Bernard Do

Prof. Dr. Bernard Do

Laboratoire et Matériaux et Santé, Université Paris-Saclay, 91400 Orsay, France

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
4 March 2022 in Pharmaceutics
Verified
Journal Article
Open access
PDF file
GGGuillaume Le Guyader
Guillaume Le Guyader
BDBernard Do
Bernard Do
Ivo Boudewijn RietveldIvo Boudewijn Rietveld
Ivo Boudewijn Rietveld
PCPascale CORIC
Pascale CORIC
SBSerge Bouaziz
Serge Bouaziz
MPMuriel Paul
Muriel Paul
Facial angiofibromas (FA) are one of the most obvious cutaneous manifestations of tuberous sclerosis complex. Topical rapamycin for angiofibromas has been reported as a promising treatment. Several types of vehicles have been used hitherto, but polymeric micelles and especially those made of d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) seem to have shown better skin bioavailability of rapamycin than the so far commonly used ointments. To better understand the influence of polymeric micelles on the behavior of rapamycin, we explored it through mixed polymeric micelles combining TPGS and poloxamer, evaluating stability and skin bioavailability to define an optimized formulation to effectively treat FA. Our studies have shown that TPGS improves the physicochemical behavior of rapamycin, i.e., its solubility and stability, due to a strong inclusion in micelles, while poloxamer P123 has a more significant influence on skin bioavailability. Accordingly, we formulated mixed-micelle hydrogels containing 0.1% rapamycin, and the optimized formulation was found to be stable for up to 3 months at 2–8 °C. In addition, compared to hydroalcoholic gel formulations, the studied system allows for better biodistribution on human skin.

17 April 2025 in International Journal of Pharmaceutics
Verified
Journal Article
Open access
MSMaxime Stoops
Maxime Stoops
BDBernard Do
Bernard Do
SRStéphanie Ramos
Stéphanie Ramos
BTBing Xun Tan
Bing Xun Tan
NCNicholas Yong Sheng Chua
Nicholas Yong Sheng Chua
MAMaxime Annereau
Maxime Annereau
Adherence to treatment is one of the major challenges in chronic diseases. Inappropriate dosage forms or bad taste are the main factor for non-adherence, especially in paediatric patients. 3D printed medicines could be tailored to specific patients to make medicines more acceptable, however the clinical implementation in hospitals is still limited. This study addresses the challenge of developing pharma-inks (mixtures of drugs and excipients) for semi-solid extrusion (SSE) to produce chewable tablets of Sulfamethoxazole (SMX) and Trimethoprim (TMP) for paediatric oncology patients in a hospital setting. SMX and TMP pharma-inks were stable and printable on demand for more than 3 months. The chewable tablets were also stable, and the drugs dissolution profiles were comparable to those of the commercial formulations, indicating potential bioequivalence. Human sensory evaluations confirmed that the formulation improved palatability compared to traditional suspensions. 3D-printed SMX/TMP formulations are an alternative to traditional formulations for paediatric patients in hospital settings, enhancing acceptability and adherence while enabling personalized dosing.

19 January 2015 in Journal of Separation Science
Verified
Journal Article
Closed access
PDF file
MBMélisande Bernard
Mélisande Bernard
WAWiem Akrout
Wiem Akrout
CBChristelle Tran Van Buu
Christelle Tran Van Buu
CMCarole Metz
Carole Metz
MAMarie Antignac
Marie Antignac
BDBernard Do
Bernard Do

30 November 2021 in Pharmaceuticals
Verified
Journal Article
Open access
PDF file
PSPhilippe-Henri Secrétan
Philippe-Henri Secrétan
TOTHIRION Olivier
THIRION Olivier
HYHassane SADOU YAYÉ
Hassane SADOU YAYÉ
TDThibaud Damy
Thibaud Damy
AAAlain Astier
Alain Astier
BDBernard Do
Bernard Do
Because of its antioxidant, antimutagenic, and anti-infectious properties, epigallocatechin gallate (EGCG) is the most interesting compound among the green tea catechins polyphenols. However, its health effects are inconclusive due to its very low bioavailability, largely due to a particular instability that does not allow EGCG to reach the potency required for clinical developments. Over the last decade, many efforts have been made to improve the stability and bioavailability of EGCG using complex delivery systems such as nanotechnology, but these efforts have not been successful and easy to translate to industrial use. To meet the needs of a large-scale clinical trial requiring EGCG in a concentrated solution to anticipate swallowing impairments, we developed an EGCG-based aqueous solution in the simplest way while trying to circumvent EGCG instability. The solution was thoroughly characterized to sort out the unexpected stability outcome by combining experimental (HPLC-UV-mass spectrometry and infrared spectroscopy) and computational (density functional theory) studies. Against all odds, the EGCG–sucrose complex under certain conditions may have prevented EGCG from degradation in aqueous media. Indeed, in agreement with the ICH guidelines, the formulated solution was shown to be stable up to at least 24 months under 2–8 °C and at ambient temperature. Furthermore, considerable improvement in bioavailability in rats, against EGCG powder formulated in hard-gel capsules, was shown after gavage. Thus, the proposed formulation may provide an easily implementable platform to administer EGCG in the context of clinical development.

7 November 2020 in Pharmaceutics
Verified
Journal Article
Open access
PDF file
GGGuillaume Le Guyader
Guillaume Le Guyader
BDBernard Do
Bernard Do
VVVictoire Vieillard
Victoire Vieillard
KAKarine Andrieux
Karine Andrieux
MPMuriel Paul
Muriel Paul
Rapamycin has been used topically to treat facial angiofibromas associated with tuberous sclerosis for more than a decade. In the absence of a commercial form, a large number of formulations have been clinically tested. However, given the great heterogeneity of these studies, particularly with regard to the response criteria, it was difficult to know the impact and thus to compare the relevance of the formulations used. The objective of this work was therefore to evaluate the link between the diffusion of rapamycin and the physico-chemical characteristics of these different formulations on Strat-M® membranes as well as on human skin using Franz cells. Our results underline the importance of the type of vehicle used (hydrogel > cream > lipophilic ointment), the soluble state of rapamycin and its concentration close to saturation to ensure maximum thermodynamic activity. Thus, this is the first time that a comparative study of the different rapamycin formulations identified in the literature for the management of facial angiofibromas has been carried out using a pharmaceutical and biopharmaceutical approach. It highlights the important parameters to be considered in the development and optimization of topical rapamycin formulations with regard to cutaneous absorption for clinical efficacy.

17 August 2022 in Pharmaceutics
Verified
Journal Article
Open access
PDF file
PSPhilippe-Henri Secrétan
Philippe-Henri Secrétan
MAMaxime Annereau
Maxime Annereau
WKWilly Kini-Matondo
Willy Kini-Matondo
BPBastien Prost
Bastien Prost
JPJade Prudhomme
Jade Prudhomme
BDBernard Do
Bernard Do
Nirmatrelvir is an antiviral drug approved for the treatment of COVID-19. The available dosage form consists of tablets marketed under the brand name PAXLOVID®. Although knowledge of nirmatrelvir’s intrinsic stability may be useful for any potential development of other pharmaceutical forms, no data regarding this matter is available to date. Preliminary forced degradation studies have shown that the molecule is stable under oxidative and photolytic conditions, while hydrolytic conditions, both acidic and basic, have proven deleterious. Indeed, the molecule presents a priori several functions that can undergo hydrolysis, i.e., three amide moieties and a nitrile function. However, considering the degradation products formed under forced conditions and which were detected and identified by LC-UV-HRMSn, the hydrolysis process leading to their formation is selective since it involved only 2 of the 4 hydrolysable functions of the molecule. Ab initio studies based on density functional theory (DFT) have helped better understand these reactivity differences in aqueous media. Some hydrolyzable functions of nirmatrelvir differ from others in terms of electrostatic potential and Fukui functions, and this seems to correlate with the forced degradation outcomes.