Chapter 15 Clinically Relevant Dissolution for Low-Solubility Immediate-Release Products

2017 ◽  
pp. 511-552
Author(s):  
Paul A. Dickinson ◽  
Talia Flanagan ◽  
David Holt ◽  
PaulW. Stott
Author(s):  
John Rojas ◽  
David Correa

Objective: To study microcrystalline cellulose II (MCCII) as new pelletization aid for a high and low solubility drugs such as verapamil. HCl and carbamazepine, respectively.Methods: Approximately, 30 g of MCCII and drug mixtures were hydrated passed through a # 20 mesh sieved and spheronizated at a frequency of 6 Hz and residence time of 480 s. A microscopy analysis was used to evaluate the shape and size descriptors. Pellets properties such as compressibility, friability, density, flowability and product yield were also evaluated. Drug release properties were tested according to the USP specifications and compared to those of MCCI.Results: The wetting level of the excipients depended on drug loading and drug solubility. Thus, a high drug loading (>50%) rendered pellets having a low yield, flowability and caused a detriment on size descriptors. Likewise, the regular morphology and strength of MCCII-based pellets was highly affected by increasing drug loads. Verapamil. HCl pellets were less friable and compressible and showed better flowability than carbamazepine pellets. Regardless of drug loading and drug solubility, MCCII-based pellets released more than 80% of verapamil. HCl within 10 min, whereas released more than 75% of carbamazepine within 15 min. Conversely, MCCI pellets had a satisfactory verapamil. HCl release, but ~30% carbamazepine release within 1h.Conclusion: MCCII proved to be a better excipient than MCCI to yield beads having optimal pellet characteristics and rendered an immediate release profile for verapamil. HCl and carbamazepine.


2016 ◽  
Vol 2 (2) ◽  
pp. 91-95
Author(s):  
Neelima Rani T ◽  
Pavani A ◽  
Sobhita Rani P ◽  
Srilakshmi N

This study aims to formulate solid dispersions (SDs) of Simvastatin (SIM) to improve the aqueous solubility, dissolution rate and to facilitate faster onset of action. Simvastatin is a BCS class II drug having low solubility & therefore low oral bioavailability. In the present study, SDs of simvastatin different drug-carrier ratios were prepared by kneading method. The results showed that simvastatin solubility & dissolution rate enhanced with polymer SSG in the ratio 1:7 due to increase in wetting property or possibly may be due to change in crystallinity of the drug.


1986 ◽  
Vol 4 (1) ◽  
pp. 22-25 ◽  
Author(s):  
A.J. Laiche ◽  
V.E. Nash

Three woody landscape species, Rhododendron indica ‘President Clay’, Ligustrum sinense ‘variegata’, and Ilex crenata ‘compacta’, were grown in media prepared from fresh pine bark, pine bark with wood, and pine tree chips. Although media were variable in physical properties, all exhibited very high hydraulic conductivity and low water holding capacity. The capacity of these media materials to hold fertilizer elements was very low. Nitrogen, potassium, and phosphorus were rapidly removed by leaching while calciuum and magnesium were retained longer because of the low solubility of dolomitic limestone. Pine bark was the best growth media tested for all plant species. Pine bark with wood was less satisfactory than pine bark and growth was poorest in pine tree chips. More research is needed on the use of the organic amendments with greater amounts of wood before being widely used as organic components of growth media.


Author(s):  
Deshkar S. S. ◽  
Pore A. R.

Platelets play an important role in hemostasis during tissue injury, which blocks the defect and terminates blood loss. Platelet aggregation inhibitors are widely used in treatment of cardiovascular disorders and Peripheral arterial disease. Clopidogrel bisulphate and Cilostazol, are FDA approved BCS class II drugs, used in treatment of Platelet aggregation, peripheral arterial disease and intermittent claudication. The aim of the present study was to develop an immediate release pellets for combination of Clopidogrel bisulphate and Cilostazol using extrusion spheronization technique. The effects of spheronization speed(X1) and binder concentration (PVP K30) (X2), on size of pellets, disintegration time and drug release were studied using 32 full factorial design. The surface response and counter plot were drawn to facilitate an understanding of the contribution of the variables and their interaction. From the results, speed of spheronization of 1100 rpm and 5% concentration of PVP K30, were selected. In vitro drug release studies revealed more than 80% of clopidogrel bisulphate release and more than 75% of cilostazol release within 30 min of dissolution which complied with the pharmacopoeal limits. Film coated pellets did not show significant change in the drug release. DSC and FTIR studies revealed no interaction of drugs and excipient during pellet formulation. The pellet formulations of clopidogrel and cilostazol were found to be stable when stored at 40ºC±2ºC/ 75%RH±5%RH for 2 months. Conclusively, clopidogrel bisulphate and cilostazol pellet fixed dose combination could be successfully developed by design of experimentation and complied with pharmacopoeal limits.


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