The Effect of the Particle Size Reduction on the Biorelevant Solubility and Dissolution of Poorly Soluble Drugs with Different Acid-Base Character

Particle size reduction is a commonly used process to improve the solubility and the dissolution of drug formulations. The solubility of a drug in the gastrointestinal tract is a crucial parameter, because it can greatly influence the bioavailability. This work provides a comprehensive investigation of the effect of the particle size, pH, biorelevant media and polymers (PVA and PVPK-25) on the solubility and dissolution of drug formulations using three model compounds with different acid-base characteristics (papaverine hydrochloride, furosemide and niflumic acid). It was demonstrated that micronization does not change the equilibrium solubility of a drug, but it results in a faster dissolution. In contrast, nanonization can improve the equilibrium solubility of a drug, but the selection of the appropriate excipient used for nanonization is essential, because out of the two used polymers, only the PVPK-25 had an increasing effect on the solubility. This phenomenon can be explained by the molecular structure of the excipients. Based on laser diffraction measurements, PVPK-25 could also inhibit the aggregation of the particles more effectively than PVA, but none of the polymers could hold the nanonized samples in the submicron range until the end of the measurements.

Smartcrystals for Efficient Dissolution of Poorly Water-Soluble Meloxicam

Nanocrystal is widely applied to improve the dissolution of poorly water-soluble drugs. We aimed to prepare meloxicam (MLX) nanocrystals using the bead mill method, followed by high-pressure homogenization (HPH). Simple drying at room temperature (RD), vacuum-drying (VD), and freeze-drying (FD) using mannitol or trehalose as a cryoprotectant were applied to obtain dry nanocrystals. The nanocrystals were fully characterized. The MLX nanosuspension containing 5% w/v MLX and 1% w/v of Pluronic F68 showing a mean particle size (MPS) of 242 nm and a polydispersity index (PDI) of 0.36 was prepared after 40 min of premilling and 30 min of HPH. The dried nanocrystals were spherical within the nano range. DSC and XRPD confirmed the absence of MLX amorphization. The smartcrystals showed enhanced MLX release. Approximately 100% release was achieved with phosphate buffer (PB), pH 5.6, and 80% was released with PB, pH 7.4, from the freeze-dried samples. The results revealed the effects of the drying method and cryoprotectant type on the properties of dry nanocrystals. The freeze-dried samples showed the smallest particle size, in particular trehalose-based samples. On the other hand, mannitol-based dried samples showed the highest crystallinity index among all nanocrystals (77.8%), whereas trehalose showed the lowest (59.2%). These factors explained the dissolution differences among the samples.

Physico-Chemical, In Vitro and Ex Vivo Characterization of Meloxicam Potassium-Cyclodextrin Nanospheres

Nasal drug delivery has many beneficial properties, such as avoiding the first pass metabolism and rapid onset of action. However, the limited residence time on the mucosa and limited absorption of certain molecules make the use of various excipients necessary to achieve high bioavailability. The application of mucoadhesive polymers can increase the contact time with the nasal mucosa, and permeation enhancers can enhance the absorption of the drug. We aimed to produce nanoparticles containing meloxicam potassium (MEL-P) by spray drying intended for nasal application. Various cyclodextrins (hydroxypropyl-β-cyclodextrin, α-cyclodextrin) and biocompatible polymers (hyaluronic acid, poly(vinylalcohol)) were used as excipients to increase the permeation of the drug and to prepare mucoadhesive products. Physico-chemical, in vitro and ex vivo biopharmaceutical characterization of the formulations were performed. As a result of spray drying, mucoadhesive nanospheres (average particle size <1 µm) were prepared which contained amorphous MEL-P. Cyclodextrin-MEL-P complexes were formed and the applied excipients increased the in vitro and ex vivo permeability of MEL-P. The highest amount of MEL-P permeated from the α-cyclodextrin-based poly(vinylalcohol)-containing samples in vitro (209 μg/cm²) and ex vivo (1.47 μg/mm²) as well. After further optimization, the resulting formulations may be promising for eliciting a rapid analgesic effect through the nasal route.

Comparison of Modern In Vitro Permeability Methods with the Aim of Investigation Nasal Dosage Forms

Nowadays, the intranasal route has become a reliable alternative route for drug administration to the systemic circulation or central nervous system. However, there are no official in vitro diffusion and dissolution tests especially for the investigation of nasal formulations. Our main goal was to study and compare a well-known and a lesser-known in vitro permeability investigation method, in order to ascertain which was suitable for the determination of drug permeability through the nasal mucosa from different formulations. The vertical diffusion cell (Franz cell) was compared with the horizontal diffusion model (Side-Bi-Side). Raw and nanonized meloxicam containing nasal dosage forms (spray, gel and powder) were tested and compared. It was found that the Side-Bi-Side cell was suitable for the investigation of spray and powder forms. In contrast, the gel was not measurable on the Side-Bi-Side cell; due to its high viscosity, a uniform distribution of the active substance could not be ensured in the donor phase. The Franz cell, designed for the analysis of semi-solid formulations, was desirable for the investigation of nasal gels. It can be concluded that the application of a horizontal cell is recommended for liquid and solid nasal preparations, while the vertical one should be used for semi-solid formulations.

Formulation and In Vitro and In Silico Characterization of "Nano-in-Micro" Dry Powder Inhalers Containing Meloxicam

Pulmonary delivery has high bioavailability, a large surface area for absorption, and limited drug degradation. Particle engineering is important to develop inhalable formulations to improve the therapeutic effect. In our work, the poorly water-soluble meloxicam (MX) was used as an active ingredient, which could be useful for the treatment of non-small cell lung cancer, cystic fibrosis, and chronic obstructive pulmonary disease. We aimed to produce inhalable “nano-in-micro” dry powder inhalers (DPIs) containing MX and additives (poly-vinyl-alcohol, leucine). We targeted the respiratory zone with the microcomposites and reached a higher drug concentration with the nanonized active ingredient. We did the following investigations: particle size analysis, morphology, density, interparticular interactions, crystallinity, in vitro dissolution, in vitro permeability, in vitro aerodynamics (Andersen cascade impactor), and in silico aerodynamics (stochastic lung model). We worked out a preparation method by combining wet milling and spray-drying. We produced spherical, 3–4 µm sized particles built up by MX nanoparticles. The increased surface area and amorphization improved the dissolution and diffusion of the MX. The formulations showed appropriate aerodynamical properties: 1.5–2.4 µm MMAD and 72–76% fine particle fraction (FPF) values. The in silico measurements proved the deposition in the deeper airways. The samples were suitable for the treatment of local lung diseases.

Patterns of clinicopathological features and outcome in epithelial ovarian cancer patients: 35 years of prospectively collected data

OBJECTIVE

Investigate the clinical landscape of ovarian carcinoma (OC) over time.

DESIGN

Register-based prospectively collected data.

SETTING

South East Scotland.

SAMPLE

A total of 2805 OC patients diagnosed in 1981-2015.

METHODS

Survival times were visualised using the Kaplan-Meier method; median survival, 5-year survival probabilities and associated restricted mean survival time analyses were used to quantify survival differences.

MAIN OUTCOME MEASURES

Disease-specific survival.

RESULTS

A significant increase in disease-specific survival (DSS) from 1981-1985 to 2011-2015 was observed (median 1.73 versus 4.23 years, P < 0.0001). Corresponding increase in progression-free survival (PFS) was not statistically significant (median 1.22 versus 1.58 years, P = 0.2568). An increase in the proportion of cases with low residual disease volume (RD) (<2 cm RD) following debulking was observed (54.0% versus 87.7%, P < 0.0001). The proportion of high grade serous (HGS) cases increased (P < 0.0001), whereas endometrioid and mucinous cases decreased (P = 0.0005 and P = 0.0002). Increases in stage IV HGS OC incidence (P = 0.0009) and stage IV HGS OC DSS (P = 0.0122) were observed. Increasing median age at diagnosis correlated with increasing Eastern Cooperative Oncology Group Performance Status (ECOG PS) over time (r = 0.86).

CONCLUSIONS

OC DSS has improved over the last 35 years. PFS has not significantly increased, highlighting that improvement in outcome has been limited to extending post-relapse survival. Distribution of stage at diagnosis, histological subtype and RD following debulking has changed over time, reflecting evolution in tumour classification, staging and optimal debulking definitions (from low RD to minimal or zero RD). Histology, stage, RD and ECOG PS remain reliable outcome predictors. Increasing median age at diagnosis and ECOG PS indicates demographic shifts in the clinical population.

TWEETABLE ABSTRACT

Significant improvement in ovarian carcinoma survival has been seen over time. Most of this improvement is due to an extension of survival following disease relapse.

Interaction Studies Between Levodopa and Different Excipients to Develop Coground Binary Mixtures for Intranasal Application

Levodopa (LEVO) as the gold standard in the treatment of Parkinson's disease is usually administrated per os but its bioavailability is low. The intranasal administration is a potential alternative route to increase bioavailability of the drug and treat the off period. Our aim was to develop LEVO-containing binary nasal powders with different excipients by dry cogrinding process. The interactions between the components were examined. The optimized cogrinding process parameters (LEVO:excipient ratio and grinding time) resulted in the desired particle size range (5-40 μm). The α-cyclodextrin and poly(vinylpyrrolidone) (PVP) had an intensive crystallinity degree reducing effect on LEVO measured by XRPD, and they functioned as cogrinding agents. Hydroxypropyl methylcellulose, poly (vinyl alcohol) (PVA), and D-mannitol associate around the LEVO crystals preventing its crystalline structure. Hydrogen bonding was detected only for LEVO-PVP and LEVO-D-mannitol used Fourier-transformed infrared spectroscopy. Chemical degradation of LEVO in the products was not detected even after the accelerated stability test. The dissolution profile of the products can be characterized by the first-order kinetic model with different dissolution rate. The dissolution rate of LEVO was increased with α-cyclodextrin and PVP, and the drug release decreased in the case of hydroxypropyl methylcellulose, PVA, and D-mannitol compared to the LEVO powder.

Investigation of Absorption Routes of Meloxicam and Its Salt Form from Intranasal Delivery Systems

The aim of this article was to study the trans-epithelial absorption to reach the blood and to target the brain by axonal transport using nasal formulations with nanonized meloxicam (nano MEL spray) and its salt form known as meloxicam potassium monohydrate (MELP spray). The physicochemical properties and the mucoadhesivity of nasal formulations were controlled. In vitro and in vivo studies were carried out. These forms were first investigated in "nose-to-brain" relation. It was found that the in vitro study and in vivo study did not show any significant correlation. In vitro experiments demonstrated faster dissolution rate and higher diffusion of MELP from the spray compared with the nano MEL spray. The administration of the nano MEL spray resulted in faster absorption and constant plasma concentration of the drug after five minutes of administration as compared to MELP. The axonal transport of the drug was justified. MEL appeared in the brain tissues after the first five minutes of administration in the case of both spray forms, but its amount was too small in comparison with the total plasma concentration. The application of the nano MEL spray resulted in the same AUC in the brain as the intravenous injection. The "nose-to-blood" results predicted the nasal applicability of MEL and MELP in pain management. The "nose-to-brain" pathway requires further study.

Effect of solubility enhancement on nasal absorption of meloxicam

Besides the opioids the standard management of the World Health Organization suggests NSAIDs (non-steroidal anti-inflammatory drugs) alone or in combination to enhance analgesia in malignant and non-malignant pain therapy. The applicability of NSAIDs in a nasal formulation is a new approach in pharmaceutical technology. In order to enhance the nasal absorption of meloxicam (MX) as an NSAID, its salt form, meloxicam potassium monohydrate (MXP), registered by Egis Plc., was investigated in comparison with MX. The physico-chemical properties of the drugs (structural analysis, solubility and dissolution rate) and the mucoadhesivity of nasal formulations were controlled. In vitro and in vivo studies were carried out to determine the nasal applicability of MXP as a drug candidate in pain therapy. It can be concluded that MX and MXP demonstrated the same equilibrium solubility at the pH5.60 of the nasal mucosa (0.017mg/ml); nonetheless, MXP indicated faster dissolution and a higher permeability through the synthetic membrane. The animal studies justified the short T_max value (15min) and the high AUC of MXP, which is important in acute pain therapy. It can be assumed that the low mucoadhesivity of MXP spray did not increase the residence time in the nasal cavity, and the elimination from the nasal mucosa was therefore faster than in the case of MX. Further experiments are necessary to prove the therapeutic relevance of this MXP-containing innovative intranasal formulation.

Cytotoxicity of Different Excipients on RPMI 2650 Human Nasal Epithelial Cells

The nasal route receives a great deal of attention as a non-invasive method for the systemic administration of drugs. For nasal delivery, specific formulations containing excipients are used. Because of the sensitive respiratory mucosa, not only the active ingredients, but also additives need to be tested in appropriate models for toxicity. The aim of the study was to measure the cytotoxicity of six pharmaceutical excipients, which could help to reach larger residence time, better permeability, and increased solubility dissolution rate. The following excipients were investigated on RPMI 2650 human nasal septum tumor epithelial cells: β-d-mannitol, sodium hyaluronate, α and β-cyclodextrin, polyvinyl alcohol and methylcellulose. 3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye conversion assay and real-time impedance analysis were used to investigate cytotoxicity. No excipient showed toxicity at 0.3% (w/v) concentration or below while 1% concentration a significantly reduced metabolic activity was measured by MTT assay for methylcellulose and cyclodextrins. Using impedance measurements, only β-cyclodextrin (1%) was toxic to cells. Mannitol at 1% concentration had a barrier opening effect on epithelial cells, but caused no cellular damage. Based on the results, all additives at 0.3%, sodium hyaluronate and polyvinyl alcohol at 1% concentrations can be safely used for nasal formulations.

Study of sodium hyaluronate-based intranasal formulations containing micro- or nanosized meloxicam particles

This article reports on the micro- and nanonization of meloxicam (MEL) with the aim of developing pre-dispersions as intermediates for the design of intranasal formulations. As a new approach, combined wet milling technology was developed in order to reduce the particle size of the MEL. Different milling times resulted in micro- or nanosized MEL in the pre-dispersions with polyvinyl alcohol as stabilizer agent, which were directly used for preparing intranasal liquid formulations with the addition of sodium hyaluronate as mucoadhesive agent. Reduction of the MEL particle size into the nano range led to increased saturation solubility and dissolution velocities, and increased adhesiveness to surfaces as compared with microsized MEL particles. A linear correlation was demonstrated between the specific surface area of MEL and the AUC. The in vitro and in vivo studies indicated that the longer residence time and the uniform distribution of nano MEL spray throughout an artificial membrane and the nasal mucosa resulted in better diffusion and a higher AUC. Nanosized MEL may be suggested for the development of an innovative dosage form with a different dose of the drug, as a possible administration route for pain management.

[Particle size reduction using acoustic cavitation]

Different pharmaceutical technological processes have been used for modification of the physico-chemical and biopharmaceutical properties of drugs. Changes of crystal size, distribution and morphology can open up new, alternative administration routes, e.g. intranasally and the pulmonary route, where the particle size is a determining factor. A wet grinding method based on acoustic cavitation (the collapse of bubbles or voids formed by sound waves) is a novel possibility for modification of the properties of particles. During our work this wet grinding technique was studied. The effect of this method was investigated on particle size reduction. The samples were treated with extreme sonication parameters. The effect of the concentration of the polymer was examined on the particle size reduction. Meloxicam was chosen as a model crystalline drug because of its poor aqueous solubility. The structural characterization and the morphological analysis of the dried products were carried out by DSC, XRPD and SEM. It was found that the acoustic cavitation resulted in crystalline micronized product.

In vitro and in vivo characterization of meloxicam nanoparticles designed for nasal administration

The nasal pathway represents a non-invasive route for delivery of drugs to the systemic circulation. Nanonization of poorly soluble drugs offers a possibility to increase dissolution properties, epithelial permeability or even bioavailability. The aim of the present study was to use in vitro methods to screen formulations which were intended for nasal application, and to perform animal experiments for recognizing the differences in plasmakinetics of intranasal- and oral-administered meloxicam nanoparticles. Due to nanonization the solubility of meloxicam elevated up to 1.2mg/mL, additionally the extent of dissolution also increased, complete dissolution was observed in 15 min. Favorable in vitro diffusion profile of meloxicam nanoparticles was observed and their epithelial permeability through human RPMI2650 cells was elevated. The pharmacokinetic parameters were significantly increased when meloxicam was administered as nanoparticles to rats either nasally (increase of Cmax 2.7-fold, AUC 1.5-fold) or orally (increase of C(max) 2.4-fold, AUC 2-fold) as compared to physical mixture of the drug and the excipients.

[Optimization of technological parameters using acustic cavitation to reach particle size reduction of pharmacon]

The main aspect in the field of pharmaceutical technology is the preformulation of the poorly water soluble drugs. The habit of particles can effect the physico-chemical properties which are important factors by drug administration. In the past years the role of the procedures by acustic cavitation increased in the field of particle engineering. Application of high power ultrasound by integration and dezintegration can lead to particle size decreasing. Meloxicam as a nonsteroid anti-inflammatory model drug was used to study the effect of power ultrasound on the particle size decreasing. During our work technological parameters, as amplitude, temperature, time, excipients and concentration were optimized based on particle size distribution. Physico-chemical stability tests were also performed (XRPD, DSC, SEM, particle size). With optimized parameters (70% amplitude, 20 min, 47 0C) using excipients, crystalline micronized product was produced.