An Innovative Method Development And Forced Degradation Studies For Simultaneous Estimation Of Sofosbuvir And Ledipasvir By Rp Hplc

Objective: To develop an innovative, rapid, simple, cost-effective, stability indicating reverse phase-high performance liquid chromatography (RP-HPLC) method for simultaneous estimation of ledipasvir (LP) and sofosbuvir (SB) in combination pill dosage form. Methods: The method was developed using C8 column, 250 mm x 4.6 mm, 5 mm using mobile section comprising of 0.1% (v/v) orthophosphoric acid buffer at pH 2.2 and acetonitrile in the ratio of 45:55 that was pumped through the column at a flow rate of 0.8 ml/min. Temperature was maintained at 30 °C, the effluents were monitored at 260 nm with the help of usage of PDA detector. Results: The retention time of LP and SB were found to be 2.246 min and 3.502 min. The approach was found to be linear with the variety of 9-36 µg/ml and 40-240 μg/ml for LP and SB respectively, the assay of estimated compounds were found to be 99.65% and 99.73% w/v for LP and SB respectively. Conclusion: The pressured samples changed into analyzed and this proposed a technique turned into determined to be particular and stability indicating as no interfering peaks of decay compound and excipients were observed. Hence, the approach was easy and economical that may be efficiently applied for simultaneous estimation of both LP and SB in bulk and combination tablet system.

Bidder's organ extract induced anaphylaxis in experimental animals.

Bidder's organ (BO, a vestigeal organ), present in toad Bufo melanostictus (Schenider), is a characteristic feature of all male bufo. Its possible anaphylactic properties are investigated on experimental animals. BO extract produced both in vivo and in vitro anaphylactic reaction in guineapig. Dyspnoea and bronchoconstriction was a major cause of anaphylactic death. Blood histamine level was significantly increased in the anaphylactic animals. BO extract significantly released histamine from chopped lung preparation, an action antagonised by disodium chromoglycate. BO extract degranulated peritoneal mast cell in vitro. Passive cutaneous anaphylactic reactions were enhanced by BO extract and were significantly inhibited by disodium chromoglycate. Anaphylotoxin (identity not known) present in bidder's organ is probably involved in toad defence.

An experimental study on evaluation of chemical antagonists induced snake venom neutralization.

The present investigation explored the snake venom neutralizing capacity of four chemical compounds (2-hydroxy-4-methoxy benzoic acid, anisic acid, salicylic acid and aspirin) in experimental animals. The venoms of common Indian snakes Viper russellii, Echis carinatus, Naja kaouthia and Ophiophagus hannah were taken to evaluate the lethal, haemorrhagic and defibrinogenation action neutralization. Lethal action of venom was maximum neutralized with 2-hydroxy-4-methoxy benzoic acid and anisic acid, both in in vitro and in vivo studies. Haemorrhagic activity of venom (Viper and Echis) was maximum neutralized with salicylic acid. Viper venom induced defibrination was maximally neutralized with 2-hydroxy-4-methoxy benzoic acid and anisic acid in vitro studies. The exact mechanisms of venom neutralization by the chemical compounds were not established, except for 2-hydroxy-4-methoxy benzoic acid, where the functional groups, methoxy and hydroxy were partly responsible for the neutralization of the lethal effect and haemorrhagic activity.

A lethal cardiotoxic protein isolated from Bidder's organ of common Indian toad, Bufo melanostictus Schneider.

A lethal cardiotoxic (BO-CT; Bidder's organ cardiotoxin) protein was purified from the Bidder's organ of the common Indian toad B. melanostictus by gel filtration on Sephadex G-200. The homogeneity of cardiotoxin was tested by gel electrophoresis. The molecular weight of lethal BO-CT was 62 KDa and was devoid of glycoprotein. LD50 of the BO-CT was 50 micrograms/20 g (i.v.) in male albino mice. On isolated heart and auricle BO-CT initially increased the rate and amplitude of contraction and finally produced irreversible blockade of contraction. BO-CT induced auricular blockade, was not influenced by verapamil, propranolol and atropine. On isolated chick biventer cervicis preparation BO-CT produced irreversible blockade of electrically induced twitch response followed by contracture. This action was not antagonized by 4-aminopyridine and neostigmine. BO-CT induced contracture on chick biventer cervicis was increased by Ca2+, decreased by Na+ and abolished by K+. Cardiotoxic and neuromuscular activity of BO-CT was heat stable and abolished by proteolytic enzyme.

Isolation, purification and partial characterization of a haemolytic protein from Bidder's organ of toad Bufo melanostictus (Schneider).

A haemolytic protein toxin (BO-HT) from Bidder's organ of toad, B. melanostictus, purified by DEAE-cellulose column chromatography was electrophoretically homogeneous and was glycoprotein in nature (PAS-positive). The molecular weight was estimated to be 14.4 kDa by SDS-polyacrylamide gel electrophoresis. The sensitivity of the haemolysin of different RBC ghost cell preparation was in the order: buffalo > goat > ox > guinea pig > mice > human > chick > rabbit > rat. The haemolytic activity was increased with the decrease in RBC concentration and was produced over a wide range of temperature. Maximum haemolytic effect was produced at 2 hr of incubation. The toxin showed maximum activity at 3 and minimum at 10 pH. Divalent cations (Ca2+, Zn2+, Cu2+, Mg2+) showed inhibitory effect on BO-HT induced haemolysis, whereas sucrose, EDTA, cholesterol, 2-mercaptoethanol and oxygen did not alter the haemolytic activity. Haemolytic activity was reduced by proteolytic enzymes (trypsin, protease) and was totally antagonized by the toad serum.

Pharmacological actions of the venom of the Indian catfish (Plotosus canius Hamilton).

The venom of the common Indian catfish P. canius Hamilton (locally called 'Kanmagur') was examined for its pharmacodynamic activity. The LD50 of the venom in mice was found to be 3.9 mg/kg (ip). At lower doses, the venom produced a positive inotropic effect on toad and rabbit hearts, while at higher doses it produced cardiac arrest. In the isolated guinea pig auricle, the venom increased the rate and amplitude of contraction. The venom increased rat blood pressure--an action antagonised by alpha-adrenergic blocker (phenoxybenzamine). It reduced the rate and amplitude of rat and guinea pig respiration leading to respiratory arrest and death. The venom did not alter the cutaneous capillary permeability of guinea pig but produced vasoconstrictor effect on rat hindquarter perfusion. It induced contractions in several smooth muscle preparations viz., ileum and colon of guinea pig, fundus, uterus and ileum of rat. On isolated guinea pig ileum, the venom produced contraction which was not antagonised by atropine and mepyramine, but was partially antagonised by methysergide associated with a residual contraction which was abolished by SC 19220, a prostaglandin receptor blocker. The venom produced irreversible blockade of electrically induced twitch response on isolated rat phrenic nerve diaphragm and chick biventer cervicis preparation. Haemolysis was not produced by the venom on mice, guinea pig and human RBC (washed).