other ◽  
Drug Dissolution ◽  
Dissolution Medium ◽  
Casting Method ◽  
Initial Dissolution Rate

Film dosage forms (FDs) containing valsartan (VST), a popular antihypertensive drug, were prepared using a casting method with sodium alginate and other polysaccharides as the film base. Drug dissolution profiles of the FDs were investigated in limited medium. The FDs were 170–200 μm thick and were easy to handle. All FDs immediately swelled and disintegrated in the medium. About 23% of the VST incorporated into the FD prepared with 1.5% sodium alginate dissolved at 5 min. The initial dissolution rate of VST increased upon the addition of chitosan to the film base; this effect was not observed in the case of chitin. On the other hand, the rate apparently decreased upon modification with alginic acid. In addition, the solubility of VST in the dissolution medium was changed by the addition of chitosan or alginic acid. FDs prepared with polysaccharides are useful for simplifying the administration of drugs to patients, and the drug dissolution rate from FDs can be controlled by modification.

scholarly journals The Role of Functional Excipients in Solid Oral Dosage Forms to Overcome Poor Drug Dissolution and Bioavailability

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 393 ◽  
Author(s):  
Jannes van der Merwe ◽  
Jan Steenekamp ◽  
Dewald Steyn ◽  
Josias Hamman
Keyword(s):  
Dissolution Rate ◽  
Solid Dispersions ◽  
Aqueous Solubility ◽  
Dosage Forms ◽  
Oral Dosage ◽  
Drug Dissolution ◽  
Specific Reference ◽  
Dissolution Rates ◽  
Bioavailability Enhancement ◽  
Poor Solubility

Many active pharmaceutical ingredients (APIs) exhibit poor solubility and low dissolution rates in aqueous environments such as the luminal fluids of the gastrointestinal tract. The oral bioavailability of these compounds is usually very low as a result of their poor solubility properties. In order to improve the bioavailability of these poorly soluble drugs, formulation strategies have been applied as a means to improve their aqueous solubility and dissolution rates. With respect to formulation approaches, excipients can be incorporated in the formulation to assist in the dissolution process of the drug, or specialized dosage forms can be formulated that improve dissolution rate through various mechanisms. This paper provides an overview of selected excipients (e.g., alkalinizing agents, surfactants and sugars) that can be used in formulations to increase the dissolution rate as well as specialized dosage forms such as self-emulsifying delivery systems and formulation techniques such as inclusion complexes and solid dispersions. These formulation approaches are discussed with available examples with specific reference to positive outcomes in terms of drug solubility and bioavailability enhancement.

scholarly journals Development of Film Dosage Form Containing Allopurinol for Prevention and Treatment of Oral Mucositis

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Yoshifumi Murata ◽  
Kyoko Kofuji ◽  
Norihisa Nishida ◽  
Ryosei Kamaguchi
Keyword(s):  
Oral Cavity ◽  
Cancer Patients ◽  
Dosage Form ◽  
Physiological Saline ◽  
Dosage Forms ◽  
Release Profile ◽  
Water Soluble ◽  
Dissolution Medium ◽  
Casting Method ◽  
Prevention And Treatment

Film dosage forms (FDs) containing allopurinol (AP) were prepared using a casting method with water-soluble polysaccharides, such as sodium alginate (ALG), and the release profile of AP from FDs was investigated in limited dissolution medium. Some ALGs were able to form FDs incorporating AP, and the thickness was about 50 μm. All FDs were easy to handle, though the rheological properties varied with ALG species. AP was homogenously present throughout the FDs and was released with disintegration in 10 mL of physiological saline. These results confirmed that FDs are useful for preventing or treating localized problems in the oral cavity, such as mucositis. FDs are also useful for administering drugs to cancer patients receiving chemotherapy and/or radiotherapy.

The Effect of Different Superdisintegrants and their Concentrations on the Dissolution of Topiramate Immediate Release Tablets

2009 ◽  
Vol 2 (2) ◽  
pp. 531-5366
Author(s):  
V A. Vamshi Priya ◽  
G. Chandra Sekhara Rao ◽  
D. Srinivas Reddy ◽  
V. Prabhakar Reddy
Keyword(s):  
Immediate Release ◽  
Drug Dissolution ◽  
Dissolution Profile ◽  
Dissolution Medium ◽  
Lactose Monohydrate ◽  
Sodium Starch Glycolate ◽  
Tablet Disintegration ◽  
Croscarmellose Sodium ◽  
Model Drug ◽  
Usp Apparatus

The purpose of this study was to investigate the efficiency of superdisintegrants: sodium starch glycolate, croscarmellose sodium and crospovidone in promoting tablet disintegration and drug dissolution of Topiramate immediate release tablets. The efficiency of superdisintegrants was tested, by considering four concentrations, viz., like 2%, 3%, 4% and 5% in the formulations. The dissolution was carried out in USP apparatus II at 50 rpm with distilled water as a dissolution medium. The dissolution rate of the model drug topiramate was found highly dependent on the tablet disintegration, on the particle size of the superdisintegrant, on the solubility of the drug and also on the type of superdisintegrant in the dissolution medium. There was no effect of the diluent (Lactose monohydrate) on the disintegration of different concentrations of superdisintegrants. These results suggest that, as determined by the f2 metric (similarity factor), the dissolution profile of the formulation containing 4% sodium starch glycolate and lactose monohydrate as a diluent was similar to that of a marketed product.

The reductive dissolution of synthetic goethite and hematite in dithionite

Clay Minerals ◽  
1987 ◽  
Vol 22 (3) ◽  
pp. 329-337 ◽  
Author(s):  
J. Torrent ◽  
U. Schwertmann ◽  
V. Barron
Keyword(s):  
Specific Surface ◽  
Dissolution Rate ◽  
Surface Area ◽  
Reductive Dissolution ◽  
Natural Environments ◽  
Dissolution Rates ◽  
Aluminium Substitution ◽  
Initial Dissolution Rate

AbstractThe reductive dissolution by Na-dithionite of 28 synthetic goethites and 26 hematites having widely different crystal morphologies, specific surfaces and aluminium substitution levels has been investigated. For both minerals the initial dissolution rate per unit of surface area decreased with aluminium substitution. At similar aluminium substitution and specific surface, goethites and hematites showed similar dissolution rates. These results suggest that preferential, reductive dissolution of hematite in some natural environments, such as soils or sediments, might be due to the generally lower aluminium substitution of this mineral compared to goethite.

scholarly journals The fate of Si and Fe while nuclear glass alters with steel and clay

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
C. Carriere ◽  
P. Dillmann ◽  
S. Gin ◽  
D. Neff ◽  
L. Gentaz ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Protective Layer ◽  
Glass Dissolution ◽  
A Value ◽  
Waste Forms ◽  
Controlling Mechanism ◽  
Geological Repository ◽  
The Mean ◽  
High Level ◽  
Initial Dissolution Rate

AbstractThe French concept developed to dispose high-level radioactive waste in geological repository relies on glassy waste forms, isolated from the claystone host rock by steel containers. Understanding interactions between glass and surrounding materials is key for assessing the performance of a such system. Here, isotopically tagged SON68 glass, steel and claystone were studied through an integrated mockup conducted at 50 °C for 2.5 years. Post-mortem analyses were performed from nanometric to millimetric scales using TEM, STXM, ToF-SIMS and SEM techniques. The glass alteration layer consisted of a crystallized Fe-rich smectite mineral, close to nontronite, supporting a dissolution/reprecipitation controlling mechanism for glass alteration. The mean glass dissolution rate ranged between 1.6 × 10−2 g m−2 d−1 to 3.0 × 10−2 g m−2 d−1, a value only 3–5 times lower than the initial dissolution rate. Thermodynamic calculations highlighted a competition between nontronite and protective gel, explaining why in the present conditions the formation of a protective layer is prevented.

Initial Dissolution Rate Studies on Dental Enamel after CO2 Laser Irradiation

1992 ◽  
Vol 71 (7) ◽  
pp. 1389-1398 ◽  
Author(s):  
J.L. Fox ◽  
D. Yu ◽  
M. Otsuka ◽  
W.I. Higuchi ◽  
J. Wong ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Laser Irradiation ◽  
Co2 Laser ◽  
Dental Enamel ◽  
Initial Dissolution Rate

scholarly journals The Development and Optimization of Hot-Melt Extruded Amorphous Solid Dispersions Containing Rivaroxaban in Combination with Polymers

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 344
Author(s):  
Jong-Hwa Lee ◽  
Hyeong Sik Jeong ◽  
Jong-Woo Jeong ◽  
Tae-Sung Koo ◽  
Do-Kyun Kim ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Dissolution Rate ◽  
Solid Dispersion ◽  
Oral Drug Delivery ◽  
Amorphous Solid ◽  
Drug Dissolution ◽  
Oral Drug ◽  
Amorphous Solid Dispersion ◽  
Screw Speed ◽  
Hot Melt

Rivaroxaban (RXB), a novel oral anticoagulant that directly inhibits factor Xa, is a poorly soluble drug belonging to Biopharmaceutics Classification System (BCS) class II. In this study, a hot-melt extruded amorphous solid dispersion (HME-ASD) containing RXB is prepared by changing the drug:polymer ratio (Polyvinylpyrrolidione-vinyl acetate 64, 1:1–1:4) and barrel temperature (200–240 °C), fixed at 20% of Cremophor® RH 40 and 15 rpm of the screw speed, using the hot-melt extruding technique. This study evaluates the solubility, dissolution behavior, and bioavailability for application to oral drug delivery and optimizes the formulation of rivaroxaban amorphous solid dispersion (RXB-ASD). Based on a central composite design, optimized RXB-ASD (PVP VA 64 ratio 1:4.1, barrel temperature 216.1 °C, Cremophor® RH 40 20%, screw speed 15 rpm) showed satisfactory results for dependent variables. An in vitro drug dissolution study exhibited relatively high dissolution in four media and achieved around an 80% cumulative drug release in 120 min. Optimized RXB-ASD was stable under the accelerated condition for three months without a change in crystallinity and the dissolution rate. A pharmacokinetic study of RXB-ASD in rats showed that the absorption was markedly increased in terms of rate and amount, i.e., the systemic exposure values, compared to raw RXB powder. These results showed the application of quality by design (QbD) in the formulation development of hot-melt extruded RXB-ASD, which can be used as an oral drug delivery system by increasing the dissolution rate and bioavailability.

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