Diffusion studies of methotrexate in Carbopol and Poloxamer gels

Lu, Gina H.; Jun, H. W.

doi:10.1016/s0378-5173(97)00187-7

Cited by 61 publications

(31 citation statements)

References 21 publications

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“…There is an inverse relationship between release or diffusion rates and gel viscosity, as predicted by the Stokes-Einstein equation (17,18). This trend was observed in the release of a series of benzoic acid derivatives from poloxamer 407 gels (19) and in the diffusion of methotrexate in Carbopol and poloxamer gels (20).…”

Section: Introductionmentioning

confidence: 74%

“…The viscosity at 5°C, 30°C and 50°C was found to be 4094 cP, 2639 cP and 1997 cP, respectively. Because it is generally believed that the release rate is governed by the viscosity of the matrix (17)(18)(19)(20), it is essential to evaluate how the variation in rhVEGF gel viscosity actually affects the release of the active ingredient, rhVEGF, from the gel matrix. Fig.…”

Section: Flow Behavior and Release Characteristics Of Rhvegf In Hpmc mentioning

confidence: 99%

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Characteristics of rhVEGF Release from Topical Hydrogel Formulations

Ji¹,

Li²,

Shire³

et al. 2010

Pharm Res

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Section: Introductionmentioning

confidence: 74%

Section: Flow Behavior and Release Characteristics Of Rhvegf In Hpmc mentioning

confidence: 99%

Characteristics of rhVEGF Release from Topical Hydrogel Formulations

Ji¹,

Li²,

Shire³

et al. 2010

Pharm Res

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“…The pH of Carbopol ® 940 aqueous dispersion was kept constant at a value of 7.4 using TEA, which was previously reported to have a positive influence on the gelling and swelling characteristics of the Carbopol ® resins. [37][38][39] This can in turn improve the rheologymodification properties of these polymers. Despite a possible reduction in active ingredient permeation properties, the polymer provides more resistance toward drug movement through the polymer-gel network.…”

Section: Drug Transfer Through Rat Skinmentioning

confidence: 99%

In vitro permeation and in vivo anti-inflammatory and analgesic properties of nanoscaled emulsions containing ibuprofen for topical delivery

Abdullah¹,

Abdulkarim²,

Salman³

et al. 2011

IJN

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Introduction: As a topical delivery system, a nanoscaled emulsion is considered a good carrier of several active ingredients that convey several side effects upon oral administration, such as nonsteroidal anti-inflammatory drugs (NSAIDs). Objective: We investigated the in vitro permeation properties and the in vivo pharmacodynamic activities of different nanoscaled emulsions containing ibuprofen, an NSAID, as an active ingredient and newly synthesized palm olein esters (POEs) as the oil phase. Methodology: A ratio of 25:37:38 of oil phase:aqueous phase:surfactant was used, and different additives were used for the production of a range of nanoscaled emulsions. Carbopol ® 940 dispersion neutralized by triethanolamine was employed as a rheology modifier. In some circumstances, menthol and limonene were employed at different concentrations as permeation promoters. All formulae were assessed in vitro using Franz diffusion cell fitted with full-thickness rat skin. This was followed by in vivo evaluation of the anti-inflammatory and analgesic activities of the promising formulae and comparison of the effects with that of the commercially available gel. Results and discussion: Among all other formulae, formula G40 (Carbopol ® 940-free formula) had a superior ability in transferring ibuprofen topically compared with the reference. Carbopol ® 940 significantly decreased the amount of drug transferred from formula G41 through the skin as a result of swelling, gel formation, and reduction in drug thermodynamic activity. Nonetheless, the addition of 10% w/w of menthol and limonene successfully overcame this drawback since, relative to the reference, higher amount of ibuprofen was transferred through the skin. By contrast, these results were relatively comparable to that of formula G40. Pharmacodynamically, the G40, G45, and G47 formulae exhibited the highest anti-inflammatory and analgesic effects compared with other formulae. Conclusion: The ingredients and the physical properties of the nanoscaled emulsions produced by using the newly synthesized POEs succeeded to deliver ibuprofen competently.

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“…Dermatological applications of Carbopol polymers are numerous; examples include formulations of local anaesthetics and cosmetics (e.g. [32][33][34]. Carbopol polymers are also reported to have good suspending properties (35).…”

Section: Formulation Developmentmentioning

confidence: 99%

“…To circumvent this problem, the Carbopol hydrogel formulation was neutralised to pH 5.0 using 0.5 M NaOH. The use of other bases for Carbopol neutralisation, such as monoethaloamine and triethylamine, has been reported in the literature (28,32,33). However, these stronger bases are usually used for gel formulations prepared from a hydro-alcoholic cosolvent system, as the inclusion of an alcohol can affect polymer solubility, leading to the precipitation of the neutralised Carbopol salt (39).…”

Section: Formulation Developmentmentioning

confidence: 99%

Using pH Abnormalities in Diseased Skin to Trigger and Target Topical Therapy

Rizi

Green

Donaldson³

et al. 2011

Pharm Res

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Permeation studies showed that the oil-in-oil-generated particles deliver essentially no drug at normal (intact) skin pH (5.0-5.5) but that delivery can be triggered and targeted to atopic dermatitis skin where the pH is elevated. The incorporation of these microparticles into Carbopol- and HPMC-based aqueous gel formulations demonstrated good stability and pH-responsive permeation into porcine skin.

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Diffusion studies of methotrexate in Carbopol and Poloxamer gels

Cited by 61 publications

References 21 publications

Characteristics of rhVEGF Release from Topical Hydrogel Formulations

Characteristics of rhVEGF Release from Topical Hydrogel Formulations

In vitro permeation and in vivo anti-inflammatory and analgesic properties of nanoscaled emulsions containing ibuprofen for topical delivery

Using pH Abnormalities in Diseased Skin to Trigger and Target Topical Therapy

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