Drumstick Mucilage Microspheres For Controlled Release Of Lamivudine: Design, Optimization And In Vitro Evaluation

Objective: The objective of this study was to design and evaluate controlled release mucoadhesive microspheres of lamivudine using mucoadhesive polymers and mucilage. Methods: Mucoadhesive microspheres of lamivudine were formulated by ionic gelation method. The response surface methodology was adapted for optimization of formulation using central composite design (CCD) for two factors at three levels each was employed to study the effect of independent variables, Sodium alginate-drumstick mucilage (X1) and calcium chloride (CaCl2) concentration (X2) on dependent variables, namely drug encapsulation efficiency (DEE) and particle size (PS). Optimized drumstick mucilage mucoadhesive microspheres of lamivudine were obtained by using numerical optimization of desirability approach. The observed microspheres were coincided well with the predicted values by the experimental design. Results: The microspheres formed were spherical in shape, and Particle size (PS) ranged between 681.63-941.57μm. Drug encapsulation efficiency (DEE) was ranged between 69.63-94.56 %. The drug release for an optimized formulation was 96.58 %. The mechanism of drug release from microspheres followed Korsemeyer’s-Peppas and exponential ‘n’ value was greater than 0.45, indicating the drug release was non-fickian i.e., swelling followed by erosion mechanism. Conclusion: This work suggests that mucoadhesive microspheres, an effective drug delivery system for lamivudine, can be prepared using drumstick mucilage in improving the bioavailability of the drug.

Preimplantation genetic diagnosis of chromosomal abnormalities by multicolour fluorescence in situ hybridisation.

Preimplantation genetic diagnosis (PGD) is an early diagnosis of genetic disorders, prior to the onset of pregnancy. PGD incorporates the latest techniques in assisted reproduction and molecular genetics. Embryos or oocytes are biopsied during culture in vitro and genetic analysis is carried out on the blastomeres or polar bodies. Embryos shown to be free of the genetic disease under investigation are transferred to the uterus. Multicolour fluorescence in situ hybridisation (FISH) is used to diagnose numerical and certain structural abnormalities of chromosomes in the embryo. The common probes used are for chromosomes 13, 18, 21, X and Y. FISH can also be used for PGD of translocations, when one of the parents is a carrier. PGD was carried out recently in 4 cases using multicolour FISH. In one of the embryos, trisomy 18 was detected. Tetraploidy was seen in another embryo. Only chromosomally normal embryos were transferred back to the uterus. Care has to be taken while interpreting FISH signals as the signal may be split, diffused, superimposed or in a different focus.