scholarly journals Solubility evaluation of didanosine: a comparison between the equilibrium method and intrinsic dissolution for biopharmaceutics classification purposes

2017 ◽  
Vol 53 (2) ◽  
Author(s):  
André Bersani Dezani ◽  
Thaisa Marinho Dezani ◽  
Julie Caroline Ferrari Ferreira ◽  
Cristina Helena dos Reis Serra
Keyword(s):  
Intrinsic Dissolution ◽  
Equilibrium Method ◽  
Biopharmaceutics Classification

scholarly journals Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

2013 ◽  
Vol 49 (4) ◽  
pp. 853-863 ◽  
Author(s):  
André Bersani Dezani ◽  
Thaisa Marinho Pereira ◽  
Arthur Massabki Caffaro ◽  
Juliana Mazza Reis ◽  
Cristina Helena dos Reis Serra
Keyword(s):  
High Speed ◽  
High Solubility ◽  
Equilibrium Solubility ◽  
Intrinsic Dissolution ◽  
Pharmaceutical Dosage Forms ◽  
Solubility Study ◽  
Equilibrium Method ◽  
Solubility Improvement ◽  
The Matrix ◽  
Solubility Determination

Solubility and dissolution rate of drugs are of major importance in pre-formulation studies of pharmaceutical dosage forms. The solubility improvement allows the drugs to be potential biowaiver candidates and may be a good way to develop more dose-efficient formulations. Solubility behaviour of lamivudine, stavudine and zidovudine in individual solvents (under pH range of 1.2 to 7.5) was studied by equilibrium solubility and intrinsic dissolution methods. In solubility study by equilibrium method (shake-flask technique), known amounts of drug were added in each media until to reach saturation and the mixture was subjected to agitation of 150 rpm for 72 hours at 37 ºC. In intrinsic dissolution test, known amount of each drug was compressed in the matrix of Wood's apparatus and subjected to dissolution in each media with agitation of 50 rpm at 37 ºC. In solubility by equilibrium method, lamivudine and zidovudine can be considered as highly soluble drugs. Although stavudine present high solubility in pH 4.5, 6.8, 7.5 and water, the solubility determination in pH 1.2 was not possible due stability problems. Regarding to intrinsic dissolution, lamivudine and stavudine present high speed of dissolution. Considering a boundary value presented by Yu and colleagues (2004), all drugs studied present high solubility characteristics in intrinsic dissolution method. Based on the obtained results, intrinsic dissolution seems to be superior for solubility studies as an alternative method for biopharmaceutical classification purposes.

The Evaluation of Valsartan Biopharmaceutics Properties

2020 ◽  
Vol 12 (1) ◽  
pp. 52-62
Author(s):  
Lara Maria Lopes de Castro ◽  
Jacqueline de Souza ◽  
Tamires Guedes Caldeira ◽  
Bruna de Carvalho Mapa ◽  
Anna Flávia Matos Soares ◽  
...  
Keyword(s):  
High Performance ◽  
Hplc Method ◽  
Regulatory Agencies ◽  
Dissolution Profile ◽  
Intrinsic Dissolution ◽  
Rate Evaluation ◽  
Low Solubility ◽  
Biopharmaceutics Classification

Background: Solubility, intestinal permeability and dissolution are the main factors that govern the rate and extent of drugs absorption and are directly related to bioavailability. Biopharmaceutics Classification System (BCS) is an important tool which uses in vitro results for comparison with bioavailability in vivo (biowaiver). Valsartan is widely used in the treatment of hypertension and shows different BCS classification in the literature (BCS class II or III). Objective: This work proposes the study of valsartan biopharmaceutics properties and its BCS classification. Methods: High Performance Liquid Chromatography (HPLC) method was developed and validated to quantify the drug in buffers pH 1.2, 4.5 and 6.8 respectively. Valsartan solubility was determined in these three different media using shake flask method and intrinsic dissolution rate. Evaluation of dissolution profile from coated tablets was conducted. Results: The low solubility (pH 1.2 and 4.5) and high solubility (pH 6.8) were observed for both solubility methods. Permeability data reported from the literature showed that valsartan is a low permeability drug. Valsartan presented the rapid release profile only in pH 6.8. Conclusion: We defined that valsartan is a class IV drug, in disagreement with what has been published so far. It is important to emphasize that the conditions considered here are indicated to define the biopharmaceutics classification by regulatory agencies.

scholarly journals An Artificial Potential Field-Based Lithium-ion Battery SOC Equilibrium Method in Electric Vehicles

2020 ◽  
Vol 53 (2) ◽  
pp. 12682-12687
Author(s):  
Fu Jiang ◽  
Cheng Jin ◽  
Hongtao Liao ◽  
Heng Li ◽  
Yue Wu ◽  
...  
Keyword(s):  
Lithium Ion Battery ◽  
Electric Vehicles ◽  
Potential Field ◽  
Lithium Ion ◽  
Artificial Potential Field ◽  
Equilibrium Method

scholarly journals Co-Amorphous Formulations of Furosemide with Arginine and P-Glycoprotein Inhibitor Drugs

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 171
Author(s):  
Marika Ruponen ◽  
Konsta Kettunen ◽  
Monica Santiago Pires ◽  
Riikka Laitinen
Keyword(s):  
Storage Conditions ◽  
Scanning Calorimetry ◽  
Glycoprotein P ◽  
Molar Ratios ◽  
P Glycoprotein ◽  
Permeation Studies ◽  
Poorly Soluble ◽  
Biopharmaceutics Classification ◽  
Permeability Assay ◽  
Simultaneous Dissolution

In this study, the amino acid arginine (ARG) and P-glycoprotein (P-gp) inhibitors verapamil hydrochloride (VER), piperine (PIP) and quercetin (QRT) were used as co-formers for co-amorphous mixtures of a Biopharmaceutics classification system (BCS) class IV drug, furosemide (FUR). FUR mixtures with VER, PIP and QRT were prepared by solvent evaporation, and mixtures with ARG were prepared by spray drying in 1:1 and 1:2 molar ratios. The solid-state properties of the mixtures were characterized with X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) in stability studies under different storage conditions. Simultaneous dissolution/permeation studies were conducted in side-by-side diffusion cells with a PAMPA (parallel artificial membrane permeability assay) membrane as a permeation barrier. It was observed with XRPD that ARG, VER and PIP formed co-amorphous mixtures with FUR at both molar ratios. DSC and FTIR revealed single glass transition values for the mixtures (except for FUR:VER 1:2), with the formation of intermolecular interactions between the components, especially salt formation between FUR and ARG. The co-amorphous mixtures were found to be stable for at least two months under an elevated temperature/humidity, except FUR:ARG 1:2, which was sensitive to humidity. The dissolution/permeation studies showed that only the co-amorphous FUR:ARG mixtures were able to enhance both the dissolution and permeation of FUR. Thus, it is concluded that formulating co-amorphous salts with ARG may be a promising option for poorly soluble/permeable FUR.

scholarly journals ICH Guideline for Biopharmaceutics Classification System-Based Biowaiver (M9): Toward Harmonization in Latin American Countries

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 363
Author(s):  
Claudia Miranda ◽  
Alexis Aceituno ◽  
Mirna Fernández ◽  
Gustavo Mendes ◽  
Yanina Rodríguez ◽  
...  
Keyword(s):  
Latin American ◽  
Classification System ◽  
Biopharmaceutics Classification System ◽  
In Vitro Dissolution ◽  
Ich Guidelines ◽  
Latin American Region ◽  
Regulatory Guidelines ◽  
Biopharmaceutics Classification

The biopharmaceutical classification system (BCS) is a very important tool to replace the traditional in vivo bioequivalence studies with in vitro dissolution assays during multisource product development. This paper compares the most recent harmonized guideline for biowaivers based on the biopharmaceutics classification system and the BCS regulatory guidelines in Latin America and analyzes the current BCS regulatory requirements and the perspective of the harmonization in the region to develop safe and effective multisource products. Differences and similarities between the official and publicly available BCS guidelines of several Latin American regulatory authorities and the new ICH harmonization guideline were identified and compared. Only Chile, Brazil, Colombia, and Argentina have a more comprehensive BCS guideline, which includes solubility, permeability, and dissolution requirements. Although their regulatory documents have many similarities with the ICH guidelines, there are still major differences in their interpretation and application. This situation is an obstacle to the successful development of safe and effective multisource products in the Latin American region, not only to improve their access to patients at a reasonable cost, but also to develop BCS biowaiver studies that fulfill the quality standards of regulators in developed and emerging markets.

scholarly journals Fibre Laser Cutting and Chemical Etching of AZ31 for Manufacturing Biodegradable Stents

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ali Gökhan Demir ◽  
Barbara Previtali ◽  
Carlo Alberto Biffi
Keyword(s):  
Magnesium Alloy ◽  
Chemical Etching ◽  
Fibre Laser ◽  
Nanosecond Laser ◽  
Intrinsic Dissolution ◽  
Biodegradable Stents ◽  
Innovative Solutions ◽  
Material Choice ◽  
Cardiovascular Pathologies ◽  
Reactive Gas

The use of magnesium-alloy stents shows promise as a less intrusive solution for the treatment of cardiovascular pathologies as a result of the high biocompatibility of the material and its intrinsic dissolution in body fluids. However, in addition to requiring innovative solutions in material choice and design, these stents also require a greater understanding of the manufacturing process to achieve the desired quality with improved productivity. The present study demonstrates the manufacturing steps for the realisation of biodegradable stents in AZ31 magnesium alloy. These steps include laser microcutting with a Q-switched fibre laser for the generation of the stent mesh and subsequent chemical etching for the cleaning of kerf and surface finish. Specifically, for the laser microcutting step, inert and reactive gas cutting conditions were compared. The effect of chemical etching on the reduction in material thickness, as well as on spatter removal, was also evaluated. Prototype stents were produced, and the material composition and surface quality were characterised. The potentialities of combining nanosecond laser microcutting and chemical etching are shown and discussed.

Sign in / Sign up

Export Citation Format

Share Document