1. Solid state stabilisation of the orally delivered drugs atenolol, glibenclamide, memantine and paracetamol through their complexation with cucurbituril
Fiona J. McInnes, Nahoum G. Anthony, Alan R. Kennedy and Nial J. Wheate*. Org. Biomol. Chem., 2010, 8, 765–773
For atenolol in an excess of CB, the largest changes are observed for the two phenyl resonances at 7.22 and 6.97 ppm, which move upﬁeld by 0.73 and 0.88 ppm, respectively (Fig. 2). A relatively small upﬁeld shift (0.17 ppm) of the neighbouring methylene resonance is also observed, among other changes in the remaining peaks.These chemical shift changes indicate that atenolol is partially bound by CB, with binding largely located over the phenyl ring of the drug. When CB is added to atenolol at a drug :CB ratio of 2 : 1, only one set of considerably broadened drug resonances is observed indicating that the binding kinetics are fast to intermediate on the NMR time scale.
2. Indirect chiral ligand exchange chromatography for enantioseparation: a modiﬁcation of conventional techniques
Rajender Kumar* and Ravi Bhushan. RSC Adv.,2014, 4,50130–50136
Method validation was done in accordance with ICH guidelines using diastereomeric complexes of atenolol prepared with Cu(II)–L-Phe. The accuracy and precision studies of the developedmethod were carried out by replicate HPLC analysis (n = 6) of (RS)-atenolol with Cu(II)–L-Phe complexes at six diﬀerent concentration levels (20, 25, 30, 35, 40, and 45 ng mL-1), and the RSD were less than 2%in almost all cases. The relative standard deviation for (R)- and (S)-atenolol varied from 0.84 to 1.08% and 0.81 to 0.1.05% for intraday assay precision and 1.00 to 1.93% and 1.08 to 1.47% for interday assay precision. The recovery for (R)- and (S)- atenolol varied from 97.6 to 99.2% and 97.8 to 108.3% for the intraday assay and 95.9 to 98.2% and 95.14 to 111.5% for the interday assay, respectively.
3. Enantio-conversion and -selectivity of racemic atenolol kinetic resolution using free Pseudomonas ﬂuorescens lipase (Amano) conducted via transesteriﬁcation reaction
Joni Agustian, Azlina Harun Kamaruddin* and Hassan Y. Aboul-Enein. RSC Adv.,2016, 6,26077–26085
Atenolol (Fig. 1) is a b-blocker compound used for treatment of high blood pressure, angina pectoris, and arrhythmia problems. The compound is still sold as a racemic mixture. As the active isomer of atenolol is the (S)-enantiomer, replacing racemic atenolol with this optically active compound would give rise to reduced side eﬀects. Two routes have been established to produce single enantiomer b-blocker compounds i.e. asymmetric syntheses and racemic resolutions. But, there are limited methods applied to give (S)-atenolol.