The Influence of Cosolvents on the In-vitro Percutaneous Penetration of Diclofenac Sodium From a Gel System

Abstract

The influence of cosolovents on the in-vitro percutaneous penetration of diclofenac sodium from a gel system was studied using a simplex lattice experimental design. Gel formulations were prepared by gelling the vehicle mixture of water, alcohol and propylene glycol with Carbomer 940. The synthetic membrane Durapore and hairless mouse skin were employed as barriers in a Franz-type diffusion cell. It was found that the penetration through the synthetic membrane was well described by the Higuchi model. There existed a better inverse relationship between the penetration rate and the drug solubility in the respective vehicle. It appeared to be a membrane-controlled mechanism when using hairless mouse skin as the barrier. The penetration rates in steady-state for nine formulations were fitted to a polynomial equation based on this simplex lattice method. A three-dimensional plot was constructed in this simplex surface studied. The maximal penetration rate was found to be from the vehicle containing water and ethanol in an exact volume ratio of 3:1 and the minimal penetration rate was observed from the vehicle containing water only.

Comparison of different water/oil microemulsions containing diclofenac sodium: Preparation, characterization, release rate, and skin irritation studies

“…24 In an earlier study, the release of diclofenac from gel dosage form through the synthetic membrane was examined, when plotting the penetration rate vs time, linear relationship was obtained. 25 The values of flux of DS through cellulose membrane from M formulations were shown in Table 3. When all formulations were evaluated according to the release rate of DS, MP showed the significantly highest flux value (0.059 mg/cm 2 /h) among all formulations (P G .05).…”

“…In former literature analyzed using a multiple linear regression model, drug permeability, was also modeled as a function of time. 25,27,28 Afterwards, 2 dummy variables 22 were selected (Equation 1) (Table 4) and 1 model was defined for 3 microemulsions (Equation 2). The calculated model showed good predictive abilities of release of DS from microemulsions through cellulose membrane.…”

Enhancement of iontophoretic transport of diphenhydramine hydrochloride thermosensitive gel by optimization of pH, polymer concentration, electrode design, and pulse rate

“…As a result, less charge is available for the drug, resulting in decreased iontophoretic transport. Also, several studies 25,26 have reported that an increase in the viscosity results in a decrease in the formulation conductivity. Therefore, to investigate the influence of Lutrol and the viscosity of the gel on the charge-carrying capacity of DPH, a conductance study was performed.…”

Rheological Characterization of Topical Carbomer Gels Neutralized to Different pH

“…The physical properties of the Carbopol gels, the time they remain on the application area, and the drug release rates are extremely sensitive to the rheological behavior of the topical gel formulations. Therefore, exhaustive characterization of the flow behavior of these systems as a function of neutralization and polymer concentration is essential to evaluate the ability of Carbopol polymers to jellify for a range of pH values and their potential uses as dermatological bases (13,14). The aim of the current work was to study the rheological behavior of topical Carbopol gels in the pH range 5.0-8.0.…”