A Comparative Preclinical Evaluation of a Novel Difluprednate 0.04% BID Ophthalmic Solution and Marketed 0.05% QID Ophthalmic Emulsion.

Purpose: The purpose of this study was to compare the efficacy, and ocular pharmacokinetics of a new 0.04% w/v bis in die means twice a day (BID) ophthalmic solution and marketed 0.05% w/v quater in die means four times a day (QID) ophthalmic emulsion of difluprednate in New Zealand white (NZW) rabbits. Methods: The preclinical proof of concept was established in paracentesis-induced acute inflammation, endotoxin-induced acute uveitis, and bovine serum albumin-induced chronic uveitis in NZW rabbit animal models. A comparison of clinical score, total cell count, and total protein was performed to determine efficacy. An ocular pharmacokinetic study was conducted to study the influence of the vehicle on the ocular absorption of the drug. Results: In both uveitis models, the new solution formulation and marketed emulsion formulation inhibited total clinical score, total cell count, PGE2, and total protein significantly more than the placebo and lipopolysaccharide (disease control) groups and were comparable. In an ocular pharmacokinetic study, the Cmax and AUC0-t of difluoroprednisolone 17-butyrate in humor were ∼2-fold higher after 14 days' instillation of new solution formulation (0.04% w/v, BID) compared with 14 days' instillation of marketed emulsion (0.05% w/v, QID). Conclusions: The study demonstrated that the efficacy of the solution formulation at a lower dose and reduced dosing regimen were comparable to that of the emulsion formulation. The reduction in strength and regimen may result in improved patient adherence and outcomes.

Preclinical Evaluation of a Novel Once-a-Day Brimonidine Ophthalmic Nanosuspension.

Purpose: This article aims to describe a preclinical proof of concept for a novel once-a-day (OD) brimonidine ophthalmic nanosuspension. Methods: The preclinical proof of concept was established using New Zealand white rabbits as animal models. Dose-finding, multiple-dose efficacy, ocular pharmacokinetic, and hemodynamic studies were performed in normotensive rabbits. Steroid-induced ocular hypertension model in rabbits was used to study efficacy in glaucomatous pathophysiology. The test (0.35% OD suspension) and reference (0.15% three times a day [TID] solution) were compared. Results: The intraocular pressure (IOP) reduction was sustained for 0.35% and 0.5% strengths but not for other lower strengths tested or reference strengths. A 0.35% OD suspension reduced IOP >2 mmHg after 24 h of dosing, which was not seen with the reference. After multiple dosing, 0.35% OD suspension reduced IOP by 4-6 mmHg after 24 h, which was comparable to the 0.15% TID reference solution. An ocular pharmacokinetic study showed that the brimonidine was rapidly absorbed and distributed throughout the eye after topical administration. Concentration was higher in tissues with high α2 receptors, such as cornea-conjunctiva, iris/ciliary body, and choroid/retina. The steady-state concentrations in these organs were also significant after 24 h of the last dose. There was an indication of increased plasma levels, so a hemodynamic study was performed to assess any adverse effects. All hemodynamic parameters were normal and no new unusual safety findings were observed. Conclusions: The study demonstrated that the novel brimonidine 0.35% ophthalmic nanosuspension is both safe and effective when administered OD and is comparable to the marketed reference formulation administered TID.

In vivo and in vitro characterization of GL0034, a novel long-acting glucagon-like peptide-1 receptor agonist.

AIMS: To describe the in vitro characteristics and antidiabetic in vivo efficacy of the novel glucagon-like peptide-1 receptor agonist (GLP-1RA) GL0034. MATERIALS AND METHODS: Glucagon-like peptide-1 receptor (GLP-1R) kinetic binding parameters, cyclic adenosine monophosphate (cAMP) signalling, endocytosis and recycling were measured using HEK293 and INS-1832/3 cells expressing human GLP-1R. Insulin secretion was measured in vitro using INS-1832/3 cells, mouse islets and human islets. Chronic administration studies to evaluate weight loss and glycaemic effects were performed in db/db and diet-induced obese mice. RESULTS: Compared to the leading GLP-1RA semaglutide, GL0034 showed increased binding affinity and potency-driven bias in favour of cAMP over GLP-1R endocytosis and ß-arrestin-2 recruitment. Insulin secretory responses were similar for both ligands. GL0034 (6 nmol/kg) led to at least as much weight loss and lowering of blood glucose as did semaglutide at a higher dose (14 nmol/kg). CONCLUSIONS: GL0034 is a G protein-biased agonist that shows powerful antidiabetic effects in mice, and may serve as a promising new GLP-1RA for obese patients with type 2 diabetes.

Enhanced antitumor activity of doxorubicin by naringenin and metformin in breast carcinoma: an experimental study.

Breast cancer is the most common malignancy in women worldwide. Strategies for cancer chemotherapy commonly require the use of combination therapy for better outcomes of results. The present work is aimed to evaluate the potential of naringenin and metformin concomitant addition with doxorubicin chemotherapy against experimental breast carcinoma. The antitumor potential of drugs under the study was evaluated against methylnitrosourea (MNU)-induced breast cancer in rats and 4T1 cells-induced orthotopic breast cancer mouse model. Parameters like tumor growth, body weight, survival rate, blood glucose, hematology, and histology were determined. There was a marked reduction in tumor weight and an observed decrease in tumor multiplicity by naringenin and metformin concomitant addition with doxorubicin against MNU-induced breast carcinoma. Likewise, naringenin and metformin with doxorubicin showed a significant reduction of tumor volume and tumor weight (p < 0.01) in 4T1-induced orthotopic mouse model as compared to the same dose of doxorubicin alone, suggesting combination treatment enhanced antitumor activity in vivo. Furthermore, histology of tumor biopsies presented the improved antitumor activity of doxorubicin via increasing tumor necrosis. Hematological parameters, body weight, and survival data presented remarkable safety of combination treatment without compromising efficacy using 50% lower dose of doxorubicin as compared to the large dose of doxorubicin alone. These results demonstrate that naringenin and metformin enhanced the antitumor effect of doxorubicin in animal models of breast carcinoma, and therefore can be useful as an adjunct treatment with doxorubicin to increase its effectiveness at the lower dose level for the treatment of cancer.

Combining naringenin and metformin with doxorubicin enhances anticancer activity against triple-negative breast cancer in vitro and in vivo.

Triple-negative breast cancer (TNBC) grows fast and represents poor prognosis and management. This work is aimed to determine the effect of concomitant use of naringenin and metformin with doxorubicin chemotherapy using in vitro and in vivo breast carcinoma models. Cell viability and xenograft study were performed using TNBC cell lines. The use of naringenin and metformin together with doxorubicin, have shown a significant increase in cytotoxicity when compared with the same concentration of doxorubicin alone in MDA-MB-231 cells and 4T1 cells in vitro. In the xenograft mouse model, a significant reduction of tumor volume and tumor weight was observed in contrast to a similar dose of doxorubicin alone; suggesting combining treatment enhanced antitumor activity in vivo. Besides, H&E and Ki-67 staining of tumor biopsies showed enhancement of the antitumor activity via increasing necrosis and inhibiting cell proliferation respectively. Additionally, there was no marked change observed in the organ weights, blood glucose, cardiac histology and cardiac Troponin I levels under the study treatment groups. The beneficial effects of using both the naringenin and metformin along with the lower dose of doxorubicin were evident from the reduced dose-related body weight loss and increase in cytokines (TNF-α and IL-1ß) compared to a large dose of doxorubicin alone. Thus, naringenin and metformin combination with doxorubicin found useful as an adjunct therapy to improve the effectiveness of doxorubicin at the lower dose against the breast carcinoma.

Preclinical Efficacy Comparison of Cyclosporine Ophthalmic Solution 0.09% vs Cyclosporine Ophthalmic Emulsion 0.05% vs Ciclosporin Ophthalmic Emulsion 0.1% in a NOD Mouse Model of Dry Eye Disease.

INTRODUCTION: Cyclosporine ophthalmic solution 0.09% (CsA 0.09% sol) is approved to increase tear production in patients with keratoconjunctivitis sicca. This study evaluated the efficacy of CsA 0.09% sol vs cyclosporine ophthalmic emulsion 0.05% (CsA 0.05% eml) vs ciclosporin ophthalmic emulsion 0.1% (CsA 0.1% eml) in a NOD mice model. METHODS: Mice were randomized and administered placebo, CsA 0.09% sol twice daily, CsA 0.05% eml twice daily, CsA 0.09% sol once daily, or CsA 0.1% eml once daily in the conjunctival sac of both eyes for 60 days. Tear volume was measured with phenol red threads at baseline and 4 hours after treatment every 15 days. On day 58, the corneal surface was observed under a slit-lamp after staining with 3% lissamine green administered into the inferior lateral conjunctival sac. On day 61, mice were euthanized, globes excised, sliced into 4 µm sections in 3 areas per section, and stained. Total number of stained goblet cell/µm was counted, and the sum per eye was averaged. Lacrimal gland tissues were removed and interleukin (IL) 1-ß cytokine levels estimated. RESULTS: Groups comprised 11 mice each, including an untreated normal and untreated diseased control group (7 groups total). CsA 0.09% sol twice daily significantly increased tear volume on day 30, 45, and 60 vs CsA 0.05% eml (P<0.05, <0.001, <0.001, respectively) and vs CsA 0.1% eml on day 60 (P<0.05); CsA 0.09% sol once daily significantly increased tear volume on day 45 vs CsA 0.05% eml (P<0.05). Goblet cell density significantly increased with CsA 0.09% sol twice daily vs placebo and NOD control (P<0.01 both). There was no significant difference in corneal staining and IL-1ß levels with CsA 0.09% sol. CONCLUSION: Sixty-day treatment with CsA 0.09% sol showed comparatively improved preclinical results vs CsA 0.05% eml and CsA 0.1% eml.

Analytical characterization of recombinant hCG and comparative studies with reference product.

INTRODUCTION: Regulatory agencies recommend a stepwise approach for demonstrating biosimilarity between a proposed biosimilar and reference biological product emphasizing for functional and structural characterization to trace if there is any difference which may impact safety and efficacy. We studied the comparative structural and biological attributes of recombinant human chorionic gonadotropin (rhCG), SB005, with reference product, Ovidrel® and Ovitrelle®. Recombiant hCG was approved in 2000 by the US Food and Drug Administration for the induction of final follicular maturation, early luteinization in infertile women as part of assisted reproductive technology program. It is also indicated for the induction of ovulation and pregnancy in ovulatory infertile patients whose cause of infertility is not due to ovarian failure. MATERIALS AND METHODS: Primary structure was studied by intact mass analysis, peptide fingerprinting, peptide mass fingerprinting and sequence coverage analysis. Higher order structure was studied by circular dichroism, ultraviolet-visible spectroscopy, fluorescence spectroscopy, and disulfide bridge analysis. Different isoforms of reference product and SB005 were identified using capillary isoelectric focusing and capillary zone electrophoresis. Glycosylation was studied by N-glycan mapping using LC-ESI-MS, point of glycosylation, released glycan analysis using ultra performance liquid chromatography and sialic acid analysis. Product related impurities such as oligomer content analysis and oxidized impurities were studied using size exclusion chromatography and reverse phase high performance liquid chromatography, respectively. Biological activity in term of potency of reference product and SB005 was studied by in vivo analysis. RESULTS AND CONCLUSION: In this study we have compared analytical similarity of recombinant rhCG (SB005) produced at Sun Pharmaceuticals with the reference product with respect to its primary, higher order structure, isoforms, charge variants, glycosylation, sialyation pattern, pharmacodynamic and in vivo efficacy. Our studies show that the in house produced rhCG has a high degree of structural and functional similarity with the reference product available in the market.

Lipodox® (generic doxorubicin hydrochloride liposome injection): in vivo efficacy and bioequivalence versus Caelyx® (doxorubicin hydrochloride liposome injection) in human mammary carcinoma (MX-1) xenograft and syngeneic fibrosarcoma (WEHI 164) mouse models.

BACKGROUND: Doxorubicin (DXR) hydrochloride (HCl) liposome injection is an important part of the treatment armamentarium for a number of cancers. With growing needs for affordable and effective anticancer treatments, the development of generics is becoming increasingly important to facilitate patient access to vital medications. We conducted studies in relevant mouse models of cancer to compare the preclinical antitumour efficacy and plasma pharmacokinetic profile of a proposed generic DXR HCl liposome injection developed by Sun Pharmaceutical Industries Ltd. (SPIL DXR HCl liposome injection) with Caelyx® (reference DXR HCl liposome injection). METHODS: Syngeneic fibrosarcoma (WEHI 164)-bearing BALB/c mice and athymic nude mice transplanted with MX-1 human mammary carcinoma xenografts were treated with SPIL DXR HCl liposome injection, reference DXR HCl liposome injection or placebo, to compare tumour volume, antitumour activity (percentage test/control [%T/C] ratio, tumour regression, and specific tumour growth delay) and toxicity (survival and weight changes) in response to treatment. The pharmacokinetic profile of the SPIL and reference product was also studied in syngeneic fibrosarcoma-bearing mice. RESULTS: Treatment with either SPIL or reference DXR HCl liposome injection resulted in significant reduction in tumour volume from baseline in both models at all doses tested. High antitumour activity (%T/C ≤ 10) was seen from Day 21 and Day 14 onwards in SPIL and reference DXR HCl liposome injection-treated syngeneic fibrosarcoma-bearing mice, respectively, at 9 mg/kg. Moderate antitumour activity (%T/C ≤ 20) was seen from Day 17 and Day 24 onwards in SPIL and reference DXR HCl liposome injection-treated MX-1-bearing mice, respectively, at 6 mg/kg. No significant differences in tumour volume and %T/C were observed between SPIL and reference DXR HCl liposome injection-treated groups at any dose (p ≥ 0.05). Toxicity profiles were considered to be generally comparable. Evaluation of test/reference (A/B) ratios and 90% confidence intervals (CIs) for peak serum concentration (Cmax) and area under the curve (AUC0-t, and AUC0-∞) demonstrated bioequivalence of SPIL and reference DXR HCl liposome injections. CONCLUSIONS: Establishing similarity is of critical importance during the development of generic treatments. SPIL and reference DXR HCl liposome injections were shown to be comparable with regards to antitumour activity, toxicity and pharmacokinetics.

Comparative plasma and tissue distribution of Sun Pharma's generic doxorubicin HCl liposome injection versus Caelyx® (doxorubicin HCl liposome injection) in syngeneic fibrosarcoma-bearing BALB/c mice and Sprague-Dawley rats.

PURPOSE: The liposomal formulation of doxorubicin [doxorubicin (DXR) hydrochloride (HCl) liposome injection, Caelyx®] alters the tissue distribution of DXR as compared with nonliposomal DXR, resulting in an improved benefit-risk profile. We conducted studies in murine models to compare the plasma and tissue distribution of a proposed generic DXR HCl liposome injection developed by Sun Pharmaceuticals Industries Limited (SPIL DXR HCl liposome injection) with Caelyx®. METHODS: The plasma and tissue distributions of the SPIL and reference DXR HCl liposome injections were compared in syngeneic fibrosarcoma-bearing BALB/c mice and Sprague-Dawley rats. Different batches and different lots of the same batch of the reference product were also compared with each other. RESULTS: The SPIL and reference DXR HCl liposome injections exhibited generally comparable plasma and tissue distribution profiles in both models. While minor differences were observed between the two products in some tissues, different batches and lots of the reference product also showed some differences in the distribution of various analytes in some tissues. The ratios of estimated free to encapsulated DXR for plasma and tissue were generally comparable between the SPIL and reference DXR HCl liposome injections in both models, indicating similar extents of absorption into the tissues and similar rates of drug release from liposomes. CONCLUSIONS: The plasma and tissue distribution profiles of the SPIL and reference DXR HCl liposome injections were shown to be generally comparable. Inconsistencies between the products observed in some tissues were thought to be due to biological variation.

Cardioprotective and antihypertensive effects of Enicostemma littorale Blume extract in fructose-fed rats.

We investigated the protective effects of Enicostemma littorale Blume (EL) extract on hypertension and insulin resistance along with its associated cardiovascular complications in high fructose (HF) fed rats. For this, rats were divided among 4 groups: (i) control, fed laboratory chow; (ii) fed with a high level of fructose; (iii) fed with a high level of fructose plus E. littorale extract; and (iv) fed with a high level of fructose plus rosiglitazone (Rg). EL and Rg treatments were given simultaneously with HF diet. The results show that untreated HF-fed rats showed altered oral glucose tolerance, increased fasting insulin, and increased fasting glucose. These rats also exhibited hypertriglyceridemia, moderate hypertension, platelet hyperaggregability, decreased prothrombin time, activated partial thromboplastin time, altered vascular reactivity, and increased serum levels of enzymes (creatine kinase, type muscle-brain (CK-MB), aspartate aminotransferase (SGOT), lactate dehydrogenase (LDH), and alanine aminotransferase (SGPT). This is the first demonstration of platelet hyperaggregation and prothrombotic alteration in HF-fed rats. HF-fed rats treated with EL showed improved insulin resistance, along with reduced hypertriglyceridemia, hypertension, platelet aggregability, blood coagulation, serum enzymes (CK-MB, SGOT, LDH and SGPT), and vascular reactivity. These effects of EL in HF-induced hypertensive rats might be associated with the suppression of hyperinsulinemia and hypertriglyceridemia, along with its antiatherogenic and antithrombogenic potential. These data indicate that the aqueous extract of EL has great therapeutic potential for the prevention and (or) management of insulin resistance and the associated hypertension.