Formulation and characterization of a 0.1% rapamycin cream for the treatment of Tuberous Sclerosis Complex-related angiofibromas.

Medicines for the treatment of rare diseases frequently do not attract the interest of the pharmaceutical industry, and hospital pharmacists are thus often requested by physicians to prepare personalized medicines. Tuberous Sclerosis Complex (TSC) is a rare disease that causes disfiguring lesions named facial angiofibromas. Various topical formulations of rapamycin (=sirolimus) have been proved effective in treating these changes in small case series. The present study provides for the first time characterization of a 0.1% rapamycin cream formulation presenting good rapamycin solubilisation. The first step of the formulation is solubilisation of rapamycin in Transcutol(®), and the second step is the incorporation of the mixture in an oil-in-water cream. A HPLC stability-indicating method was developed. Rapamycin concentration in the cream was tested by HPLC and confirmed that it remained above 95% of the initial concentration for at least 85days, without characteristic degradation peaks. The preparation met European Pharmacopoeia microbial specifications throughout storage in aluminum tubes, including when patient use was simulated. Odour, appearance and colour of the preparation were assessed and no change was evidenced during storage. The rheological properties of the cream also remained stable throughout storage. To conclude, we report preparation of a novel cream formulation presenting satisfactory rapamycin solubilisation for the treatment of TSC cutaneous manifestations, with stability data. The cream is currently being used by our patients. Efficacy and tolerance will be reported later.

Stability of micafungin sodium solutions at different concentrations in glass bottles and syringes.

Micafungin is a costly treatment and packaging of 50 mg or 100 mg bottles only are available, while doses lower than 5 mg and 20 mg are often necessary in neonates and paediatrics patients, respectively. The stability of micafungin sodium in polypropylene syringes and glass bottles was studied at different concentrations. Solutions of micafungin diluted with NaCl 0.9% were prepared in glass bottles (20 and 10 mg/mL) or syringes (1 and 0.5 mg/mL) and stored at 25 °C, 60% humidity (RH), in the dark (ICH conditions). Solutions were also exposed to heat (70 °C) or alkaline solution (NaOH) in order to force degradation. Samples were analysed at days 1, 5, 8 (for bottles) and also 15 (for syringes) after the preparation and assayed in triplicate. Stability was studied using a stability-indicating high-performance liquid chromatographic method. Syringes stored at 25 °C retained over 90% of their initial concentration over the study period. Temperature and alkaline conditions had significant effect on the stability of micafungin, leading to apparition of degradation products. Moreover, sub visible particles were in the specification of the European Pharmacopeia along 15 days. To conclude, micafungin diluted in NaCl 0.9% and stored in polypropylene syringes was chemically stable for at least 15 days at 25 °C in the dark.

Design and stability study of a paediatric oral solution of methotrexate 2 mg/ml.

Oral paediatric forms development by pharmaceutical industry is still insufficient. The present study was performed to propose an adapted and pleasant formulation of liquid oral formulation of MTX. The solution is composed of injectable methotrexate, water, Ora Sweet(®) and sodium bicarbonate. After 120 days storage, pH remained stable at about 8 in all formulations, insuring no risk of MTX precipitation. MTX content in solution formulation, determined by high performance liquid chromatography measurements, remained in the specifications of >90% of the initial concentration when stored at 4 and 25°C. Forced degradation of MTX by heat and acidic conditions allowed formation and detection of degradation products by the analytical method. Microbial study of the preparation shows that the solution remains in the specifications during all the storage, or after one sample each week during one month, eventually indicating the microbial properties are not affected by patient use. To conclude, we here propose a new MTX liquid formulation stable for at least 120 days.

Aqueous core nanocapsules: a new solution for encapsulating doxorubicin hydrochloride.

In this study, we propose a new solution for the nanoencapsulation of hydrophilic anticancer drug, doxorubicin hydrochloride (DOX). The drug molecules are solubilized in the core of aqueous nanoreservoirs, so-called aqueous core nanocapsules (ACN) recently developed by our team, and dispersed in aqueous bulk media. Since it is well acknowledged that the nanoencapsulation of DOX has many advantages, like reducing the sides effects (e.g. cardiac toxicity), we propose through the present study a novel formulation solution for this purpose. After focusing on the formulation process for optimizing the drug encapsulation yield, the DOX-release profiles were followed up and analyzed. Different physicochemical and in vitro characterization were performed, and complement activation experiments. ACN were shown efficient to encapsulate DOX reaching yields as high as 80%, followed by a sustained release governed by a diffusion-controlled mechanism. The loaded nanocarriers showed low levels of complement activation, compatible with stealth properties. To summarize, this study brings out a new tool for the nanoencapsulation of hydrophilic anticancers and could open new doors for the administration of this particular class of drugs.

Design, optimization and in vitro evaluation of reverse micelle-loaded lipid nanocarriers containing erlotinib hydrochloride.

Erlotinib hydrochloride (ERLO) belongs to the tyrosine kinase inhibitor family and is used for the treatment of pancreatic cancers. In the present study, ERLO was entrapped in lipid nanocarriers by means of reverse micellar incorporation. This study aims to optimize the formulation of ERLO-loaded nanoparticles. Surfactants forming reverse micelles in Labrafac(®) were filled with ERLO under various conditions. Both the initial amount of drug incubated with reverse micelles and the surfactant composing the reverse micelles are crucial parameters for reverse micelle capacity to load ERLO. The optimal loading system for reverse micelles was obtained with a mix of sorbitan trioleate (Span(®) 85) and Labrafac(®) oil at a 1:1 (w/w) ratio. Reverse micelle composition influenced the nanocarrier's hydrodynamic diameter, polydispersity index, and zeta potential. In lipid nanoparticles formulated by using the phase inversion temperature (PIT) method, ERLO entrapment efficiency was around 56%. In vitro, the efficacy of ERLO-loaded nanocarriers on BxPC-3 pancreatic adenocarcinoma cells was comparable to free ERLO, and led to a cell death rate of around 40%.

Strategies for the nanoencapsulation of hydrophilic molecules in polymer-based nanoparticles.

Hydrophilic drug delivery still remains a challenge; this either being attributed to the fragility and poor cellular penetration of macromolecules, or to the unsuitable pharmacokinetics and toxicity of small drugs, for instance anticancer agents. By offering more favourable pharmacokinetics and protection of the drug, encapsulation in polymer nanoparticles constitutes an attractive possibility to overcome these problems. This review provides an overview of the strategies that have been developed for encapsulating hydrophilic molecules in polymer-containing nanoparticles, e.g. nanospheres and nanocapsules. Polymer nanospheres are loaded either by drug entrapment (by pH modification, use of reverse micelles or the addition of a polyanion) and generally produce a poor level of entrapment efficiency, or molecule sorption onto the nanosphere surface (by pH modification, use of high drug concentration, or ion-pair formation) with the drawbacks of a less-well protected drug from degradation and a faster drug release. Another strategy consists of the use of aqueous-core nanocapsules, generally surrounded by a thin polymer layer, in which hydrophilic molecules are directly solubilised in internal water, and are thus entrapped within the nanocapsule core, assuring drug protection and sustained release. Nanocapsules require less polymer compared to nanospheres; on the other hand, when the drug is entrapped, it has to be added before or during the formulation process, and is thus likely to be degraded. Overall, drug encapsulation in polymer nanoparticles provides a better pharmacokinetic profile and bioavailability, enhanced anticancer activity, reduced drug toxicity and modified drug distribution as compared to free drugs.

Reverse micelle-loaded lipid nanocarriers: a novel drug delivery system for the sustained release of doxorubicin hydrochloride.

In this study, we are pioneering new nanotechnology for the encapsulation of anticancer drugs (doxorubicin (DOX) and/or docetaxel (DOCE)), whatever their solubility and water affinity. The purpose of this study is to highlight the potential of this recently patented technology, by carrying out a thorough physicochemical characterisation of these multiscaled nanocarriers, followed by the study of an encapsulation and release model of hydrophilic anticancer drug. The formulation process is based on a low-energy nano-emulsification method and allows the generation of a structure composed of oil-based nanocarriers loaded with reverse micelles. Thanks to this, hydrophilic contents can be solubilised in the oily core of this kind of nano-emulsion along with lipophilic content. The results emphasise some original structure particularities due to the multistep formulation process, and the diffusion-based behaviour revealed for the DOX release profile that is shown to be intimately linked to the morphology of the particles.

Aqueous-core lipid nanocapsules for encapsulating fragile hydrophilic and/or lipophilic molecules.

This paper presents the original method of producing aqueous-core lipid nanocapsule, able to encapsulate both hydrophilic and lipophilic species with relevant yields. The scope offered by the integration of both hydrophilic and lipophilic molecules within the same colloidal objects make this method a prime candidate for the numerous anticancer therapies for which chemotherapy frequently requires the association of several molecules. The proof of concept study is proposed here (i) describing in detail the formulation of such objects and their characterization (TEM, cryo-TEM, soft particle analysis), (ii) showing the encapsulation of hydrophilic species alone, using examples of very different molecular weights, such as a dye (methylene blue) and a protein (BSA-isothycianate fluorecein labeled), and (iii) showing the simultaneous encapsulation of hydrophilic (methylene blue) and lipophilic (also a dye, red Sudan III) species.