The impacts of method selectivity and binders on the properties of carbamazepine granules and their applications: A case study

Background: Carbamazepine (CBZ) is a BCS II class drug, having many challenges in solubility, flowability, and compactibility. The study focused on the improvement of solubility, flow behavior, and drug release of carbamazepine. Methods: Low shear granulation (LSG), extrusion spheronization (ES), high shear granulation (HSG), fluid bed granulation (FBG), and hot melt granulation (HMG) methods were employed to prepare CBZ granules. Polyvinylpyrrolidone (PVP) K29/32, PVP K90, and Hydroxypropyl methylcellulose (HPMC) E5 were used as a binder. The drug to binder ratio was maintained in the proportion of 95:5. The nature of granules was analyzed by using X-ray Diffraction and Differential Scanning Calorimetry techniques. A powder flow tester was utilized to study the flow characteristics of the granules. Results: The HMG has successfully converted the crystalline structure of CBZ granules into an amorphous form. Dispersive and distributive mixing in the HMG has achieved better solid dispersion and fast drug release. The ES technique has reported the incompressible nature of the granules. PVP K90 and HPMC E5 were superior binders for imparting strength to the CBZ granules than PVP K29/32. The FBG has exhibited the free-flowing nature of granules due to their uniform and spherical shape. Conclusion: The HMG and FBG were the most effective methods that have remarkably improved drug release, flow properties, and compactibility of CBZ granules.

Fluidized Hot Melt Granulation Technique: An Approach to Improve Micromeritics Properties and Dissolution Rate of Efavirenz

The Fluidized hot melt granulation technique is a process by which pharmaceutical powders are efficiently agglomerated using a low melting binder. The effect of the binder properties and concentrations on agglomerate growth mechanisms were studied in this research paper using this technique with the primary objective of improvement in the solubility and dissolution rate of efavirenz by melt-dispersion granulation employing meltable hydrophilic carrier and then to convert the melt dispersion into flowable and compressible dispersion granules to yield a rapidly dissolving tablet formulation. The Optimized concentrations of co-polymers like PEG 6000, PEG 4000, Gelucire 50/13, Gelucire 44/14, Poloxamer 188 and Poloxamer 407 in different ratios (i.e., 1:1, 1:2, 1:3 and 1:4) as meltable binder along with the drug were sprayed dropwise over lactose as diluent loaded into fluid bed chamber for the preparation of the granules of efavirenz and characterized for its micromeritical properties, DSC, XRD etc. The tablets prepared from the granules were evaluated for drug dissolution rate. The prepared granules were found to have excellent flow properties indicated by mean diameter D50:138µm, Carr’s index 13.92% and the drug content uniformity of 98.10%. XRD data exhibited partial loss of crystallinity as indicated by significantly less intensity of efavirenz peak in sample than pure efavirenz. Drug release from tablet was fast found 99.12% w/v within 30 minutes. Absence of Efavirenz endothermic peak at higher proportions of meltable binder reported by DSC data exhibited amorphous form of efavirenz led to complete solubilization and thus faster dissolution rate of efavirenz.

Development of gastroretentive floating granules with gentian root extract by hot-melt granulation

The roots of yellow gentian, Gentiana lutea L. (Gentianaceae) are used in traditional medicine for the treatment of gastrointestinal disorders, with the literature data indicates a local gastric effect of gentian root extract (GRE) and support the use of the solid pharmaceutical forms. Gentiopicroside, as a dominant secoiridoid in the GRE, has a short elimination half-life and low bioavailability and, consequently, its bioactivity is limited. The aim of the study was to develop gastroretentive floating delivery system with GRE, and to provide prolonged release of gentiopicroside. Floating granules with dry GRE (DGRE) were prepared by the hot-melt granulation technique, while formulations included effervescent components (citric acid and sodium bicarbonate), hydroxypropyl methylcellulose (HPMC) and meltable binders (Compritol® 888 ATO and Gelucire® 50/13). The flowability of the DGRE and prepared formulations was determined by calculating the Carr index and Hausner ratio. Floating properties and in vitro dissolution rate of gentiopicroside from investigated formulations were examined. Floating granules were characterized with improved flowability (Carr index 14-22 %; Hausner ratio 1.16-1.28) in comparison to the DGRE (Carr index 28.99 %; Hausner ratio of 1.41). Furthermore, the floating granules exhibited immediate and long-lasting buoyancy and prolonged-release of gentiopicroside (over 8 h). Compritol® 888 ATO has provided sustained release of gentiopicroside from floating granules, while HPMC has decreased release rate additionally. On the other hand, Gelucire® 50/13 has increased gentiopicroside release rate. The results have shown that hot-melt granulation technique, as a green granulation method was successfully employed for obtaining gastroretentive floating granules with DGRE.

Tenofovir Hot-Melt Granulation using Gelucire® to Develop Sustained-Release Vaginal Systems for Weekly Protection against Sexual Transmission of HIV

Hot-melt granulation is a technique used to obtain granules by dispersing a drug in polymers at a high temperature. Tenofovir, an antiretroviral drug with proven activity as a vaginal microbicide, was dispersed in melted Gelucire® (or a mixture of different Gelucire®) to obtain drug-loaded granules. Studies performed on the granules proved that the drug is not altered in the hot-melt granulation process. The granules obtained were included in a matrix formed by the hydrophilic polymers hydroxypropylmethylcellulose and chitosan to obtain vaginal tablets that combine different mechanisms of controlled release: The Gelucire® needs to soften to allow the release of the Tenofovir, and the hydrophilic polymers must form a gel so the drug can diffuse through it. The studies performed with the tablets were swelling behavior, Tenofovir release, and ex vivo mucoadhesion. The tablets containing granules obtained with Tenofovir and Gelucire® 43/01 in a ratio of 1:2 in a matrix formed by hydroxypropylmethylcellulose and chitosan in a ratio of 1.9:1 were selected as the optimal formulation, since they release Tenofovir in a sustained manner over 216h and remain attached to the vaginal mucosa throughout. A weekly administration of these tablets would therefore offer women protection against the sexual transmission of HIV.