Viscoelastic Properties of Carbopol 940 Gels and Their Relationships to Piroxicam Diffusion Coefficients in Gel Bases

Asasutjarit, Rathapon; Sirivat, Anuvat; Vayumhasuwan, Panida

doi:10.1007/s11095-005-8244-2

Cited by 62 publications

(20 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reduced crystallite amount and size can be analyzed considering the effect of the polymer as nucleation agent of the drug and the steric hindrance produced by the interpenetrating structure of the BC-Alg film network (Figure 3). Besides, there might be diffusional restrictions of Dox to the solution imposed by the film [39,40]. The spectrofluorimetric analysis of supernatants containing Dox released from BC-Alg films did not show any shift in maximum wavelengths, suggesting the absence of potential complex formation between Dox and polymers after drug release that could affect the drug antitumor activity (data not shown).…”

Section: Cell Viability Assaysmentioning

confidence: 96%

Modified bacterial cellulose scaffolds for localized doxorubicin release in human colorectal HT-29 cells

Cacicedo

León

Gonzalez

et al. 2016

Colloids and Surfaces B: Biointerfaces

View full text Add to dashboard Cite

Bacterial cellulose (BC) films modified by the in situ method with the addition of alginate (Alg) during the microbial cultivation of Gluconacetobacter hansenii under static conditions increased the loading of doxorubicin by at least three times. Biophysical analysis of BC-Alg films by scanning electron microscopy, thermogravimetry, X-ray diffraction and FTIR showed a highly homogeneous interpenetrated network scaffold without changes in the BC crystalline structure but with an increased amorphous phase. The main molecular interactions determined by FTIR between both biopolymers clearly suggest high compatibility. These results indicate that alginate plays a key role in the biophysical properties of the hybrid BC matrix. BC-Alg scaffold analysis by nitrogen adsorption isotherms revealed by the Brunauer-Emmett-Teller (BET) method an increase in surface area of about 84% and in pore volume of more than 200%. The Barrett-Joyner-Halenda (BJH) model also showed an increase of about 25% in the pore size compared to the BC film. Loading BC-Alg scaffolds with different amounts of doxorubicin decreased the cell viability of HT-29 human colorectal adenocarcinoma cell line compared to the free Dox from around 95-53% after 24h and from 63% to 37% after 48 h. Dox kinetic release from the BC-Alg nanocomposite displayed hyperbolic curves related to the different amounts of drug payload and was stable for at least 14 days. The results of the BC-Alg nanocomposites show a promissory potential for anticancer therapies of solid tumors.

show abstract

Section: Cell Viability Assaysmentioning

confidence: 96%

Modified bacterial cellulose scaffolds for localized doxorubicin release in human colorectal HT-29 cells

Cacicedo

León

Gonzalez

et al. 2016

Colloids and Surfaces B: Biointerfaces

View full text Add to dashboard Cite

show abstract

“…The physical appearances of semisolid formulations are affected from their viscoelastic properties that may alter the patient or consumer opinion (16). Viscoelastic properties also affect the contact times of gels that are related to bioavailability and therapeutic efficacy of the preparations (17,18).…”

Section: Resultsmentioning

confidence: 99%

A Novel Preparation Method for Organogels: High-Speed Homogenization and Micro-irradiation

et al. 2013

View full text Add to dashboard Cite

Abstract. The aim of this work was to prepare organogels of Carbopol 974P NF (C974) in PEG 400 by using a novel technique, high-speed homogenization followed by microwave heating. Triclosan (TCS) was used as a model drug. C974, at concentrations ranging between 2% and 4%, was dispersed in 25 ml of PEG 400, and the dispersion was homogenised for 5 min at 24,000 rpm. The dispersion was either heated at 80°C in water bath under mechanic stirring at 200 rpm or exposed to micro-irradiation (1,200 W/1 h) for 2 min. The formulations prepared with both methods performed a well-structured gel matrix characteristic at 3% and 4% of C974 concentrations. As the concentrations of the polymer increased, the elastic properties also increased. The viscosity profiles indicated a shear-thinning system. DSC data revealed that TCS was dissolved in gel. Skin accumulation ability of TCS had been improved by these novel organogels regardless of the preparation method. TCS was still microbiologically effective after the microwave process was applied. It was determined that microwave heating is a suitable method to obtain C974 organogels. This novel production technique developed might be promising especially in industrial scale when the dramatic reduction in the preparation time and energy were considered.

show abstract

“…This is consistent with reports that Carbopol (all grades) is known to have a dominant effect on the texture properties of the formulations containing it. 23,[39][40][41][42][43][44] The shear-thinning rheology of the gels coupled with favorable firmness and adhesivity values would aid in the stabilization of the gel film over the ocular surface without affecting the corneal tear film. 34,38,45 Since all the gelling formulations (B2, B4, B6, and B8) exhibited similar rheological and textural properties, the most optimum gelling system was selected on the basis of guar gum-to-boric acid ratio.…”

Section: Discussionmentioning

confidence: 99%

Carboxyvinyl Polymer and Guar-Borate Gelling System Containing Natamycin Loaded PEGylated Nanolipid Carriers Exhibit Improved Ocular Pharmacokinetic Parameters

Patil

Lakhani

Taskar

et al. 2020

Journal of Ocular Pharmacology and Therapeutics

View full text Add to dashboard Cite

Purpose: Natamycin (NTM) ophthalmic suspension is the only FDA-approved formulation commercially available for treating ocular fungal infections. However, precorneal residence times and losses/drainage remain the foremost challenges associated with current ocular antifungal pharmacotherapy. In our previous investigations, NTM loaded polyethylene glycol nanolipid carriers (NTM-PNLCs) showed enhanced corneal permeation, both in vitro and in vivo. To further improve the corneal retention of NTM-PNLCs, this study aimed to develop a gelling system composed of carboxyvinyl polymer, guar gum, and boric acid in which the NTM-PNLCs were loaded. Methods: A 2 3 factorial design was employed in formulating and optimizing the gelling system for NTM-PNLCs, where the independent factors were the gelling excipients (guar gum, boric acid, and Carbopol Ò 940) and dependent variables were gelling time, gel depot collapse time, rheology, firmness, and work of adhesion. Optimized gel was evaluated for transcorneal permeation using rabbit cornea, in vitro; and tear pharmacokinetics and ocular biodistribution in male New Zealand White rabbits, in vivo. Results: Optimized NTM-PNLC-GEL was found to exhibit shear thinning rheology, adequate firmness, and spreadability, and formed a depot that did not collapse immediately. In addition, the in vitro transcorneal evaluation studies indicated that the NTM-PNLC-GEL exhibited a lower/slower flux and rate in comparison to Natacyn Ò suspension. NTM-PNLC-GEL (0.3%), at a 16-fold lower dose, exhibited mean residence time and elimination half-life comparable to Natacyn (5%), and provided similar in vivo concentrations in the innermost tissues of the eye. Conclusion: The data indicate that the NTM-PNLC-GEL formulation could serve as an alternative during ophthalmic antifungal therapy.

show abstract

Viscoelastic Properties of Carbopol 940 Gels and Their Relationships to Piroxicam Diffusion Coefficients in Gel Bases

Abstract: There is a potential for predicting drug diffusion coefficients from their correlations to rheological parameters. This could be beneficial to the formulation design of transdermal drug delivery systems including mucoadhesive drug delivery systems.

Cited by 62 publications

References 13 publications

Modified bacterial cellulose scaffolds for localized doxorubicin release in human colorectal HT-29 cells

Modified bacterial cellulose scaffolds for localized doxorubicin release in human colorectal HT-29 cells

A Novel Preparation Method for Organogels: High-Speed Homogenization and Micro-irradiation

Carboxyvinyl Polymer and Guar-Borate Gelling System Containing Natamycin Loaded PEGylated Nanolipid Carriers Exhibit Improved Ocular Pharmacokinetic Parameters

Contact Info

Product

Resources

About