{"id":75277,"date":"2026-05-28T17:59:13","date_gmt":"2026-05-28T15:59:13","guid":{"rendered":"https:\/\/rades-development.com\/services\/case-studies\/rational-design\/"},"modified":"2026-06-07T16:41:45","modified_gmt":"2026-06-07T14:41:45","slug":"rational-design","status":"publish","type":"page","link":"https:\/\/rades-development.com\/en\/services\/case-studies\/rational-design\/","title":{"rendered":"Rational Design"},"content":{"rendered":"<div class=\"wpb-content-wrapper\"><p>[vc_row row_height_percent=&#8221;0&#8243; override_padding=&#8221;yes&#8221; h_padding=&#8221;2&#8243; top_padding=&#8221;3&#8243; bottom_padding=&#8221;3&#8243; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; column_width_percent=&#8221;100&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243;][vc_column column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; zoom_width=&#8221;0&#8243; zoom_height=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text el_class=&#8221;rades-main-headline&#8221; uncode_shortcode_id=&#8221;274188&#8243;]<\/p>\n<div class=\"rades-main-headline-icon\"><img decoding=\"async\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2018\/01\/rades-icon-1.png\" \/><\/div>\n<div class=\"rades-main-headline-content\"><span class=\"rades-main-headline-text\">RaDes stands for: Rational Design<\/span><\/div>\n<p>[\/vc_column_text][vc_column_text uncode_shortcode_id=&#8221;148848&#8243;]We founded RaDes out of the conviction that topical products can be developed more effectively than has been the case so far. While creams, ointments, and gels are well-established dosage forms, they are often not fully understood. However, scientific and technical advances in our understanding of these dosage forms now make it possible to develop better products more efficiently.[\/vc_column_text][\/vc_column][\/vc_row][vc_row row_height_percent=&#8221;0&#8243; override_padding=&#8221;yes&#8221; h_padding=&#8221;2&#8243; top_padding=&#8221;3&#8243; bottom_padding=&#8221;3&#8243; back_color=&#8221;color-375106&#8243; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; column_width_percent=&#8221;100&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243;][vc_column column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; zoom_width=&#8221;0&#8243; zoom_height=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_row_inner row_inner_height_percent=&#8221;0&#8243; back_color=&#8221;color-xsdn&#8221; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243; el_class=&#8221;rades-why-rades-row-first&#8221;][vc_column_inner column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; override_padding=&#8221;yes&#8221; column_padding=&#8221;2&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text el_class=&#8221;rades-main-headline&#8221; uncode_shortcode_id=&#8221;578086&#8243;]<\/p>\n<div class=\"rades-smaller-headline-icon\"><img decoding=\"async\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2018\/01\/rades-icon-column-3.png\" \/><\/div>\n<div class=\"rades-smaller-headline-content\"><span class=\"rades-smaller-headline-text\">Rational Design as a mindset<\/span><\/div>\n<p>[\/vc_column_text][vc_column_text uncode_shortcode_id=&#8221;129691&#8243;]Rational design is based on the idea that even complex topical semi-solids <strong>can be understood and developed systematically<\/strong>. This means that essential questions about a formulation can be answered, such as how it works, why a particular format or excipients were chosen. Also, how it reacts to changes, stress, and variability in processes and excipients, and how skin penetration is enhanced or the API is stabilized is better understood.[\/vc_column_text][vc_separator sep_color=&#8221;color-uydo&#8221; el_width=&#8221;100%&#8221; el_height=&#8221;1px&#8221;][vc_column_text uncode_shortcode_id=&#8221;127025&#8243;]<strong>RaDes has developed this concept based on decades of industry experience <\/strong>and multiple learning cycles. We have laid out the concept in detail in a publication [1].<\/p>\n<p>Like other dosage forms, topical products are not matters of art, but of science. Experience, pattern recognition, and manual dexterity are helpful additions to a structured, science-based approach. Topical formulation development is often <strong>a complex optimization challenge<\/strong>. Formulation platforms have proven unsuitable for solving such problems because they limit potential solutions. <strong>Rational formulation design is API-centric<\/strong> and formulations are tailor made to the individual molecule and target product profile.<\/p>\n<p>This approach allows us to complete development projects with fewer experiments and iteration cycles, <strong>saving time and costs<\/strong>.<\/p>\n<p>Rational Formulation Design opens up a <strong>world of opportunities in topical formulation development<\/strong>. This includes:<\/p>\n<ul>\n<li>Many difficult-to-formulate molecules can be systematically developed into safe and effective products.<\/li>\n<li>Existing molecules used by millions of patients can be formulated to be easier or more pleasant to use, thereby improving compliance and therapeutic outcomes.<\/li>\n<li>Often, current formulations are not optimized for delivery to the skin and use an unnecessarily high drug concentration. There is often potential to reduce the concentration. This can make products safer and more cost-effective, as well as reduce their environmental impact. In addition, this offers opportunities to generate IP.<\/li>\n<\/ul>\n<p>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner row_inner_height_percent=&#8221;0&#8243; back_color=&#8221;color-xsdn&#8221; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243; el_class=&#8221;rades-why-rades-row&#8221;][vc_column_inner column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; override_padding=&#8221;yes&#8221; column_padding=&#8221;2&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text el_class=&#8221;rades-main-headline&#8221; uncode_shortcode_id=&#8221;190224&#8243;]<\/p>\n<div class=\"rades-smaller-headline-icon\"><img decoding=\"async\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2018\/01\/rades-icon-column-3.png\" \/><\/div>\n<div class=\"rades-smaller-headline-content\"><span class=\"rades-smaller-headline-text\">Rational Design as a tool of systematic design and characterization of topicals<\/span><\/div>\n<p>[\/vc_column_text][vc_column_text uncode_shortcode_id=&#8221;180858&#8243;]Rational Desing is based on a thorough understanding what a topical pharmaceutical formulation really is.[\/vc_column_text][vc_separator sep_color=&#8221;color-uydo&#8221; el_width=&#8221;100%&#8221; el_height=&#8221;1px&#8221;][vc_column_text uncode_shortcode_id=&#8221;203148&#8243;]<strong>1)<\/strong> A topical pharmaceutical formulation is a <strong>DRUG DELIVERY SYSTEM<\/strong>. It must deliver an active through the formidable barrier of the skin.<\/p>\n<p>Key features to be known and optimized are:<\/p>\n<ul>\n<li>The <strong>SOLUBILITY <\/strong>of the active in the formulation. Solubility is single excipients is typically not predictive. Dilution and distribution processes in a formulation must be considered.<\/li>\n<\/ul>\n<p>According to Fick&#8217;s First Law, the flux of an active across the skin is proportional to the concentration gradient. Since the concentration in the skin is zero, it is proportional to the concentration in the formulation. Increasing solubility can help improve penetration.<\/p>\n<ul>\n<li>Numerous studies have shown that the <strong>SATURATION <\/strong>of the active in a formulation is a major driving force for skin penetration (1,2). The higher the saturation, the higher the chemical potential and skin penetration. However, saturation must be balanced with product robustness: over-saturation during shelf life can cause reprecipitation which is a severe quality issue.<\/li>\n<\/ul>\n<p><img decoding=\"async\" class=\"alignnone wp-image-75311 size-full\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Tacrolimus_Skin_Penetration_vs_Saturation.png\" alt=\"\" width=\"633\" height=\"392\" srcset=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Tacrolimus_Skin_Penetration_vs_Saturation.png 633w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Tacrolimus_Skin_Penetration_vs_Saturation-300x186.png 300w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Tacrolimus_Skin_Penetration_vs_Saturation-350x217.png 350w\" sizes=\"(max-width: 633px) 100vw, 633px\" \/><\/p>\n<h6>Tacrolimus shows higher penetration from more saturated creams. The Protopic\u00ae references is a low saturated ointment<\/h6>\n<p>&nbsp;<\/p>\n<ul>\n<li><strong>DISTRIBUTION<\/strong>: Topical formulations often have two or more phases, e.g. an oil and a water phase. Actives and excipients can be distributed between the phases. This may affect release and penetration. It can have a strong impact on the chemical stability of actives; the formulation of hydrolysis-prone actives can be enabled by trapping them in the oil phase (3). The efficacy of preservatives depends on the phase in which they are present (4).<\/li>\n<li><strong>TRANSFORMATION <\/strong>upon application can change everything. Solubility, saturation, distribution can change impacting on release and penetration. It\u2019s important to understand transformation processes and anticipate their impact.<\/li>\n<\/ul>\n<p><strong>2) <\/strong>A topical formulation is a <strong>PHYSICAL BODY<\/strong>: Semi-solids are &#8220;structured liquids&#8221;. At rest, they behave mostly like solids due to the inner structures built up by e.g. polymeric thickeners or liquid crystalline structures. This solid-like behavior at rest is very important for physical stability (e.g. against sedimentation) and bioavailability (residence time at the site of action). Under shear, the structures are destroyed (mostly reversibly) and behave more like liquids. This is important to make it spreadable, sprayable, pumpable, etc. Rheology is of great help in designing, analyzing and optimizing the physical properties of semi-solids.<\/p>\n<p>3) Semi-solid topical pharmaceuticals are <strong>QUALITY PRODUCTS<\/strong>. They must meet extensive regulatory and quality requirements to be commercially viable. No quality, no approval, no patient benefit.<\/p>\n<p>Quality requirements are often absolute, binary: meet or fail. This can be extremely costly and time-consuming if not considered early on. Therefore, it is critical to consider whether processes, excipients, methods, and controls are generally suitable to meet quality requirements.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner row_inner_height_percent=&#8221;0&#8243; back_color=&#8221;color-xsdn&#8221; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243; el_class=&#8221;rades-why-rades-row&#8221;][vc_column_inner column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; override_padding=&#8221;yes&#8221; column_padding=&#8221;2&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text el_class=&#8221;rades-main-headline&#8221; uncode_shortcode_id=&#8221;493398&#8243;]<\/p>\n<div class=\"rades-smaller-headline-icon\"><img decoding=\"async\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2018\/01\/rades-icon-column-3.png\" \/><\/div>\n<div class=\"rades-smaller-headline-content\"><span class=\"rades-smaller-headline-text\">Rational selection of the active pharmaceutical ingredients (API)<\/span><\/div>\n<p>[\/vc_column_text][vc_column_text uncode_shortcode_id=&#8221;374497&#8243;]For NCE projects, there is often great potential to develop better products faster, even before formulation begins, by <strong>selecting the right API<\/strong>. Since most molecules are not designed for topical delivery, selecting those with favorable developability properties increases the likelihood of success for topical projects while reducing time and costs. RaDes has developed a 35-mg approach to screening candidates for solubility\/formulability, chemical stability, and skin penetration [2].[\/vc_column_text][vc_separator sep_color=&#8221;color-uydo&#8221; el_width=&#8221;100%&#8221; el_height=&#8221;1px&#8221;][vc_column_text uncode_shortcode_id=&#8221;188218&#8243;]In a case study, reliable and discriminative developability data could be generated for 34 topical compound candidates with a maximum of 35 mg of substance per compound.<\/p>\n<ul>\n<li>The formulatability of the compounds was assessed based on their solubility in five solvents that are representative of different formulation approaches.\n<ul>\n<li>After the solubility screening, the number could be reduced to 18<\/li>\n<\/ul>\n<\/li>\n<li>Chemical stability was assessed by forced degradation studies\n<ul>\n<li>At least some susceptibility to oxidation was seen for all compounds which can mostly be overcome. Stability at acidic pH, most critical for developability, was generally good<\/li>\n<\/ul>\n<\/li>\n<li>Cutaneous bioavailability in viable skin was investigated at the side of action\n<ul>\n<li>Relevant skin concentration in the order of magnitude of approved references was shown. A concrete target concentration was not yet established<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><img decoding=\"async\" class=\"alignnone size-large wp-image-75320\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Cassette_Dosing_Study-1024x588.png\" alt=\"\" width=\"840\" height=\"482\" srcset=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Cassette_Dosing_Study-1024x588.png 1024w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Cassette_Dosing_Study-300x172.png 300w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Cassette_Dosing_Study-768x441.png 768w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Cassette_Dosing_Study-350x201.png 350w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Rades_Rational_Design_-_Cassette_Dosing_Study.png 1394w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/p>\n<h6>Epidermal skin penetration of 19 test and 4 reference compounds from propylene glycol vehicle (cassette dosing study)<\/h6>\n<p>&nbsp;<\/p>\n<p>For 7 of the molecules, good technical developability can be assumed. Provided a comparable biological\/toxicological profile, compounds from this group should be selected for further steps<\/p>\n<p>A poster publication of this study is available under: <a href=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2025\/07\/RaDes-Poster-Skin-Forum-2025_topical-compound-selection.pdf\">RaDes Poster Skin Forum 2025_topical compound selection<\/a>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner row_inner_height_percent=&#8221;0&#8243; back_color=&#8221;color-xsdn&#8221; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243; el_class=&#8221;rades-why-rades-row&#8221;][vc_column_inner column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; override_padding=&#8221;yes&#8221; column_padding=&#8221;2&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text el_class=&#8221;rades-main-headline&#8221; uncode_shortcode_id=&#8221;155208&#8243;]<\/p>\n<div class=\"rades-smaller-headline-icon\"><img decoding=\"async\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2018\/01\/rades-icon-column-3.png\" \/><\/div>\n<div class=\"rades-smaller-headline-content\"><span class=\"rades-smaller-headline-text\">Rational Design as an enabler for new and better products<\/span><\/div>\n<p>[\/vc_column_text][vc_column_text uncode_shortcode_id=&#8221;117168&#8243;]The most prominent challenges in topical product development are i) penetration through the skin barrier (or eye for ophthalmic delivery), ii) poor solubility, particulary for new NCEs and iii) chemical stability of actives as they are typically dissolved in complex matrices.[\/vc_column_text][vc_separator sep_color=&#8221;color-uydo&#8221; el_width=&#8221;100%&#8221; el_height=&#8221;1px&#8221;][vc_column_text uncode_shortcode_id=&#8221;143191&#8243;]<strong>Skin penetration<\/strong> can be improved by an appropriate understanding and design of the drug delivery as outlined above.<\/p>\n<p>For <strong>solubilization<\/strong> of poorly soluble actives, rational design provides many options. As opposed to peroral drug delivery where aqueous solubility is essential, in topical drug delivery also other options of solubilization can be employed, most importantly oil solubility. Here, different types of oils can act synergistically to improve solubility. The addition of surfactants and more polar organic solvents and sophisticated engineering of their distribution within the formulation can further improve solubility.<\/p>\n<p>An example for this is RaDes reformulation of mometasone furoate, a modern corticosteroid with superior risk-benefit profile that so far was only available in greasy, essentially, anhydrous formulations or alcoholic solutions. The reason for that was its unfavorable solubility profile. At RaDes, using our rational design approach, we managed to formulate this molecule in cosmetically attractive, patient-preferred formats of lotion (O\/W emulsion), cream and foam. A European and an US patent have been granted for this innovation (5,6).<\/p>\n<p>In topical formulations, the API is typically dissolved in complex matrices and can undergo many chemical reactions. This makes <strong>chemical stability <\/strong>an important challenge. Therefore, powerful analytical methods and expertise in chemical stabilization are critical to the success of a project. Insufficient analytical methods in the early stages of development can lead to project failure at later stages. RaDes scientists have a strong track record of successfully developing degradation-prone APIs. A public example is the stabilization of the strongly hydrolysis-prone tacrolimus in an aqueous cream (4). It was achieved through a combination of chemical stabilization and optimization of distribution of the API between the phases of the formulation. This highlights another characteristic of rational design of topicals: that formulation design and analytics go hand in hand in all phases of a project.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner row_inner_height_percent=&#8221;0&#8243; back_color=&#8221;color-xsdn&#8221; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243; el_class=&#8221;rades-why-rades-row&#8221;][vc_column_inner column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; override_padding=&#8221;yes&#8221; column_padding=&#8221;2&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text el_class=&#8221;rades-main-headline&#8221; uncode_shortcode_id=&#8221;712339&#8243;]<\/p>\n<div class=\"rades-smaller-headline-icon\"><img decoding=\"async\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2018\/01\/rades-icon-column-3.png\" \/><\/div>\n<div class=\"rades-smaller-headline-content\"><span class=\"rades-smaller-headline-text\">Rational Design as an economic advantage<\/span><\/div>\n<p>[\/vc_column_text][vc_column_text uncode_shortcode_id=&#8221;100697&#8243;]Rational design of topical improves the probability of success of topical program. The thorough understanding of formulations and use of predictive tools also enable more precise risk assessment.<\/p>\n<p>Better hypotheses and a more targeted approach make it possible to gain more insights with fewer experiments, <strong>saving both time and money<\/strong>.[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner row_inner_height_percent=&#8221;0&#8243; back_color=&#8221;color-xsdn&#8221; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243; el_class=&#8221;rades-why-rades-row&#8221;][vc_column_inner column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; override_padding=&#8221;yes&#8221; column_padding=&#8221;2&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text uncode_shortcode_id=&#8221;971469&#8243;]<\/p>\n<h3>References:<\/h3>\n<p>&nbsp;<\/p>\n<ol>\n<li><a href=\"https:\/\/doi.org\/10.3390\/pharmaceutics15071822\" target=\"_blank\" rel=\"noopener\">Herbig, M.E.; Evers, D.-H.; Gorissen, S.; K\u00f6llmer, M. Rational Design of Topical Semi-Solid Dosage Forms-How Far Are We?\u00a0<em>Pharmaceutics<\/em> <strong>2023<\/strong>,\u00a0<em>15<\/em>, 1822.<\/a><\/li>\n<li>Davis, A.F.; Hadgraft, J. Effect of supersaturation on membrane transport: 1. Hydrocortisone acetate. Int. J. Pharm. 1991, 76, 1\u20138.<\/li>\n<li>WO2019233722, Pharmaceutical Composition Comprising Tacrolimus.<\/li>\n<li>Puschmann, J.; Herbig, M.E.; M\u00fcller-Goymann, C.C. Correlation between free aqueous preservative concentration in emulsion gels measured by equilibrium dialysis and antimicrobial efficacy.\u00a0<em> J. Pharm. Biopharm.<\/em><strong>2018<\/strong>,\u00a0<em>131<\/em>, 152\u2013161.<\/li>\n<li>EP4108235B1 Topical pharmaceutical formulation,<\/li>\n<li>US12447161B2 Topical pharmaceutical formulation<\/li>\n<\/ol>\n<p>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner row_inner_height_percent=&#8221;0&#8243; back_color=&#8221;color-xsdn&#8221; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243; el_class=&#8221;rades-why-rades-row-first&#8221;][vc_column_inner column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; override_padding=&#8221;yes&#8221; column_padding=&#8221;2&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text el_class=&#8221;rades-main-headline&#8221; uncode_shortcode_id=&#8221;141256&#8243;]<\/p>\n<div class=\"rades-smaller-headline-icon\"><img decoding=\"async\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2018\/01\/rades-icon-column-3.png\" \/><\/div>\n<div class=\"rades-smaller-headline-content\"><span class=\"rades-smaller-headline-text\">Your contact on this topic<\/span><\/div>\n<p>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][vc_row_inner row_inner_height_percent=&#8221;0&#8243; back_color=&#8221;color-xsdn&#8221; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243; el_class=&#8221;rades-why-rades-row&#8221;][vc_column_inner column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; override_padding=&#8221;yes&#8221; column_padding=&#8221;2&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; width=&#8221;1\/1&#8243;][vc_column_text uncode_shortcode_id=&#8221;181196&#8243; css=&#8221;.vc_custom_1780840339623{padding-left: 60px !important;}&#8221;]<img decoding=\"async\" class=\"size-medium wp-image-75327\" src=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-300x300.jpg\" alt=\"\" width=\"300\" height=\"300\" srcset=\"https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-300x300.jpg 300w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-1024x1024.jpg 1024w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-150x150.jpg 150w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-768x768.jpg 768w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-1536x1536.jpg 1536w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-2048x2048.jpg 2048w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-350x350.jpg 350w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait-348x348.jpg 348w, https:\/\/rades-development.com\/wordpress\/wp-content\/uploads\/2026\/06\/Michael-Herbig-Portrait.jpg 2180w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>Michael Herbig, Co-Founder &amp; CEO RaDes<br \/>\n<a href=\"mailto:michael.herbig@rades-development.com\">michael.herbig@rades-development.com<\/a>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_column][\/vc_row]<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>[vc_row row_height_percent=&#8221;0&#8243; override_padding=&#8221;yes&#8221; h_padding=&#8221;2&#8243; top_padding=&#8221;3&#8243; bottom_padding=&#8221;3&#8243; overlay_alpha=&#8221;50&#8243; gutter_size=&#8221;3&#8243; column_width_percent=&#8221;100&#8243; shift_y=&#8221;0&#8243; z_index=&#8221;0&#8243;][vc_column column_width_percent=&#8221;100&#8243; gutter_size=&#8221;3&#8243; overlay_alpha=&#8221;50&#8243; shift_x=&#8221;0&#8243; shift_y=&#8221;0&#8243; shift_y_down=&#8221;0&#8243; z_index=&#8221;0&#8243; medium_width=&#8221;0&#8243; mobile_width=&#8221;0&#8243; [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":75273,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-75277","page","type-page","status-publish","hentry","page_category-rades-en"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Rational Design - RaDes GmbH<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/rades-development.com\/en\/services\/case-studies\/rational-design\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Rational Design - RaDes GmbH\" \/>\n<meta property=\"og:description\" content=\"[vc_row row_height_percent=&#8221;0&#8243; 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