Deproteinized natural rubber film forming polymeric solutions for nicotine transdermal delivery

Enhancing Pharmacokinetics and Pharmacodynamics of Rosuvastatin Calcium through the Development and Optimization of Fast-Dissolving Films

Rosuvastatin (RSV) is a widely used cholesterol-lowering medication, but its limited bioavailability due to its susceptibility to stomach pH and extensive first-pass metabolism poses a significant challenge. A fast-dissolving film (FDF) formulation of RSV was developed, characterized, and compared to the conventional marketed tablet to address this issue. The formulation process involved optimizing the thickness, disintegration time, and folding durability. All formulations were assessed for in vitro disintegration, thickness, folding endurance, in vitro dissolution, weight, and content uniformity. The study's results revealed that the optimized RSV-FDF displayed a significantly faster time to maximum plasma concentration (tmax) of 2 h, compared to 4 h for the marketed tablet. The maximum plasma concentration (Cmax) for the RSV-FDF (1.540 µg/mL ± 0.044) was notably higher than that of the marketed tablet (0.940 µg/mL ± 0.017). Additionally, the pharmacodynamic assessment in male Wistar rats demonstrated that the optimized RSV-FDF exhibited an improved lipid profile, including reduced levels of low-density lipoproteins (LDLs), elevated high-density lipoproteins (HDLs), decreased triglycerides (TGs), and lower very-low-density lipoproteins (VLDLs) compared to the conventional tablet. These findings underscore the potential of RSV-FDFs as a promising alternative to enhance the bioavailability and therapeutic efficacy of rosuvastatin in treating dyslipidemia. The faster onset of action and improved lipid-lowering effects make RSV-FDFs an attractive option for patients requiring efficient cholesterol management.

Evaluation of in vivo bond strength and skin irritation test for new skin adhesive

Objectives

This study developed a new skin-deproteinized natural rubber latex (DNRL) silicone adhesive for adhering to silicone prostheses and compared the properties with a commercial Daro-Hydrobond adhesive.

Materials and methods

The new DNRL skin adhesive formulation was made from non-vulcanized natural rubber-based adhesives consisting of DNRL, 20% polyvinyl alcohol, cumarone resin, 2% methylcellulose, and Wingstay L. The peel bond strength of the adhesives was tested using a 90-degree peel test. Biocompatibility was accessed using in vitro keratinocyte cell viability. Animals (rabbits) and humans were tested for skin irritation tests. Results were analyzed using SPSS Version 24 and compared between the two adhesives.

Results

The peel bond strength of the new DNRL skin adhesive was 103.61 ± 23.18 N/m whereas that of the Daro-hydrobond adhesive was 131.52 ± 21.72 N/m. There was no significant difference (p>0.05) between the peel bond strengths of the two test adhesives. Cell proliferation under the DNRL skin adhesive-soaked medium showed higher cell viability than the positive control (p<0.05). The DNRL skin adhesive produced moderate erythema and edema on rabbit skins, however, the skin lesions recovered within 14 days. Two volunteers showed mild irritation at the first hour of the contact which was reduced within an hour without any therapy. The patient satisfaction with the DNRL skin adhesive ranged from slightly satisfied to completely satisfied.

Conclusion

The new DNRL skin adhesive showed comparable peel bond strength and patient satisfaction to those of commercial adhesives. The adhesive was biocompatible and can be used carefully.

Applying design of experiments (DoE) on the properties of buccal film for nicotine delivery

Design of experiments is used to optimize ratios between deproteinized natural rubber latex, Eudragit® NM 30 D, and pectin for nicotine buccal film with dependent variables as moisture content, moisture uptake, and swelling index in simulated saliva 3 and 5 h. Mathematical models were linear for moisture content and moisture uptake, while swelling index in simulated saliva 3 and 5 h was a quadratic model. Optimized polymer ratio was 0.319:0.362:0.319, respectively. Experimental values were 13.17 ± 0.92%, 3.96 ± 0.84%, 112.58 ± 22.63%, and 124.69 ± 8.01% for dependent variables, respectively. The buccal film showed high swelling at pH 7 and swelling–deswelling behaviors in a water/ethanol environment. The surface pH, weight, and thickness were 8.11, 63.28 ± 6.18 mg, and 219.87 ± 44.28 µm, respectively. Nicotine content was found as 10.22 ± 0.46 mg/4 cm2. Maximum cumulative nicotine release was 9.82 ± 0.94 mg/4 cm2. Kinetic model fitted to the Korsmeyer-Peppas model and release exponent was 0.36, representing that release mechanism was controlled by Fickian diffusion release.

Formulation optimization and characterization of transdermal film of curcumin by response surface methodology

Objective

India is referred as goldmine of herbal drugs but still lack of optimization of herbal drugs, which has kept us on the back foot. The rationale of the study is to prepare optimized transdermal drug delivery system of curcumin employing response surface methodology to study the collective effect of independent variables like concentration of ethyl cellulose, hydroxyl propyl methyl cellulose and dibutyl phthalate which significantly influenced characteristics like percentage elongation and in vitro drug release.

Method

Twenty formulations containing varying concentrations of polymers and permeation enhancer were prepared using solvent casting technique.

Result

The study revealed that the effect of dibutyl phthalate (DBP) concentration was the highest on percentage elongation (P < 0.0001), while hydroxy propyl methyl cellulose (HPMC) concentration exhibited pronounced effect on drug release (P < 0.0001) through dialysis membrane. Linear model fitted the best for curcumin release and elongation for all formulations. According to Derringer’s desirability prediction tool, the composition of optimized film was found to be 242.14% of HPMC, 109.59% of ethyl cellulose (EC), and 1.03% of DBP. Under these conditions, the optimized patch exhibited a predicted value of %elongation and in vitro drug release of 94.35% and 80.0306%, respectively, which was comparable to the actual values of percent elongation and in vitro drug release i.e. 95.02% and 81.03% respectively. FTIR and thermal studies were also performed which revealed no interaction or complexation between drug and excipients. The ex vivo study performed using rat skin showed that the cumulative drug release from the optimized patch showed flux of (30.68 ± 18) µg/cm²/h.

Conclusion

It can be concluded that in future if proper optimization of herbal formulations is carried out, they can become the first choice for patients as compare to synthetic drugs.

Novel Herbal Topical Patch Containing Curcumin and Arnica montana for the Treatment of Osteoarthritis

BACKGROUND

Osteoarthritis (OA) ranks fifth among all forms of disability affecting 10% of the world population. Current treatments available are associated with multiple side effects and do not slow down the progression of the disease. Moreover, no such effective treatment is available to date in various systems of medicine to treat osteoarthritis. Curcumin and Arnica have shown evident clinical advances in the treatment of osteoarthritis.

OBJECTIVE

The aim of the present study was to design, optimize and characterize novel herbal transdermal patches of curcumin and Arnica montana using factorial design.

METHODS

A multiple factorial design was employed to investigate the effect of hydroxypropyl methyl cellulose, ethyl cellulose and jojoba oil on elongation and drug release. Transdermal patches were evaluated by FTIR, DSC, FESEM, ex vivo drug permeation, anti osteoarthritic activity and analgesic activity.

RESULTS

Independent variables exhibited a significant effect on the physicochemical properties of the prepared formulations. The higher values of drug release and elongation were observed with the higher concentration of hydroxypropyl methylcellulose and jojoba oil. Anti osteoarthritic activity was assessed by complete Freund's adjuvant arthritis model; using rats and analgesic activity by Eddy's hot plate method, using mice. Combination patch exhibited good anti osteoarthritic and analgesic activity as compare to individual drug patches.

CONCLUSION

The design results revealed that the combination patch exhibited good physicochemical, anti osteoarthritic and analgesic activity for the treatment of osteoarthritis in animals. More plants and their combinations should be explored to get reliable, safe and effective formulations that can compete with synthetic drugs.

Comparison of Pectin Layers for Nicotine Transdermal Patch Preparation

Purpose: The objective of the present investigation was to prepare and evaluate transdermal patches for nicotine.

Methods: Pectin isolated from the hulls of Monthong durian or leaves of Krueo Ma Noy was used as a matrix membrane for the controlled release of nicotine and compared with commercial pectin. The mechanical properties, moisture uptake, and Fourier transform infrared spectra were characterized. The in vitro stability of these patches was evaluated and compared to commercial nicotine patches.

Results: The mechanical properties of the patches made from isolated pectin were greater than those prepared from commercial pectin; brittle commercial patches were obtained after nicotine loading. The moisture uptake of the patches made with isolated pectin was in the range of 30.20-44.29%. There was no incompatibility between the ingredients of the nicotine transdermal patches or any degradation of the drug. The matrix layer made from isolated pectin controlled the nicotine release more effectively than did commercial nicotine patches. In addition, these patches were stable at in a refrigerator (approximately 4±2 °C) and at ambient temperature (approximately 30±2 °C) for 3 months, retaining 90% of the loaded nicotine.

Conclusion: Our study suggests that using isolated pectin as the matrix layer should control the release of nicotine from transdermal patches.

Mechanical Properties of Herbal Patches from Chitosan-Based Polymer Blends for Medical Applications

Recently, Thai herbs are widely used as medicine to treat some illnesses. Zingiber cassumunar Roxb., known by the Thai name “Plai”, is a popular anti-inflammatory, antispasmodic herbal body and muscle treatment. This research aimed to prepare herbal patches that incorporated the 3 g of crude Z. cassumunar oil. The herbal patches made from different polymer blends were 2 g of 3.5%w/v chitosan and 5 g of 20%w/v hydroxypropyl methylcellulose (HPMC), or 2 g of 3.5%w/v chitosan and 5 g of 20%w/v polyvinyl alcohol (PVA) using 2 g of glycerin as a plasticizer. They were prepared by mixing all ingredients in a beaker and produced by solvent casting method in hot air oven at 70±2oC. The completed herbal patches were evaluated for their mechanical properties including Young’s modulus, ultimate tensile strength, elongation at break, T-peel strength, and tack adhesion. The thickness of blank and herbal patches was 0.263-0.282 mm and 0.269-0.275 mm, respectively. Young’s modulus, ultimate tensile strength, elongation at break, T-peel strength, and tack adhesion were 104.73-142.71 MPa, 87.92-93.28 MPa, 154.39-174.98 %, 3.43-4.88 MPa, and 5.29-7.02 MPa, respectively, for blank patches, and 116.83-147.28 MPa, 89.49-100.47 MPa, 133.78-159.27 %, 2.01-3.98 MPa, and 4.03-5.19 MPa, respectively, for herbal patches. We prepared herbal blended patches made from chitosan/PVA or chitosan/HPMC polymer matrix blends incorporating the crude Z. cassumunar oil. They had good mechanical properties that might be developed for herbal medicinal application.

Antifungal activity of fluconazole-loaded natural rubber latex against Candida albicans

Aim: This work aimed to produce a membrane based on fluconazole-loaded natural rubber latex (NRL), and study their interaction, drug release and antifungal susceptibility against Candida albicans. Materials & methods: Fluconazole-loaded NRL membrane was obtained by casting method. Results: The Fourier Transform Infrared Spectroscopy showed no modifications either in NRL or fluconazole after the incorporation. Mechanical test presented low Young's modulus and high strain, indicating the membranes have sufficient elasticity for biomedical application. The bio-membrane was able to release the drug and inhibit the growth of C. albicans as demonstrated by disk diffusion and macrodilution assays. Conclusion: The biomembrane was able to release fluconazole and inhibit the growth of C. albicans, representing a promising biomaterial for skin application.

Deproteinised natural rubber latex grafted poly(dimethylaminoethyl methacrylate) - poly(vinyl alcohol) blend membranes: Synthesis, properties and application

Natural rubber latex was initially deproteinised (DNRL) and then subjected to physicochemical modifications to make high functional membranes for drug delivery applications. Initially, DNRL was prepared by incubating with urea, sodiumdodecylsulphate and acetone followed by centrifugation. The deproteinisation was confirmed by CHN analysis. The DNRL was then chemically modified by grafting (dimethylaminoethyl methacrylate) onto NR particles by using a redox initiator system viz; cumene hydroperoxide/tetraethylenepentamine, followed by dialysis for purification. The grafting was confirmed by dynamic light scattering, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The grafted system was blended with a hydrophilic adhesive polymer PVA and casted into membranes. The membranes after blending showed enhanced mechanical properties with a threshold concentration of PVA. The moisture uptake, swelling and water contact angle experiments indicated an increased hydrophilicity with an increased PVA content in the blend membranes. The grafted DNRL possessed significant antibacterial property which has been found to be retained in the blended form. A notable decrease in cytotoxicity was observed for the modified DNRL membranes than the bare DNRL membranes. The in-vitro drug release studies using rhodamine B as a model drug, confirmed the utility of the prepared membranes to function as a drug delivery matrix.

New Pharmacological Agents to Aid Smoking Cessation and Tobacco Harm Reduction: What Has Been Investigated, and What Is in the Pipeline?

A wide range of support is available to help smokers to quit and to aid attempts at harm reduction, including three first-line smoking cessation medications: nicotine replacement therapy, varenicline and bupropion. Despite the efficacy of these, there is a continual need to diversify the range of medications so that the needs of tobacco users are met. This paper compares the first-line smoking cessation medications with (1) two variants of these existing products: new galenic formulations of varenicline and novel nicotine delivery devices; and (2) 24 alternative products: cytisine (novel outside Central and Eastern Europe), nortriptyline, other tricyclic antidepressants, electronic cigarettes, clonidine (an anxiolytic), other anxiolytics (e.g. buspirone), selective serotonin reuptake inhibitors, supplements (e.g. St John's wort), silver acetate, Nicobrevin, modafinil, venlafaxine, monoamine oxidase inhibitors (MAOIs), opioid antagonists, nicotinic acetylcholine receptor (nAChR) antagonists, glucose tablets, selective cannabinoid type 1 receptor antagonists, nicotine vaccines, drugs that affect gamma-aminobutyric acid (GABA) transmission, drugs that affect N-methyl-D-aspartate (NMDA) receptors, dopamine agonists (e.g. levodopa), pioglitazone (Actos; OMS405), noradrenaline reuptake inhibitors and the weight management drug lorcaserin. Six 'ESCUSE' criteria-relative efficacy, relative safety, relative cost, relative use (overall impact of effective medication use), relative scope (ability to serve new groups of patients) and relative ease of use-are used. Many of these products are in the early stages of clinical trials; however, cytisine looks most promising in having established efficacy and safety with low cost. Electronic cigarettes have become very popular, appear to be efficacious and are safer than smoking, but issues of continued dependence and possible harms need to be considered.

Matrix-type transdermal films to enhance simvastatin ex vivo skin permeability

This study aimed at employing Plackett-Burman design in screening formulation variables that affect quality of matrix-type simvastatin (SMV) transdermal film. To achieve this goal, 12 formulations were prepared by casting method. The investigated variables were Eudragit RL percentage, polymer mixture percentage, plasticizer type, plasticizer percentage, enhancer type, enhancer percentage and dichloromethane fraction in organic phase. The films were evaluated for physicochemical properties and ex vivo SMV permeation. SMV initial, delayed flux, diffusivity and permeability coefficient were calculated on the delayed flux phase with constraint to minimize the initial flux and approaching steady-state flux. The obtained results revealed flat films with homogeneous distribution of SMV within the films. Thickness values changed from 65 to 180 μm by changing the factors' combinations. Most of the permeation profiles showed sustained release feature with fast permeation phase followed by slow phase. Analysis of variance (ANOVA) showed significant effects (p < 0.05) of the investigated variables on the responses with Prob > F values of 0.0147, 0.0814, 0.0063 and 0.0142 for the initial and delayed fluxes, permeability coefficients and diffusivities, respectively. The findings of screening study showed the importance of the significant variables to be scaled up for full optimization study as a promising alternative drug delivery system.

Characterization of supramolecular gels based on β-cyclodextrin and polyethyleneglycol and their potential use for topical drug delivery

Novel gels were prepared by blending β-cyclodextrin and polyethyleneglycol (PEG) in the presence of K2CO3. The objective of this study was thus to characterize the gels using rheology, modulated temperature differential scanning calorimetry (MTDSC), turbidity measurements, and hot stage microscopy, and then investigate the potential use of the gel for topical drug delivery. Two types of supramolecular gels, GelL and GelH were prepared at a low temperature (below 50 °C) and at a high temperature (above 70 °C), respectively. Both gels were thermo-reversible. Upon heating, GelL could turn to GelH. Nevertheless, upon cooling, GelH that was more stable than GelL precipitated and GelL could not be reformed. GelL may form through simple complexation of polyethyleneglycol (PEG) with β-cyclodextrin in the presence of K2CO3. However, GelH may form a specific complex or a pseudopolyrotaxane gel. For pharmaceutical application, GelL was investigated instead of GelH because the forming temperature of this gel was close to the human body temperature. The interactions among diclofenac sodium (DS), a model drug, and the components of the gel were examined using FTIR. These interactions may include ionic attraction and hydrogen bonds between the carboxylate groups of DS and the hydroxyl groups of PEG or β-cyclodextrin and probably also the inclusion of the aromatic ring of DS into the cavity of β-cyclodextrin. Furthermore, the release and permeation of diclofenac from GelL were significantly greater than those from a commercial gel. Therefore, GelL may be useful for the topical delivery of drugs.

Novel delivery systems for nicotine replacement therapy as an aid to smoking cessation and for harm reduction: rationale, and evidence for advantages over existing systems

Nicotine replacement therapy (NRT) has been used in the treatment of tobacco dependence for over three decades. Whilst the choice of NRT was limited early on, in the last ten years there has been substantial increase in the number of nicotine delivery devices that have become available. This article briefly summarises existing forms of NRT, evidence of their efficacy and use, and reviews the rationale for the development of novel products delivering nicotine via buccal, transdermal or pulmonary routes (including nicotine mouth spray, nicotine films, advanced nicotine inhalers and electronic cigarettes). It presents available evidence on the efficacy, tolerability and abuse potential of these products, with a focus on their advantages as well as disadvantages compared with established forms of NRT for use as an aid to both smoking cessation as well as harm reduction.

Pseudolatex from STR 5L Block Rubber for Drug Delivery

Pseudolatex is colloidal dispersion containing spherical solid or semisolid particles and can be prepared from any existing thermoplastic water-insoluble polymers. It is useful for drug encapsulation and controlled drug release. In this study, pseudolatex base was prepared from STR 5L block rubber. The various parameters such as speed and time of homogenization, type and concentration of surfactants, amount of mineral oil, and type of drug loading were studied to prepare the stable pseudolatex. These preparations were evaluated in particle size, pH, viscosity, emulsion stability, drug encapsulation, and in vitro drug release. It was found that the most stable formulation contained 3.5% block rubber, 0.2% methyl cellulose, 6% mineral oil, 4% dibutyl phthalate, 2% sodium lauryl sulfate, and 2% Uniphen P-23 using the speed and time of homogenizer as 20000 rpm and 20 minutes, respectively. Furthermore, the pseudolatex bases reduced the protein impurity form 0.5516% to 0.2108% in formulation with mineral oil and to 0.1781% in formulation without mineral oil, that could decrease contact allergy caused by the protein allergens. Dichloromethane residues in pseudolatex bases were 22.05 mg/L and 7.85 mg/L in formulations with and without mineral oil, respectively, that were satisfied from USP recommendation value of lower than 600 mg/L. Propranolol HCl, lidocaine HCl, and indomethacin could be loaded into pseudolatex only in the concentration of 1%. However, lidocaine base in the concentration of 1-5% could be loaded into pseudolatex which had the similar physical properties and stability to pseudolatex base. The in vitro drug release from pseudolatexs provided the controlled drug release for more than 24 hr.