Pharmaceutical cocrystals: a rising star in drug delivery applications

Pharmaceutical cocrystals, owing to their manifold applications, are acting as bridge between drug discovery and pharmaceutical product development. The ability to scale up pharmaceutical cocrystals through continuous manufacturing approaches offers superior and economic pharmaceutical products. Moreover, cocrystals can be an aid for the nanoparticulate systems to solve the issues related to scale-up and cost. Cocrystals grabbed attention of academic researchers and pharmaceutical scientist due to their potential to target various diseases like cancer. The present review is mainly focussed on the diverse and comprehensive applications of pharmaceutical cocrystals in drug delivery including solubility and dissolution enhancement, improvement of bioavailability of drug, mechanical and flow properties of active pharmaceutical ingredients, controlled/sustained release and colour tuning of API. Besides, phytochemical based cocrystals, multi-drug cocrystals and cocrystals for tumour therapy have been discussed in this review. Additionally, recent progress pertinent to pharmaceutical cocrystals is also included, which may provide future directions to manufacturing and scale-up of cocrystals.

Isolation, identification, and cytotoxicity evaluation of phytochemicals from chloroform extract of Spathodea campanulata

Background

Spathodea campanulata P. Beauv. known as the African tulip tree has potential medicinal properties that have been shown traditionally for the treatment of various ailments. The aim of the present study was isolation, identification, and evaluation of the cytotoxic activity of phytochemicals from the chloroform extract of S. campanulata.

Result

Three compounds were isolated by using column chromatography and preparative TLC from chloroform extract of leaves of S. campanulata. The structures of the isolated compounds were elucidated by using spectroscopic methods, including, FTIR, ESI-TOF MS, 1H NMR, and 13C NMR spectroscopy. In vitro cytotoxic activity of compounds was evaluated by using SRB assay against human leukemia cancer cell lines (HL-60). Results were expressed in IC50 values. Stigmasta-5,22-dien-3-ol, octadecenamide, and umbelliferone were isolated and identified from chloroform extract. The isolated compounds showed cytotoxicity with decreasing cell viability in a dose-dependent manner, but it was found low as compared to positive control, i.e., Adriamycin against HL-60 cell lines.

Conclusion

The results indicate that isolated compounds, i.e., stigmasta-5,22-dien-3-ol (44.12μg/ml), octadecenamide (35.65μg/ml), and umbelliferone (80.60μg/ml) showed antiproliferative activity, but it was low compared to positive control Adriamycin (10.09 μg/ml). Also, according to our knowledge, this study is the first report on the isolation and identification of octadecenamide and umbelliferone from the leaves of S. campanulata.

Graphical abstract

Test characteristics of the urine Gram stain in infants <or= 60 days of age with fever

OBJECTIVE

The utility of the Gram stain for the preliminary diagnosis of urinary tract infections (UTI) in infants <or= 60 days of age has not been clearly defined. Our purpose was to assess the test characteristics of the Gram stain in febrile infants and compare them to urinalysis (UA) and microscopy.

METHODS

The study was prospective and observational. Urine samples were obtained from a consecutive sample of infants <or= 60 days of age with a temperature of >or= 38.0 degrees C presenting to a pediatric emergency department during 2 consecutive winter seasons. Single pathogen growth of >or= 10(4) cfu/mL from a catheterized specimen and >or= 10(3) cfu/mL from a suprapubic specimen was considered positive. A positive Gram stain was defined as the identification of any organisms. Urinalysis was tested for the presence of nitrites and for leukocyte esterase (LE). Urine microscopy was analyzed for white blood cells per high power field (WBC/hpf).

RESULTS

Fourteen of 246 patients were excluded; 11 because no Gram stain was completed. Of the remaining 232 patients, Gram stain had a sensitivity of 85.2% (95% CI 71.9-98.6%), a specificity of 99.0% (95% CI 97.7-100%), a likelihood ratio for a positive test of 87.3 (95% CI 21.8-349.9), and a likelihood ratio for a negative test of 0.15 (95% CI 0.06-0.37). There were 193 specimens for which a Gram stain and a complete UA and microscopy were completed and compared. Urine microscopy had a lower sensitivity and specificity than Gram stain for both >or= 5 WBC/hpf and >or= 10 WBC/hpf. In addition to the Gram stain, a dipstick negative for nitrites and LE had a low negative likelihood ratio (0.16), useful for decreasing the likelihood of a UTI.

CONCLUSIONS

The Gram stain has excellent test characteristics for the preliminary diagnosis of a UTI in febrile infants. Patient disposition and therapy will likely change if clinical protocols and guidelines use the Gram stain rather than urine microscopy for preliminary diagnosis of UTI in infants.

Malignant transformation of Syrian hamster embryo (SHE) cells in culture by malachite green: an agent of environmental importance

Malachite green (MG), consisting of green crystals with a metallic lustre, is very soluble in water and is highly cytotoxic to mammalian cells in culture and also acts as a liver tumour promoter. In view of its industrial importance and possible exposure to human beings, MG poses a potential environmental health hazard. Accordingly, we have studied the effect of MG on the formation of free radicals using Electron Spin Resonance (ESR) analysis with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping agent. ESR analysis showed formation of reactive free radicals during exposure of MG to Syrian hamster embryo (SHE) cells. As per mechanism-based toxicology in cancer risk assessment, the chemicals that have the potential to be metabolized to active free radical species could be human cancer hazards. So, we have investigated the effect of MG on the formation of Type II and Type III morphologically transformed foci using SHE cell transformation assay. MG induced dose related transformed foci. Some of these transformed foci were taken out using selective trypsinisation and established immortal cell lines. One of these immortal cell lines was characterized extensively. This immortal cell line showed enhanced DNA synthesis in the form of BrdU incorporation, increased presence of proliferating cell nuclear antigen (PCNA), bcl-2 and p53 proteins by immunohistochemistry. When these immortal cells were injected subcutaneously into nude mice, they developed tumors which were transplantable and histopathologically sarcomas. The present studies indicate that MG could be a potential candidate for two year chemical carcinogenesis rodent bioassays.

Effects of cadmium on osteoclast formation and activity in vitro

Chronic exposure to cadmium has been linked to bone loss, low bone mass, and increased incidence of fracture. To determine if Cd could directly increase the formation of cells responsible for bone resorption, we cultured normal canine bone marrow cells containing the progenitor cells for osteoclasts. Cultures were evaluated for the number of multinucleate osteoclast-like cells (MNOCs) formed. Exposure to Cd (10-100 nM) increased the number of MNOCs formed over control values when cultured in the presence but not in the absence of a bone wafer. The MNOCs formed were functional, evidenced by pits excavated on the bone wafers included in the cultures. By 12 days, MNOCs formed in the presence of 50 nM Cd excavated significantly more pits and a greater pit area than did untreated MNOCs. By 14 days, the control values were similar to those of the Cd-exposed MNOCs, but pit formation was enhanced by Cd in that the ratio of pit complexes to single pits was increased twofold over that for untreated cultures. Mature osteoclasts, isolated from the long bones of rat neonates and cultured for 1-3 days on bone slices, provided a direct method to assess the effect of Cd on osteoclast activity. Exposure of osteoclast cultures to 100 nM Cd increased the number of osteoclasts present over that for untreated osteoclasts by a factor of 1.7 +/- 0.1, the number of pits excavated by 2.8 +/- 0.6, the area excavated by 3.2 +/- 0.8, and the area excavated per osteoclast by 1.8 +/- 0.4 (mean +/- SE; n = six experiments). These data suggest that Cd accelerates the differentiation of new osteoclasts from their progenitor cells and activates or increases the activity of mature osteoclasts.

A new graft spreader

A new graft spreader for applying the skin graft is described that solves the problems of removing subgraft fluid collection and reverting the curled edge of the graft.