ABSTRACT
Efavirenz, a non-nucleotide reverse transcriptase inhibitor is an important drug for treating patients with Human Immunodeficiency Virus infections. It belongs to BCS class II have low solubility and poor intrinsic dissolution rate. It is highly basic (pKa 10.2) which makes it suitable candidate for floating dosage form for continuous delivery in stomach.The study was aimed to improve the solubility by solid dispersion technique.Saturation solubility study and drug content were evaluated for solid dispersion preparation. Saturation solubility shows 8 fold increases in 0.1 N HCL compared to plain drug and drug content was found to be between 95%-102%. Further effervescent floating gastroretentive drug delivery system was prepared by 32 full factorial design with independent variables i.e., concentration of HPMC K100 as matrix forming agent and citric acid as gas generating agent. Lag time, floating time, percent drug release were studied as responses. The optimized batch exhibited floating lag time of 40 sec and the in vitro release studies showed 89.5% drug release in 9 h and tablet remained floating for greater than 8 h. The study thus demonstrated that solubility is increased by solid dispersion technique and floating delivery systems may increase solubility and bioavailability of Efavirenz.
ABSTRACT
Lacidipine (LCDP) is a dihydropyridine derivative categorized as an Anti-hypertensive Ca+2 channel blocker belonging to BCS class IV drug with low solubility and low permeability which presents a challenge to the formulation scientists. The development of a solid dispersion by solvent evaporation is a practically viable method to enhance dissolution of LCDP from oral dosage form. Solvent evaporation by Fluidized Bed Process (FBP) was the method of choice for SD as it improves wettability with simultaneous increase in porosity of granules resulting enhanced surface area producing higher dissolution rate and bioavailability of poorly water-soluble drug. Thus, the main object of the present invention is to provide stable pharmaceutical dosage form of LCDP with desired dissolution rate i.e. at least 80% drug release within 45 minutes, without use of disintegrant(s) and/or surfactant(s) or without micronization of the active ingredient per se. One more object of this invention is to provide a sophisticated robust process for the preparation of said pharmaceutical dosage form by Quality by Design (QbD) concept focusing on thorough understanding of the product and process by which it is developed and manufactured along with a knowledge of the risks involved in manufacturing by IRMA & FMEA study of the product with process and how best to mitigate those risks by developing design space with DoE & MVDA with outlined control strategy.