Intranasal cabergoline: pharmacokinetic and pharmacodynamic studies

Nose to brain delivery of mirtazapine via lipid nanocapsules: Preparation, statistical optimization, radiolabeling, in vivo biodistribution and pharmacokinetic study

Mirtazapine (MZPc) is an antidepressant drug which is approved by the FDA. It has low bioavailability, which is only 50%, in spite of its rapid absorption when orally administered owing to high first-pass metabolism. This study was oriented towards delivering intranasal (IN) mirtazapine by a direct route to the brain by means of preparing lipid nanocapsules (LNCs) as a targeted drug delivery system. MZP-LNCs were constructed by solvent-free phase inversion temperature technique applying D-Optimal mixture design to study the impact of 3 formulation variables on the characterization of the formulated nanocapsules. Independent variables were percentage of Labrafac oil, percentage of Solutol and percentage of water. Dependent variables were particle size, polydispersity index (PDI), Zeta potential and solubilization capacity. Nanocapsules of the optimized formula loaded with MZP were of spherical shape as confirmed by transmission electron microscopy with particle diameter of 20.59 nm, zeta potential of - 5.71, PDI of 0.223 and solubilization capacity of 7.21 mg/g. The in vivo pharmacokinetic behavior of intranasal MZP-LNCs in brain and blood was correlated to MZP solution after intravenous (IV) and intranasal administration in mice. In vivo biodistribution of the drug in mice was assessed by a radiolabeling technique using radioiodinated mirtazapine (131I-MZP). Results showed that intranasal MZP-LNCs were able to deliver higher amount of MZP to the brain with less drug levels in blood when compared to the MZP solution after IV and IN administration. Moreover, the percentage of drug targeting efficiency (%DTE) of the optimized MZP-LNCs was 332.2 which indicated more effective brain targeting by the intranasal route. It also had a direct transport percentage (%DTP) of 90.68 that revealed a paramount contribution of the nose to brain pathway in the drug delivery to the brain.

Preparation and characterization of vaginal suppository of semisynthetic derivatives of ergot alkaloids cabergoline

Background

There is evidence that vaginal cabergoline can help to prevent ovarian hyperstimulation syndrome. Therefore, the vaginal suppository may be a good choice because it can be administered directly into the vagina and has no adverse effects on the stomach. In this regard we developed a cabergoline suppository as an alternative to cabergoline tablets. Design-Expert was used to determine the most suitable concentrations of PEG 6000/400, and Tween 80 to obtain a stable suppository. Specific ratios of PEG6000/400 and Tween 80 were entered as factors, and release, melting time, and hardness were evaluated as responses. In addition, the final formulation was evaluated for weight changes, pH, drug content, degradation time, deformation time, in vitro drug release, DSC analysis, infrared spectroscopy, and stability properties.

Results

The suppositories were all smooth and white. They all had a weight that averaged less than 5 %. The formulations showed a pH between 6 and 6.5. The active ingredient content ranged between 79.666 ± 8.54 % and 99.67 ± 6.55 %. Suppository stiffness was between 2.74 ± 0.04 and 4.20 ± 0.03. The decomposition time of the suppositories varied between 11.25 ± 0.15 to 20.19 ± 0.08 min. The deformation time was between 26.11 ± 0.06 to 38.59 ± 0.47 min. Cabergoline content was released over 45 min from formulations of F10 (∼46 %), F2 (∼64 %), F6 (∼69 %), F4 (∼79 %), F1 (∼88 %), and F7 (∼93 %). However, other formulations released more than 95 % within 45 min.

Conclusions

All variables except melting time significantly affected our responses. In vitro studies have indicated that the optimized cabergoline formula could be an excellent alternative to cabergoline oral formulations.

Design and Application in Delivery System of Intranasal Antidepressants

One of the major reasons why depressed patients fail their treatment course is the existence of the blood-brain barrier (BBB), which prevents drugs from being delivered to the central nervous system (CNS). In recent years, nasal drug delivery has achieved better systemic bioavailability and activity in low doses in antidepressant treatment. In this review, we focused on the latest strategies for delivery carriers (or formation) of intranasal antidepressants. We began this review with an overview of the nasal drug delivery systems, including nasal drug delivery route, absorption mechanism, advantages, and limitations in the nasal drug delivery route. Next, we introduced the development of nasal drug delivery devices, such as powder devices, liquid-based devices, and so on. Finally, intranasal delivery carriers of antidepressants in clinical studies, including nanogels, nanostructured lipid, liposomes nanoparticles, nanoemulsions/microemulsion, were summarized. Moreover, challenges and future perspectives on recent progress of intranasal delivery carriers in antidepressant treatments were discussed.

Preparation and Evaluation of Mebendazole Microemulsion for Intranasal Delivery: an Alternative Approach for Glioblastoma Treatment

Although mebendazole (MBZ) has demonstrated antitumor activity in glioblastoma models, the drug has low aqueous solubility and therefore is poorly absorbed. Considering that other strategies are needed to improve its bioavailability, the current study was aimed to develop and evaluate novel microemulsions of MBZ (MBZ-NaH ME) for intranasal administration. MBZ raw materials were characterized by FTIR, DSC, and XDP. Subsequently, the raw material that contained mainly polymorph C was selected to prepare microemulsions. Two different oleic acid (OA) systems were selected. Formulation A was composed of OA and docosahexaenoic acid (3:1% w/w), while formulation B was composed of OA and Labrafil M2125 (1:1% w/w). Sodium hyaluronate (NaH) at 0.1% was selected as a mucoadhesive agent. MBZ MEs showed a particle size of 209 nm and 145 nm, respectively, and the pH was suitable for nasal formulations (4.5-6.5). Formulation B, which showed the best solubility and rheological behavior, was selected for intranasal evaluation. The nasal toxicity study revealed no damage in the epithelium. Furthermore, formulation B improved significantly the median survival time in the orthotopic C6 rat model compared to the control group. Moreover, NIRF signal intensity revealed a decrease in tumor growth in the treated group with MBZ-MaH ME, which was confirmed by histologic examinations. Results suggest that the intranasal administration of mebendazole-loaded microemulsion might be appropriated for glioblastoma treatment. Graphical abstract.

Brain targeting of chitosan-based diazepam mucoadhesive microemulsions via nasal route: formulation optimization, characterization, pharmacokinetic and pharmacodynamic evaluation

OBJECTIVE

The aim of present investigation was to develop microemulsions (MEs) and mucoadhesive microemulsions (MME) of diazepam for brain uptake through nasal administration for the treatment of seizure emergency.

SIGNIFICANCE

Status epilepticus (SE) is a medical emergency, requires intravenous administration of diazepam which requires hospitalization of patient. Initiation of therapy at home via nasal administration of diazepam could prevent the damage of brain due to delay of therapy initiation.

METHODS

Diazepam MEs were prepared by phase titration method, optimized by using Box-Behnken design. The influence of independent variables oleic acid, surfactant mixture (tween 80:propylene glycol), and water on dependent variables size, flux, and zeta potential was investigated. Optimized MEs, MMEs, and Calmpose (i.v route) were evaluated for pharmacokinetic and pharmacodynamic studies on rats.

RESULTS

MME2 composed of oleic acid (5), surfactant mixture (50), water (45), and chitosan (0.5) showed size of 96.45 nm, PDI 0.21 and zeta potential 13.52 mV. MME2 showed significantly high flux of 846.96 ± 34 µg/cm2/h and AUCbrain 1206.49 ± 145.8. The drug targeting efficiency (314%) and direct nose-to-brain transport (68.1%) of MME2 were significantly high compared to Calmpose (i.v) and ME. The latency periods of minimal clonal seizures and generalized tonic-clonic seizures of MME2 was significantly increased (p < 0.0001) compared to drug solution and Calmpose (i.v).

CONCLUSION

The brain uptake of diazepam from chitosan-based MMEs via nasal route is significantly high compared to i.v route.

Recent advances in carrier mediated nose-to-brain delivery of pharmaceutics

Central nervous system (CNS) disorders (e.g., multiple sclerosis, Alzheimer's disease, etc.) represent a growing public health issue, primarily due to the increased life expectancy and the aging population. The treatment of such disorders is notably elaborate and requires the delivery of therapeutics to the brain in appropriate amounts to elicit a pharmacological response. However, despite the major advances both in neuroscience and drug delivery research, the administration of drugs to the CNS still remains elusive. It is commonly accepted that effectiveness-related issues arise due to the inability of parenterally administered macromolecules to cross the Blood-Brain Barrier (BBB) in order to access the CNS, thus impeding their successful delivery to brain tissues. As a result, the direct Nose-to-Brain delivery has emerged as a powerful strategy to circumvent the BBB and deliver drugs to the brain. The present review article attempts to highlight the different experimental and computational approaches pursued so far to attain and enhance the direct delivery of therapeutic agents to the brain and shed some light on the underlying mechanisms involved in the pathogenesis and treatment of neurological disorders.

Preclinical Study of Ibuprofen Loaded Transnasal Mucoadhesive Microemulsion for Neuroprotective Effect in MPTP Mice Model

Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), showed very promising neuroprotection action, but it suffers from high first pass metabolism and limited ability to cross blood brain barrier. Severe gastric toxicity following oral administration further limits its utility. Hence, the aim of this study was to investigate whether ibuprofen loaded mucoadhesive microemulsion (MMEI) could enhance the brain uptake and could also protect the dopaminergic neurons from MPTP-mediated neural inflammation. In this work, ibuprofen loaded polycarbophil based mucoadhesive microemulsion (MMEI) was developed by using response surface methodology (RSM). Male C57BL/6 mice were intranasally given 2.86 mg ibuprofen/kg/day for 2 consecutive weeks, which were pre-treated with four MPTP injections (20 mg/kg of body weight) at 2 h interval by intraperitoneal route and immunohistochemistry was performed. Globule size of optimal MMEI was 46.73 nm ± 3.11 with PdI value as 0.201 ± 0.19. Histological observation showed that optimal MMEI was biocompatible and suitable for nasal application. The result showed very significant effect (p < 0.05) of all three independent variables on the responses of the developed MMEI. Noticeable improvement in motor performance with spontaneous behavior was observed. TH neurons count in substantia nigra with the density of striatal dopaminergic nerve terminals after MMEI administration. Results of this study confirmed neuroprotection action of ibuprofen through intranasal MMEI against MPTP induced inflammation in dopaminergic nerves in animal model and hence, MMEI can be useful for prevention and management of Parkinson disease (PD).

Nanosystems in nose-to-brain drug delivery: A review of non-clinical brain targeting studies

The treatment of neurodegenerative and psychiatric disorders remains a challenge in medical research. Several strategies have been developed over the years, either to overcome the blood-brain barrier or to achieve a safer or faster brain delivery, one of them being intranasal (IN) administration. The possibility of direct nose-to-brain transport offers enhanced targeting and reduced systemic side effects. Nevertheless, labile, low soluble, low permeant and/or less potent drugs might need a formulation other than the common solutions or suspensions. For that, the formulation of nanosystems is considered to be a promising approach, since it can protect drugs from chemical and/or metabolic degradation, enhance their solubility, or offer transport through biological membranes. However, the understanding of the factors promoting efficient brain targeting when using nanosystems through the nasal route is currently patchy and incomplete. The main purpose of the present review was to evaluate the association between brain delivery efficacy (in terms of brain targeting, brain bioavailability and time to reach the brain) and nanosystem type. For that, we performed a systematic bibliographic search and analysis. Furthermore, study designs, nanosystem properties, and reporting quality were also analyzed and discussed. It was found a high heterogeneity in how pre-clinical brain targeting studies have been conducted, analyzed and reported in scientific literature, which surely originates a significant degree of bias and data dispersion. This review attempts to provide some systematization recommendations, which may be useful for researchers entering the field, and assist in increasing the uniformity of future reports. The analysis of literature data confirmed that there is evidence of the advantage of the IN route (when compared to the intravenous route) and in using carrier nanosystems (when compared to IN solutions) for brain delivery of a large set of drugs. Among the most represented nanosystem classes, microemulsions had some of the lowest pharmacokinetic ratios values, while polymeric micelles had some of the best. Nevertheless, brain targeting efficacy comparisons between nanosystem groups had little statistical significance, and the superiority of the polymeric micelles group disappeared when nanosystems were compared to the respective IN drug solutions. In fact, some drugs reached the brain so efficiently, even as drug solutions, that further benefit from formulating them into nanosystems became less evident.

Design and evaluation of mucoadhesive microemulsion for neuroprotective effect of ibuprofen following intranasal route in the MPTP mice model

BACKGROUND

The present study is to investigate the neuroprotective effect of ibuprofen by intranasal administration of mucoadhesive microemulsion (MMEI) against inflammation-mediated by dopaminergic neurodegeneration in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson's disease (PD).

METHODS

Ibuprofen-loaded polycarbophil-based MMEI was developed by using response surface methodology (RSM). Ibuprofen with dose of 2.86 mg/kg/day was administered intranasally to male C57BL/6 mice for two consecutive weeks which were pre-treated with four intraperitoneal injections of MPTP (20 mg/kg of body weight) at 2 h intervals. Immunohistochemistry was performed.

RESULTS

Optimal MMEI was stable and non-ciliotoxic with 66.29 ± 4.15 nm as average globule size and -20.9 ± 3.98 mV as zeta potential. PDI value and transmission electron microscopy result showed the narrow globule size distribution of MMEI. The result showed that all three independent variables had a significant effect (p < 0.05) on the responses. Rota-rod and open-field test findings revealed the significant improvement in motor performance and gross behavioral activity of the mice. The results from in vivo study and immunohistochemistry showed that nasal administration of Ibuprofen significantly reduced the MPTP-mediated dopamine depletion. Furthermore TH neurons count in the substantia nigra and the density of striatal dopaminergic nerve terminals were found to be significant higher for ibuprofen treated groups.

CONCLUSION

Findings of the investigation revealed that Ibuprofen through developed MMEI was shown to protect neurons against MPTP-induced injury in the Substantia nigra pars compacta (SNpc) and striatum and hence, could be a promising approach for brain targeting of Ibuprofen through intranasal route to treat PD.

Nose-To-Brain Delivery of PLGA-Diazepam Nanoparticles

The objective of the present investigation was to optimize diazepam (Dzp)-loaded poly(lactic-co-glycolic acid) nanoparticles (NP) to achieve delivery in the brain through intranasal administration. Dzp nanoparticles (DNP) were formulated by nanoprecipitation and optimized using Box-Behnken design. The influence of various independent process variables (polymer, surfactant, aqueous to organic (w/o) phase ratio, and drug) on resulting properties of DNP (z-average and drug entrapment) was investigated. Developed DNP showed z-average 148-337 d.nm, polydispersity index 0.04-0.45, drug entrapment 69-92%, and zeta potential in the range of -15 to -29.24 mV. Optimized DNP were further analyzed by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), ex-vivo drug release, and in-vitro cytotoxicity. Ex-vivo drug release study via sheep nasal mucosa from DNP showed a controlled release of 64.4% for 24 h. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay performed on Vero cell line showed less toxicity for DNP as compared to Dzp suspension (DS). Gamma scintigraphy and biodistribution study of DNP and DS was performed on Sprague-Dawley rats using technetium-99m-labeled ((99m)Tc) Dzp formulations to investigate the nose-to-brain drug delivery pathway. Brain/blood uptake ratios, drug targeting efficiency, and direct nose-to-brain transport were found to be 1.23-1.45, 258, and 61% for (99m)Tc-DNP (i.n) compared to (99m)Tc-DS (i.n) (0.38-1.06, 125, and 1%). Scintigraphy images showed uptake of Dzp from nose-to-brain, and this observation was in agreement with the biodistribution results. These results suggest that the developed poly(D,L-lactide-co-glycolide) (PLGA) NP could serve as a potential carrier of Dzp for nose-to-brain delivery in outpatient management of status epilepticus.

Mucoadhesive microemulsion of ibuprofen: design and evaluation for brain targeting efficiency through intranasal route

This study aimed at designing mucoadhesive microemulsion gel to enhance the brain uptake of Ibuprofen through intranasal route. Ibuprofen loaded mucoadhesive microemulsion (MMEI) was developed by incorporating polycarbophil as mucoadhesive polymer into Capmul MCM based optimal microemulsion (MEI) and was subjected to characterization, stability, mucoadhesion and naso-ciliotoxicity study. Brain uptake of ibuprofen via nasal route was studied by performing biodistribution study in Swiss albino rats. MEI was found to be transparent, stable and non ciliotoxic with 66.29 ± 4.15 nm, -20.9 ± 3.98 mV and 98.66 ± 1.01% as average globule size, zeta potential and drug content respectively. Transmission Electron Microscopy (TEM) study revealed the narrow globule size distribution of MEI. Following single intranasal administration of MMEI and MEI at a dose of 2.86 mg/kg, uptake of ibuprofen in the olfactory bulb was around 3.0 and 1.7 folds compared with intravenous injection of ibuprofen solution (IDS). The ratios of AUC in brain tissues to that in plasma obtained after nasal administration of MMEI were significantly higher than those after intravenous administration of IDS. Findings of the present investigation revealed that the developed mucoadhesive microemulsion gel could be a promising approach for brain targeting of ibuprofen through intranasal route.

Formulation and optimization of polymeric nanoparticles for intranasal delivery of lorazepam using Box-Behnken design: in vitro and in vivo evaluation

The aim of the present study was to optimize lorazepam loaded PLGA nanoparticles (Lzp-PLGA-NPs) by investigating the effect of process variables on the response using Box-Behnken design. Effect of four independent factors, that is, polymer, surfactant, drug, and aqueous/organic ratio, was studied on two dependent responses, that is, z-average and % drug entrapment. Lzp-PLGA-NPs were successfully developed by nanoprecipitation method using PLGA as polymer, poloxamer as surfactant and acetone as organic phase. NPs were characterized for particle size, zeta potential, % drug entrapment, drug release behavior, TEM, and cell viability. Lzp-PLGA-NPs were characterized for drug polymer interaction using FTIR. The developed NPs showed nearly spherical shape with z-average 167–318 d·nm, PDI below 0.441, and −18.4 mV zeta potential with maximum % drug entrapment of 90.1%. In vitro drug release behavior followed Korsmeyer-Peppas model and showed initial burst release of 21.7 ± 1.3% with prolonged drug release of 69.5 ± 0.8% from optimized NPs up to 24 h. In vitro drug release data was found in agreement with ex vivo permeation data through sheep nasal mucosa. In vitro cell viability study on Vero cell line confirmed the safety of optimized NPs. Optimized Lzp-PLGA-NPs were radiolabelled with Technitium-99m for scintigraphy imaging and biodistribution studies in Sprague-Dawley rats to establish nose-to-brain pathway.

Evaluation of brain targeting efficiency of intranasal microemulsion containing olanzapine: pharmacodynamic and pharmacokinetic consideration

The objective of this study was to develop and evaluate olanzapine (OZP) -loaded microemulsions (OZPME) for intranasal delivery in the treatment of schizophrenia. The OZPME was formulated by the spontaneous microemulsification method and characterized for physicochemical parameters. Pharmacodynamic assessments (apomorphine - induced compulsive behavior and spontaneous locomotor activity) were performed using mice. All formulations were radiolabeled with technetium-99 ((99m)Tc), and biodistribution of drug in the brain was investigated using Swiss albino rats. Brain scintigraphy imaging in rabbits was performed to determine the uptake of the OZP into the brain. OZPME were found clear and stable with average globule size of 23.87 ± 1.07 nm. In pharmacodynamic assessments, significant (p < 0.05) difference in parameters estimated were found between the treated and control groups. (99m)Tc-labeled OZP solution (OZPS)/OZPME/OZP mucoadhesive microemulsion (OZPMME) were found to be stable and suitable for in vivo studies. Brain/blood ratio at all sampling points up to 8 h following intranasal administration of OZPMME compared to intravenous OZPME was found to be five to six times higher signifying larger extent of distribution of the OZP in brain. Drug targeting efficiency and direct drug transport were found to be highest for intranasal OZPMME, compared to intravenous OZPME. Furthermore, rabbit brain scintigraphy also demonstrated higher intranasal uptake of the OZP into the brain. This investigation demonstrates a prompt and larger extent of transport of OZP into the brain through intranasal OZPMME, which may prove beneficial for treatment of schizophrenia.

A systematic review of inhaled intranasal therapy for central nervous system neoplasms: an emerging therapeutic option

The intranasal route for drug delivery is rapidly evolving as a viable means for treating selected central nervous system (CNS) conditions. We aimed to identify studies pertaining to the application of intranasal drug administration for the treatment of primary CNS tumors. A systematic literature review was conducted to identify all studies published in the English language pertaining to intranasal therapy for CNS neoplasms, and/or general mechanisms and pharmacokinetics regarding targeted intranasal CNS drug delivery. A total of 194 abstracts were identified and screened. Thirty-seven studies met inclusion criteria. Of these, 21 focused on intranasal treatment of specific primary CNS tumors, including gliomas (11), meningiomas (1), and pituitary adenomas (4). An additional 16 studies focused on general mechanisms of intranasal therapy and drug delivery to the CNS using copolymer micelles, viral vectors, and nanoparticles. Inhaled compounds/substances investigated included perillyl alcohol, vesicular stomatitis virus, parvovirus, telomerase inhibitors, neural stem and progenitor cells, antimetabolites, somatostatin analogues, and dopamine agonists. Radiolabeling, CSF concentration measurement, imaging studies, and histological examination were utilized to clarify the mechanism and distribution by which drugs were delivered to the CNS. Successful drug delivery and tumor/symptom response was reported in all 21 tumor-specific studies. The intranasal route holds tremendous potential as a viable option for drug delivery for CNS neoplasms. A variety of antitumoral agents may be delivered via this route, thereby potentially offering a more direct delivery approach and ameliorating the adverse effects associated with systemic drug delivery.

Development of udenafil-loaded microemulsions for intranasal delivery: in vitro and in vivo evaluations

To achieve rapid onset of action and improved bioavailability of udenafil, a microemulsion system was developed for its intranasal delivery. Phase behavior, particle size, transmission electron microscope (TEM) images, and the drug solubilization capacity of the microemulsion were investigated. A single isotropic region was found in pseudo-ternary phase diagrams developed at various ratios with CapMul MCM L8 as an oil, Labrasol as a surfactant, and Transcutol or its mixture with ethanol (1:0.25, v/v) as a cosurfactant. Optimized microemulsion formulations with a mean diameter of 120-154 nm achieved enhanced solubility of udenafil (>10mg/ml) compared with its aqueous solubility (0.02 mg/ml). An in vitro permeation study was performed in human nasal epithelial (HNE) cell monolayers cultured by the air-liquid interface (ALI) method, and the permeated amounts of udenafil increased up to 3.41-fold versus that of pure udenafil. According to the results of an in vivo pharmacokinetic study in rats, intranasal administration of udenafil-loaded microemulsion had a shorter T(max) value (1 min) compared with oral administration and improved bioavailability (85.71%) compared with oral and intranasal (solution) administration. The microemulsion system developed for intranasal administration may be a promising delivery system of udenafil, with a rapid onset of action and improved bioavailability.

Bilateral angle-closure glaucoma in a young female receiving cabergoline: a case report

Purpose

To report a case of bilateral acute angle-closure glaucoma after oral administration of cabergoline for the treatment of galactorrhea.

Methods

A diagnosis of secondary drug-induced angle-closure glaucoma was made in a patient with elevated intraocular pressure (IOP) and myopic refractive shift, which was confirmed by ultrasound biomicroscopy (UBM) of the ciliary body and anterior segment, sonography, and optical coherence tomography. The treatment included the discontinuation of the culprit drug and the administration of topical anti-glaucoma drops. The treatment course was followed with serial measurements of the IOP and refraction, and with performing UBM.

Results

Five hours after he received a single 0.5-mg oral cabergoline tablet, the patient suffered from acute secondary angle-closure glaucoma and myopic refractive error. UBM demonstrated both effusion of the ciliary body and an anterior rotation of the iris-ciliary body. IOP was reduced 8 h after cessation of the causative agent and administration of anti-glaucoma drops. Refractive errors returned to normal levels after 8 days.

Conclusion

Secondary acute angle-closure glaucoma has been reported to occur after the administration of some drugs. In this report, an attempt has been made to describe this adverse reaction after oral cabergoline intake.