A deformation model for Case II diffusion

Thomas, Noreen L.; Windle, A. H.

doi:10.1016/0032-3861(80)90316-x

Cited by 200 publications

(114 citation statements)

References 32 publications

Supporting

Mentioning

105

Contrasting

Order By: Relevance

“…24 Just ahead of the front, the presence of solvent plasticizes the polymer and causes it to undergo a glass to rubber transition. 25 Now, the following possibilities could arise:…”

Section: Mechanism Of Water Transportmentioning

confidence: 98%

Ionizable interpenetrating polymer networks of carboxymethyl cellulose and polyacrylic acid: Evaluation of water uptake

Bajpai¹,

Mishra²

2004

J of Applied Polymer Sci

View full text Add to dashboard Cite

A semi interpenetrating polymer network (IPN) of carboxymethyl cellulose (CMC) and crosslinked polyacrylic acid (PAA) has been prepared and its watersorption capacity has been evaluated as a function of chemical architecture of the IPN, pH, and temperature of the swelling medium. The water uptake potential of the IPNs has also been investigated in inorganic salt containing aqueous solutions and simulated biological fluids. The IPN was characterized by IR spectral analysis, and the network parameters such as average molecular weight between crosslinks (M c ), crosslink density (q), and number of elastically effective chains (V e ) have been evaluated by watersorption measurements.

show abstract

“…24 Just ahead of the front, the presence of solvent plasticizes the polymer and causes it to undergo a glass to rubber transition. 25 Now, the following possibilities could arise:…”

Section: Mechanism Of Water Transportmentioning

confidence: 98%

Ionizable interpenetrating polymer networks of carboxymethyl cellulose and polyacrylic acid: Evaluation of water uptake

Bajpai¹,

Mishra²

2004

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…30 Just ahead of the front, the presence of solvent plasticized the polymer and caused it to undergo a glass-to-rubber transition. 31 Then, the following possibilities arose:…”

Section: Modeling Of the Release Mechanismmentioning

confidence: 99%

Evaluation of the water sorption and controlled‐release potential of binary polymeric beads of starch and alginate loaded with potassium nitrate as an agrochemical

Mishra¹,

Bajpai²,

Bajpai³

2004

J of Applied Polymer Sci

View full text Add to dashboard Cite

Binary polymeric beads of sodium alginate and starch were prepared and characterized by IR spectral and scanning electron microscopy (SEM) techniques. The beads were examined for water uptake potential, and he influence of various factors, including chemical composition of the macromolecular matrix, pH, ionic strength, and temperature of the swelling medium, were investigated on the degree of water sorption. The prepared beads were loaded with KNO 3 , as a model agrochemical, and the release kinetics of KNO 3 were studied under varying experimental conditions, as mentioned previously. The release data were analyzed by Fick's equation, and the mechanism of KNO 3 release was worked out at different experimental conditions.

show abstract

“…This elongation is then counter balanced by an elastic-restrictive force to oppose the swelling. Eventually a state of equilibrium is reached when both forces are balanced, these process can significantly alter the kinetics of drug diffusion through the polymer network and are highly influenced by time-scale associated structural changes in the polymer [69][70][71][72] . The move towards anomalous transport over 8 weeks may suggest a polymer network timeassociated affect 73,74 , which becomes more apparent over the longer stability study.…”

Section: Stability Assessmentmentioning

confidence: 99%

Development and Evaluation of a Novel Intranasal Spray for the Delivery of Amantadine

Lungare

Bowen

Badhan

2016

Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

The aim of this study was to develop and characterise an intranasal delivery system for amantadine (AMT). Optimal formulations (F) consisted of a thermosensitive polymer Pluronic ® 127 (P127) and either carboxy methyl cellulose (CMC) or chitosan (CS) which demonstrated gel-transition at nasal cavity temperatures (34 °C ± 1 °C). Rheologically, the loss tangent (Tan δ) confirmed a three-stage gelation phenomena at 34 °C ± 1 °C and nonNewtonian behaviour. Storage of FCMC and FCS at 4 °C for 8 weeks resulted in repeatable release profiles at 34 °C when sampled, with a Fickian mechanism earlier on but moving towards anomalous transport by week 8. Polymers (P127, CMC and CS) demonstrated no significant cellular toxicity to human nasal epithelial cells up to 4 mg/mL and up to 1 mM for AMT (IC50: 4.5 mM ± 0.05 mM). FCMC and FCS demonstrated slower release across an in-vitro human nasal airway model (43-44 % vs 79 % ± 4.58 % for AMT). Using a human nasal cast model, deposition into the olfactory regions (potential nose-to-brain) was demonstrated upon nozzle insertion (5 mm) whereas tilting of the head forward (15°) resulted in greater deposition in the bulk of the nasal cavity. KEYWORDSParkinson's disease; rheology; nasal; RPMI 2650; nose to brain; thermoresponsive; 3 INTRODUCTION Parkinson's disease (PD) is an ageing associated progressive neurological disorder and affects 1.5 % of the population over 65-years of age 1 , with age-adjusted prevalence rates thought to be around 150 per 100,000 with a suggested mean onset in the 70's 1 . Ageing is the largest single risk factor for the development of PD and the pathogenesis of PD is composed of a range of events leading towards neuronal apoptosis, primarily of degradation of dopamine neurones in the sustantia nigra. The mainstay of clinical drug therapy focuses on increases the levels of dopamine (DA) in the brain, with oral dosing of levodopa being the most commonly used to pharmacological intervention treatment to reverse the symptoms of PD. It is also common to use adjunct therapies in conjunction with levodopa, such as the weak NMDA-type receptor antagonist amantadine, which can aid in blocking dopamine reuptake.

show abstract

A deformation model for Case II diffusion

Cited by 200 publications

References 32 publications

Ionizable interpenetrating polymer networks of carboxymethyl cellulose and polyacrylic acid: Evaluation of water uptake

Ionizable interpenetrating polymer networks of carboxymethyl cellulose and polyacrylic acid: Evaluation of water uptake

Evaluation of the water sorption and controlled‐release potential of binary polymeric beads of starch and alginate loaded with potassium nitrate as an agrochemical

Development and Evaluation of a Novel Intranasal Spray for the Delivery of Amantadine

Contact Info

Product

Resources

About