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 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.

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.

Cardioprotective effect of melatonin against isoproterenol induced myocardial infarction in rats: A biochemical, electrocardiographic and histoarchitectural evaluation.

The present study was designed to investigate the cardioprotective effect of melatonin against isoproterenol induced myocardial infarction in rats by studying myocyte injury markers, antioxidant defense system, serum and heart lipid profile, inflammatory markers, electrocardiographic and histopathological changes. Male Sprague Dawley (SD) rats were randomly divided into four groups, namely control, melatonin, isoproterenol and melatonin+isoproterenol treated group. Melatonin treatment group received melatonin (10mg/kg/day, i.p.) for 7days. Myocardial infarction in rats was induced by isoproterenol administration (150mg/kg, s.c.) at an interval of 24h on 6th and 7th day. On 8th day ECG, gravimetric, biochemical and histopathological parameters were assessed. Isoproterenol administration showed changes in ECG pattern, including ST-segment elevation (diagnostic of myocardial infarction) increase in the serum levels of cardiac injury markers (creatine kinase-MB, lactate dehydrogenase, aspartate transaminase and alanine transaminase), decreased antioxidant defense system in the heart and altered lipid profile in the serum and heart. Isoproterenol administration also resulted in release of inflammatory markers and neutrophil infiltration along with histopathological changes. Melatonin pre-co-treatment prevented almost all the parameters of isoproterenol induced myocardial infarction in rats. The above finding was confirmed by the histopathological examination. In the baseline group (melatonin alone treated group) no significant change was observed. Results of the present study suggest that melatonin has a significant effect on the protection of the heart against isoproterenol induced myocardial infarction through maintaining endogenous antioxidant enzyme activities.

Nebivolol reduces experimentally induced warm renal ischemia reperfusion injury in rats.

Ischemia/reperfusion injury, which is commonly seen in the field of renal surgery or transplantation, is a major cause of acute renal failure. The objective of the present study was to examine the role of nebivolol in modulating peroxynitrite species-induced inflammation and apoptosis after renal warm ischemia/reperfusion injury in rats. The present study was designed to investigate the effects of nebivolol on the renal warm ischemia/reperfusion injury in rats treated with the nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine methyl ester. After right nephrectomy, nebivolol was administered for 15 days. On the 16(th) day, ischemia was induced in contra lateral kidney for 45 min, followed by reperfusion for 24 hr. Renal function, inflammation, and apoptosis were estimated at the end of 24 hr reperfusion. Nebivolol improved the renal dysfunction and reduced inflammation and apoptosis after renal ischemia/reperfusion injury. In conclusion, nebivolol shows potent anti-apoptotic and anti-inflammatory properties due to its NO-releasing property. These findings may have major implications in the treatment of human ischemic acute renal failure.