scholarly journals Modulatory effect of high molecular weight polyethylene glycols on drug release from ibuprofen matrix tablets

2017 ◽  
Vol 21 (5) ◽  
pp. 847
Author(s):  
S.O. Eraga ◽  
E Eboh ◽  
M.A. Iwuagwu
Keyword(s):  
Molecular Weight ◽  
Drug Release ◽  
High Molecular Weight ◽  
Matrix Tablets ◽  
Polyethylene Glycols

scholarly journals Carbopol 71G-NF polymer –The next pillar of oral solid dosage form

2020 ◽  
Vol 1 (1) ◽  
pp. 010-017
Author(s):  
R. Priyanka ◽  
R. Senthil Prabhu
Keyword(s):  
Molecular Weight ◽  
Drug Release ◽  
Acrylic Acid ◽  
High Molecular Weight ◽  
Dosage Form ◽  
Carboxyl Groups ◽  
Dry Powders ◽  
Solid Dosage Form ◽  
Solid Dosage ◽  
Pharmaceutical Application

For pharmaceutical Oral Solid Dosage Form (OSDF) there are lots of excipients used and these excipients influence the drug release. In the recent decades there has been considerable interest in using carbopol polymers as excipients in a distinctive range of pharmaceutical application. Carbopol polymers are high molecular weight, cross linked, acrylic, acid-based polymers. Carbopol homopolymers are polymers of acrylic acid cross linked with ally sucrose or allylPentaerythritol. These polymers are offered as fluffy, white, dry powders. The carboxyl groups provided by the acrylic acid backbone of the polymer are responsible for many of the product benefits. This review work aims at guesstimate the characteristic of Carbopol 71G-NF polymer to be used as excipients in oral solid dosage form (OSDF).

scholarly journals Intratumoral Distribution and pH-Dependent Drug Release of High Molecular Weight HPMA Copolymer Drug Conjugates Strongly Depend on Specific Tumor Substructure and Microenvironment

2020 ◽  
Vol 21 (17) ◽  
pp. 6029
Author(s):  
Anne-Kathrin Noack ◽  
Henrike Lucas ◽  
Petr Chytil ◽  
Tomáš Etrych ◽  
Karsten Mäder ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Drug Release ◽  
High Molecular Weight ◽  
Cell Lines ◽  
Tumor Tissue ◽  
Tumor Type ◽  
Acidic Microenvironment ◽  
Drug Conjugates ◽  
Ph Dependent ◽  
Intratumoral Distribution

Stimulus-sensitive polymer drug conjugates based on high molecular weight N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers carrying doxorubicin via a pH-dependent cleavable bond (pHPMA-Dox) were previously shown to be able to overcome multi-drug resistance. Nevertheless, a tumor type dependent differential response was observed. Although an improved and more selective tumor accumulation of pHPMA-Dox is generally achieved due to the enhanced permeability and retention (EPR) effect, little is known about the fate of these conjugates upon entering the tumor tissue, which could explain the different responses. In this study, we compared in vitro and in vivo accumulation and Dox-activation of pHPMA-Dox in three cancer cell line models (1411HP, A2780cis, HT29) and derived xenograft tumors using a near-infrared fluorescence-labeled pHPMA-Dox conjugate. Firstly, cytotoxicity assays using different pH conditions proved a stepwise, pH-dependent increase in cytotoxic activity and revealed comparable sensitivity among the cell lines. Using multispectral fluorescence microscopy, we were able to track the distribution of drug and polymeric carrier simultaneously on cellular and histological levels. Microscopic analyses of cell monolayers confirmed the assumed mechanism of cell internalization of the whole conjugate followed by intracellular cleavage and nuclear accumulation of Dox in all three cell lines. In contrast, intratumoral distribution and drug release in xenograft tumors were completely different and were associated with different tissue substructures and microenvironments analyzed by Azan- and Hypoxisense®-staining. In 1411HP tumors, large vessels and less hypoxic/acidic microenvironments were associated with a pattern resulting from consistent tissue distribution and cellular uptake as whole conjugate followed by intracellular drug release. In A2780cis tumors, an inconsistent pattern of distribution partly resulting from premature drug release was associated with a more hypoxic/acidic microenvironment, compacted tumor tissue with compressed vessels and specific pre-damaged tissue structures. A completely different distribution pattern was observed in HT29 tumors, resulting from high accumulation of polymer in abundant fibrotic structures, with small embedded vessels featuring this tumor type together with pronounced premature drug release due to the strongly hypoxic/acidic microenvironment. In conclusion, the pattern of intratumoral distribution and drug release strongly depends on the tumor substructure and microenvironment and may result in different degrees of therapeutic efficacy. This reflects the pronounced heterogeneity observed in the clinical application of nanomedicines and can be exploited for the future design of such conjugates.

Impact of salt form and molecular weight of chitosan on swelling and drug release from chitosan matrix tablets

2013 ◽  
Vol 97 (1) ◽  
pp. 26-33 ◽  
Author(s):  
Kampanart Huanbutta ◽  
Kamonrak Cheewatanakornkool ◽  
Katsuhide Terada ◽  
Jurairat Nunthanid ◽  
Pornsak Sriamornsak
Keyword(s):  
Molecular Weight ◽  
Drug Release ◽  
Matrix Tablets ◽  
Salt Form ◽  
Chitosan Matrix
Sign in / Sign up

Export Citation Format

Share Document