methylcellulose and carvone

The aim of the present study was to use the in vitro human skin sandwich system in order to quantify the influence of formulation variables on intrafollicular hydrocortisone permeation. The investigated variables were the pH and the viscosity of the topical formulation as well as the presence of chemical enhancers (carvone, menthone, oleic acid and sodium lauryl sulphate). Furthermore, skin sandwich hydration was also varied in order to determine if the method itself can be run using only partially hydrated skin tissues. It was determined that the follicular contribution to hydrocortisone flux decreased marginally with increasing alkalinity in the pH range 3-8.8. Intrafollicular penetration was markedly reduced when HPMC gels were used instead of an aqueous solution. Pretreating the skin with chemical enhancers also reduced the follicular contribution to flux, probably due to permeabilisation of the continuous stratum corneum. Furthermore, it was not possible to satisfactorily modify the skin sandwich method so that it could be deployed using less hydrated skin.

Topics: Administration, Topical; Buffers; Chemistry, Pharmaceutical; Cyclohexane Monoterpenes; Epidermis; Hair Follicle; Humans; Humidity; Hydrocortisone; Hydrogen-Ion Concentration; Hypromellose Derivatives; In Vitro Techniques; Methylcellulose; Monoterpenes; Oleic Acid; Pharmaceutical Vehicles; Skin; Skin Absorption; Sodium Dodecyl Sulfate; Viscosity

The objective of the study was to investigate the effect of nerodilol and carvone on the in vitro transdermal delivery of nicorandil so as to fabricate a membrane-moderated transdermal therapeutic system. The in vitro permeation studies were carried across the rat epidermal membrane from the hydroxypropyl methylcellulose (HPMC) gels (prepared with 70:30 v/v ethanol-water) containing selected concentrations of a terpene such as nerodilol (0%w/w, 4%w/w, 8%w/w, 10%w/w, or 12%w/w) or carvone (0%w/w, 4%w/w, 8%w/w, 12%w/w, or 16%w/w). The amount of nicorandil permeated (Q(24)) from HPMC gel drug reservoir without a terpene was 3424.6+/-51.4 microg/cm(2), and the corresponding flux of the drug was 145.5+/-2.2 microg/cm(2). h. The flux of nicorandil increased with an increase in terpene concentration in HPMC gel. It was increased ranging from 254.9+/-3.1 to 375.7+/-3.2 microg/cm(2).h or 207.6+/-4.7 to 356.7+/-15.3 microg/cm(2). h from HPMC gels containing nerodilol (4%w/w to 12%w/w) or carvone (4%w/w to 16%w/w), respectively. Nerodilol increased the flux of nicorandil by about 2.62-folds whereas carvone increased the flux of the drug by about 2.49-folds across the rat epidermal membrane. The results of the Fourier Transform Infrared (FT-IR) study indicated that the enhanced in vitro transdermal delivery of nicorandil might be due to the partial extraction of stratum corneum lipids by nerodilol or carvone. It was concluded that the terpenes, nerodilol and carvone, produced a marked penetration enhancing effect on the transdermal delivery of nicorandil that could be used in the fabrication of membrane-moderated transdermal therapeutic systems.

Topics: Administration, Cutaneous; Animals; Cyclohexane Monoterpenes; Epidermis; Gels; Hypromellose Derivatives; In Vitro Techniques; Methylcellulose; Models, Biological; Monoterpenes; Nicorandil; Permeability; Rats; Skin Absorption; Spectroscopy, Fourier Transform Infrared; Terpenes; Vasodilator Agents

The aim of this investigation was to find the effect of the ethanol-water solvent system and the ethanolic solution of carvone on the permeation of nimodipine across rat abdominal skin in order to select a suitable solvent system and optimal concentration of carvone for the development of membrane-moderated transdermal therapeutic system of nimodipine. The solubility of nimodipine in water, ethanol, and ethanol-water cosolvent systems, or the selected concentration of carvone [2% (w/w) to 12% (w/w)] in 60:40 (v/v) ethanol-water were determined. The effect of these solvents or cosolvent systems on the transdermal permeation of nimodipine was also studied using in vitro permeability studies across the rat abdominal skin. The co-solvent system containing 60:40 (v/v) of ethanol-water showed highest permeability across the rat abdominal skin. Further, the effect of ethanolic solution [60% (v/v) ethanol-water] of carvone [2% (w/w) to 12% (w/w)] on the in vitro permeation of nimodipine across the rat abdominal skin from 2% (w/w) hydroxypropyl methylcellulose (HPMC) gel was also investigated. The transdermal permeability of nimodipine across rat abdominal skin was enhanced further by the addition of carvone to HPMC gel prepared with 60% (v/v) of ethanol. There was a steady effect on the flux of nimodipine (161.02 +/- 4.14 microg/cm2/hr) with an enhancement ratio of 4.56 when carvone was incorporated at a concentration of 10% (w/w) in HPMC gels prepared with 60% (v/v) ethanol. The Fourier transform infrared data indicated that ethanolic solution of carvone increased the transdermal permeability of nimodipine across the rat abdominal skin by partial extraction of lipids in the stratum corneum. The results suggest that 10% (w/w) of carvone in 60% (v/v) ethanol-water, along with HPMC as antinucleating agent may be useful for enhancing the skin permeability of nimodipine from the membrane-moderated transdermal therapeutic system.

Topics: Abdomen; Administration, Cutaneous; Animals; Cyclohexane Monoterpenes; Ethanol; Gels; In Vitro Techniques; Lactose; Male; Methylcellulose; Monoterpenes; Nimodipine; Oxazines; Permeability; Rats; Skin; Solvents; Terpenes; Water

The purpose of this investigation was to develop a membrane-moderated transdermal therapeutic system (TTS) of nimodipine using 2% w/w hydroxypropylmethylcellulose (HPMC) gel as a reservoir system containing 10% w/w of carvone (penetration enhancer) in 60% v/v ethanol. The flux of nimodipine through an ethylene vinyl acetate (EVA) copolymer membrane was found to increase with an increase in vinyl acetate content in the copolymer. The effect of a pressure-sensitive adhesive (TACKWHITE A 4MED) on the permeability of nimodipine through an EVA 2825 membrane (28% w/w vinyl acetate) or an EVA 2825 membrane/skin composite was also studied. An EVA 2825 membrane coated with TACKWHITE 4A MED was found to provide the required flux of nimodipine (117 +/- 5 microg/cm2/h) across rat abdominal skin. Thus a new transdermal therapeutic system for nimodipine was formulated using EVA 2825 membrane, coated with a pressure-sensitive adhesive TACKWHITE 4A MED, and 2% w/w HPMC gel as reservoir containing 10% w/w of carvone as a penetration enhancer. Studies in healthy human volunteers indicated that the TTS of nimodipine, designed in the present study, provided steady-state plasma concentration of the drug with minimal fluctuations.

Topics: Administration, Cutaneous; Algorithms; Animals; Biological Availability; Calcium Channel Blockers; Chromatography, High Pressure Liquid; Cyclohexane Monoterpenes; Excipients; Gels; Humans; In Vitro Techniques; Lactose; Male; Membranes, Artificial; Methylcellulose; Monoterpenes; Nimodipine; Oxazines; Permeability; Polyvinyls; Rats; Skin Absorption; Spectrophotometry, Ultraviolet; Tablets; Terpenes