Advances on nanoformulation approaches for delivering plant-derived antioxidants: A case of quercetin.

Oxidative stress has been implicated in tumorigenic, cardiovascular, neuro-, and age-related degenerative changes. Antioxidants minimize the oxidative damage through neutralization of reactive oxygen species (ROS) and other causative agents. Ever since the emergence of COVID-19, plant-derived antioxidants have received enormous attention, particularly in the Indian subcontinent. Quercetin (QCT), a bio-flavonoid, exists in the glycosylated form in fruits, berries and vegetables. The antioxidant potential of QCT analogs relates to the number of free hydroxyl groups in their structure. Despite presence of these groups, QCT exhibits substantial hydrophobicity. Formulation scientists have tested nanotechnology-based approaches for its improved solubilization and delivery to the intended site of action. By the virtue of its hydrophobicity, QCT gets encapsulated in nanocarriers carrying hydrophobic domains. Apart from passive accumulation, active uptake of such formulations into the target cells can be facilitated through well-studied functionalization strategies. In this review, we have discussed the approaches of improving solubilization and bioavailability of QCT with the use of nanoformulations.

Development and Validation of Stability-indicating RP-HPLC Method for Estimation of Pranlukast Hydrate in its Laboratory Mixture.

Pranlukast hydrate is an anti-asthmatic drug and used in the treatment of acute asthma. Stability-indicating RP-HPLC method for pranlukast hydrate has been developed and validated. The reverse phase high performance liquid chromatographic method was developed using Shimadzu Column: Kromosil 100 C18 (150 mm × 4.6 mm × 5 µm) and mobile phase Acetonitrile: 0.1% Glacial acetic acid (85: 15% v/v). Eluent was monitored with UV-detector at 262 nm with a flow rate of 0.5 mL/min, temperature maintained at 30°C. Stress testing was carried out in acidic, alkaline, oxidative, photolytic and dry heat degradation conditions. The method was validated as per the International Conference for Harmonization guidelines and includes specificity, accuracy, precision, linearity and limit of quantitation and detection parameters. A relative standard deviation <2% indicates the developed method was precise. The accuracy of the method was represented by recovery studies ranging between 99.41 and 99.72%. In acid, alkaline, oxidative stress conditions, pranlukast hydrate degrades significantly and in photolytic, dry heat, hydrolytic conditions remain stable. This proposed method is suitable for the analysis of pranlukast hydrate in its laboratory mixture.

Multiple drug delivery from the drug-implants-laden silicone contact lens: Addressing the issue of burst drug release.

A fixed combination of bimatoprost/timolol eye drop solution is used to manage the elevated intra-ocular pressure in glaucoma patients, including individuals whose condition is poorly controlled by monotherapy. Eye drop solutions are generally given in high dose, due to poor ocular bioavailability. The high ocular dose of bimatoprost and timolol lead to hyperaemia and systemic cardiac side effects respectively. Here, we introduce multiple implant-laden contact lenses (IM) to passively deliver timolol, bimatoprost and hyaluronic acid at therapeutically relevant doses without high burst release. The drug-loaded implants were individually implanted in the outer periphery of the silicone contact lenses. Atomic force microscopy showed the smooth surface of the implant contact lens, as the implants were inside the contact lens matrix. The implant lens (IM) showed major loss of drugs [timolol = 60.60%, bimatoprost = 61.75% and HA = 46.03%] during the monomer extraction and wet sterilization, while the option of dry radiation sterilization (IM-R lens) and hydration for 24 h prior to use showed relatively lower loss of drugs [timolol = 16.87%, bimatoprost = 47.95% and HA = 24.41%]. The in-vitro drugs release data of IM-R lens, showed sustained release for 72 h, with low burst release in comparison to the soaked (SM) and direct drug-laden contact lenses (DL). The in vivo drug release data in the rabbit tear fluid showed sustained release using IM-R lens in comparison to the SM lens and eye drop therapy. The burst release with the IM-R lens was many folds reduced, which could bypass the side effects associated with multiple eye drop therapy. The in vivo pharmacodynamic study in the rabbit model showed peak and valley profile with multiple eye drop therapy, while IM-R lens showed prolong reduction in intra ocular pressure (IOP) for 120 h. The study demonstrates the application of implantation technology to deliver multiple drug through contact lenses to treat glaucoma.

Lidocaine tripotassium phosphate complex laden microemulsion for prolonged local anaesthesia: In vitro and in vivo studies.

Lidocaine is widely used as a local anaesthetic in the clinical practice to manage pre- and post-operative pain, skin burns, etc. However, the short duration of action (< 2 h) of marketed dosage forms limit their ability to meet clinical needs. Herein, we prepared a lidocaine-tPP(tri potassium phosphate)-complex loaded microemulsion to achieve greater penetration, followed by destabilization of microemulsion in the skin layer to precipitate oil-complex to produce a depot effect in the skin for prolonging the effects of anaesthesia. The lidocaine-tPP-complex-microemulsion was compared with lidocaine base loaded microemulsion, marketed ointment USP and lidocaine HCl. The pseudo ternary phase diagrams at three Smix ratios (1:2, 1:3 and 1:4; Pluronic F127: PEG 400) were constructed using Capmul MCM C8 EP as oil phase. The Smix at 1:4 ratio showed large microemulsion area in comparison to 1:2 and 1:6 ratio. The lidocaine base (LD-1:4-ME10O45SM and LD-1:4-ME20O45SM) and lidocaine-tPP-complex (LDC-1:4-ME10O45SM and LDC-1:4-ME20O45SM) loaded microemulsion batches (1:4 ratio) were thermodynamically stable. The ex vivo diffusion study showed sustained release up to 12 h with microemulsion batches, in comparison to lidocaine HCl (4 h) and ointment base (7 h). The selected LDC-1:4-ME20O45SM batch was non-irritating on the rabbit skin. In drug retention studies, LD-1:4-ME20O45SM and LDC-1:4-ME20O45SM batches showed 2.68- and 3.93-fold greater lidocaine retention in comparison to ointment USP. The radiant heat tail-flick test showed prolong local anaesthesia using LDC-1:4-ME20O45SM in comparison to ointment USP. The findings suggest that lidocaine-tPP-complex loaded microemulsion could be a potential strategy for providing prolong local anaesthesia.

Co-delivery of timolol and hyaluronic acid from semi-circular ring-implanted contact lenses for the treatment of glaucoma: in vitro and in vivo evaluation.

Glaucoma is a chronic disease, which is currently treated using frequent high dose applications of an eye drop solution; this method is tedious, and most of patients are non-compliant to it. Contact lenses are emerging as a convenient option to sustain the release of ophthalmic drugs. However, the incorporation of a drug/formulation changes the optical and physical properties of contact lenses. Contact lens users have also reported pink eye syndrome; this makes contact lenses unsuitable to be accepted as a medical device. The objective of the present study was to design novel timolol and hyaluronic acid (comfort agent)-loaded semi-circular ring-implanted contact lenses that could uphold the release at therapeutic rates without compromising the critical lens properties. The drug-loaded rings were individually implanted within the periphery of the contact lenses using modified cast-moulding technology. Atomic force microscopy showed an average roughness of 12.38 nm for the implanted lens that was significantly lower as compared to that of the Freshlook contact lenses (116.27 nm). A major amount of timolol was leached (from 46.47 to 58.79%) during the monomer extraction and moist sterilization (autoclave) steps; therefore, the lenses were sterilized by radiation and packaged under dry conditions (dehydrated). The in vitro release data showed sustained release of timolol and hyaluronic acid up to 96 h. The in vivo drug release study on rabbit eyes showed the presence of timolol in tear fluid up to 72 h. The in vivo pharmacodynamics studies showed a reduction in IOP till 144 h with a low drug loading (154 µg) as compared to the case of a single instillation eye drop solution (250 µg). This study has demonstrated the successful application of implantation technology to co-deliver timolol and hyaluronic acid from contact lenses for an extended period of time to treat glaucoma.

Laparoscopic right donor nephrectomy: endo TA stapler is safe and effective.

Although laparoscopic donor nephrectomy is now a well-accepted alternative to traditional open donor nephrectomy at many transplantation centers, there are always concerns regarding quality of graft and vessels after laparoscopic harvest, especially with right donor nephrectomy. Several methods of graft retrieval have been explored to achieve acceptable graft outcome. We share our initial experience at the Institute of Kidney Diseases and Research Center, Amedabad, India of laparoscopic right donor nephrectomy performed by subcostal open, and pure laparoscopic approach with the use of Endo TA stapler. Nine laparoscopic right donor nephrectomies were performed by the trans-peritoneal approach at our centre from January 2006 to March 2007. In the first five cases, the grafts were retrieved through subcostal incision (Group A) and the last four cases were performed purely laparoscopically by using Endo TA stapler device (Group B). None of the patients needed open conversion. The mean operative time and hospital stay were comparable in each group. The warm ischemia time was longer in pure laparoscopic group (415 seconds) than the subcostal open approach group (176 seconds). The serum creatinine of the recipients on day seven was comparable in both the groups. The recipient surgery was effectively performed with graft retrieved using Endo TA stapler device (Group B) without any compromise to the renal vein length. Our study suggests that the Endo TA stapler device is safe and provides all the benefits of minimally invasive surgery to the donor.

Laparoscopic pyelovesicostomy for giant hydronephrosis in a solitary kidney.

Pyelovesicostomy has rarely been described in the literature. Most of the time this procedure has been performed in cases of ureteral obstruction in an ectopic kidney or in a transplanted kidney. We report the case of a 16-year-old male who presented with a history of large abdominal swelling and pain. On investigation he was found to have a solitary right kidney with giant hydronephrosis and to be in renal failure. An initial percutaneous nephrolithotomy diversion was performed followed 1 month later by right laparoscopic pyelovesicostomy. The postoperative period was uneventful. We describe laparoscopic pyelovesicostomy in the management of giant hydronephrosis for the first time. Our case illustrates that laparoscopic pyelovesicostomy is a feasible option in the management of giant hydronephrosis.

Preparation and characterization of etoricoxib-polyethylene glycol 4000 plus polyvinylpyrrolidone K30 solid dispersions.

The objective of the present investigation was to study the influence of polyethylene glycol 4000 (PEG) and polyvinylpyrrolidone K30 (PVP) on in vitro dissolution of etoricoxib from solid dispersions. Preliminary studies were carried out using a physical mixture of the drug and carriers. Solid dispersions were prepared using the solvent evaporation method. A 32 factorial design was adopted in the solvent evaporation method using the concentration of PEG and PVP as independent variables. Full and reduced models were evolved for dependant variables, such as the percentage of drug release in 10 min (Q10), percentage of drug release in 30 min (Q30), percentage of drug release in 45 min (Q45) and percent dissolution efficiency (DE). The reduced models were validated using two check points. Q10 > 65%, Q30 > 75%, Q45 > 85% and DE > 80% were used as constraints for the selection of an optimized batch. Contour plots are presented for the selected dependant variables. PEG was found to be more effective in increasing the drug dissolution compared to PVP. Wettability study was carried out for the pure drug and optimized batch. FT-IR spectroscopy, microscopic study, differential scanning calorimetry and X-ray diffraction study were carried out in order to characterize the drug in solid dispersions. Improved dissolution was attributed to decreased crystallinity of the drug, improved wetting and solubilizing effects of carriers such as PEG and PVP from the solid dispersion of etoricoxib. In conclusion, dissolution of etoricoxib can be modulated using appropriate levels of hydrophilic carriers.

High-dose peripheral blood stem cell infusion: a strategy to induce donor-specific hyporesponsiveness to allografts in pediatric renal transplant recipients.

We designed and implemented a clinical trial to achieve zero-rejection status in pediatric renal allograft recipients, using granulocyte-macrophage colony-stimulating factor (GM-CSF)-stimulated peripheral blood stem cell (PBSC) infusion. We studied 44 consecutive patients: 24 volunteers in a treated group (Tn) and 20 in a control group (Cn). Both groups were comparable with respect to clinical and laboratory parameters. The Tn group had 70.8% one haplo-match donors and the Cn group had 80% one haplo-match donors. Patients in the Tn group received cyclosporin A (CsA) and 0.4 mg/kg body weight prednisolone as immunosuppressants; azathioprine was added for patients of the Cn group, who received 1 mg/kg body weight prednisolone together with CsA. Living-related donors (LRD) of patients in the Tn group received GM-CSF 450 microg on four consecutive days followed by leucopheresis and immediate transfusion of unmodified PBSC into the recipient. This procedure was repeated once/twice, with one portal and one/two systemic infusions. Our aim was to maximize the dose of PBSC. The total average dose was 22 x 10(8) cells/kg body weight. Lymphocyte cross-match (LCM) was performed before GM-CSF injection and after the last PBSC infusion. Follow-up over an 18-month period revealed 100% graft survival with sustained low serum creatinine (SCr) values in patients of the Tn group as compared with 80% graft survival in patients of the control group who had marginally higher SCr levels. Absence of graft vs. host disease (GvHD), acute rejection episodes, and low incidence of cytomegalovirus (CMV) disease were the principal benefits of this protocol.