7002-58-6Relevant academic research and scientific papers
API ionic liquids: Probing the effect of counterion structure on physical form and lipid solubility
Benameur, Hassan,Ford, Leigh,Nguyen, Tri-Hung,Porter, Christopher J. H.,Scammells, Peter J.,Tay, Erin,Williams, Hywel D.
, p. 12788 - 12799 (2020/04/22)
Lipid based formulations (LBFs) are extensively utilised as an enabling technology in drug delivery. The use of ionic liquids (ILs) or lipophilic salts (LS) in drug delivery has also garnered considerable interest due to unique solubility properties. Conversion of active pharmaceutical ingredients (API) to ILs by pairing with an appropriately lipophilic counterion has been shown to decrease melting point of the salt complex and improve solubility in LBFs. However, the relationship between the structure of the counterion, the physicochemical properties of the resulting salts and solubility in LBFs has not been systematically explored. This study investigates the relationship between alkyl sulfate counterion structure and melting temperature (Tm or Tg) in addition to LBF solubility, utilizing cinnarizine and lumefantrine as model weakly basic APIs. Three series of structurally diverse alkyl sulfate counterions were chosen to probe this relationship. Pairing cinnarizine and lumefantrine with a majority of these alkyl sulfate counterions resulted in a reduction in melting temperature and enhanced solubility in model medium chain and long chain LBFs. The chain length of the alkyl sulfate plays a crucial role in performance, and consistently branched alkyl sulfate counterions perform better than straight chain alkyl sulfate counterions, as predicted. Most interestingly, trends in counterion performance were found to be consistent across two APIs with disparate chemical structures. The findings from this study will facilitate the design of counterions which enhance solubility of ionisable drugs and unlock the potential to develop compounds previously restrained by poor solubility.
Stereoselective synthesis of (z)-1-benzhydryl-4-cinnamylpiperazines via the wittig reaction
Shivprakash,Reddy, G. Chandrasekara
, p. 600 - 609 (2014/01/17)
A synthetic method of producing (E)- and (Z)-isomers of 1-benzhydryl-4-cinnamylpiperazines in a specific ratio from corresponding benzhydrylpiperazine is described. Of the three compounds synthesized (5a-c), the ratio of E/Z-isomers remained around 15:85. The key intermediates, 1-benzhydryl-4-(2,2-dimethoxyethyl)piperazine derivatives (3a-c), were prepared by nucleophilic substitution reaction of benzhydrylpiperazines (2a-c) with chloroacetaldehyde dimethylacetal in good yield (up to 88%). Hydrolysis of 3a-c gave the corresponding aldehydes 4a-c, which when subjected to the Wittig reaction followed by column purification to afford 1a-c (E-isomers) and 6a-c (Z-isomers) in pure form. The isolated compounds were characterized by NMR and mass spectral analysis. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.] Copyright
