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Insoluble Salt Technology for Drug Physicochemical Improvement

Insoluble Salt Technology for Drug Physicochemical Improvement

Salt-forming techniques are generally used to increase the solubility of insoluble compounds. Refractory salt technology, in contrast, is used to control drug release and prolong drug action by converting water-soluble drugs into insoluble salts. For a drug molecule to become a salt it needs to contain both an ionized drug active ingredient and another counter ion, while having a certain stoichiometric ratio of anions and cations in order to maintain charge balance. For acidic active ingredients, sodium ions are usually chosen as the counter ion, while for basic active ingredients, chloride ions are usually chosen as the counter ion. CD Formulation can provide technical support for refractory salt technology to help customers make targeted slow release formulations to delay the release of the drug.

About Insoluble Salt Technology

Insoluble salt technology, as an easy way in sustained release formulations, opens up a broader scientific research space for the development of sustained release formulations. At present, the most researched insoluble salt technology is bis(hydroxynaphthalate). The formation of dihydroxynaphthalates of drugs can significantly reduce the solubility and dissolution rate, and prolong the action time of drugs in the body. The mechanism of drug release is that dihydroxynaphthalate is formed into a salt with the drug and then suspended in an aqueous solution to make an extended release injection. After injection administration, the dihydroxynaphthalate of the drug stays at the site of administration for a long time, and the insoluble salt dissolves slowly, releasing two salt-forming compounds: the drug compound and dihydroxynaphthalic acid. The salt dissolves slowly and the drug is gradually released into the body's circulation, maintaining a duration of action of several weeks.

Insoluble Salt Technology Services

The main goal of pharmaceutical salt formation is to improve the water solubility and thus the bioavailability of the drug. The ability to circumvent undesirable properties of drug molecules (e.g. poor water solubility) without affecting their pharmacological activity makes this technology particularly attractive.

Product preparation

CD Formulation has a professional team of pharmaceutical formulation and technical support, and we are ready to provide development and preparation of insoluble drugs for our customers, helping them complete the development of projects.

Salt-based screening techniques

Salt-type screening is primarily performed by manually mixing ionizable drugs with selected counter ions to form salt precipitates, which are then fully characterized by various techniques. The final salt form of the drug is determined based on factors such as crystallinity, melting point, hygroscopicity, physicochemical stability and crystal shape of the salt.

Screening of salt types through four experimental steps (sample preparation, solid generation, solid assay and sample analysis) allows to obtain a large amount of experimental data quickly and find the target salt type quickly.

The substances of different salt types prepared by the above experimental operations are usually first characterized by Raman spectroscopy and X-ray powder diffraction. Samples identified as target salt types are then analyzed technically to determine if the basic criteria are met, including hygroscopicity, solubility and stability analysis of the different salt types. After initial identification of viable salt forms by screening, larger quantities can be produced to assess the suitability of the synthesis process and ultimately to assess whether the properties of the prepared salt forms meet the criteria.

If you are interested in our technology, please do not hesitate to contact us.

Please note: Our products and services are not intended to be used directly in diagnostic or therapeutic procedures.
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