1. Solid-state NMR studies of pharmaceutical solids in polymer matrices
Joseph W. Lubach • Brian E. Padden • Stephanie L. Winslow • Jonathon S. Salsbury. Anal Bioanal Chem (2004) 378 : 1504–1510
The multiple polymorphic and pseudopolymorphic forms of bupivacaine-HCl that can be generated upon heating or recrystallization are shown in Fig. 3. If bupivacaine HCl is heated at 100 °C for 12 h, the material becomes disordered, as indicated by the increase in the breadth of the lines in the NMR spectrum. However, the material does not become amorphous. Further heating to 170 °C for 12 h produces yet a different spectrum. This spectrum could be composed of either a mixture of two different forms, or there could be two different crystallographically non-equivalent sites in the unit cell. Yet another form can be generated by recrystallization from ethanol. There is a strong possibility that this is an ethanol solvate, as there is a peak at ～60 ppm that is characteristic of ethanol.
2. Different anesthetic agents-soaked sinus packings on pain management after functional endoscopic sinus surgery: which is the most effective?
Suheyl Haytoglu • Gokhan Kuran • Nuray Bayar Muluk • Osman Kursat Arıkan. Eur Arch Otorhinolaryngol (2016) 273:1769–1777
In the present study, we investigated the efﬁcacy of local anesthetics soaked merocel sinus packs after FESS. Topical anesthetics are classiﬁed in two groups, amide and ester derivates. Lidocaine, Bupivacaine, Ropivacaine and Prilocaine are the amide group of topical anesthetic. In 5 groups, 2% lidocaine HCl, 0.25 % Bupivacaine HCl, 0.2 % Ropivacaine, 2 % Prilocaine and 0.9 % NaCl (Saline) were applied, respectively. In our study, preoperative Lund–Mackay CT Score values of the groups were not different. There was no signiﬁcant difference between bleeding grade of the groups. In Bupivacaine group, number of gauze/24 h use was lower than lidocaine, ropivacaine and prilocaine groups. In saline group, number of gauze/24 h use was higher than lidocaine, ropivacaine and prilocaine groups.
3. The effect of bupivacaine•HCl on the physical properties of neuronal membranes
K. I. Koo & J. H. Bae & C. H. Lee & C. D. Yoon & J. H. Pyun & S. H. Shin & Y. C. Jeon & M. K. Bae. Protoplasma (2008) 234:3–12
Figure 5 shows that the anisotropy (r) of DPH in the TNBS untreated membrane (inner plus outer monolayers) decreased gradually (fluidization) with increasing bupivacaine HCl concentrations (Fig. 5, filled squares). There was a similar, but more gradual, decrease in the calculated anisotropy of the inner monolayer at any bupivacaine•HCl concentration (Fig. 5, filled triangles). The anisotropy of DPH in SPMVs inner monolayer incubated with 1 mM bupivacaine HCl was 0.182±0.005** (n=5, P<0.01), and the change in anisotropy value before and after adding 1 mM bupivacaine•HCl was 0.038. The values in the inner monolayer were 0.220±0.003 (n=5) and 0.269±0.005 (n=5) at 37°C and 25°C, respectively. Thus the effect of 1 mM bupivacaine HCl was equivalent to that produced by a temperature increase of approximate 9.3°C. However, there was no statistically significant decrease in the anisotropy (the rotational mobility range) of the outer monolayer at 0.01∼0.02 mM of the bupivacaine•HCl concentrations used. These results suggest that the fluidizing effect (range of rotational mobility) of bupivacaine•HCl is selective.
4. Controlled release of bupivacaine HCl through microchannels of biodegradable drug delivery device
Kang Ju Lee & Sung Yeun Yang & WonHyoung Ryu. Biomed Microdevices (2012) 14:583–593
Release of bupivacaine HCl in deionized water and phosphate buffered saline solution
To assess the effect of release media, microfluidic devices containing BHCl were tested in both deionized water (DI water) and phosphate buffered saline (PBS) solutions. Two groups of devices were fabricated to have the channel lengths of 0.7 mm and one group of devices had the release channels of 1.6 mm. The amount of bupivacaine loaded in each device (2.4 mg/device on average)was determined such that the solubility limit of the analgesic was maintained over three days. Under this condition, diffusional transport of BHCl was expected to be at a constant rate for at least three days. As shown in Fig. 4, when devices with 0.7 mm long channels were placed in DI water, BHCl was released at a constant rate close to the estimated value from Table 1. However, devices with the same channel lengths (0.7 mm) was tested in a PBS solution, the release profile showed biphasic patterns. Until day one, it showed zero-order release almost identical to the devices in DI water.