Prashant B Musmade

Preparation,In vitro, preclinical and clinical evaluations of once daily sustained release tablets of aceclofenac

The objective of the present study was to develop“once daily” sustained release tablets of aceclofenac by direct compression using hydroxypropyl methylcellulose-K4M (HPMC). The solubility studies of aceclofenac were conducted to select suitable dissolution media. The drug-excipient mixtures were subjected to preformulation studies. The tablets were subjected to physicochemical,in vitro drug release and stability studies. Preclinical (anti-inflammatory, analgesic, pharmacokinetic and toxicity studies) and clinical pharmacokinetic studies were conducted for optimized tablets. Based on the preformulation results, microcrystalline cellulose (MCC), dicalcium phosphate and spray dried lactose (SDL) were selected as directly compressible vehicles. Because of the incompatibility with aceclofenac, SDL was excluded from the study. The physicochemical properties of tablets were found within the limits. By comparing the dissolution profiles with the marketed product, the tablet containing HPMC (45%) and MCC (30%) along with talc and magnesium stearate (1% w/w, each) (Tablet B7) was considered as a better formulation. This tablet exhibited almost similar drug release profile in different dissolution media as that of marketed tablet. Tablet B7 was stable in accelerated conditions for 6 months. The composition of this tablet showed almost similar preclinical pharmacological activities compared to marketed tablet composition and did not exhibit any toxicity in rats and mice with respect to tested haematological and biochemical parameters along with body weight, food and water intake. The pharmacokinetic study in healthy human volunteers indicated that B7 tablet produced an extended drug release of drug upto 24 h as that of marketed product with almost identical pharmacokinetic parameters.

Preparation and characterization of co-amorphous Ritonavir-Indomethacin systems by solvent evaporation technique: improved dissolution behavior and physical stability without evidence of intermolecular interactions.

The aim of this study was to stabilize the amorphous form of Ritonavir (RTV) a BCS class-II drug with known amorphous stabilizing small molecule Indomethacin (IND) by co-amorphous technology. The co-amorphous samples were prepared by solvent evaporation technique in the molar ratios RTV:IND (2:1), RTV:IND (1:1), RTV:IND (1:2) and their amorphous nature was confirmed by XRPD, DSC and FT-IR. Physical stability studies were carried out at temp 25°C and 40°C for maximum up to 90 days under dry conditions. Solubility and dissolution testing were carried out to investigate the dissolution advantage of prepared co-amorphous systems. The amorphous mixtures of all tested molar ratios were found to become amorphous after solvent evaporation. The same was confirmed by detecting halo pattern in diffractograms of co-amorphous mixtures. The Tg values of all three systems were found to be more than 40°C, the highest being 51.88°C for RTV:IND (2:1) system. Theoretical Tg values were calculated by Gordon-Taylor equation. Insignificant deviation of theoretical Tg values from that of practical one, corroborated by FT-IR studies showed no evidence of intermolecular interactions between RTV and IND. Almost 3-folds increase in the solubility for both amorphous RTV and IND was found as compared to their respective crystalline counterparts. The study demonstrated significant increase in the dissolution rate as well as increase in the total amount of drug dissolved for amorphous RTV, however it failed to demonstrate any significant improvement in the dissolution behavior of IND.

Enhanced oral absorption of saquinavir with Methyl-Beta-Cyclodextrin-Preparation and in vitro and in vivo evaluation.

Saquinavir (SQV) is a weak base compound, whose solubility is strongly influenced by pH variations. Thus, in the present work, we thought it worthy of interest to investigate in-depth the combined effect of pH control and cyclodextrin (CyD) complexation on SQV solubilization. Phase-solubility studies were performed by adding excess drug to buffered (pH from 1.1 to 7.4) aqueous solutions containing increasing concentrations of Methyl-Beta-CyD (M-β-CyD) in order to evaluate the role of the unionized species of SQV in improving solubility by CyD complexation and to be able to select the most suitable conditions for optimizing drug solubilization. Our study reveals that the integrated approach of pH adjustment and CyD complexation can be successfully used for improving the CyD solubilizing power towards an ionizable drug such as SQV, thus allowing a smaller quantity of CyD to solubilize a given amount of drug, offering clear economic and technologic advantages as well. When biopharmaceutics of the optimized cyclodextrin-based formulation of SQV was studied in Wistar rats after intravenous and oral administrations, we found that inclusion of SQV into M-β-CyD could dramatically improve its oral bioavailability and decrease the variation of its oral pharmacokinetics. Compared to the control, the presence of M-β-CyD significantly increased the area under the plasma concentration-time curve (439.7±161.35 to 2312.03±159.53, p<0.01) and the peak plasma concentration (117.24±35.77 to 1347.88±276.76, p<0.01) of orally administered SQV. The modulating effect of M-β-CyD on the bidirectional transport of SQV was also investigated using a modified Ussing chamber system. The results demonstrated that the enhancing effect of M-β-CyD on the oral bioavailability of SQV is due not only to its solubilizing effect on SQV but also, at least in part, to the inhibitory effect of M-β-CyD on the P-glycoprotein (P-gp) mediated efflux of SQV in the gastrointestinal tract. The present results suggest that M-β-CyD is particularly useful in designing oral preparations of SQV with an enhanced bioavailability and a reduced variability in absorption.

Informed consent: Issues and challenges.

Informed consent is an ethical and legal requirement for research involving human participants. It is the process where a participant is informed about all aspects of the trial, which are important for the participant to make a decision and after studying all aspects of the trial the participant voluntarily confirms his or her willingness to participate in a particular clinical trial and significance of the research for advancement of medical knowledge and social welfare. The concept of informed consent is embedded in the principles of Nuremberg Code, The Declaration of Helsinki and The Belmont Report. Informed consent is an inevitable requirement prior to every research involving human being as subjects for study. Obtaining consent involves informing the subject about his or her rights, the purpose of the study, procedures to be undertaken, potential risks and benefits of participation, expected duration of study, extent of confidentiality of personal identification and demographic data, so that the participation of subjects in the study is entirely voluntary. This article provides an overview of issues in informed consent: The obligations of investigator, sponsor and Institutional Review Board to protect rights and welfare of human research subjects. It discusses about the basic elements of informed consent and the process to be followed while obtaining informed consent. Some of the circumstances under which informed consent can be waived and ethical challenges faced by physicians in obtaining informed consent from subjects are also highlighted in this article.

Stability-indicating HPTLC determination of imatinib mesylate in bulk drug and pharmaceutical dosage form

A simple, selective, precise and stability-indicating high-performance thin-layer chromatographic method of analysis of imatinib mesylate both as a bulk drug and in formulations was developed and validated. The method employed HPTLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of chloroform:methanol (6:4, v/v). The system was found to give compact spot for imatinib mesylate (R(f) value of 0.53+/-0.02). Densitometric analysis of imatinib mesylate was carried out in the absorbance mode at 276 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r(2)=0.9966+/-0.0013 with respect to peak area in the concentration range 100-1000 ng per spot. The mean value+/-S.D. of slope and intercept were 164.85+/-0.72 and 1168.3+/-8.26 with respect to peak area. The method was validated for precision, recovery and robustness. The limits of detection and quantitation were 10 and 30 ng per spot, respectively. Imatinib mesylate was subjected to acid and alkali hydrolysis, oxidation and thermal degradation. The drug undergoes degradation under acidic, basic, oxidation and heat conditions. This indicates that the drug is susceptible to acid, base hydrolysis, oxidation and heat. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of said drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of imatinib mesylate in bulk drug and dosage forms.

Fabrication, solid state characterization and bioavailability assessment of stable binary amorphous phases of Ritonavir with Quercetin

In the current study, Quercetin (QRT) was characterized for thermodynamic and kinetic parameters and found as an excellent glass former. QRT was paired with Ritonavir (RTV) (BCS class-IV antiretroviral) to form stable amorphous form and pharmacologically relevant combination. Binary amorphous forms of RTV and QRT in molar ratios 1:1, 1:2 and 2:1 were prepared by solvent evaporation technique and characterized by XRPD, DSC and FTIR. The prepared binary phases were found to become amorphous after solvent evaporation which was confirmed by disappearance of crystalline peaks from X-ray diffractograms and detecting single Tg in DSC studies. The physical stability studies at 40 °C for 90 days found RTV:QRT 1:2 and RTV:QRT 2:1 phases stable, while trace crystallinity was detected for 1:1M ratio. The temperature stability of RTV:QRT 1:2 and RTV:QRT 2:1 amorphous forms can be attributed to phase solubility of both components where the drug in excess acts as a crystallization inhibitor. Except for RTV:QRT 1:2 ratio, there was no evidence of intermolecular interactions between two components. Almost 5 fold increase in the saturation solubility was achieved for RTV, compared to crystalline counterpart. While for QRT, the solubility advantage was not achieved. In vivo oral bioavailability study was conducted for 1:2 binary amorphous form by using pure RTV as a control. Cmax was improved by 1.26 fold and Tmax was decreased by 2h after comparing with control indicating improved absorption. However no significant enhancement of oral bioavailability (1.12 fold after comparing with control) was found for RTV.

Preparation, in vitro characterization, pharmacokinetic, and pharmacodynamic evaluation of chitosan-based plumbagin microspheres in mice bearing B16F1 melanoma

The present study was aimed to evaluate the anti-tumor efficacy and systemic toxicity of chitosan-based plumbagin microspheres in comparison to free plumbagin. The optimized formulation had a mean particle size of 106.35 μm with an encapsulation efficiency of 80.12%. Pharmacokinetic studies showed a 22.2-fold increase in elimination half-life (t1/2) of plumbagin from chitosan microspheres as compared to free plumbagin. Administration of plumbagin microspheres resulted in a significant tumor growth inhibition and reduced systemic toxicity. These results suggest that chitosan-based microspheres could be a promising strategy for the systemic delivery of anti-cancer agents like plumbagin.

A simple and rapid high performance liquid chromatographic method with fluorescence detection for the estimation of fexofenadine in rat plasma-Application to preclinical pharmacokinetics

A sensitive high performance liquid chromatographic (HPLC) method involving fluorescence detection was developed for the determination of fexofenadine (FEX), known to have low oral bioavailability, in rat plasma. In order to understand the effect of various chromatographic factors on the separation of analytes and to simultaneously optimize the resolution and analysis run time, a response surface method was used. The chromatographic separation was achieved using a Supelco C(18)-DB (250 mm x 4.6mm I.D./5 microm particle size) column with mobile phase comprising of ammonium acetate buffer and acetonitrile (63:37, v/v), delivered isocratically at a flow rate of 1.0 mL min(-1). Diphenhydramine was used as an internal standard (I.S.). The statistical evaluation of the method was examined and the method was found to be precise and accurate with a linearity range of 1-500 ng mL(-1) (r>0.9980). The intra- and inter-day precision studies showed good reproducibility with coefficients of variation (C.V.) less than 12.26%. The advantages of our method are small sample volume (100 microL), short time of analysis (13 min) and a simple sample extraction and clean-up as compared to the previously published methods. The established method provides a reliable bioanalytical methodology to carry out FEX pharmacokinetics in rat plasma.

Development and evaluation of sunscreen creams containing morin-encapsulated nanoparticles for enhanced UV radiation protection and antioxidant activity

The objective of present work was to develop novel sunscreen creams containing polymeric nanoparticles (NPs) of morin. Polymeric NPs containing morin were prepared and optimized. The creams containing morin NPs were also prepared and evaluated. Optimized NPs exhibited particle size of 90.6 nm and zeta potential of −31 mV. The entrapment efficiency of morin, within the polymeric NPs, was found to be low (12.27%). Fourier transformed infrared spectroscopy and differential scanning calorimetry studies revealed no interaction between morin and excipients. Transmission electron microscopy and atomic force microscopy revealed that the NPs were spherical in shape with approximately 100 nm diameter. Optimized NPs showed excellent in vitro free radical scavenging activity. Skin permeation and deposition of morin from its NPs was higher than its plain form. Different sunscreen creams (SC1–SC8) were formulated by incorporating morin NPs along with nano zinc oxide and nano titanium dioxide. SC5 and SC8 creams showed excellent sun protection factor values (≈40). In vitro and in vivo skin permeation studies of sunscreen creams containing morin NPs indicated excellent deposition of morin within the skin. Morin NPs and optimized cream formulations (SC5 and SC8) did not exhibit cytotoxicity in Vero and HaCaT cells. Optimized sunscreen creams showed excellent dermal safety. SC5 and SC8 creams demonstrated exceptional in vivo antioxidant effect (estimation of catalase, superoxide dismutase, and glutathione) in UV radiation-exposed rats. The optimized sunscreen creams confirmed outstanding UV radiation protection as well as antioxidant properties.

Simultaneous improvement of solubility and permeability by fabricating binary glassy materials of Talinolol with Naringin: Solid state characterization, in-vivo in-situ evaluation

The aim of the current study was to prepare binary amorphous forms of Talinolol (TLN) by using Naringin (NRG) as a stabilizing agent. The secondary objective of this study was to study the effect of P-gp inhibitor NRG on the P-gp probe drug TLN. The binary amorphous samples were prepared by quench cooling technique in the molar ratios TLN:NRG (1:1), TLN:NRG (1:2), TLN:NRG (2:1). The prepared samples were characterized by DSC, FTIR and XRD. Amorphicity of the prepared binary amorphous samples was confirmed by spotting diffuse halo in the diffractograms and further corroborated by detecting glass transition event (Tg) in the thermograms of the respective samples. The Tgs for all prepared systems were found above room temperature, the highest being 45.43 °C. The systems were found physically stable at 25 °C and 40 °C at dry conditions for 60 days. The temperature stability of prepared amorphous forms may be attributed to strong intermolecular hydrogen bond interaction between TLN and NRG, which was confirmed by Gordon-Taylor calculations and FTIR data. The solubility of TLN in amorphous form was increased by approximately 9-fold as compared to its crystalline counterpart. The in-vivo bioavailability study conducted on wistar rats demonstrated 5.4-fold increase in the AUC0-t value for TLN as compared to its crystalline counterpart. Further to learn the contribution of P-gp inhibition by NRG on the permeability of TLN, In-vitro single pass perfusion studies were conducted on the ileum of wistar rats. The permeability of TLN in rat ileum in the presence of NRG was significantly increased to 3.16×10(-5) cm/s as compare to control value 2.48×10(-5) cm/s. The current study demonstrated the ability of binary amorphous technology to simultaneously overcome both the BCS barriers i.e. solubility and permeability.