Development of safety profile evaluating pharmacokinetics, pharmacodynamics and toxicity of a combination of pioglitazone and olmesartan medoxomil in Wistar albino rats

Impact of Disease States on the Oral Pharmacokinetics of EIDD-1931 (an Active Form of Molnupiravir) in Rats for Implication in the Dose Adjustment

The pharmacokinetic alteration of an antimicrobial medication leading to sub-therapeutic plasma level can aid in the emergence of resistance, a global threat nowadays. In this context, molnupiravir (prodrug of EIDD-1931) is the most efficacious orally against corona virus disease (COVID-19). In addition to drug-drug interaction, the pharmacokinetics of a drug can significantly vary during any disease state, leading to disease-drug interaction. However, no information is available for such a recently approved drug. Therefore, we aimed to explore the oral pharmacokinetics of EIDD-1931 in seven chemically induced disease states individually compared to the normal state using various rat models. Induction of any disease situation was confirmed by the disease specific study(s) prior to pharmacokinetic investigations. Compared to the normal state, substantially lowered plasma exposure (0.47- and 0.63-fold) with notably enhanced clearance (2.00- and 1.56-fold) of EIDD-1931 was observed in rats of ethanol-induced gastric injury and carbon tetrachloride-induced liver injury states. Conversely, paclitaxel-induced neuropathic pain and cisplatin-induced kidney injury states exhibited opposite outcomes on oral exposure (1.43- and 1.50-fold) and clearance (0.69- and 0.65-fold) of EIDD-1931. Although the highest plasma concentration (2.26-fold) markedly augmented in the doxorubicin-induced cardiac injury state, streptozocin-induced diabetes and lipopolysaccharide-induced lung injury state did not substantially influence the pharmacokinetics of EIDD-1931. Exploring the possible phenomenon behind the reduced or boosted plasma exposure of EIDD-1931, results suggest the need for dose adjustment in respective diseased conditions in order to achieve desired efficacy during oral therapy of EIDD-1931.

Effect of Disease State on the Pharmacokinetics of Bedaquiline in Renal-Impaired and Diabetic Rats

Bedaquiline (TMC-207) is a key anti-tubercular drug to fight against multidrug resistance tuberculosis. Little information is available till date on the impact of any disease state toward its pharmacokinetic behavior. The present research work aimed to investigate the effect of renal impairment and diabetes mellitus on the oral pharmacokinetics of bedaquiline in the rat model. Renal impairment and diabetes mellitus were induced in the Wistar rat model separately using cisplatin and streptozotocin, respectively, and thereafter, an oral pharmacokinetic study of bedaquiline was carried out in the individual disease models as well as in the normal rat model. Pharmacokinetic parameters of bedaquiline were not altered markedly in cisplatin-induced renal-impaired rats compared to normal rats except an area under the curve (AUC) for plasma concentration of bedaquiline in the experimental time frame (AUC_0-t ) reduced to 3477 ± 228 from 4984 ± 1174 ng h/mL, respectively. Maximum plasma concentrations of bedaquiline (259 ± 77 ng/mL), AUC_0-t (3112 ± 1046 ng h/mL), and AUC_0-∞ (3673 ± 1493 ng h/mL) were significantly reduced along with an increase in the clearance of bedaquiline (3.1 ± 1.1 L/h/kg) in the case of streptozotocin-induced diabetic rats compared to respective pharmacokinetic parameters of bedaquiline (482 ± 170 ng/mL, 4984 ± 1174 ng h/mL, and 6137 ± 1542 ng h/mL) in the normal rats. Preclinical findings suggest that dose adjustment of bedaquiline is required in the diabetes mellitus condition to prevent the therapeutic failure of bedaquiline treatment, but clinical exploration is needed to establish the fact. It is the first report for the consequence of renal impairment and diabetes mellitus on the pharmacokinetics of bedaquiline in the preclinical model.

Target specific intracellular quantification of etoposide by quadrupole-time of flight based mass spectrometric method

Etoposide (ETP), a widely used chemotherapeutic agent has an intracellular target site of action. Unfortunately, the concentration of ETP in plasma does not properly reflect the concentration in its intracellular site of action. As per our knowledge, no reported bioanalytical method is available for intracellular quantification of ETP. In this research, we developed an LC-MS/MS method to quantitate ETP in intracellular compartments of MCF-7 cells. The Abcam nuclear extraction kit was used for extracting the nuclear and cytosolic protein from MCF-7 cells. The method showed excellent linearity in the 20-1000 ng/mL range. The intra and inter-day precision (%CV) including LLOQ were found to be in the range of 2.19-16.96% and 6.71-11.21%, respectively, with an accuracy of 86.87 to 110.37% and 93.03 to 100.50%, respectively. The concentration of ETP in nuclear and cytosolic fraction was successfully quantitated using the developed method. The developed method can be applied to understand the efficacy of different formulations based on the intracellular ETP concentration in vitro. It can be considered as a model method for quantification of other similar categories of drugs in their actual intracellular site of action after required optimization in the methodology.

Effect of IS01957, a para-coumaric acid derivative on pharmacokinetic modulation of diclofenac through oral route for augmented efficacy

Diclofenac is one of the world's largest selling nonsteroidal anti-inflammatory drugs. The major concerns related to oral diclofenac therapy are gastrointestinal and cardiovascular side effects for which explicitly emphasis has been given to use it at lowest effective dose for the shortest duration. On the other hand, IS01957 has been designed under the purview of anti-inflammatory drug and bioavailability enhancer. IS01957 have dual action on inflammation and nociception with acceptable safety profile. In the quest for a suitable combination with improved therapeutic efficacy and better tolerability, pharmacodynamic and pharmacokinetic interaction studies were performed for diclofenac with or without IS01957 in mice model. Results showed that IS01957 enhanced both anti-inflammatory effect and plasma concentration of diclofenac upon concomitant oral administration. These interesting results steered to enumerate the possible role of IS01957 towards diclofenac pharmacokinetics through a panel of mechanistic investigations: (a) BCRP dependent ATPase activity was markedly interfered by IS01957; (b) IS01957 increased the intestinal permeability of diclofenac in the single pass in-situ perfusion model; (c) IS01957 inhibited the CYP2C9 catalyzed diclofenac 4-hydroxylation in human liver microsomes. Immunoblotting results suggest that diclofenac action was improved significantly in the presence of IS01957 involving MAPK pathways. Finally acute gastric damage study showed that IS01957 in combination with diclofenac was better to improve the desired PGE₂ level as compare to alone. In nutshell, IS01957 have potential to augment the efficacy of diclofenac through pharmacokinetic modulation. Further investigations are required for dose reduction of diclofenac to combat its liabilities before going into clinical setting.

Linalyl acetate prevents olmesartan-induced intestinal hypermotility mediated by interference of the sympathetic inhibitory pathway in hypertensive rat

Olmesartan-associated enteropathy (OAE) is a life-threatening pathological condition, but its underlying mechanisms have not been elucidated. Although intestinal hypermotility is frequently accompanied by chronic diarrhea, there have been no studies of olmesartan-induced hypermotility. Intestinal motility should be well regulated by the enteric nervous system, but degeneration of enteric neurons has been reported in patients with chronic diarrheal diseases, such as irritable bowel syndrome, suggesting a connection between OAE and intestinal hypermotility. In this study, interference with this inhibitory pathway was analyzed in a model of olmesartan-induced intestinal hypermotility (OIH) in rats with nicotine-induced hypertension exposed to chronic immobilizing stress. The effects of the potent inhibitory neurotransmitters norepinephrine (NE) and sodium nitroprusside (SNP), which act via different pathways, were assessed ex vivo, with only NE-modulated frequency and amplitude of spontaneous contractions found to be elevated in OIH rat jejunum. Clinical symptoms frequent in OAE, including atrophy of the intestinal epithelium and weight loss, were observed in these rats. Interestingly, olmesartan significantly elevated heart rate while lowering blood pressure in OIH rats. These abnormal conditions were prevented by adding linalyl acetate (LA), while the blood pressure-lowering effects of olmesartan were maintained. These findings suggest that olmesartan induces intestinal hypermotility by interfering with the sympathetic inhibitory pathway, and reduces epithelial cell size or body weight in hypertensive rats. As LA prevented these effects, combination treatment with olmesartan plus LA may provide better antihypertensive efficacy without inducing OAE.

Development and validation of a high throughput LC-MS/MS method for simultaneous quantitation of pioglitazone and telmisartan in rat plasma and its application to a pharmacokinetic study

Management of cardiovascular risk factors in diabetes demands special attention due to their co-existence. Pioglitazone (PIO) and telmisartan (TLM) combination can be beneficial in effective control of cardiovascular complication in diabetes. In this research, we developed and validated a high throughput LC-MS/MS method for simultaneous quantitation of PIO and TLM in rat plasma. This developed method is more sensitive and can quantitate the analytes in relatively shorter period of time compared to the previously reported methods for their individual quantification. Moreover, till date, there is no bioanalytical method available to simultaneously quantitate PIO and TLM in a single run. The method was validated according to the USFDA guidelines for bioanalytical method validation. A linear response of the analytes was observed over the range of 0.005-10 µg/mL with satisfactory precision and accuracy. Accuracy at four quality control levels was within 94.27%-106.10%. The intra- and inter-day precision ranged from 2.32%-10.14 and 5.02%-8.12%, respectively. The method was reproducible and sensitive enough to quantitate PIO and TLM in rat plasma samples of a preclinical pharmacokinetic study. Due to the potential of PIO-TLM combination to be therapeutically explored, this method is expected to have significant usefulness in future.

In vitro and in vivo effects of morin on the intestinal absorption and pharmacokinetics of olmesartan medoxomil solid dispersions

PURPOSE

In-situ evaluation to corroborate morin effects on the intestinal absorption and pharmacokinetic behavior of freeze-dried OLM-loaded solid dispersions with Caco-2 and in-vivo studies Methods: Intestinal transport and absorption studies were examined by Caco-2 permeability, in-situ single pass perfusion and closed-loop models along with in-vivo pharmacokinetic studies to evaluate and confirm the effect of P-gp-mediated activity of morin. We evaluated the intestinal membrane damage in the presence of morin by measuring the release of protein and lactate dehydrogenase (LDH) followed by using qualitative and quantitative morphometric analysis to describe the surface characteristics of intestinal epithelium.

RESULTS

Morin showed the highest P_eff value 13.8 ± 0.34 × 10^-6cm/s in jejunum than ileum (p < .01) at 100 µM with absorption enhancement of 1.31-fold together with enhanced (p < .01) secretory transport of 6.27 ± 0.27 × 10 ^-6cm/s in Caco-2 monolayer cells. Our findings noticed 2.37 (in-situ); 2.39 (in-vivo) and 1.43 (in-situ); 1.36 (in-vivo) fold increase in AUC_0-t with elevated C_max and shortened T_max for freeze-dried solid dispersion in the presence of morin as compared to pure OLM and freeze-dried solid dispersions without morin, respectively.

CONCLUSIONS

Our study demonstrated that increased solubilization through freeze-dried OLM-loaded solid dispersion together with efflux inhibition improved intestinal permeability to one system that might lead to novel solubilization and efflux pump inhibition as a novel alternative potential to increase oral absorption and bioavailability of OLM.