scholarly journals Swelling and Drug Release in Polymers through the Theory of Poisson–Kac Stochastic Processes

Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 32
Author(s):  
Alessandra Adrover ◽  
Claudia Venditti ◽  
Massimiliano Giona

Experiments on swelling and solute transport in polymeric systems clearly indicate that the classical parabolic models fail to predict typical non-Fickian features of sorption kinetics. The formulation of moving-boundary transport models for solvent penetration and drug release in swelling polymeric systems is addressed hereby employing the theory of Poisson–Kac stochastic processes possessing finite propagation velocity. The hyperbolic continuous equations deriving from Poisson–Kac processes are extended to include the description of the temporal evolution of both the Glass–Gel and the Gel–Solvent interfaces. The influence of polymer relaxation time on sorption curves and drug release kinetics is addressed in detail.

Author(s):  
Mohammad Salim Hossain ◽  
Reza-ul Jalil ◽  
Selim Reza ◽  
Mohiuddin Abdul Quadir ◽  
CF Hossain

Efficiency of kollicoat EMM 30 D and SR 30D as matrix forming material was investigated. It was found that, theophylline loaded granules prepared with these two polymers could not sustain drug release for a significant period of time. However, compression of these granules into tablets retarded drug release for up to 8 hours. Release was faster from EMM 30D polymeric system than that from SR 30D matrix. Effects of fillers and rate modifiers on drug liberation have been assessed. Incorporation of Avicel RC 591 and starch caused substantial release of theophylline from both the polymeric systems. Avicel PH 101 intensified the retardation effect of both EMM 30D and SR 30D on theophylline release. HPMC 50 cps, when added to the matrix, caused the release of theophylline to follow near zero order pattern. Increasing the content of HPMC in both EMM 30D and SR 30D compressed tablets decreased the rate and extent of theophylline release. In the presence of excipients, no significant differences between rate and extent of drug release from EMM 30D and SR 30D systems were found. Biexponential equation was applied to explore and explain drug release kinetics. It was found that drug release followed Fickian or case I kinetics from EMM 30D compressed tablet while anomalous or non-fickian kinetics of drug release was observed for SR 30D system. Key words: Kolliocoat SR 30D, Kollicoat EMM 30D, Theophylline, Matrix system, Controlled release Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


2019 ◽  
Author(s):  
Chem Int

This work focus on the study and the elaboration of microspheres based on amoxicillin (AMO), those microspheres were prepared through the oil/water emulsion evaporation technique. Polybutylene succinate (PBS) and Poly(methylmethacrylate) (PMMA) polymeric matrix were used with Tween 80 (T80) and Polyvinyl alcohol (PVA) as emulsifiers. These polymeric systems were analyzed by SEM, FTIR and optical microscopy. The conditions of the microspheres forming were varied and the preparation was performed by changing different parameters such as: the nature of the polymer, the stirring speed, organic solvent, surfactant nature, and concentration, which allows the study of their effect on encapsulation efficiency and drug release kinetics. These parameters affect strongly the size of microspheres, the drug content and the drug release, the latter is settled in an artificially reconstituted media of pH = 1.2 transcribed from the stomachal medium.


1970 ◽  
Vol 8 (2) ◽  
pp. 153-159
Author(s):  
Mohammad Borhan Uddin ◽  
Jakir Ahmed Chowdhury ◽  
Kazi Rashidul Azam ◽  
Reza-ul Jalil ◽  
Md Selim Reza

In the present study efficiency of Eudragit NE 30 D and RS 30 D as matrix forming materials was investigated. It was found that theophylline loaded granules prepared with these two polymers could not sustain drug release for a significant period of time. However, compression of these granules into tablets retarded drug release for up to 7 hours. Release was similar with both of the polymers. Effects of fillers and rate modifiers on drug release have been assessed. Incorporation of lactose and starch caused substantial release of theophylline from both the polymeric systems. Avicel PH 101 intensified the retardation effect of both NE 30 D and RS 30 D on theophylline release. Hydrophobic excipients also show retardation of release from both NE 30 D and RS 30 D. Key words: Eudragit RS 30 D; Eudragit NE 30 D; Theophylline; Matrix system; Controlled release DOI: 10.3329/dujps.v8i2.6030 Dhaka Univ. J. Pharm. Sci. 8(2): 153-159, 2009 (December)


Author(s):  
Rajesh Dubey ◽  
Udaya K. Chowdary ◽  
Venkateswarlu V.

A controlled release formulation of metoclopramide was developed using a combination of hypromellose (HPMC) and hydrogenated castor oil (HCO). Developed formulations released the drug over 20 hr with release kinetics following Higuchi model. Compared to HCO, HPMC showed significantly higher influence in controlling the drug release at initial as well as later phase. The difference in the influence can be explained by the different swelling and erosion behaviour of the polymers. Effect of the polymers on release was optimized using a face-centered central composite design to generate a predictable design space. Statistical analysis of the drug release at various levels indicated a linear effect of the polymers’ levels on the drug release. The release profile of formulations containing the polymer levels at extremes of their ranges in design space was found to be similar to the predicted release profile


2017 ◽  
Vol 23 (3) ◽  
pp. 467-480 ◽  
Author(s):  
Satyanarayan Pattnaik ◽  
Kamla Pathak

Background: Improvement of oral bioavailability through enhancement of dissolution for poorly soluble drugs has been a very promising approach. Recently, mesoporous silica based molecular sieves have demonstrated excellent properties to enhance the dissolution velocity of poorly water-soluble drugs. Description: Current research in this area is focused on investigating the factors influencing the drug release from these carriers, the kinetics of drug release and manufacturing approaches to scale-up production for commercial manufacture. Conclusion: This comprehensive review provides an overview of different methods adopted for synthesis of mesoporous materials, influence of processing factors on properties of these materials and drug loading methods. The drug release kinetics from mesoporous silica systems, the manufacturability and stability of these formulations are reviewed. Finally, the safety and biocompatibility issues related to these silica based materials are discussed.


Author(s):  
Anjali P.B ◽  
Jawahar N. ◽  
Jubie S. ◽  
Neetu Yadav ◽  
Selvaraj A. ◽  
...  

Background: : Epilepsy is a genuine neurological turmoil that effects around 50 million individuals around the world. Practically 30% of epileptic patients experience the ill effects of pharmaco-obstruction, which is related with social seclusion, subordinate conduct, low marriage rates, joblessness, mental issues and diminished personal satisfaction. At present accessible antiepileptic drugs have a restricted viability, and their negative properties limit their utilization and cause challenges in patient administration. Gabapentin 1-(aminomethyl)cyclohexane acetic acid, Gbp , (trade name Neurontin), a structural analog of γ-aminobutyric acid (GABA), BCS class 3 drug with having permeability issues. Objective: This work was an attempt to formulate and characterize a new approach to treat epilepsy by targeting to Phospholipase A2 Enzyme through Nanostructured Lipid Carrier. Methods: Docking studied carried out using Accelrys Discovery studio 4.1 Client and gabapentin and phosphotidylcholine were conjugated through chemical conjugation. Nanostructured lipid carrier (NLC) was prepared using hot homogenization technique. Results: The libdock score of Gabapentin- Phosphotidylcholine conjugate (192.535) were found to be more than Gabapentin (77.1084) and Phosphotidylcholine (150.212). For the optimized formulation the particle size (50.08), zeta potential (-1.48), PDI (0.472) and entrapment efficiency (77.8) was observed. The NLC was studies for in-vitro drug release studies and release kinetics. Finally found that the drug release from the NLC followed Higuchi release kinetic and the mode of drug release from the NLC was found to be Non- Fickian diffusion. Conclusion: The formulated Nanostructured lipid carrier of Gabapentin-Phosphotidylcholine conjugate may be able to use to prevent seizure.


Author(s):  
Sahil Kumar ◽  
Bandna Sharma ◽  
Tilak R. Bhardwaj ◽  
Rajesh K. Singh

Aims: In the present study, polymer-drug conjugates were synthesized based on azo-bond cleavage drug delivery approach for targeting erlotinib as anticancer drug specifically to the colon for the proficient treatment of colon cancer. Background: Colon cancer (CC) is the third commonly detected tumor worldwide and it make up about 10 % of all cases of cancers. Most of the chemotherapeutic drugs available for treating colon cancer are not only toxic to cancerous cells but also to the normal healthy cells. Among the various approaches to get rid of the adverse effects of anticancer agents, prodrugs are one of the most imperative approaches. Objective: The objective of the study is to chemically modify the erlotinib drug through azo-bond linkage and suitable spacer which will be finally linked to polymeric backbone to give desired polymer linked prodrug. The azo reductase enzyme present in colon is supposed to cleave the azo-bond specifically and augment the drug release at the colon. Methods: The synthesized conjugates were characterized by IR and 1H-NMR spectroscopy. The cleavage of aromatic azobond resulted in a potential colon-specific liberation of drug from conjugate studied in rat fecal contents. In vitro release profiles of polyphosphazene-linked conjugates of erlotinib have been studied at pH 1.2, pH 6.8 and pH 7.4. The stability study was designed to exhibit that free drug was released proficiently and unmodified from polyphosphazene-erlotinib conjugates having aromatic azo-bond in artificial colon conditions. Results: The synthesized conjugates were demonstrated to be stable in simulated upper gastro-intestinal tract conditions. The drug release kinetics shows that all the polymer-drug conjugates of erlotinib follow zero-order release kinetics which indicates that the drug release from the polymeric backbone is independent of its concentration. Kinetic study of conjugates with slope (n) shows the anomalous type of release with an exponent (n) > 0.89 indicating a super case II type of release. Conclusion: These studies indicate that polyphosphazene linked drug conjugates of erlotinib could be the promising candidates for the site-specific treatment of colon cancer with least detrimental side-effects.


Author(s):  
Kumar Nishchaya ◽  
Swatantra K.S. Kushwaha ◽  
Awani Kumar Rai

Background: Present malignant cancer medicines has the advancement of magnetic nanoparticles as delivery carriers to magnetically accumulate anticancer medication in malignant growth tissue. Aim: In the present investigation, a silica nanoparticles (MSNs) stacked with hydroxyurea were combined and was optimized for dependent and independent variables. Method: In this study, microporous silica nanoparticle stacked with neoplastic medication had been prepared through emulsification followed with solvent evaporation method. Prepared MSNs were optimized for dependent and independent variables. Different formulations were prepared with varying ratio of polymer, lipid and surfactant which affects drug release and kinetics of drug release pattern. The obtained MSNs were identified by FTIR, SEM, drug entrapment, in-vitro drug release, drug release kinetics study, stability testing in order to investigate the nanoparticle characteristics. Results: The percentage drug entrapment of the drug for the formulations F1, F2, F3, was found to be 27.78%, 65.52% and 48.26%. The average particle size for F2 formulation was found to be 520 nm through SEM. The cumulative drug release for the formulations F1, F2, F3 was found to be 64.17%, 71.82% and 32.68%. The formulations were found to be stable which gives controlled drug delivery for 6 hours. Conclusion: From the stability studies data it can be culminated that formulations are most stable when stored at lower temperature or in refrigerator i.e. 5˚C ± 3˚C. It can be concluded that MSN’s loaded with hydroxyurea is a promising approach towards the management of cancer due to its sustained release and less side effects.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1130
Author(s):  
Mariana Pires Figueiredo ◽  
Ana Borrego-Sánchez ◽  
Fátima García-Villén ◽  
Dalila Miele ◽  
Silvia Rossi ◽  
...  

This work presents the development of multifunctional therapeutic membranes based on a high-performance block copolymer scaffold formed by polyether (PE) and polyamide (PA) units (known as PEBA) and layered double hydroxide (LDH) biomaterials, with the aim to study their uses as wound dressings. Two LDH layer compositions were employed containing Mg2+ or Zn2+, Fe3+ and Al3+ cations, intercalated with chloride anions, abbreviated as Mg-Cl or Zn-Cl, or intercalated with naproxenate (NAP) anions, abbreviated as Mg-NAP or Zn-NAP. Membranes were structurally and physically characterized, and the in vitro drug release kinetics and cytotoxicity assessed. PEBA-loading NaNAP salt particles were also prepared for comparison. Intercalated NAP anions improved LDH–polymer interaction, resulting in membranes with greater mechanical performance compared to the polymer only or to the membranes containing the Cl-LDHs. Drug release (in saline solution) was sustained for at least 8 h for all samples and release kinetics could be modulated: a slower, an intermediate and a faster NAP release were observed from membranes containing Zn-NAP, NaNAP and Mg-NAP particles, respectively. In general, cell viability was higher in the presence of Mg-LDH and the membranes presented improved performance in comparison with the powdered samples. PEBA containing Mg-NAP sample stood out among all membranes in all the evaluated aspects, thus being considered a great candidate for application as multifunctional therapeutic dressings.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 691
Author(s):  
O. Sánchez-Aguinagalde ◽  
Ainhoa Lejardi ◽  
Emilio Meaurio ◽  
Rebeca Hernández ◽  
Carmen Mijangos ◽  
...  

Chitosan (CS) and poly (vinyl alcohol) (PVA) hydrogels, a polymeric system that shows a broad potential in biomedical applications, were developed. Despite the advantages they present, their mechanical properties are insufficient to support the loads that appear on the body. Thus, it was proposed to reinforce these gels with inorganic glass particles (BG) in order to improve mechanical properties and bioactivity and to see how this reinforcement affects levofloxacin drug release kinetics. Scanning electron microscopy (SEM), X-ray diffraction (XRD), swelling tests, rheology and drug release studies characterized the resulting hydrogels. The experimental results verified the bioactivity of these gels, showed an improvement of the mechanical properties and proved that the added bioactive glass does affect the release kinetics.


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