Formulation, in vitro and in vivo evaluation of transdermal patches containing risperidone

Fabrication, evaluation, and enhanced penetration of vinyl and cellulose-engineered transdermal patch of nifedipine using essential oil as penetration enhancer

The aim of this study was to develop and evaluate the transdermal patch formulations of nifedipine. The patch formulations containing nifedipine were prepared and optimized with different ratios of vinyl and cellulose-derived polymers, drug contents, and permeation enhancers. Among the various formulations, the patch formulation containing a 1:5 ratio of ethyl cellulose and polyvinyl pyrrolidone was selected for ex vivo pharmacokinetic study based on in vitro permeation studies using stratum corneum of the pig's skin. The cumulative percentage release after the transdermal administration of the optimized patch formulation was 71.43%, and the plasma concentration of nifedipine was maintained for 16 hrs. The physicochemical evaluation study including flatness, thickness, moisture content and uptake, drug content in vitro release, and ex vivo permeation indicated satisfactory results. The formulation batch with clove oil as a penetration enhancer has shown better ex vivo permeation as compared to the formulations without enhancers and another synthetic enhancer. These results suggest that the optimized patch formulation Q3 could be further developed for clinical applications, providing the therapeutic plasma level of nifedipine over an extended period. Hence analyzing the results of the evaluation tests, in vitro and ex vivo data on the preparation and optimization of nifedipine-loaded transdermal patch, it can be concluded that the formulation shows its feasibility as an effective transdermal delivery system for nifedipine.

Translation from Preclinical Research to Clinical Trials: Transdermal Drug Delivery for Neurodegenerative and Mental Disorders

Neurodegenerative diseases (NDs), particularly dementia, provide significant problems to worldwide healthcare systems. The development of therapeutic materials for various diseases has a severe challenge in the form of the blood-brain barrier (BBB). Transdermal treatment has recently garnered widespread favor as an alternative method of delivering active chemicals to the brain. This approach has several advantages, including low invasiveness, self-administration, avoidance of first-pass metabolism, preservation of steady plasma concentrations, regulated release, safety, efficacy, and better patient compliance. Topics include the transdermal method for therapeutic NDs, their classification, and the mechanisms that allow the medicine to enter the bloodstream through the skin. The paper also discusses the obstacles and potential outcomes of transdermal therapy, emphasizing the benefits and drawbacks of different approaches.

Systematic Review on the Effectiveness of Essential and Carrier Oils as Skin Penetration Enhancers in Pharmaceutical Formulations

Oils, including essential oils and their constituents, are widely reported to have penetration enhancement activity and have been incorporated into a wide range of pharmaceutical formulations. This study sought to determine if there is an evidence base for the selection of appropriate oils for particular applications and compare their effectiveness across different formulation types. A systematic review of the data sources, consisting of Google Scholar, EMBASE, PubMed, Medline, and Scopus, was carried out and, following screening and quality assessment, 112 articles were included within the analysis. The research was classified according to the active pharmaceutical ingredient, dosage form, in vitro/in vivo study, carrier material(s), penetration enhancers as essential oils, and other chemical enhancers. The review identified four groups of oils used in the formulation of skin preparations; in order of popularity, these are terpene-type essential oils (63%), fatty acid-containing essential oils (29%) and, finally, 8% of essential oils comprising Vitamin E derivatives and miscellaneous essential oils. It was concluded that terpene essential oils may have benefits over the fatty acid-containing oils, and their incorporation into advanced pharmaceutical formulations such as nanoemulsions, microemulsions, vesicular systems, and transdermal patches makes them an attractive proposition to enhance drug permeation through the skin.

Fabrication of Tizanidine Loaded Patches Using Flaxseed Oil and Coriander Oil as a Penetration Enhancer for Transdermal Delivery

Transdermal drug delivery is important to maintain plasma drug concentrations for therapeutic efficacy. The current study reports the design, formulation, and evaluation of tizanidine transdermal patches formulated using chitosan and thiolated chitosan, ethyl cellulose (EC), polyvinylpyrrolidone (PVP), and Eudragit RL100 in different ratios. The tizanidine patches were formulated using flaxseed oil and coriander oil in the concentrations of 1% v/w, 2% v/w, 3% v/w, 4% v/w, 5% v/w, and 10% v/w. The patches were subjected to characterization of physicochemical property (thickness, weight uniformity, drug content, efficiency, percentage moisture uptake/loss), in vitro drug release and drug permeation, skin irritation, in vivo application, pharmacokinetics analysis, and stability studies. The results indicate that the interaction of thiolated chitosan with the negative charges of the skin opens the tight junctions of the skin, whereas flaxseed and coriander oils change the conformational domain of the skin. The novelty of this study is in the use of flaxseed and coriander oils as skin permeation enhancers for the formulation of tizanidine transdermal patches. The formulations follow non-Fickian drug release kinetics. The FTZNE23, FTZNE36 and FTZNE54, with 5% v/w flaxseed oil loaded formulations, exhibited higher flux through rabbit skin compared with FTZNE30, FTZNE35, FTZNE42, and FTZNE47, formulations loaded with 10% v/w coriander oil. The study concludes that flaxseed oil is a better choice for formulating tizanidine patches, offering optimal plasma concentration and therapeutic efficacy, and recommends the use of flaxseed and coriander oil based patches as a novel transdermal delivery system for tizanidine and related classes of drugs.

Therapeutic benefits of natural oils along with permeation enhancing activity

The skin is the largest organ of the integumentary system with a multifunctional purpose to protect the body from heat and microbes, regulate body temperature, and act as a sensory organ. A topical dosage form applied on the skin will have to cross the stratum corneum, which would then allow the dosage form to traverse the subsequent layers of the skin. The drug with poor solubility and short half-life would serve as an ideal candidate for its delivery via the transdermal route. This review reports the role of natural oils in enhancing the permeation of drugs through skin as they possess different features like natural origin, favorable penetration enhancement, and partitioning action in the skin. Chemical penetration enhancers have been used widely but are associated with toxicities. Thus, more research should be channelized in the area of extraction of oils from natural sources, along with their active constituents, which can serve as therapeutic alternatives to various disorders and diseases. Natural oils are obtained from leaves, fruits, flowers, seeds, bark, and roots, which have a therapeutic potential as well as penetration enhancing activity. The demerits of oral drug delivery include degradation of drugs in the gastrointestinal tract, addition of taste masking, and coating of tablets, which can be overcome by delivering the drug via the transdermal route. Natural oil contains lipids, flavonoids, and terpenes, which play a significant role in anti-inflammatory and penetration enhancing activity.

Development, optimization and characterization of flurbiprofen matrix transdermal drug delivery system using Box–Behnken statistical design

Background

Present investigation for research was to develop matrix-type transdermal drug delivery system of flurbiprofen (FBP) with the various ratio of matrix polymers (hydrophilic and hydrophobic), the concentration of plasticizer and natural penetration enhancer by Box–Behnken statistical design to investigate the combined outcome of selected independent variables for effective management of rheumatoid arthritis.

The influence of a binary mixture of polymers, plasticizer and penetration enhancer on physicochemical considerations including thickness, tensile strength, percent elongation, weight variation, percent moisture content, percent moisture uptake, water vapour transmission rate, folding endurance, drug content, in vitro drug dissolution study and then ex vivo drug permeation study was evaluated.

Results

The study demonstrated that the tensile strength of films improved by matrix polymer ratio and to a slighter gradation in the rise of plasticizer and natural penetration enhancer. Ex vivo drug permeation study was accompanied via excised porcine skin as a permeation barrier in Franz diffusion cell. Ex vivo drug permeation study indicated that matrix polymer ratio (HPMC K15M:ERL100) at 3:1 and natural penetration enhancer (d-limonene) at highest concentration 7.5% w/w containing formulation FBPT7 delivered maximum flux and supplementary improved the permeation of drug. The result of the skin irritation test revealed that the developed formulation is free from any type of skin irritation effects like erythema and oedema.

Conclusion

Based on the findings of this research, it can be established that a well-controlled release and very effective skin penetration of the drug was accomplished by the film FBPT7 in the existence of permeation enhancers for prolonged periods.

A Novel Eutectic-Based Transdermal Delivery System for Risperidone

This paper reports for the first time the possible formation of a novel room temperature therapeutic deep eutectic solvent (THEDES) of risperidone (RIS) with some fatty acids, namely capric acid (C10; CA), lauric acid (C12; LA), and myristic acid (C14; MA). All mixtures of RIS and MA yielded a solid or pasty-like solid and were readily discarded. Some of the prepared THEDESs from RIS and CA or LA have spontaneously transformed into a transparent liquid, without any precipitate at room temperature by simple physical mixing of the components. From the DSC thermograms, phase diagrams of the eutectic systems were constructed and the lowest obtained melting point for a RIS:CA mixture was 17°C at 40:60% w/w ratio. While 22°C was recorded as the lowest melting point for RIS:LA at a ratio of 30:70% w/w, solubility improvement of RIS was up to 70,000-fold compared with water. Freeze-drying microscopy provided valuable information regarding the phase change and transitions the drug undergoes as a function of temperature and it clarifies the interpretation of the DSC results and provides valuable evidence of drug crystals co-melting within the fatty acid base. The presence of natural fatty acid as one component of THEDES and the depression in the melting point significantly (P < 0.05) enhanced RIS skin permeation. Rheological studies showed a viscosity temperature dependency of the DES and well fitted to the Arrhenius equation. Application of the obtained THEDES on the shaved skin of rats revealed the absence of any irritation or edema effects.

Schizophrenia; A Review on Promising Drug Delivery Systems

Background:

Schizophrenia belongs to mental illnesses affecting 1% of the worldwide population. Its therapy is still unmet; thus, researchers aimed to develop new pharmacological molecules which can improve its management.

Methods:

Moreover, the current typical and atypical antipsychotics should be formulated in more efficacious systems that can deliver the drug in the brain with as few side effects as possible. Further, the development of long-acting efficient drug delivery systems could be significant in minimizing frequent dosing which is nonpreferred to schizophrenics.

Results:

Herein, authors focused on current developments of antipsychotic medications used in schizophrenia management. Various studies, which include the use of first and second-generation antipsychotics, were analyzed according to their efficacy. In fact, in this review, oral, injectable, transdermal and intranasal formulations entrapped antipsychotics are presented to be valuable guidance for scientists to formulate more effective drug delivery systems for schizophrenic patients.

Conclusions:

This review aimed to assist researchers working on schizophrenia management by summarizing current medications and newly synthesized drug delivery systems recently found in the literature.

Role of sodium l-cysteine alginate conjugate and isopropyl myristate to enhance the permeation enhancing activity of BCS class III drug from TDDS; optimization by central composite design and in vivo pharmacokinetics study

OBJECTIVE

The objective of the present research was to study the effect and optimization of sodium alginate l-cysteine conjugate and permeation enhancer on permeation of high soluble low permeable ropinirole hydrochloride from the transdermal formulation.

METHODS

Sodium alginate l-cysteine conjugate was prepared and characterized and the same was added into a transdermal formulation along with IPM as a permeation enhancer. Twelve primary formulations were prepared by solvent casting method and evaluated. The results were fed into Design Expert® Software to obtain optimized formulation. The optimized formulation was evaluated for physicochemical, ex vivo permeation, stability, skin irritation, and pharmacokinetic studies.

RESULTS

The results of the characterization of prepared sodium alginate l-cysteine conjugate confirmed the thiolation process. Stability studies suggested that the drug was compatible with all the excipients. SEM images of the transdermal patch revealed that the amorphous drug was uniformly distributed. From the design space, the optimized formulation from the polymer's ratio (SA: SACC; 4:6) and IPM 9.5%w/w of polymers weight showed target steady state flux 9.004 µg/cm²/h with maximum drug permeation. The increased target flux and maximum drug permeation from an optimized patch suggested that there was an effect of SACC on ropinirole hydrochloride permeation in the presence of IPM as a permeation enhancer. Pharmacokinetic studies in rabbits showed that the optimized patch improved bioavailability as compared to marketed oral tablets.

CONCLUSIONS

The study was concluded that there was a positive effect of sodium alginate l-cysteine conjugate and IPM on ropinirole hydrochloride permeation from the transdermal formulation.

Transdermal Delivery of Antipsychotics: Rationale and Current Status

The aim of this article is to provide the rationale for the development of transdermal formulations of antipsychotics by highlighting their main advantages, starting with an overview of the antipsychotic formulations that are currently available on the market. Progress regarding transdermal antipsychotic formulations was investigated by performing a search of papers, patents and clinical trials published in the last 10 years. Available data on antipsychotic transdermal formulations are reported and discussed, focusing on the characteristics of the dosage forms and their ability to promote drug absorption. Despite the current availability of a large number of antipsychotics, only a few of these drugs (e.g. aripiprazole, asenapine, blonanserin, chlorpromazine, haloperidol, olanzapine, prochlorperazine, quetiapine, and risperidone) have been developed as transdermal delivery systems. Several papers and patents show that transdermal formulations, such as creams, films, gels, nanosystems, patches, solutions, and sprays, have been evaluated with the aim of expanding the clinical utility of antipsychotic drugs. In particular, the employment of different strategies, such as the use of nanoparticles/vesicles, or permeation enhancers as well as microneedles with iontophoresis, may improve the absorption of antipsychotic drugs through the skin. However, few clinical trials on transdermal delivery of antipsychotic drugs are available and only delivery systems containing asenapine and blonanserin have shown interesting clinical results in terms of pharmacokinetic data, efficacy, and tolerability. Recently, the transdermal patch formulation of blonanserin was approved in Japan for the treatment of schizophrenia.

Effect of permeation enhancers on in vitro release and transdermal delivery of lamotrigine from Eudragit®RS100 polymer matrix-type drug in adhesive patches

The drug-in-adhesive (DIA)-type matrix patches of lamotrigine are developed using variable permeation enhancers (oleic acid, PG, lemon oil and aloe vera), and drug in vitro release and its permeation are evaluated. Lamotrigine has been long used as an anti-epileptic, mood stabilizer, to treat bipolar disorder in adults and off label as an antidepressant. lamotrigine matrix patches comprising of Eudragit®RS100 (rate-controlling polymer) and DuroTak® 387-2510 (adhesive) were prepared by pouring the solution on backing membrane (3M-9720). The thickness of 120 µm was adjusted through micrometer film applicator. USP Apparatus V was used for the evaluation of release profile, which was fitted into various mathematical models. Quality characteristics of patches were determined through weight variation, moisture content, moisture uptake and drug content evaluation. FTIR studies were performed for drug-excipient compatibility; Franz diffusion cell was employed for studying in vitro permeation parameters such as flux, lag time, and ER. Skin sensitivity study of optimized patch was also performed. The release from patches comprising of PG and oleic acid was maximum, i.e., 96.24 ± 1.15% and 91.12 ± 1.11%, respectively. Formulations (A1-A5) exhibited Makoid-Banakar release profile. Formulation A3 consisting of oleic acid was optimized due to enhanced permeation of drug across skin compared to other enhancers with enhancement ratio of 3.55. Skin sensitivity study revealed patch as safe and non-allergenic. The study demonstrates that oleic acid can be used as a suitable permeation enhancer for transdermal delivery of lamotrigine from matrix-type patches.

Cocoa Pod Husk Pectin Intended as a Pharmaceutical Excipient Has No Adverse Effects on Haematological Parameters in Sprague Dawley Rats

Natural polymer research has recently become the focus of intensive research in the quest for new enabling excipients for novel drugs in pharmaceutical formulation for optimal treatment outcomes. Evaluations of some excipients have shown deleterious haematological effects of varying extents on the safety profile of these excipients. A 90-day subchronic toxicity study was conducted to evaluate the influence of cocoa pod husk (CPH) pectin on indicators for haematotoxicity. Male and female Sprague Dawley rats (SDRs) were fed with CPH pectin in doses up to 71.4 mg/kg. The effects of CPH pectin on the haematological indices, direct and total bilirubin, and the spleen were determined. The results indicated that CPH pectin did not induce any untoward toxic effects on the haematological indices, bilirubin levels, and the spleen. There were, however, elevations in MCV at day 30, which was not sustained after the 90 days. The data obtained from this study did not reveal any remarkable findings of toxicological relevance to the haematopoietic system.

Tuning the rheological properties of an ammonium methacrylate copolymer for the design of adhesives suitable for transdermal patches

Eudragit® RL (EuRL) matrices have been proposed to release a drug to the skin. However, no information is available on both viscoelastic and adhesive properties of such compositions. This work focuses on the evaluation of both rheological and texture properties of EuRL differently plasticized with tributyl citrate (TBC) or triacetin (TRI) in order to design a pressure sensitive adhesive suitable for transdermal patch preparation. The patch adhesive properties (i.e. tack, peel adhesion and shear adhesion) as well as its in vitro biopharmaceutical performances were determined after loading ibuprofen, ketoprofen or flurbiprofen. The addition of 40-60% w/w TBC or 40-50% w/w TRI to EuRL permitted to obtain matrices with the desired adhesive properties. Moreover, the increase of plasticizer content and loading of the drug reduced the relaxation time (τ_R). Consequently, the shear adhesion values decreased and the in vitro drug release constants (k) increased. Indeed, the k values from patches containing TBC were lower than the corresponding with TRI because of the lower fluidity of such matrices. In conclusion, the 60/40 EuRL/TBC binary blend is suitable for the design of transdermal patches since the in vitro permeability of the three selected drugs appeared comparable to those described in literature for marketed products.

Development of a Prolonged-Release Pramipexole Transdermal Patch: In Vitro and In Vivo Evaluation

The current study aimed to develop a prolonged-release pramipexole (PPX) transdermal patch for the treatment of Parkinson's disease. Permeation parameters of PPX were investigated using human cadaver skin. Pramipexole patches were prepared using DURO-TAK^® pressure-sensitive-adhesive (PSA) and evaluated for drug stability, drug loading, in vitro drug release, and in vitro permeation through mouse skin. The results indicated that blends of DURO-TAK^® 87-2852 and DURO-TAK^® 87-2510 were suitable for creating a prolonged-release PPX patch due to their advantages in drug release, drug loading, and stability. The final formulation consisted of 87-2852/87-2510 (70:30), 10% PG, and 15% PPX and showed a cumulative permeation amount of 1497.19 ± 102.90 μg/cm² with a continuous flux over 6.0 μg/(cm²·h) across human cadaver skin for 7 days. In vivo studies in rats indicated that PPX patch produced a significantly longer (p < 0.001) half-life (t _1/2, 75.16 ± 17.37 h) and mean residence time (MRT, 135.89 ± 24.12 h) relative to oral tablets (Sifrol^®) and had a relative bioavailability of 51.64 ± 21.32%. Therefore, this study demonstrated the feasibility of developing a prolonged-release PPX patch, which proposed the potential to serve as an alternate to conventional oral tablets and may therefore improve patient compliance.

Influence of the Component Excipients on the Quality and Functionality of a Transdermal Film Formulation

The influence of formulation variables, i.e., a hydrophilic polymer (Methocel(®) E15) and a film-forming polymer (Eudragit(®) RL 100 and Eudragit(®) RS 100), on the physicochemical and functional properties of a transdermal film formulation was assessed. Several terpenes were initially evaluated for their drug permeation enhancement effects on the transdermal film formulations. D-Limonene was found to be the most efficient permeation enhancer among the tested terpenes. Transdermal film formulations containing granisetron (GRN) as a model drug, D-limonene as a permeation enhancer, and different ratios of a hydrophilic polymer (Methocel(®) E15) and a film-forming polymer (Eudragit(®) RL 100 or Eudragit(®) RS 100) were prepared. The prepared films were evaluated for their physicochemical properties such as weight variation, thickness, tensile strength, folding endurance, elongation (%), flatness, moisture content, moisture uptake, and the drug content uniformity. The films were also evaluated for the in vitro drug release and ex vivo drug permeation. The increasing ratios of Methocel(®):Eudragit(®) polymers in the formulation linearly and significantly increased the moisture content, moisture uptake, water vapor transmission rate (WVTR), and the transdermal flux of GRN from the film formulations. Increasing levels of Methocel(®) in the formulations also increased the rate and extent of the GRN release and the GRN permeation from the prepared films.

Influence of the Component Excipients on the Quality and Functionality of a Transdermal Film Formulation

The influence of formulation variables, i.e., a hydrophilic polymer (Methocel(®) E15) and a film-forming polymer (Eudragit(®) RL 100 and Eudragit(®) RS 100), on the physicochemical and functional properties of a transdermal film formulation was assessed. Several terpenes were initially evaluated for their drug permeation enhancement effects on the transdermal film formulations. D-Limonene was found to be the most efficient permeation enhancer among the tested terpenes. Transdermal film formulations containing granisetron (GRN) as a model drug, D-limonene as a permeation enhancer, and different ratios of a hydrophilic polymer (Methocel(®) E15) and a film-forming polymer (Eudragit(®) RL 100 or Eudragit(®) RS 100) were prepared. The prepared films were evaluated for their physicochemical properties such as weight variation, thickness, tensile strength, folding endurance, elongation (%), flatness, moisture content, moisture uptake, and the drug content uniformity. The films were also evaluated for the in vitro drug release and ex vivo drug permeation. The increasing ratios of Methocel(®):Eudragit(®) polymers in the formulation linearly and significantly increased the moisture content, moisture uptake, water vapor transmission rate (WVTR), and the transdermal flux of GRN from the film formulations. Increasing levels of Methocel(®) in the formulations also increased the rate and extent of the GRN release and the GRN permeation from the prepared films.

Long-acting injectable antipsychotics for first-episode schizophrenia: the pros and cons

Clinical and psychosocial deterioration associated with schizophrenia occurs within the first few years following the onset of the illness. Therefore, to improve the long-term prognosis, it is important to provide schizophrenia patients with intensive treatment following their first episode. Relapse is highly associated with partial medication adherence or nonadherence in patients with first-episode schizophrenia. Recent studies suggest that long-acting injectable (LAI) antipsychotics compared with oral antipsychotics are more effective for medication adherence and relapse prevention. Moreover, some clinical guidelines for the treatment of schizophrenia suggested that LAI antipsychotics should be considered when patients are nonadherent "at any stage." Decreased compliance is a common cause of relapse during the initial stages of the disease. Therefore, LAI antipsychotics should be highly considered when treating patients with first-episode schizophrenia. In the present paper, clinical trial data and current guidelines on the use of LAI antipsychotics for first-episode schizophrenia are discussed as well as the pros and cons of this treatment option.