Undergraduate students' perception of the Indian dental curriculum: A focus-group based, multi-centric questionnaire survey.

Aim: the present study was designed to take a student's perception regarding the current dental education curriculum. Methodology: A structured, pre-validated questionnaire made on Google Forms was shared amongst participants pursuing undergraduate dental program in a DCI recognized dental college via e-mail, Facebook or WhatsApp. The questionnaire consisted of questions about the admission procedure (5questions), curriculum design (12 questions) teaching methods (5 questions) and assessment (5 questions) methods. The respondents were divided into 2 focus groups; Pre-clinical: BDS first & second year students and Clinical: BDS third & fourth year students. Results: The questionnaire was circulated amongst a total of 510 potential candidates, out of which 403 responded (response rate 79%). 48.4% (195/403) were from government dental colleges and 51.6% (206/403) were from private dental colleges. Preclinical group had 89 students (1st year = 27, 2nd year = 62) and clinical group 344 students (3rd year = 138, 4th year = 176). Students of both focus groups responded similarly to many questions relating to curriculum (need of syllabus revision, p = 0.912; horizontal/vertical integration, p = 0.076; and early clinical exposure p = 0.843), teaching methods (need of mixed teaching methods) and assessment methods (methods which are not based on quota-chasing p = 0.588). Statistically significant difference was seen to "whether the students are able to retain or relate to the basic sciences subjects taught in first & second year" (p < 0.0001). Conclusion: Students expressed a need for a horizontal & vertical integration of topics, frequent syllabus revision, Early Clinical Exposure, a mixed teaching method, and better assessment methods.

Application of simplex lattice design for the development of extended release tablets of model drug diclofenac sodium.

Aim: Simplex lattice design was applied to predict extent of drug release from extended release diclofenac sodium tablets. Methods: The effects of composition on dissolution rate were evaluated by varying the levels of hydroxypropyl methylcellulose, dicalcium phosphate and cornstarch via three component design. Results: The rate of drug release was primarily dictated by the proportion of hydroxypropyl methylcellulose and was also affected by the proportion of dicalcium phosphate and the method of processing (direct compression/wet granulation). Polynomial equations constructed for directly compressed and wet-granulated formulations could successfully predict the extent of drug release at an arbitrary time point of 3 h. Conclusion: Simplex lattice design is a viable tool to predict the drug release patterns of extended release formulations.

Thermodynamic analysis of r-hGH-polymer surface Interaction using isothermal titration calorimetry.

Delivery of protein drugs would be an effective approach if mechanistic understanding of protein adsorption at solid/liquid surface is obtained and nonspecific adsorption can be controlled. This study involves evaluation of the thermodynamic parameters for interaction between recombinant human growth hormone (r-hGH) and nanoparticles of poly (lactic- co- glycolic) acid polymer of different molecular weight. Energy changes related to protein-nanoparticle interactions are usually very small and isothermal titration calorimetry (ITC) is the only technique that determines the binding constant (Ka), enthalpy, (ΔH) and stoichiometry, (n) in a single experiment. Therefore, we used ITC to study the energetics of the binding of r-hGH with PLGA nanoparticles. The largely negative ∆H and ∆S suggested that binding was driven by non-classical hydrophobic effect for interaction with PLGA 50501A and PLGA 8515E nanoparticles at pH 7.2 where higher surface coverage was noted for the latter. Endothermic, entropically driven reaction was observed upon interaction of r-hGH with PLGA 5050 5E nanoparticles at pH 7.2, PLGA 5050 1A nanoparticles at pH 5.3 and pH 4.0. Moreover, negative value of ΔCp for PLGA 50501A NPs at pH 7.2 indicated cooperative disorder of hydrogen-bonding networks and no evidence of hydrophobic elements. ITC proved to be very efficient method in studying the thermodynamics of the protein polymer interaction. In agreement with results from previous studies using fluorescence spectroscopy, circular dichroism and dynamic light scattering in our laboratory, this study demonstrated that adsorption can be controlled by selecting the polymer of low to moderate hydrophobicity depending on the pH of media.

Effect of the Interaction Between an Ionic Surfactant and Polymer on the Dissolution of a Poorly Soluble Drug.

Surfactants are commonly incorporated in conventional and enabled formulations to enhance the rate and extent of dissolution of drugs exhibiting poor aqueous solubility. Generally the interactions between the drug and excipients are systematically evaluated, however, limited attention is paid towards understanding the effect of interaction between functional excipients and its impact on the performance of the product. In the current study, the effect of potential interaction between a nonionic polymer binder, povidone, and anionic surfactant docusate sodium on the rate and extent of dissolution of a drug exhibiting poor aqueous solubility was evaluated by varying the proportions of the binder and the surfactant in the formulation. Potential complexation or aggregation between the excipients was investigated by fluorescence spectroscopy and zeta potential measurements of the aqueous solutions of docusate sodium, povidone, and sodium lauryl sulfate (SLS). The rate and extent of drug release was found to decrease with an increase in the proportion of docusate sodium and povidone in the formulations. Difference in magnitude of surface charge (zeta potential) of docusate sodium in presence of povidone indicated potential surfactant-polymer aggregation during dissolution which was corroborated by CAC/CMC values derived from fluorescence spectroscopic measurements. The decrease in the rate of drug release was attributed to an increase in the viscosity of the microenvironment of dissolving particles due to the interaction of docusate sodium and povidone in the aqueous media during dissolution. These findings highlight the importance of systematic evaluation of the interaction of ionic surfactants with the polymeric components within the formulation to ensure the appropriate selection of the type of surfactant as well as its proportion in the formulation.