SciCombinator

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Concept: Transdermal patch

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OBJECTIVE: To compare the effects of continuous use of oral (OC), transdermal, and vaginal combined contraceptives on the pituitary-ovarian axis and inhibition of follicular development. DESIGN: Spin-off study of a prospective, randomized trial. SETTING: University clinic. PATIENT(S): Forty-two of 54 healthy women completed the study. INTERVENTION(S): Treatment with combined OCs (ethinyl E(2) [EE] and desogestrel), transdermal patches (EE and norelgestromin), or vaginal rings (EE and etonogestrel) for 9 weeks continuously. Blood sampling was performed before and at 5 and 9 weeks of treatment. MAIN OUTCOME MEASURE(S): Changes in serum hormone levels induced by combined contraceptives. RESULT(S): Serum antimüllerian hormone (AMH), FSH, inhibin B, LH, and E(2) levels had decreased significantly in all study groups after 9 weeks of treatment. Significant declines were already detected after 5 weeks' use of combined contraceptives with regard to all hormone levels apart from those of serum AMH, where the decrease between baseline and 5 weeks was only moderate. Between groups, serum levels of AMH, inhibin B, LH, and E(2) were comparable at baseline and after 5 and 9 weeks of treatment. CONCLUSION(S): The decrease of serum AMH levels during the use of all combined contraceptives indicates that folliculogenesis is arrested independently of administration route. CLINICAL TRIAL REGISTRATION NUMBER: NCT01087879.

Concepts: Pharmacology, Sexual intercourse, Hormonal contraception, Transdermal patch, Contraceptive patch, Menstrual cycle, Route of administration, Follicular phase

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In the present study, novel ultradeformable liposomes (menthosomes; MTS), deformable liposomes (transfersomes; TFS) and conventional liposomes (CLP) were compared in their potential for transdermal delivery of meloxicam (MX). MTS, TFS and CLP were investigated for size, size distribution, zeta potential, elasticity, entrapment efficiency and stability. In vitro skin permeation using hairless mice skin was evaluated. Vesicular morphology was observed under freeze-fractured transmission electron microscopy (FF-TEM). Intrinsic thermal properties were performed using differential scanning calorimetry (DSC) and X-ray diffraction. The skin permeation mechanism was characterized using confocal laser scanning microscopy (CLSM). The results indicated that the difference in physicochemical characteristics of MTS, TFS and CLP affected the skin permeability. MTS and TFS showed higher flux of MX than CLP. CLSM image showed deformable vesicles mechanism for delivery of MX across the hairless mice skin. Our study suggested that ultradeformable and deformable liposomes (MTS and TFS) had a potential to use as transdermal drug delivery carriers for MX.

Concepts: Electron, Diffraction, X-ray, Transdermal patch, X-ray crystallography, Differential scanning calorimetry, Scientific techniques, Transmission electron microscopy

160

Transdermal delivery is an attractive option for drug delivery. Nevertheless, the skin is a tough barrier and only a limited number of drugs can be delivered through it. The most difficult to deliver are hydrophilic drugs. The stinging mechanism of the cnidarians is a sophisticated injection system consisting of microcapsular nematocysts, which utilize built-in high osmotic pressures to inject a submicron tubule that penetrates and delivers their contents to the prey. Here we show, for the first time, that the nematocysts of the starlet sea anemone Nematostella vectensis can be isolated and incorporated into a topical formulation for continuous drug delivery. We demonstrate quantitative delivery of nicotinamide and lidocaine hydrochloride as a function of microcapsular dose or drug exposure. We also show how the released submicron tubules can be exploited as a skin penetration enhancer prior to and independently of drug application. The microcapsules are non-irritant and may offer an attractive alternative for hydrophilic transdermal drug delivery.

Concepts: Pharmacology, Transdermal patch, Animal, Coral, Anthozoa, Sea anemone, Starlet sea anemone, Nematostella

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The efficacy of oral risperidone treatment in prevention of schizophrenia is well known. However, oral side effects and patient compliance is always a problem for schizophrenics. In this study, risperidone was formulated into matrix transdermal patches to overcome these problems. The formulation factors for such patches, including eudragit RL 100 and eudragit RS 100 as matrix forming polymers, olive oil, groundnut oil and jojoba oil in different concentrations as enhancers and amount of drug loaded were investigated. The transdermal patches containing risperidone were prepared by solvent casting method and characterized for physicochemical and in vitro permeation studies through excised rat skin. Among the tested preparations, formulations with 20% risperidone, 3:2 ERL 100 and ERS 100 as polymers, mixture of olive oil and jojoba oil as enhancer, exhibited greatest cumulative amount of drug permeated (1.87 ± 0.09 mg/cm(2)) in 72 h, so batch ROJ was concluded as optimized formulation and assessed for pharmacokinetic, pharmacodynamic and skin irritation potential. The pharmacokinetic characteristics of the optimized risperidone patch were determined using rabbits, while orally administered risperidone in solution was used for comparison. The calculated relative bioavailability of risperidone transdermal patch was 115.20% with prolonged release of drug. Neuroleptic efficacy of transdermal formulation was assessed by rota-rod and grip test in comparison with control and marketed oral formulations with no skin irritation. This suggests the transdermal application of risperidone holds promise for improved bioavailability and better management of schizophrenia in long-term basis.

Concepts: Pharmacology, Transdermal patch, In vivo, In vitro, Antipsychotic, Pharmacokinetics, Bioavailability, Transdermal patches

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Context: The transdermal drug delivery system was prepared and the bioavailability of the selected drug was enhanced by reducing first-pass metabolism. Objective: The objective of this study was to enhance the bioavailability of carvedilol through transdermal patches. Materials and methods: To develop a matrix-type transdermal patch containing carvedilol with different ratios of polymer combinations by solvent evaporation technique. Results and discussion: In-vitro permeation studies were performed by Franz diffusion cells. The results followed Higuchi kinetics, and mechanism of release was diffusion mediated. On the basis of the in-vitro and physicochemical parameters of carvedilol patches, the code F-1(PVP: Ethyl Cellulose = 4:1) was chosen for the study of in-vivo, ex-vivo, histocompatibility study, and pharmacological study. The bioavailability studies in rats indicated that the carvedilol-loaded transdermal patches provided steady-state plasma concentration and improved bioavailability of 72% in comparison to oral administration. The ex-vivo permeation study in rat’s skin indicated that the flux and permeability co-efficient of optimized F-1 patch was 30.08 ± 0.7 μg/cm(2)/h and 0.416 ± 0.05 μg/cm(2)/h, respectively, which was more as compared to plain carvedilol. The histocompatibility study of the F-1 patch on the rat’s skin after 24 h ex-vivo study gave less pathological changes as compared to other. The antihypertensive activity of the patch in comparison with oral administration was studied using N-nitro-L-arginine methyl ester-induced hypertensive rats. It was observed that the optimized patch (F-1) significantly controlled hypertension (p < 0.05). Conclusion: The developed patch increases the efficacy of carvedilol through enhancement of bioavailability for the therapy of hypertension.

Concepts: Pharmacology, Transdermal patch, Route of administration, Transdermal patches, Clonidine

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The transport of proteins through skin can be facilitated potentially by using terpenes as chemical enhancers. However, we do not know about the effects of these enhancers on the stability and biological activity of proteins which is crucial for the development of safe and efficient formulations. Therefore, this project investigated the effects of terpene-based skin penetration enhancers which are reported as nontoxic to the skin (e.g., limonene, p-cymene, geraniol, farnesol, eugenol, menthol, terpineol, carveol, carvone, fenchone, and verbenone), on the conformational stability and biological activity of a model protein lysozyme. Terpene (5% v/v) was added to lysozyme solution and kept for 24 h (the time normally a transdermal patch remains) for investigating conformational stability profiles and biological activity. Fourier transform infrared spectrophotometer was used to analyze different secondary structures, e.g., α-helix, β-sheet, β-turn, and random coil. Conformational changes were also monitored by differential scanning calorimeter by determining midpoint transition temperature ™ and calorimetric enthalpy (ΔH). Biological activity of lysozyme was determined by measuring decrease in A (450) when it was added to a suspension of Micrococcus lysodeikticus. The results of this study indicate that terpenes 9, 10, and 11 (carvone, L-fenchone, and L-verbenone) decreased conformational stability and biological activity of lysozyme significantly (p < 0.05) less than other terpenes used in this study. It is concluded that smaller terpenes containing ketones with low lipophilicity (log K (ow) ∼2.00) would be optimal for preserving conformational stability and biological activity of lysozyme in a transdermal formulation containing terpene as permeation enhancer.

Concepts: DNA, Gene, Transdermal patch, Differential scanning calorimetry, Terpene, Terpenes and terpenoids, Fourier transform spectroscopy, Limonene

27

To reduce the adverse effects of aceclofenac that accompanied with oral administration of this drug, transdermal patches in the form of drug-in-adhesive (DIA) patches, containing aceclofenac, were formulated. The effect of formulation factors on the skin permeation of the drug and physical properties of the patch were evaluated using excised rat skins. The optimized patch contained 12 % aceclofenac and 20 % lauryl alcohol in DT-2852 as a pressure-sensitive adhesive. The pharmacokinetic characteristics of the DIA patch were determined after application of the transdermal patches to human volunteers. The calculated relative bioavailability of the aceclofenac DIA patch was 18.2 % compared to oral administration of the drug. The findings of this study suggest that transdermal application of aceclofenac can substitute for oral administration of the drug.

Concepts: Pharmacology, Transdermal patch, Transdermal patches

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The purpose of the present investigation was to explore feasibility of nanocarrier based transdermal delivery of Huperzine A (HupA) for the treatment of Alzheimer’s disease. For this investigation, microemulsion (ME), solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs) were formulated and characterized for physicochemical parameters. The pseudo-ternary phase diagrams for microemulsion region were developed using generally recognized as safe (GRAS) excipients. The SLNs and NLCs were prepared by microemulsion template technique. These nanodispersions were formulated into gels for transdermal application and evaluated for various physicochemical parameters. In vitro permeation profiles in rat skin exhibited zero order kinetics. HupA loaded ME exhibited superior permeation than NLCs followed by SLNs and cumulative amount permeated after 24h was found to be 147.68±9.42μg/cm(2), 129.11±32.76μg/cm(2) and 10.74±0.68μg/cm(2) respectively. Furthermore, optimized gels were subjected to primary skin irritation testing over a period of 48h and were found to be safe for skin application. In vivo efficacy tested in scopolamine induced amnesia model indicated significant improvement in cognitive function in mice group treated with developed nanocarrier based formulations as compared to the control group.

Concepts: Transdermal patch, In vivo, In vitro, Acetylcholinesterase inhibitor, Huperzine A

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BACKGROUND:: To the best of our knowledge, there have been no reports on the pharmacokinetics and pharmacodynamics during the conversion from continuous intravenous infusion (CII) to transdermal fentanyl administration. The primary objective of the present study was to clarify the pharmacokinetic characteristics during this conversion. A secondary objective was to identify an association between serum albumin and the absorption of fentanyl from the transdermal patch. METHODS:: A prospective study was conducted from February 2010 to August 2011 that enrolled 19 patients with chronic cancer pain. Patients were classified into 2 study groups according to body mass index and albumin level. All patients received the conversion from CII to transdermal fentanyl using a 2-step taper of CII over 6 hours. Comparisons of efficacy, toxicity, and serum fentanyl concentrations between study groups were analyzed at baseline, 3, 6, 9, 12, 15, 18, and 24 hours after initiation of the conversion. RESULTS:: The dose-adjusted serum fentanyl concentrations for all patients were significantly decreased at 15 to 24 hours after conversion compared with baseline, although pain intensity and the number of rescue events remained stable during the conversion. The dose-adjusted serum fentanyl concentrations at 9 to 24 hours were significantly reduced in the low albumin group compared with the normal albumin group (P<0.05). CONCLUSIONS:: Our study demonstrated that the dose-adjusted serum fentanyl concentrations remained relatively stable, and pain intensity and the number of rescue events remained stable during conversion. Hypoalbuminemia was strongly associated with poor absorption of transdermally administered fentanyl.

Concepts: Pharmacology, Transdermal patch, Body mass index, Albumin, Route of administration, Pharmacokinetics, Fentanyl, Pharmacodynamics

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The aim of the current investigation is to develop and statistically optimize nanoethosomes for transdermal valsartan delivery. Box-Behnken experimental design was applied for optimization of nanoethosomes. The Independent variables were phospholipids 90G (X(1)), ethanol (X(2)), valsartan (X(3)) and sonication Time (X(4)) while entrapment efficiency (Y(1)), vesicle size (Y(2)) and flux (Y(3)) were the dependent variables. The optimized formulation obtained was then tested in rats for an in vivo pharmacokinetic study. Results indicate that the nanoethosomes of valsartan provides better flux, reasonable entrapment efficiency, more effectiveness for transdermal delivery as compared to rigid liposomes. Optimized nanoethosomal formulation with mean particle size is 103±5.0nm showed 89.34±2.54% entrapment efficiency and achieved mean transdermal flux 801.36±21.45μg/cm(2)/hr. Nanoethosomes proved significantly superior in terms of, amount of drug permeated in the skin, with an enhancement ratio of 43.38±1.37 when compared to rigid liposomes. Confocal laser scanning microscopy revealed an enhanced permeation of Rhodamine-Red loaded nanoethosomes to the deeper layers of the skin as compared to conventional liposomes. In vivo pharmacokinetic study of nanoethosomal transdermal therapeutic system showed a significant increase in bioavailability (3.03 times) compared with oral suspension of valsartan. Our results suggest that nanoethosomes are an efficient carrier for transdermal delivery of valsartan.

Concepts: Pharmacology, Statistics, Transdermal patch, Skin, Pharmacokinetics, Optimization, Applied mathematics, Confocal laser scanning microscopy