Since the biopharmaceutical quality of generic drug formulations depends on the quality of the reference products and also information about the in-vitro release performance of drugs under different conditions is scarce in the literature, a dissolution study of four reference tablets was performed. Each drug was representative of one Class of the Biopharmaceutical Classification System. The in-vitro release performance of propranolol-HCl, carbamazepine, ranitidine-HCl, and metronidazole was evaluated using a USP basket and paddle apparatus at different agitation rates (50, 75, and 100 rpm) with two doses of each drug. In all experiments, pharmacopeial dissolution media was used and the samples were taken with automatic equipment at specific times up to 60 min, except for propranolol-HCl, for which the samples were taken up to 30 min. The dissolution profiles were compared by model-independent, model-dependent, and ANOVA-based comparisons. The three methods of data comparison showed that low vs. high doses were significantly different (P < 0. 05), which may influence cases in which biowaivers of propranolol-HCl and ranitidine-HCl are requested. Additionally, the results showed that despite different hydrodynamic environments produced by the basket and paddle apparatus, under certain conditions, both types of equipment generated comparable in-vitro results. Variables such as the dose, agitation rate, and type of dissolution apparatus are important factors to consider in designing dissolution tests for drug products. This information can be used to test a new dosage when there is no pharmacopeial method available to perform a dissolution study. Further researches on the in-vitro release performance of reference drug products are required.

Purpose: Biopharmaceutics classification system (BCS) class IV compounds, exhibits least oral bioavailability, low solubility and intestinal permeability among all pharmaceutical classes of drugs. Thus, these drugs need more compatible and efficient delivery system. Since, their solubility in various medium, remains a limitation so, polymeric nano coacervates based drug loading with modified approach for them may prove to be a solution ahead. Therefore, in present study Chitosan is opted for encapsulating the BCS class IV drug (Hydrochlorothiazide) to attain better stability, enhanced permeability and lower toxicity. Methods: For this study, Hydrochlorothiazide (HCTZ) was opted for formulating chitosan based nano-coacervate system. Results: Optimized HCTZ nanocoacervates exhibited the average particle size of 91. 39 ± 0. 75 nm with Poly-dispersity index score of 0. 159 ± 0. 01, indicating homogeneity of colloidal solution. Zeta potential and encapsulation efficiency of HCTZ nanocoacervates were recorded as-18. 9 ± 0. 8 mV and 76. 69 ± 0. 82 % respectively. Further, from TEM and SEM evaluation the average particle size for the same were found in conformity (35-50 nm), with almost spherical morphology. Also, the EDX (Electron Dispersive X-ray) spectrometry and FT – IR analysis of optimized formulation indicated the balanced chemical composition and interaction between the polymeric molecules. The HCTZ nano coacervates showed the linear diffusion profile through the dialysis membrane. Conclusion: We can conclude from the present study that the optimized HCTZ nano coacervates may prove to be a suitable potential option for effective delivery of BCS class IV drugs.

Most of the drugs are administered orally and they must be absorbed from gastrointestinal tract for systemic effect. Generally, drug molecules get dissolved in GI fluids before absorption. Solubility and permeability of drugs are considered as two parameters in biopharmaceutical classification system (BCS). Many researches were performed to change permeability and solubility of the drugs to improve abruption and bioavailability of them. Lipidic nanocarriers such as nanoliposomes are one approach to dissolve poorly water soluble drugs. Furosemide (FMD) as a typical molecule in BCS IV has low solubility and permeability. Thermodynamically, molecules of FMD could stay in the space of liposomal membrane. In this study effective parameters to preparation of nanoliposomes coated by chitosan (CCLs) were screened optimized by experimental design. Particle size, polydispersity index, and surface potential of optimized CCLs have 155. 8 ± 3. 5 nm, 0. 229 ± 0. 022, and 25. 2 ± 3. 5 mV, respectively. FMD was loaded in optimized CCLs 98. 94 ± 0. 7%. Size of CCLs have verified by atomic force electron microscope. CCLs loaded by FMD were dried and in-vitro study was performed to test release of FMD from powder. Results demonstrated that solubility and dissolution of FMD increased by loading in CCLs in comparison to crystalline FMD and physical mixture of FMD and materials of CCLs.